JP4671432B2 - Method for treating heavy metal-containing liquid - Google Patents

Description

  The present invention relates to a method for treating a heavy metal-containing liquid. More specifically, the present invention relates to a treatment method and apparatus that removes heavy metals from wastewater or the like and renders them harmless by bringing hydrogen sulfide into contact with the heavy metal dissolved in the wastewater or the like to insolubilize it.

  When hydrogen sulfide is blown into an aqueous solution containing metal ions, a precipitate such as metal sulfide is generated, and heavy metal ions in the aqueous solution are insolubilized. A heavy metal processing technique using such a phenomenon has been proposed.

For example, Patent Document 1 discloses a technique for removing selenium from selenium-containing wastewater. Specifically, after adding copper powder or copper compound to selenium-containing wastewater, leaching / reducing with copper, hydrogen sulfide gas was blown into the selenium to precipitate and collect the selenium together with copper. Try to remove.
JP 2006-116469 A

  When employing a technique such as Patent Document 1, in order to prevent hydrogen sulfide, which is a toxic gas, from diffusing into the surrounding environment, the supply amount (flow rate) of hydrogen sulfide gas is set to various valves, instruments, and the like. Need to be carefully controlled. However, when such a control method is adopted, the operation management is very complicated, and the equipment cost and the processing cost become great.

  In addition, sulfate-reducing bacteria are known as microorganisms that produce sulfate by using sulfate ion as an electron acceptor and sulfate respiration. A technique for precipitating heavy metals using hydrogen sulfide produced by sulfate-reducing bacteria has also been proposed. In the heavy metal-containing liquid, various substances exhibiting microbial toxicity, such as cadmium, mercury, and selenium, may be present in high concentrations. Therefore, when biological treatment is carried out by directly adding sulfate-reducing bacteria to the heavy metal-containing solution, the microorganisms may be deactivated and the treatment efficiency may be significantly reduced.

  Therefore, the present invention provides a method and apparatus for controlling supply of hydrogen sulfide to a heavy metal-containing liquid easily and at low cost without performing complicated operation management and insolubilizing the liquid to be processed without being contaminated with hydrogen sulfide. The purpose is to do.

  Another object of the present invention is to provide a method and an apparatus for efficiently supplying hydrogen sulfide to a liquid to be treated by allowing sulfate-reducing bacteria to function without being inhibited by microbial toxic substances in the liquid to be treated. And

  Furthermore, an object of the present invention is to provide a method for insolubilizing selenate ions that are difficult to insolubilize with hydrogen sulfide.

  In order to achieve this object, the present inventors have focused on the molecular permeability of non-porous membranes such as polyethylene membranes and polypropylene membranes. Then, by utilizing the molecular permeability of the non-porous membrane, we found that hydrogen sulfide capable of insolubilizing various heavy metals can be supplied to the liquid to be treated with uniform and gentle sustained release, It came to this invention.

Based on such knowledge, the method for treating a heavy metal-containing liquid according to the present invention includes filling a hydrogen sulfide into a container having a sealed structure having at least a part of a non-porous membrane, immersing the container in a liquid to be treated, Hydrogen sulfide is supplied from the porous membrane portion to the periphery of the container at a speed governed by the molecular permeation performance of the non-porous membrane to insolubilize the heavy metal contained in the liquid to be treated. In addition, the method for treating a heavy metal-containing liquid according to the present invention comprises filling a hydrogen sulfide-producing raw material in a sealed container having at least a part of a non-porous membrane, immersing the container in a liquid to be treated, Hydrogen sulfide produced from the hydrogen sulfide production raw material is supplied to the periphery of the container at a rate governed by the molecular permeation performance of the non-porous membrane from the porous membrane portion, and the heavy metal contained in the liquid to be treated is insolubilized. The process is included. In the method for treating a heavy metal-containing liquid according to the present invention, a carrier capable of supporting an insolubilized heavy metal is disposed in the vicinity of the non-porous membrane of the container. In the method for treating a heavy metal-containing liquid of the present invention, selenate ions (SeO ₄ ²⁻ ) are converted to selenite ions (SeO ₄ ) before or simultaneously with the step of insolubilizing heavy metals contained in the liquid to be treated. _The selenate-reducing microorganism that is reduced to ₃ ²⁻ ) and the liquid to be treated are brought into contact under anaerobic conditions. Next, the hydrogen sulfide supply apparatus for heavy metal-containing liquid treatment according to the present invention based on such knowledge includes a container having a sealed structure including at least part of a non-porous film that allows hydrogen sulfide to pass through , and hydrogen sulfide or a hydrogen sulfide production raw material. And the container is filled with hydrogen sulfide or a raw material for producing hydrogen sulfide. In the hydrogen sulfide supply apparatus for processing a heavy metal-containing liquid according to the present invention, a carrier capable of supporting an insolubilized heavy metal is provided on at least a part of the surface of the non-porous membrane of the container .

  Hydrogen sulfide produced by hydrogen sulfide or a hydrogen sulfide production raw material filled in the container is gradually released at a rate governed by the molecular permeation performance of the non-porous membrane. Therefore, hydrogen sulfide is constantly supplied slowly by adjusting the non-porous membrane permeation rate of hydrogen sulfide with the membrane material, film thickness, membrane density, etc., which are the factors that determine the molecular permeation performance of the non-porous membrane. Thus, the insolubilization treatment of the heavy metal in the liquid to be treated can be performed over a long period of time. In addition, since hydrogen sulfide is supplied to the periphery of the container, the hydrogen sulfide concentration only in the periphery of the container can be locally increased, so that the liquid to be treated is not acidified or contaminated. .

  In the present specification, “insolubilization” means that the heavy metal contained in the liquid to be treated is hardly soluble in water or insoluble in water, that is, sulfide precipitation or hydroxide precipitation of heavy metal is generated. This means that the heavy metal is reduced to the elemental state, so that it can be solid-liquid separated from the liquid to be treated.

More specifically, the heavy metal that can be insolubilized in the method for treating a heavy metal-containing liquid of the present invention includes selenium (Se) present in the form of selenite ion (SeO ₃ ²⁻ ) in the liquid to be treated and Copper (Cu), silver (Ag), lead (Pb), cadmium (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt (existing in the cation form in the treatment liquid Co), iron (Fe), zinc (Zn), manganese (Mn), and aluminum (Al).

Selenium (Se) present in the form of selenite ion (SeO ₃ ²⁻ ) in the liquid to be treated generates sulfide precipitates by the supplied hydrogen sulfide, or the supplied hydrogen sulfide By acting as a reducing agent, it is insolubilized as elemental selenium. Copper (Cu), silver (Ag), lead (Pb), cadmium (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt present in the form of cations in the liquid to be treated (Co), iron (Fe), zinc (Zn), manganese (Mn), and aluminum (Al) react with the supplied hydrogen sulfide to produce sulfide precipitates, which are insolubilized. Incidentally, aluminum (Al) is not in the form of sulfide precipitation but becomes Al (OH) ₃ which is hydroxide precipitation and is insolubilized. Accordingly, since the heavy metal can be separated from the liquid to be treated in a solid-liquid separation, the heavy metal-containing liquid after the treatment is subjected to solid-liquid separation, for example, filtration, etc. to recover the heavy metal from the heavy metal-containing liquid. Can be rendered harmless.

Next, the hydrogen sulfide production raw material used in the method for treating a heavy metal-containing liquid of the present invention and the hydrogen sulfide supply apparatus for treating a heavy metal-containing liquid is not particularly limited as long as it is a raw material capable of producing hydrogen sulfide. Fill the container with sulfate-reducing bacteria, sulfate ions (SO ₄ ²⁻ ) and an electron-donor substance that is an energy source for sulfate-reducing bacteria, and reduce the sulfate ions by sulfuric acid respiration to produce hydrogen sulfide. can do. Furthermore, by using iron, the generation of hydrogen sulfide is promoted, and the insolubilization efficiency of heavy metals contained in the liquid to be treated is improved.

Moreover, iron sulfide and an acid can be filled in a container, and hydrogen sulfide can also be produced | generated by the chemical reaction of iron sulfide and an acid. For example, when iron sulfide and hydrochloric acid are mixed, as shown in Chemical Formula 1, hydrogen sulfide and iron chloride are generated.
[Chemical Formula 1] FeS + 2HCl → FeCl ₂ + H ₂ S

  In addition, a reducing agent capable of generating hydrogen sulfide, for example, one or more of sodium thiosulfate, sodium sulfide, and sodium hydrogen sulfide can be filled in the container, and hydrogen sulfide can be generated by the reducing agent.

  Here, examples of the non-porous film used in the present invention include polyethylene and polypropylene. Since polyethylene and polypropylene are hydrophobic membranes, it is difficult to pass heavy metal-containing liquids. Moreover, it has hydrogen sulfide permeability. Furthermore, it has thermoreversibility, has the advantage of being flexible and easy to mold. Moreover, since polyethylene and polypropylene are inexpensive and easily available, they are very excellent materials from the viewpoint of cost and performance.

  In addition, the container of the hydrogen sulfide supply device for processing a heavy metal-containing liquid according to the present invention includes a supply unit for replenishing hydrogen sulfide or a hydrogen sulfide-producing raw material, so that hydrogen sulfide or a hydrogen sulfide-producing raw material can be replenished. It becomes possible to continuously release hydrogen sulfide from the non-porous membrane portion of the container over a long period of time.

Here, in the method for treating a heavy metal-containing liquid according to the present invention, hydrogen sulfide is filled in a container having a sealed structure including at least a part of a non-porous membrane, and the container is immersed in the liquid to be treated. Supplying a hydrogen sulfide to the periphery of the container at a rate governed by the molecular permeation performance of the nonporous membrane from the porous membrane portion, or insolubilizing heavy metals contained in the liquid to be treated, or a nonporous membrane At least a part of the sealed structure of the container is filled with hydrogen sulfide production raw material, the container is immersed in the liquid to be treated, and the speed is governed by the molecular permeation performance of the nonporous film from the nonporous film part of the container. Before or simultaneously with the step of supplying the hydrogen sulfide produced from the hydrogen sulfide production raw material to the periphery of the vessel and insolubilizing the heavy metal contained in the liquid to be treated, selenium ions (SeO ₄ ²⁻ ) are added to selenium selenite. instead of acid ion _(SeO ^{3 2-)} Since selenate reducing microorganisms and the liquid to be treated is to be in contact under anaerobic conditions, it is reduced to easily selenite ions insolubilized insolubilized hardly selenate ions with hydrogen sulfide in the feed of hydrogen sulfide Can do.

The selenate-reducing microorganism used in the present invention is not particularly limited as long as it is a selenate-reducing microorganism that reduces selenate ion (SeO ₄ ²⁻ ) to selenite ion (SeO ₃ ²⁻ ). Examples include selenate-reducing microorganisms belonging to the genus Pseudomonas, Paracoccus, Delayer, Bacillus, and Enterobacter. These selenate-reducing microorganisms are selenate-reducing microorganisms that function using yeast extract, sulfur-containing amino acids, lactate and the like as energy sources.

Here, it is preferable to use a selenate-reducing microorganism that reduces selenate ions to selenite ions using lower alcohols such as methanol, ethanol, and propanol as an energy source in consideration of reduction in treatment costs. Examples of such selenate-reducing microorganisms include Pseudomonas sp. 4C-C (Pseudomonas sp. 4C-C, FERM P-20840). Pseudomonas sp. 4C-C is a selenate-reducing microorganism that can reduce selenate ions to elemental selenium according to the following chemical formula 2 using lower alcohols such as methanol, ethanol, and propanol as energy sources.
[Chemical Formula 2] SeO ₄ ²⁻ → SeO ₃ ²⁻ → Se

Here, Pseudomonas sp 4C-C has a high rate of reducing SeO ₄ ²⁻ (selenate ion) to SeO ₃ ²⁻ (selenite ion), and efficiently generates selenite ion from selenate ion. be able to. Therefore, selenite ions generated in the reduction process from selenate ions to elemental selenium can be efficiently insolubilized with hydrogen sulfide, and selenate ions can be removed from the liquid to be treated. In addition, Pseudomonas sp 4C-C, even when nitrate ions and nitrite ions are contained in the heavy metal-containing liquid, selenate ion in the heavy metal-containing liquid is not inhibited by these ions. It is a selenate-reducing microorganism having an excellent function capable of reducing nitrate ions and nitrite ions to nitrogen gas simultaneously with reduction to ions.

In this way, a selenate-reducing microorganism that reduces selenate ions (SeO ₄ ²⁻ ) to selenite ions (SeO ₃ ²⁻ ) using a lower alcohol having 1 to 3 carbon atoms as an energy source is treated with a heavy metal-containing liquid. By using it, it is possible to use an inexpensive and easily available lower alcohol having 1 to 3 carbon atoms as an energy source, and the processing cost can be greatly reduced.

  Here, the supply of the lower alcohol having 1 to 3 carbon atoms to the selenate-reducing microorganism may be performed by a control device such as a pump, but in the container having at least a part of the nonporous membrane, Preferably, the lower alcohol or waste alcohol of No. 3 is sealed and the rate is controlled from the non-porous membrane portion of the container to the molecular permeation performance of the non-porous membrane.

  The lower alcohol filled in the container is gradually released at a rate governed by the molecular permeation performance of the non-porous membrane. Therefore, the lower alcohol is constantly supplied slowly by adjusting the non-porous membrane permeation rate of the lower alcohol with the membrane material, film thickness, membrane density, etc., which are the factors that determine the molecular permeation performance of the non-porous membrane. Thus, by allowing the selenate-reducing microorganism to continue functioning, it is possible to efficiently reduce selenate ions to selenite ions.

  In addition, it is preferable from the environmental and economic viewpoints to use waste alcohol as an energy source for the selenate-reducing microorganism. The non-porous membrane has a role like “molecular sieve”, and as the molecular weight of the molecule to be permeated increases, it becomes difficult to permeate the molecule. In addition, the permeability varies greatly depending on properties such as the polarity of the molecule. Therefore, when the non-porous membrane is a hydrophobic membrane represented by polyethylene or polypropylene, antibacterial molecules that are toxic to microorganisms such as impurities such as catechin and cyanide are mixed in the waste alcohol. However, catechins having a large molecular size or cyan compounds having a high polarity are difficult to permeate, and it is possible to permeate a lower alcohol that is harmless to microorganisms as a main component.

In the processing method of the heavy metal-containing liquid of the present invention, in the vicinity of the non-porous membrane of the container, and to arrange the carrier may carry insolubilized heavy metals. Further, the hydrogen sulfide supply apparatus for processing a heavy metal-containing liquid according to the present invention is provided with a carrier capable of supporting an insolubilized heavy metal on at least a part of the surface of the non-porous membrane that transmits hydrogen sulfide in the container. It is what. Therefore, heavy metal can be collected by being attached to and accumulated on the carrier, so that the heavy metal can be easily recovered simply by taking out the container after the treatment.

The carrier may carry the selenate-reducing microorganism described above. In this case, just immersing the vessel of the hydrogen sulfide supply device in the liquid to be treated, the selenium (Se) existing in the form of selenite ion (SeO ₃ ²⁻ ) and the cation form are present. Copper (Cu), silver (Ag), lead (Pb), cadmium (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn ), Manganese (Mn), aluminum (Al), and selenium (Se) present in the form of selenate ions (SeO ₄ ²⁻ ) can be insolubilized. In addition, since heavy metals can be collected and collected on the carrier, the heavy metals can be easily recovered simply by removing the container after the treatment.

According to the method for treating a heavy metal-containing liquid and the hydrogen sulfide supply apparatus for treating a heavy metal-containing liquid according to the present invention, hydrogen sulfide or a hydrogen sulfide production raw material is filled in a sealed container having at least a part of a non-porous membrane. Since hydrogen sulfide is supplied to the periphery of the container at a speed governed by the molecular permeation performance of the non-porous membrane, the heavy metal is insolubilized simply by immersing the container in the liquid to be treated. Can do. Therefore, it is not necessary to provide a facility for maintaining the hydrogen sulfide supply amount at a constant amount, and the heavy metal-containing liquid can be processed easily and at low cost. Then, selenium (Se) present in the form of selenite ion (SeO ₃ ²⁻ ) in the liquid to be treated, and copper (Cu), silver (present in the form of cation in the liquid to be treated) Ag), lead (Pb), cadmium (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn), manganese (Mn) and aluminum ( A plurality of heavy metals such as Al) can be simultaneously insolubilized with hydrogen sulfide. Therefore, recovery of heavy metals and detoxification of the liquid to be processed can be performed only by performing solid-liquid separation, for example, filtration, etc. on the liquid to be processed after the treatment.

  Further, by continuing to supply hydrogen sulfide to the peripheral portion of the container, the hydrogen sulfide concentration in the peripheral portion of the container can be kept locally high. Therefore, since the insolubilization speed of heavy metals can be locally increased in the high concentration hydrogen sulfide region around the container, it is possible to minimize the supply of excess hydrogen sulfide to increase the concentration of hydrogen sulfide in the entire liquid to be treated. A heavy metal insolubilization process can be performed with a limited amount of hydrogen sulfide supplied, and there is no waste. Moreover, since the heavy metal dissolved in the liquid to be treated tends to diffuse uniformly into the liquid to be treated, it dissolves in the liquid to be treated around the container where the heavy metal concentration tends to be low due to the insolubilization treatment of hydrogen sulfide. Heavy metal is supplied or attracted to hydrogen sulfide. That is, according to the method for treating a heavy metal-containing liquid and the hydrogen sulfide supply apparatus for treating a heavy metal-containing liquid according to the present invention, a region for insolubilizing heavy metal with high efficiency is locally formed in the liquid to be treated. By continuing to supply the heavy metal dissolved in the region, most of the heavy metal present in the liquid to be treated can be insolubilized. In addition, since the hydrogen sulfide concentration is high only in the periphery of the container, the liquid to be treated is not acidified. Therefore, since the liquid to be treated is not contaminated with hydrogen sulfide, it is possible to perform environmentally friendly treatment despite using toxic gas, hydrogen sulfide.

  In addition, since the hydrogen sulfide generating raw material is filled in a sealed structure container having at least a part of the non-porous membrane, the container is in a state of being partitioned from the liquid to be processed. Therefore, even if a microbial toxic substance or a chemical reaction inhibiting substance is contained in the heavy metal-containing liquid, hydrogen sulfide can be generated in the container without being affected by them. In other words, when hydrogen sulfide is generated by a chemical reaction between iron sulfide and acid, even if a chemical reaction inhibitor is contained in the heavy metal-containing liquid, hydrogen sulfide is generated in the container without being affected by it. It can be gradually released out of the container. In addition, when hydrogen sulfide is generated by sulfuric acid respiration by sulfate-reducing bacteria, even if microbial toxic substances are contained in the heavy metal-containing liquid, hydrogen sulfide is generated inside the container without being affected by it. Slow release. In addition, when sulfate-reducing bacteria are directly added to the wastewater treatment tank, the wastewater treatment tank needs to be a preferable environment for the sulfate-reducing bacteria. According to the hydrogen supply device, hydrogen sulfide is efficiently produced by sulfuric acid respiration of sulfate-reducing bacteria only by making the inside of a sealed structure container having at least a part of a non-porous membrane a preferable environment for sulfate-reducing bacteria. Therefore, labor and processing costs can be greatly reduced. Further, according to the method for treating a heavy metal-containing liquid and the hydrogen sulfide supply apparatus for treating a heavy metal-containing liquid of the present invention, the heavy metal can be insolubilized from the liquid to be treated simply by immersing the container in the liquid to be treated. It can be introduced easily with almost no improvement such as providing additional equipment to the wastewater treatment equipment. Therefore, the cost for capital investment can be significantly reduced.

  Furthermore, together with an electron donor substance that serves as an energy source for sulfate-reducing bacteria, sulfate ions, and sulfate-reducing bacteria, by filling iron into the vessel as a hydrogen sulfide production raw material, the hydrogen sulfide production rate of the sulfate-reducing bacteria is increased, It becomes possible to process the heavy metal-containing liquid efficiently.

Moreover, in the processing method of the heavy metal containing liquid of this invention, before performing the process of insolubilizing a heavy metal, or simultaneously with the process of insolubilizing a heavy metal, a selenite ion (SeO ₄ ²⁻ ) is converted to a selenite ion (SeO ₃ ^{2). -} ) By contacting a selenate-reducing microorganism that is reduced to) and the liquid to be treated under anaerobic conditions, selenate ions that are hardly insolubilized by reaction with hydrogen sulfide are reduced to selenite ions that are easily insolubilized by hydrogen sulfide. It becomes possible to do. Therefore, it is possible to insolubilize selenium (Se) present in the form of selenate ions that are difficult to insolubilize by reaction with hydrogen sulfide.

  Furthermore, selenate-reducing microorganisms that can reduce selenate ions to selenite ions using lower alcohols such as methanol, ethanol, and propanol as energy sources, such as Pseudomonas sp. 4C-C (FERM P-20840) By using the lower alcohol having 1 to 3 carbon atoms can be used as an energy source, the processing cost can be greatly reduced.

  In addition, Pseudomonas sp 4C-C, even when nitrate ions and nitrite ions are contained in the heavy metal-containing liquid, selenate ion in the heavy metal-containing liquid is not inhibited by these ions. It is a selenate-reducing microorganism having an excellent function of reducing ions to elemental selenium and simultaneously detoxifying nitrate ions and nitrite ions to nitrogen gas. Therefore, Pseudomonas sp 4C-C is contained in the liquid to be treated together with selenium present in the liquid to be treated in the form of selenate ions and other heavy metals by using it for the treatment of the heavy metal-containing liquid. Detoxification treatment of nitrate ions and nitrite ions can be performed at the same time.

  Further, the supply of the lower alcohol having 1 to 3 carbon atoms to the selenate-reducing microorganism is performed by sealing the lower alcohol having 1 to 3 carbon atoms or the waste alcohol in a container having at least a part of the nonporous membrane, By performing a slow release from the non-porous membrane part at a rate governed by the molecular permeation performance of the non-porous membrane, it is not necessary to provide equipment for maintaining a constant supply amount of the lower alcohol, as in the conventional case. In addition, the equipment cost and running cost can be greatly reduced compared to the case where the supply amount is controlled by a pump or a control device.

  In addition, even when using undiluted alcohol, which may kill microorganisms when in direct contact with microorganisms, the permeation rate of alcohol molecules per unit area is sufficiently reduced to reduce the concentration, thus killing microorganisms. There is nothing to do. In addition, it is possible to save labor by omitting the conventional process of adjusting the concentration so that microorganisms do not die by diluting alcohol with water, and supplying alcohol with the same volume of liquid for a long time. Is possible.

  Furthermore, the reuse of waste alcohol can reduce the amount of waste, which is favorable to the environment, and can make the waste useful and reduce the cost of the energy source. For example, waste alcohol that is currently regenerated through processes such as distillation and purification can be used as is without performing these treatments, and a significant cost reduction can be realized. More specifically, waste alcohol generated in food and pharmaceutical manufacturing processes can be effectively used as an energy source for selenate-reducing microorganisms without going through a process such as distillation for removing microbial toxic substances (catechins, etc.). .

Further, at least a portion of the near and non-porous film surface of the non-porous film, by providing a carrier may carry insolubilized heavy metals, can be recovered heavy metals and the adhesion and accumulation on the carrier. Therefore, the heavy metal can be easily recovered simply by taking out the container after the treatment. Further, by supporting the selenate-reducing microorganisms on the carrier, selenium (Se) and cations existing in the form of selenite ion (SeO ₃ ²⁻ ) simply by immersing the vessel of the hydrogen sulfide supply device. Copper (Cu), silver (Ag), lead (Pb), cadmium (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt (Co), iron (Fe ), Zinc (Zn), manganese (Mn), aluminum (Al), and selenium (Se) present in the form of selenate ions (SeO ₄ ²⁻ ) can be insolubilized. In addition, since heavy metals can be collected and collected on the carrier, the heavy metals can be easily recovered simply by removing the container after the treatment.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 15 shows an embodiment of a hydrogen sulfide supply apparatus for processing heavy metal-containing liquid according to the present invention. The hydrogen sulfide supply device 1 includes a hydrogen sulfide production raw material 3 and a container 4 having a sealed structure including at least a part of the nonporous membrane 2, and the hydrogen sulfide production raw material 3 is filled in the container 4. Is. The hydrogen sulfide 3 ′ produced by the hydrogen sulfide production raw material 3 filled in the container 4 is transferred from the portion of the nonporous membrane 2 of the container 4 at a speed controlled by the molecular permeation performance of the nonporous membrane 2. 4 is gradually released. The container 4 may be filled with hydrogen sulfide 3 ′ instead of the hydrogen sulfide production raw material 3 and gradually released around the container 4. The container 4 in the present embodiment is formed into a bag shape composed entirely of the non-porous membrane 2, and the hydrogen sulfide production raw material 3 is formed by welding the periphery with a heat seal or bonding with an adhesive. Although it is made to seal, a form and structure are not specifically limited. For example, the container 4 may be tube-shaped. In addition, the bag-like container (sometimes simply referred to as a bag) 4 is not particularly limited to one constituted entirely by a non-porous membrane, and only one side may be constituted by a non-porous membrane, A part of the film may be composed of only a non-porous film. When a non-porous membrane is partially used, a metal or plastic rigid frame or a membrane that does not transmit hydrogen sulfide may be used for other portions. Further, when the container 4 floats when immersed in the liquid to be treated, the container 4 is provided with a weight, or a film that does not allow hydrogen sulfide 3 ′ to permeate a portion that is not immersed in drainage. As described above, the sustained release of hydrogen sulfide 3 ′ from other than the portion in contact with the liquid to be treated may be suppressed.

  The non-porous membrane 2 used in the container of the hydrogen sulfide supply device of the present invention is gradually released by allowing the hydrogen sulfide 3 'molecules to permeate little by little. This non-porous membrane 2 can control the number of molecules of hydrogen sulfide 3 ′ permeating per unit area by the membrane material, film thickness, temperature, and hydrogen sulfide concentration in the container 4. For example, even when the same container is used, the permeation rate of hydrogen sulfide can be increased by increasing the hydrogen sulfide concentration in the container 4. Therefore, by increasing the hydrogen sulfide generation rate in the container 4 and increasing the hydrogen sulfide concentration, the desired hydrogen sulfide permeation rate can be controlled. In addition, by increasing or decreasing the surface area of the non-porous membrane 2, the sustained release surface of the hydrogen sulfide 3 'can be increased or decreased. Therefore, the non-porous membrane 2 is brought into contact with a part of the liquid to be treated, and the sustained release surface can be increased or decreased according to the surface area of the contact surface between the liquid to be treated and the non-porous film.

Here, in the non-porous membrane 2, the molecular permeation amount varies depending on the density and structure of the membrane constituent molecules. Taking polyethylene as an example, high-density polyethylene (density 942 kg / m3) is compared with the case of using low-density polyethylene (density 910 kg / m ³ or more and less than 930 kg / m ³ ) classified according to JIS K6922-2. When m ³ or more) is used, the permeation amount of hydrogen sulfide 3 ′ to the outside of the membrane decreases. Therefore, the supply amount of hydrogen sulfide 3 ′ may be controlled by the balance between the film thickness and the film density of the non-porous membrane 2 in accordance with the desired supply amount of hydrogen sulfide 3 ′. In addition, since the molecular structure of the polyethylene chain inside the membrane is variable by, for example, stretching, the amount of hydrogen sulfide 3 ′ permeating out of the membrane is changed by changing the membrane density and molecular structure of the desired membrane material by stretching. Can be controlled.

  As the non-porous membrane 2, a hydrophobic membrane such as polyethylene, polypropylene or other olefin-based membrane can be used. Further, polyester, nylon (polyamide), polyvinyl alcohol, vinylon, cellophane, polyglutamic acid and the like which are hydrophilic films having a hydrophilic group in the molecular structure can be used. Furthermore, an ethylene vinyl alcohol copolymer (EVOH) which is a film having both hydrophilic and hydrophobic properties, that is, a copolymer film having both a hydrophobic polyethylene structure and a hydrophilic polyvinyl alcohol structure is used. be able to. A membrane having both hydrophilic and hydrophobic properties can be made more hydrophobic or more hydrophilic by changing the content ratio of hydrophobic polyethylene and hydrophilic polyvinyl alcohol. In addition, the permeability is inferior to the above non-porous membrane, but when extremely slow sustained release performance is required, gas-liquid systems such as polyvinylidene chloride, polycarbonate, ethylene acrylic acid copolymer, polyethylene terephthalate mixture system, etc. A membrane, that is, a membrane whose permeability changes depending on the state of a hydrophilic group or a polar group in its molecular structure.

  Permeation of hydrogen sulfide 3 ′ through the non-porous membrane 2 occurs when hydrogen sulfide molecules dissolve in the membrane, and the dissolved molecules diffuse inside the membrane and reach the opposite side. Hydrophobic membranes such as polyethylene and polypropylene do not have functional groups that are compatible with water and are of low polarity, so polar molecule water is difficult to dissolve in the membrane, but it is possible to pass hydrogen sulfide. It has been confirmed by the experiment.

  In addition, hydrophilic membranes such as polyvinyl alcohol have a structure in which hydrogen bonds are formed inside the membrane in a dry state, so that fluctuations due to thermal vibration of molecular chains do not easily occur, and there are few gaps between molecular chains. , Molecules are difficult to penetrate. However, when water molecules enter between the molecular chains, the hydrogen bond is broken, and the structure is likely to fluctuate due to thermal vibration of the molecular chains, so that the water molecules further enter the membrane. As a result, a water molecule passage is formed, and water-soluble molecules diffuse through the water molecule passage. That is, hydrogen sulfide, which is a water-soluble molecule, diffuses through the water molecule passage.

  As described above, hydrogen sulfide 3 ′ can be permeated regardless of whether the non-porous membrane 2 is hydrophobic or hydrophilic. However, when a hydrophilic non-porous membrane is used, the container There is a possibility that an ionic component in the liquid to be treated enters 4 or the ionic component in the container 4 permeates. Therefore, when the hydrogen sulfide production raw material 3 is filled in the container 4 and hydrogen sulfide is produced in the container 4, the production of hydrogen sulfide may be hindered. In this case, it is preferable to use a hydrophobic film, particularly polyethylene or polypropylene, as the non-porous film 2. By using polyethylene or polypropylene as a non-porous membrane, the mixing of ionic components from the liquid to be treated into the container 4 and the permeation of the ionic components in the container 4 hardly occur, so the production of hydrogen sulfide 3 ′ is inhibited. Not. In addition, polyethylene and polypropylene have an appropriate material permeability and thermoreversibility, and are flexible and easy to mold. In addition, polyethylene and polypropylene are inexpensive and easy to obtain, and are extremely excellent in terms of cost and performance.

The hydrogen sulfide generating raw material 3 used in the present invention is not particularly limited as long as it is a raw material capable of generating hydrogen sulfide 3 ′. For example, sulfate-reducing bacteria, sulfate ions (SO ₄ ²⁻ ). And an electron donor material (hereinafter also referred to simply as an electron donor material) that serves as an energy source for sulfate-reducing bacteria is filled in the container 4, and sulfate ions are reduced by sulfur respiration by sulfate-reducing bacteria to sulfidize. Hydrogen can be produced.

Known or novel microorganisms can be used as the sulfate-reducing bacteria. For example, microorganisms belonging to the genus Desulfovibrio can be mentioned. More specifically, Desulfovibrio desulfuricans and Desulfovibrio vulgaris are mentioned. These microorganisms perform sulfate respiration using sulfate ions (SO ₄ ²⁻ ) as electron acceptors, and reduce the sulfate ions to produce hydrogen sulfide. Therefore, by filling the container 4 with sulfate-reducing bacteria, sulfate ions, and an electron donor substance, the sulfate-reducing bacteria respired with sulfate ions as electron acceptors, and as a result, the produced hydrogen sulfide 3 ′ is stored in the container 4. Slow release from the portion of the non-porous membrane 2 is possible.

  Examples of the electron donor substance that is an energy source for sulfate-reducing bacteria include yeast extract, sulfur-containing amino acid, lactate, formic acid, acetic acid, pyruvate, fumarate, oxalate, malate, and ethanol. Although alcohol and hydrogen gas can be used in general, the substance is not limited to these as long as it is a substance that serves as an energy source for sulfate-reducing bacteria.

  Here, in order to efficiently perform the sulfuric acid respiration of the sulfate-reducing bacteria filled in the container 4 to generate hydrogen sulfide, it is necessary to make the inside of the container 4 a favorable environment for the respiration of the sulfate-reducing bacteria. For example, the culture medium may be placed in the container 4 and sulfate-reducing bacteria may be added to the culture medium. An example of the medium is to mix magnesium sulfate, trisodium citrate dihydrate, calcium sulfate, ammonium chloride, dipotassium hydrogen phosphate, distilled water, sodium lactate, yeast extract, etc. to make the pH neutral. However, the medium is not limited to such a medium, and medium components suitable for the sulfate-reducing bacteria to be used may be appropriately used. According to the experiments by the present inventors, by adding a small amount of iron to the medium, the production rate of hydrogen sulfide 3 ′ by sulfate-reducing bacteria is increased, the amount of hydrogen sulfide 3 ′ permeation is increased, It was confirmed that the insolubilization treatment speed can be improved. Therefore, it is preferable to add iron to the medium. Iron may be added, for example, in the form of iron powder, or may be added in the form of an iron salt, such as iron sulfate, but is not limited to such a form.

  As described above, it is preferable to use a hydrophobic non-porous film such as polyethylene or polypropylene when filling the hydrogen sulfide production raw material 3 into the container 4. Here, the superiority of using a hydrophobic non-porous membrane such as polyethylene or polypropylene is specifically described by taking as an example the case of using sulfate-reducing bacteria, sulfate ions, and an electron donor substance as a hydrogen sulfide production raw material. In other words, since sulfate ions are water-soluble, they easily pass through a hydrophilic membrane. Therefore, when a hydrophilic membrane is used, sulfate ions serving as an electron acceptor for sulfate-reducing bacteria permeate the membrane, reducing the sulfate ion concentration in the container 4 and reducing the amount of hydrogen sulfide produced. . On the other hand, by using a hydrophobic membrane such as polyethylene or polypropylene, sulfate ions serving as an electron acceptor for sulfate-reducing bacteria hardly pass through the membrane, and sulfate ions in the container 4 resulting from permeation through the membrane. A decrease in the concentration can be suppressed and a decrease in the amount of hydrogen sulfide produced can be prevented.

  Moreover, iron sulfide and an acid can be filled in a container, and hydrogen sulfide can also be produced | generated by the chemical reaction of iron sulfide and an acid. As the acid, sulfuric acid, hydrochloric acid and other inorganic acids can be used. Also in this case, by using a hydrophobic membrane such as polyethylene or polypropylene, the water-soluble acid hardly passes through the membrane, and the acid concentration in the container 4 is reduced due to permeation through the membrane. Can be suppressed, and a decrease in the amount of hydrogen sulfide produced can be prevented.

  As another method for generating hydrogen sulfide 3 ′ in the container 4, a reducing agent capable of generating hydrogen sulfide, for example, one or more of sodium thiosulfate, sodium sulfide, and sodium hydrogen sulfide is used as the hydrogen sulfide production raw material 3. Can be mentioned.

  Next, FIG. 16 and FIG. 17 show another embodiment. The hydrogen sulfide supply device 1 of this embodiment has means for introducing hydrogen sulfide 3 ′ or a hydrogen sulfide generating raw material 3 without making the container 4 made of the nonporous membrane 2 completely sealed and independent. A sealed bag-like container is used, and hydrogen sulfide 3 ′ or hydrogen sulfide generating raw material 3 can be replenished from the outside.

  The mechanism for replenishing the hydrogen sulfide 3 ′ or the hydrogen sulfide generating raw material 3 is provided with a supply unit 5 for injecting the hydrogen sulfide 3 ′ or the hydrogen sulfide generating raw material 3 at a part of the edge of the container 4 and a nozzle or pipe 7. A structure to be mounted may be used, or a nozzle or pipe 7 integrated with the container 4 in advance may be used. The hydrogen sulfide supply device 1 shown in FIG. 17 includes a supply nozzle 7 that is detachably attached to a supply unit 5 provided at an edge of the container 4 or a supply nozzle 7 that is integrated with the container 4, and a hydrogen sulfide production raw material 3. Is connected with a tube 8 or the like so that the hydrogen sulfide generating raw material 3 can be replenished as necessary. In this case, since the tank 6 and the container 4 are communicated with each other through the tube 8, if the hydrogen sulfide generating raw material 3 ″ is stored in the tank 6, the hydrogen sulfide generating raw material 3 in the bag 4 is reduced. Then, using the siphon principle, the hydrogen sulfide generating raw material 3 ″ can be replenished from the tank by utilizing the difference in pressure at both ends of the tube. Since the container 4 is provided with the supply unit 5 or the nozzle 7, it does not have a strict meaning of sealing structure, but the supply nozzle 7 is filled with the hydrogen sulfide production raw material 3 ″ supplied from the tank. Then, the liquid level becomes a seal and the inside of the container is practically sealed. For this reason, hydrogen sulfide 3 ′ produced by the hydrogen sulfide production raw material 3 does not leak out of the container 4 through the supply unit 5 and the nozzle 7.

  The vessel 4 of the hydrogen sulfide supply device 1 described above is immersed in the liquid to be treated, and the hydrogen sulfide 3 ′ is transferred from the portion of the nonporous membrane 2 of the vessel 4 to the periphery of the vessel at a speed controlled by the molecular permeation performance of the nonporous membrane. By supplying to, the hydrogen sulfide concentration around the container 4 can be locally increased. Therefore, the insolubilization speed of heavy metals can be locally increased in the high concentration hydrogen sulfide region around the container. Since the heavy metal dissolved in the liquid to be treated tends to diffuse uniformly in the liquid to be treated, the heavy metal concentration continues to be supplied to the periphery of the container where the concentration of heavy metal tends to be low due to the insolubilization treatment of hydrogen sulfide, It is attracted to hydrogen. In other words, a region where the heavy metal is insolubilized with high efficiency is locally formed in the liquid to be processed, and the heavy metal in the liquid to be processed is continuously supplied to the region, so that the heavy metal in the liquid to be processed can be efficiently obtained. Can be insolubilized. Moreover, since the hydrogen sulfide concentration is high only in the periphery of the container, the liquid to be treated is not acidified. Therefore, since the liquid to be treated is not contaminated with hydrogen sulfide, it is possible to perform environmentally friendly treatment despite using toxic gas, hydrogen sulfide.

Here, the liquid to be treated using the method for treating a heavy metal-containing liquid of the present invention exists in the form of selenium (Se) and cation that exist in the form of selenite ion (SeO ₃ ²⁻ ). Copper (Cu), silver (Ag), lead (Pb), cadmium (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt (Co), iron (Fe), zinc ( Wastewater (waste water) containing one or more of Zn), manganese (Mn), and aluminum (Al). Furthermore, sludge and groundwater can be targeted.

Selenium (Se) present in the form of selenite ion (SeO ₃ ²⁻ ) in the liquid to be treated generates sulfide precipitates by the supplied hydrogen sulfide, or the supplied hydrogen sulfide By acting as a reducing agent, it is insolubilized as elemental selenium. Copper (Cu), silver (Ag), lead (Pb), cadmium (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt present in the form of cations in the liquid to be treated (Co), iron (Fe), zinc (Zn), manganese (Mn), and aluminum (Al) react with the supplied hydrogen sulfide to produce sulfide precipitates, which are insolubilized. Incidentally, aluminum (Al) is not in the form of sulfide precipitation but becomes Al (OH) ₃ which is hydroxide precipitation and is insolubilized.

  Here, when sludge, groundwater, or the like is to be treated, solid-liquid separation treatment is difficult even if heavy metals are insolubilized. Therefore, the carrier 10 capable of adhering / accumulating heavy metals insolubilized on the surface of the non-porous membrane is provided on at least a part of the non-porous membrane 2 of the container 4, thereby adhering / accumulating heavy metals insolubilized in the carrier 10. And can be recovered. Therefore, the heavy metal can be easily recovered simply by removing the container 4 after the treatment. That is, it is possible to reduce the labor by omitting the filtration process for performing the solid-liquid separation process. As the carrier 10, for example, a fibrous member such as a polymer gel or a nonwoven fabric can be used. Further, when the carrier 10 is formed of a highly rigid material and the carrier 10 is formed into a sheath shape with a highly rigid member as shown in FIG. 18, the inner bag-like container 4 is made of hydrogen sulfide 3 ′. Since it can prevent swelling, it is preferable when the hydrogen sulfide supply device is made compact. In this case, the bag-like container does not swell and its thickness is limited to reduce the thickness of the bag. This increases the packing density when the bag-like container is placed in a closed space such as a processing tank, and the non-container of the container 4. It becomes possible to protect the portion of the porous membrane 2 from external impact. The carrier 10 does not need to be provided on the entire surface of the non-porous membrane 2, and may be attached to only a part of the non-porous membrane, or the carrier 10 inhibits the sustained release of hydrogen sulfide 3 ′. In this case, the carrier 10 may be provided with a large number of fine holes. Further, when the sheath-like carrier 10 is used, it is not necessary to stick the non-porous membrane 2 and the carrier 10 of the container 4, and the container 4 may be inserted into the carrier 10. Alternatively, the carrier 10 formed in an annular shape may be wound around the container 4 and used. Alternatively, the carrier 10 may be simply disposed in the vicinity of the container 4 so that the insoluble heavy metal is adhered and accumulated. By using the carrier 10 without sticking, if a large amount of heavy metal insolubilized on the carrier 10 adheres and accumulates, it is possible to attach and accumulate the insolubilized heavy metal again simply by replacing it with a new carrier 10. Become.

  Examples of the polymer gel used as the carrier 10 include collagen, fibrin, albumin, casein, cellulose fiber, cellulose triacetate, agar, calcium alginate, carrageenan, agarose, and other natural polymers, polyacrylamide, poly-2-hydroxyethyl Synthetic polymers such as methacrylic acid, polyvinyl chloride, γ-methylpolyglutamic acid, polystyrene, polyvinylpyrrolidone, polydimethylacrylamide, polyurethane, photocurable resins (polyvinyl alcohol derivatives, polyethylene glycol derivatives, polypropylene glycol derivatives, polybutadiene derivatives, etc.), Or these composite_body | complex is mentioned. It is also possible to use a water-absorbing polymer. When the water-absorbing polymer is used, the liquid to be processed is more easily absorbed than when the polymer gel is used, and the heavy metal in the liquid to be processed can be more efficiently processed. As the water-absorbing polymer, those generally used can be used, and specific examples include polyacrylic acid, polyaspartic acid, polyglutamic acid, modified products thereof, modified polyethylene glycol, and the like. . The modified product referred to here is a product obtained by crosslinking a polymer having an ionic group to a part of the polymer.

Here, the selenate ion (SeO ₄ ²⁻ ) is reduced to selenite ion (SeO ₃ ²⁻ ) before or simultaneously with the immersion of the container 4 of the hydrogen sulfide supply device 1 in the liquid to be treated. By contacting the selenate-reducing microorganism and the liquid to be treated under anaerobic conditions, selenate ions that are hardly insolubilized by supplying hydrogen sulfide can be reduced to selenite ions that are easily insolubilized by hydrogen sulfide.

The selenate-reducing microorganism used in the present invention is not particularly limited as long as it is a selenate-reducing microorganism that reduces selenate ion (SeO ₄ ²⁻ ) to selenite ion (SeO ₃ ²⁻ ). Examples include selenate-reducing microorganisms belonging to the genus Pseudomonas, Paracoccus, Delayer, Bacillus, and Enterobacter. These selenate-reducing microorganisms are microorganisms that function using yeast extract, sulfur-containing amino acids, lactate, and the like as energy sources.

Here, it is preferable to use a selenate-reducing microorganism that can use an alcohol, for example, a lower alcohol having 1 to 3 carbon atoms, such as methanol, ethanol, and propanol, as an energy source. As a selenate-reducing microorganism that can use a lower alcohol as an energy source, for example, Pseudomonas sp. 4C-C can be used, but is not limited to this microorganism, and a known or novel microorganism can be used. Pseudomonas sp. 4C-C is a selenate-reducing microorganism belonging to the genus Pseudomonas, and has been entrusted to the Patent Organism Depositary, National Institute of Advanced Industrial Science and Technology as the accession number FERM P-20840 on March 13, 2006. . Pseudomonas sp 4C-C reduces selenate ion (hexavalent selenium) to selenite ion (tetravalent selenium) as shown in the following chemical formula 3, and further selenite ion (4-day selenium). Is reduced to elemental selenium (zero-valent selenium).
[Chemical Formula 3] SeO ₄ ²⁻ → SeO ₃ ²⁻ → Se

  In order to allow a selenate-reducing microorganism to function and reduce selenate ions to selenite ions, the place where the selenate-reducing microorganisms exist is subjected to anaerobic conditions, that is, dissolved oxygen is substantially contained in the liquid to be treated. Preferably it is not present. In addition, when there is a lot of dissolved oxygen and the function of selenate reduction is reduced, a treatment such as reducing the dissolved oxygen by introducing an inert gas such as nitrogen gas or rare gas into the liquid to be treated is performed. The selenate-reducing microorganism may function.

  Here, Pseudomonas sp 4C-C does not inhibit the reaction of reducing selenate ions to selenite ions even in an environment where nitrate ions are present in high concentrations, and at the same time, nitrate ions and Nitrate ions can be reduced to harmless nitrogen gas. Furthermore, even in an environment where sulfate ions are present, the reaction of reducing selenate ions to selenite ions is not inhibited. That is, when treating selenate compounds from desulfurization effluent discharged from thermal power plants, etc., the function does not deteriorate and nitrate ions and nitrite ions are reduced to harmless nitrogen gas. Can do. Therefore, by using both the contact treatment of the liquid to be treated by Pseudomonas sp 4C-C and the immersion treatment in the liquid to be treated of the container 4 of the hydrogen sulfide supply device 1, not only heavy metals but also nitrate ions can be obtained. And nitrite ions can be removed.

Here, the above-mentioned selenate-reducing microorganisms may be supported on the carrier 10 provided by sticking or the like on at least a part of the surface of the non-porous membrane. In this case, the selenium (Se) existing in the form of selenite ion (SeO ₃ ²⁻ ) and the cation form exist only by immersing the container 4 of the hydrogen sulfide supply device 1. Copper (Cu), silver (Ag), lead (Pb), cadmium (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn), Manganese (Mn), aluminum (Al), and selenium (Se) present in the form of selenate ions (SeO ₄ ²⁻ ) can be insolubilized. In addition, since heavy metals can be attached to and accumulated on the carrier 10 and recovered, the heavy metals can be easily recovered simply by removing the container 4 after processing.

  Next, if the supply amount of the lower alcohol, which is an energy source material of Pseudomonas sp. 4C-C, is excessive, the selenate-reducing microorganisms may not be consumed and remain in the liquid to be treated, which may deteriorate the water quality. On the other hand, if the supply amount is small, the energy source becomes insufficient, and the selenate-reducing microorganism does not function sufficiently, and the selenate compound may not be sufficiently reduced. Therefore, as described below, it is preferable to seal the lower alcohol in a container provided with at least a part of the non-porous membrane, and supply the lower alcohol gradually from the non-porous membrane to the periphery of the container.

  FIG. 19 shows an embodiment of an electron donor supply apparatus in which a lower alcohol (hereinafter sometimes simply referred to as alcohol) is sealed in a container having at least a part of a non-porous membrane. The electron donor supply device 11 includes an alcohol 12 and a container 14 having a sealed structure including at least a part of the non-porous membrane 2. The container 14 is filled with the alcohol 12, and the alcohol 12 is stored in the container 14. The porous membrane 2 is supplied to the periphery of the container 14 at a speed governed by the molecular permeation performance of the nonporous membrane 2, and the alcohol 12 is gradually supplied to the selenate-reducing microorganisms around the container 14. . In the present embodiment, the entire container 14 forms a bag shape composed of the non-porous membrane 2, and the alcohol 12 is sealed by welding the periphery with a heat seal or bonding with an adhesive. However, the form and structure are not particularly limited. For example, the container 14 may have a tube shape or a sheet shape. In addition, the bag-like container (sometimes simply referred to as a bag) 4 is not particularly limited to one constituted entirely by a non-porous membrane, and only one side may be constituted by a non-porous membrane, A part of the film may be composed of only a non-porous film. When a non-porous membrane is partially used, a metal or plastic rigid frame or a membrane that does not transmit alcohol may be used for other portions. If the container 4 floats when placed in the liquid to be treated, the container 4 is provided with a weight, or a portion that is not immersed in the liquid to be treated is formed as a film that does not allow alcohol to permeate. You may make it suppress slow release of alcohol from the part other than the part which is contacting the process liquid.

  The non-porous membrane 2 used in the electron donor supply device 11 is a sustained release by allowing the molecules of the alcohol 12 to pass through little by little. This non-porous membrane 2 can control the molecular weight of the alcohol 12 permeating per unit area depending on the membrane material, film thickness, molecular weight and properties of the alcohol 12 to be sealed, temperature, and alcohol concentration. For example, even when the same container is used, if the concentration of the alcohol 12 is increased, the permeation rate of the alcohol 12 can be increased. Moreover, the sustained release surface of the alcohol 12 can be increased or decreased by increasing or decreasing the surface area of the nonporous membrane 2. Therefore, the non-porous membrane 2 is brought into contact with a part of the liquid to be treated, and the sustained release surface can be increased or decreased according to the surface area of the contact surface between the liquid to be treated and the non-porous film. According to the inventors' experiments on polyethylene membranes, it has been confirmed that in the case of the same membrane material, the molecular permeation amount per unit area varies depending on the film thickness. Therefore, a necessary amount of alcohol can be supplied at a necessary rate by appropriately selecting a film thickness or the like according to the amount of alcohol necessary for the selenate-reducing microorganism. At this time, the alcohol leaks at a moderate rate governed by the molecular permeation performance of the non-porous membrane 2. Therefore, even when using undiluted alcohol that may kill selenate-reducing microorganisms when supplied directly, it is diluted to a concentration that does not affect survival of selenate-reducing microorganisms around the container. Supplied in.

Here, in the non-porous membrane 2, the molecular permeation amount varies depending on the density and structure of the membrane constituent molecules. Taking polyethylene as an example, high-density polyethylene (density 942 kg / m3) is compared with the case of using low-density polyethylene (density 910 kg / m ³ or more and less than 930 kg / m ³ ) classified according to JIS K6922-2. When m ³ or more) is used, the permeation amount of the alcohol 12 to the outside of the membrane decreases. Therefore, the supply amount of the alcohol 12 may be controlled according to the balance between the film thickness and the film density of the nonporous membrane 2 according to the desired supply amount of the alcohol 12. Further, since the molecular structure of the polyethylene chain inside the membrane can be changed by, for example, a stretching process, it is possible to control the supply amount of the alcohol 12 by changing the film density of a desired film material by the process. .

  The molecule of alcohol 12 has both an alkyl group that is a hydrophobic group and a hydroxyl group that is a hydrophilic group. Therefore, as the non-porous membrane 2, the alcohol 12 can be permeated by using either a hydrophobic membrane, a hydrophilic membrane, or a membrane having both hydrophilic and hydrophobic properties. Examples of the hydrophobic membrane include polyethylene, polypropylene, and other olefinic membranes. Examples of the hydrophilic film include a film having a hydrophilic group in the molecular structure, such as polyester, nylon (polyamide), polyvinyl alcohol, vinylon, cellophane, polyglutamic acid and the like. Examples of the membrane having both hydrophilic and hydrophobic properties include ethylene vinyl alcohol copolymer (EVOH), that is, a copolymer membrane having both a hydrophobic polyethylene structure and a hydrophilic polyvinyl alcohol structure. Can be mentioned. A membrane having both hydrophilic and hydrophobic properties can be made more hydrophobic or more hydrophilic by changing the content ratio of hydrophobic polyethylene and hydrophilic polyvinyl alcohol. In addition, the permeability is inferior to the above non-porous membrane, but when extremely slow sustained release performance is required, gas-liquid systems such as polyvinylidene chloride, polycarbonate, ethylene acrylic acid copolymer, polyethylene terephthalate mixture system, etc. A membrane, that is, a membrane whose permeability changes depending on the state of a hydrophilic group or a polar group in its molecular structure.

  Polyethylene and polypropylene can satisfactorily divide the water area, soil, and sludge, which are microbial activities, and other areas. Further, it has an appropriate substance permeability and thermoreversibility, and is flexible and easy to mold. Moreover, since polyethylene and polypropylene are inexpensive and easily available, it is very preferable to use polyethylene and polypropylene from the viewpoint of cost and performance.

  Here, the permeation of the alcohol 12 through the non-porous membrane 2 occurs when the molecules of the alcohol 12 dissolve in the non-porous membrane 2 and the dissolved molecules diffuse inside the membrane and reach the opposite side. Therefore, catechins and the like having a molecular weight that is so large that the membrane does not dissolve hardly penetrate the non-porous membrane. In addition, since polyethylene, polypropylene, and the like are highly hydrophobic membranes that do not have a functional group compatible with water and have low polarity, water that is a polar molecule hardly dissolves in the membrane. Therefore, a cyanide compound, which is a highly polar substance that easily dissolves in water, can hardly pass through. In addition, since water has strong hydrogen bonds between water molecules, water hardly permeates the membrane at room temperature. Therefore, the non-porous membrane 2 functions as a “molecular sieve” that allows the alcohol 12 to permeate as a main component while hardly allowing impurities such as water, a highly polar cyanide, and a catechin having a large molecular weight to permeate. Therefore, when a hydrophobic membrane represented by polyethylene or polypropylene is used as the non-porous membrane, antibacterial molecules that are toxic to microorganisms such as impurities such as catechin and cyanide are mixed in the alcohol. Waste alcohol can be used. The use of waste alcohol in place of alcohol is preferable both environmentally and economically. Further, alcohol is released in a molecular state to the outside of the container regardless of whether the container is in a liquid state or a volatilized state. That is, alcohol permeates through the non-porous membrane 2 and is gradually released in a gas (gas) state that does not aggregate due to the attractive force between molecules like a liquid. Therefore, the non-porous membrane 2 can also be expressed as a gas permeable membrane. Further, even when the environment outside the container is a liquid phase (drainage, groundwater, etc.), it is possible to gradually release alcohol in a molecular state outside the container.

  Next, FIG. 20 and FIG. 21 show another embodiment of the electron donor supply apparatus. The electron donor supply device of this embodiment is not a completely sealed independent container 14 made of a nonporous membrane 2, but a sealed bag-like container having means for introducing alcohol 12 The alcohol 12 can be replenished from the outside.

  The mechanism for replenishing the alcohol 12 may have a structure in which the supply part 5 for injecting the alcohol 12 is provided at a part of the edge of the container 14 and the nozzle or pipe 7 is mounted, or a nozzle integrated with the container 14 in advance. Or a thing like the pipe 7 may be sufficient. The electron donor supply device 11 shown in FIG. 21 stores the supply nozzle 7 detachably attached to the supply unit 5 provided at the edge of the container 14 or the supply nozzle 7 integrated with the container 14 and the alcohol 12. The tank 6 to be connected is connected by a tube 8 or the like so that the alcohol 12 can be replenished as necessary. In this case, since the tank 6 and the container 14 are communicated with each other through the tube 8, if the alcohol 12 ′ is stored in the tank 6, the alcohol 9 in the bag 14 is reduced when the siphon is reduced. Using the principle, the alcohol 12 'can be replenished from the tank by the pressure difference across the tube. Although the container 14 is provided with the supply unit 5 or the nozzle 7, it does not have a strict sealing structure. However, in the state where the supply nozzle 7 is filled with the alcohol 12 'supplied from the tank, the liquid level Becomes a seal, and the inside of the container is effectively sealed. For this reason, the liquid or gasified alcohol 12 does not leak out of the container 14 through the supply unit 5 and the nozzle 7.

  Here, the method of supplying the lower alcohol to the selenate-reducing microorganism is not limited to that shown in FIGS. 19 to 21. For example, the lower alcohol may be directly supplied into the liquid to be treated. As described above, if the supply of lower alcohol, which is an energy source, is excessive, the selenate-reducing microorganisms cannot be consumed and remain in the liquid to be treated, which may deteriorate the water quality. On the other hand, if the supply amount of the lower alcohol is small, the energy source is insufficient, and the selenate-reducing microorganism does not function sufficiently, and the selenate compound may not be sufficiently treated. Therefore, it is preferable to control the supply amount and timing using a pump or the like.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, in order to keep the anaerobic atmosphere of the liquid to be treated for a long time and keep the selenate-reducing microorganisms that are anaerobic microorganisms functioning, the oxygen-absorbing substance is contained in a sealed structure container having a non-porous membrane in part. You may make it immerse the oxygen-absorbing apparatus filled with in the liquid to be treated. Any oxygen-absorbing substance may be used as long as it can absorb oxygen and does not corrode the non-porous membrane. A solid reducing agent such as reduced iron or a solution containing a reducing agent such as a sodium sulfite solution may be used. Although it can, it is not limited to these. According to this oxygen absorber, dissolved oxygen in the liquid to be treated can be absorbed at a moderate rate governed by the oxygen molecule permeation performance of the non-porous membrane, so that the anaerobic atmosphere of the liquid to be treated can be maintained for a long time. Can do.

Further, in combination with the treatment of the heavy metal-containing liquid according to the present invention, a microorganism that produces hydrogen sulfide, sulfuric acid, iron (III) sulfate, carbon dioxide, oxygen, ammonia, organic acid, a substance having a chelating action in the liquid to be treated. In addition to the direct addition, and by immersing the electron donor supply device 11 shown in FIGS. 19 to 21, heavy metals are insolubilized by supplementarily using the action of microorganisms that exist in the liquid to be treated. May be performed more efficiently. For example, the sulfate-reducing bacteria are directly added to the liquid to be treated, and the electron donor supply device 11 is immersed to supply the alcohol 12 as the electron donor substance to activate the sulfate-reducing bacteria. Hydrogen sulfide may be generated from sulfate ions added therein, and the hydrogen sulfide and heavy metal may be reacted to generate a metal sulfide precipitate. Selenium (Se) present in the form of selenite ion (SeO ₃ ²⁻ ) and copper (Cu), silver (Ag), lead (Pb), cadmium (Cd) present in the form of cation Mercury (Hg), Tin (Sn), Nickel (Ni), Cobalt (Co), Iron (Fe), Zinc (Zn), Manganese (Mn) and Aluminum (Al) produce sulfides or hydroxides Therefore, the heavy metal insolubilization treatment of the present invention can be performed more efficiently by precipitating these heavy metals by the treatment. In addition, without using the treatment of the heavy metal-containing liquid according to the present invention, microorganisms that produce hydrogen sulfide, sulfuric acid, iron (III) sulfate, carbon dioxide, oxygen, ammonia, organic acids, and chelating substances are inhabited. By placing the electron donor supply device 11 in an environment (soil, groundwater, sludge, etc.), an environment in which these microorganisms are added to soil, groundwater, sludge, etc., or an artificial environment (such as a wastewater treatment facility or bioreactor) Heavy metal treatment may be performed. For example, sulfate-reducing bacteria are cultured in the treatment solution in a free state, and the electron donor substance 12 is given by the electron donor supply device 11 shown in FIGS. 19 to 21, and sulfate ions are added to the treatment solution. Selenium (Se) existing in the form of selenite ion (SeO ₃ ²⁻ ) and copper (Cu), silver (Ag), lead (Pb), cadmium existing in the form of cation (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn), manganese (Mn) and aluminum (Al) are removed from the environment. It is possible to purify the environment.

  The electron donor supply device 11 can also be used when heavy metals are reduced and precipitated as the final electron acceptor of anaerobic respiration of microorganisms. For example, the electron donor material 12 is supplied to the microorganisms by the electron donor supply device 11 to reduce uranium from hexavalent to tetravalent, and selenium from hexavalent to zero valent to precipitate, The precipitate may be removed by solid-liquid separation or the like and removed from the environment. Examples of microorganisms that reduce uranium include Alteromonas putrefaciens, Geobacter metallireductans, Enterobacter cloacae, and the like. Examples of microorganisms that reduce selenium include Bacillus sp. And Pseudomonas sp. Such microbial treatment may be performed in combination with the present invention or alone.

  Furthermore, the electron donor supply device 11 of the present invention can also be used when hexavalent chromium is reduced by chromium reducing bacteria to render it harmless and recovered as trivalent chromium. Examples of chromium-reducing bacteria include Shwanella, Pseudomonas, Sulfate reducing bacteria, Arthrobacter, Bacillus, Aerococcus, Micrococcus, Aeromonas, Thermoanaerobacter, Cellulomonas, Geobacter, Streptomyces, Escherichia, Enterobacter and the like. In addition to chromium-reducing bacteria, the electron donor supply device 11 of the present invention can be used for microorganisms capable of reducing and detoxifying silver, copper, mercury, iodine, arsenous acid, nickel, cadmium and the like. . In other words, donate electrons to environments where these microorganisms live (soil, groundwater, sludge, etc.), environments where these microorganisms are added to soil, groundwater, sludge, etc., or artificial environments (such as wastewater treatment facilities and bioreactors) By providing the body supply device 11 and supplying the electron donor substance, silver, copper, mercury, iodine, arsenous acid, nickel, cadmium, and the like can be reduced and detoxified. Such microbial treatment may be performed in combination with the present invention or alone.

  In addition, as described above, the sulfate-reducing bacteria used as the hydrogen sulfide production raw material 3 can use all alcohols such as ethanol as the electron donor substance. As described above, all alcohols such as ethanol are sealed in the container 4. Then, alcohol will leak from the portion of the non-porous membrane 2 of the container 4. Therefore, the electron donor supply device 11 shown in FIGS. 19 to 21 is accommodated in the container 4 of the hydrogen sulfide supply device 1 and the alcohol is gradually released from the electron donor supply device 11 so that sulfate-reducing bacteria can be obtained. An electron donor material 12 may be provided to allow the sulfate reducing bacteria to function.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1
Using a polyethylene film (trade name: Mipolon film, manufactured by Mitsuwa Co., Ltd.) having a thickness of 0.05 mm, a bag of 50 mm × 30 mm is formed, and various hydrogen sulfide generating raw materials are sealed in the bag to form bags A to A E was produced. Moreover, in order to compare with the function of bag AE, the bags F and G were produced.

  The hydrogen sulfide generation raw material of the bag A was 0.4 g of powdered FeS (manufactured by Wako Pure Chemical Industries, Ltd.) and 1 ml of hydrochloric acid (manufactured by Wako Pure Chemical Industries, Ltd., 2N).

  The hydrogen sulfide production raw material of the bag B was 3 ml of a medium and one platinum loop of a sulfate-reducing bacterium Desulfovibrio desulfuricans NBRC 13699 (Independent Administrative Institution, Product Evaluation Technology Infrastructure, hereinafter referred to as a sulfate-reducing bacterium Desulfovibrio desulfuricans). The composition of the medium is shown in Table 1.

  The hydrogen sulfide generating raw material of the bag C was 3 ml of an iron-containing medium and one platinum loop of sulfate-reducing bacteria Desulfovibrio desulfuricans. Table 2 shows the composition of the iron-containing medium.

The raw material for producing hydrogen sulfide in bag D was 3 ml of a medium having the same composition as in Table 1 and a sulfate-reducing bacterium Desulfovibrio desulfuricans having an initial OD ₆₀₀ value of 0.01 in the medium.

The raw material for producing hydrogen sulfide in bag E was 3 ml of an iron-containing medium having the same composition as in Table 2 and a sulfate-reducing bacterium, Desulfovibrio desulfuricans, having an initial OD ₆₀₀ value of 0.01 in the medium.

  In the bag F, only 3 ml of the medium having the same composition as in Table 1 was sealed.

  In the bag G, only 3 ml of the medium having the same composition as in Table 2 was sealed.

(Example 2)
In a 200 ml tall beaker, 100 ml of a 100 mg-Se / L aqueous solution of selenic acid (SeO ₄ ²⁻ ) is placed, and the bag A is immersed in the aqueous solution. After the bag A is immersed, 0 hour, 0.17 hour, 1 hour The selenate ion (SeO ₄ ²⁻ ) concentration after 18 hours was measured. The measurement was performed with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX). The measurement results are shown in FIG. In FIG. 1 (A), no decrease in selenate ion concentration was observed even after 18 hours had passed since bag A was immersed. Further, the color of the aqueous solution did not change at all before and after the immersion of the bag A, and remained colorless and transparent.

Next, 100 ml of a 100 mg-Se / L aqueous solution of selenious acid (SeO ₃ ²⁻ ) is placed in a 200 ml tall beaker, and the bag A is immersed in the aqueous solution. The selenite ion (SeO ₃ ²⁻ ) concentration after 1 hour and 18 hours was measured. The measurement was performed with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX). The measurement results are shown in FIG. In FIG. 1 (B), the selenite ion concentration rapidly decreased until 1 hour after the dipping of the bag A, and continued to decrease little by little until 18 hours had passed. Moreover, although the color of the aqueous solution before immersion of the bag A was colorless and transparent, the color of the aqueous solution was dark orange after 18 hours from the immersion of the bag A. In other words, it was confirmed that selenite ions react with hydrogen sulfide to become sulfide precipitates or elemental selenium and are insolubilized.

  As mentioned above, it became clear that the density | concentration can be reduced by insolubilizing the selenite ion in a to-be-processed liquid by immersing the bag A in a to-be-processed liquid. On the other hand, it was found difficult to reduce the selenate ion concentration. This is considered due to the low chemical reactivity of selenate ions. That is, it is possible to supply hydrogen sulfide into the liquid to be treated by the bag A, but selenate ions having low chemical reactivity do not react with hydrogen sulfide, and form selenate ions in the liquid to be treated. It is thought that it continued to remain.

(Example 3)
30 ml of an iron-containing medium having the same composition as in Table 2 with a selenite ion concentration of 50 mg-Se / L (hereinafter referred to as a selenite-containing medium) was placed in four 50 ml vials, and each vial was On the other hand, the operations shown in the following (a), (b), (c) and (d) were performed, the lid of the vial was closed, and culture was performed at 30 ° C. with shaking (100 rpm). And the selenite ion (SeO ₃ ²⁻ ) concentration and the sulfate ion (SO ₄ ²⁻ ) concentration of the selenite containing medium were measured immediately after the start of culture and after 3 days from the culture. The measurement was performed with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX).
(A) No operation.
(B) One platinum loop of the sulfate-reducing bacterium Desulfovibrio desulfuricans was added to the selenite-containing medium.
(C) Immerse the bag G in the selenious acid-containing medium.
(D) Immerse bag C in a selenious acid-containing medium.

  The measurement results are shown in FIG. 2A shows the selenite ion concentration, and FIG. 2B shows the sulfate ion concentration. In FIG. 2A, when the operations of (a) and (c) are performed, a decrease in selenite ion concentration in the selenite-containing medium is hardly seen even after 3 days from the start of the culture. There wasn't. On the other hand, when the operations of (b) and (d) were performed, the selenite ion concentration in the selenite containing medium became 0 mg-Se / L after 3 days from the start of the culture, and the selenite containing medium It was confirmed that the selenite ion therein was insolubilized.

  In FIG. 2B, when the operations of (a) and (c) are performed, since microorganisms consuming sulfate ions are not present in the selenite-containing medium, 3 days have passed since the start of the culture. However, almost no decrease in the sulfate ion concentration in the selenite-containing medium was observed. On the other hand, when the operation of (b) is performed, sulfate ions are consumed by sulfate respiration of the sulfate-reducing bacterium Desulfovibrio desulfuricans present in the selenite-containing medium, and the sulfate after 3 days from the start of the culture. The ion concentration was 566 mg / L, which was less than half of the sulfate ion concentration immediately after the start of culture. In addition, when the operation (d) was performed, a decrease in the sulfate ion concentration in the selenite-containing medium was hardly observed even after 3 days from the start of the culture. Therefore, the sulfate-reducing bacterium Desulfovibrio desulfuricans in the bag C generates hydrogen sulfide by respiring with sulfate ions in the medium in the bag C as an electron acceptor, and the hydrogen sulfide permeates the bag C. It was revealed that selenite ions in the selenite-containing medium were insolubilized.

  As described above, it has been clarified that by immersing the bag C in the liquid to be treated, hydrogen sulfide can be supplied into the liquid to be treated to insolubilize selenite ions. Therefore, in addition to selenite ions, heavy metals that can be insolubilized by reacting with hydrogen sulfide or sulfide ions derived from hydrogen sulfide, such as copper (Cu), silver (Ag), lead (Pb), cadmium (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn), manganese (Mn) and aluminum (Al) can be insolubilized. It was.

Example 4
30 ml of phosphate buffer (9 g / l Na ₂ HPO ₄ · 12H ₂ O, 1.5 g / l KH ₂ PO ₄ , pH = 7.5) with a selenite ion concentration of 50 mg-Se / L (Referred to as selenite-containing phosphate buffer) in four 50 ml vials, and for each vial the same as (a), (b), (c) and (d) of Example 3 The vial bottle lid was closed, and culture was performed at 30 ° C. with shaking (100 rpm). Then, immediately after the start of culture, 3 days and 10 days after the culture, the selenite ion (SeO ₃ ²⁻ ) concentration of the selenite-containing phosphate buffer was measured. The measurement was performed with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX).

  The results are shown in FIG. In FIG. 3, when the operations (a) and (c) were performed, almost no change in selenite ion concentration was observed even 10 days after the start of the culture. In addition, when the operation (b) was performed, almost no change in the selenite ion concentration was observed even 10 days after the start of the culture. On the other hand, when the operation of (d) was performed, the selenite ion concentration was hardly changed from the beginning of the culture to the third day, but was significantly decreased on the tenth day. This is because the sulfate ions in the medium sealed in the bag C were reduced by the sulfate-reducing bacteria Desulfovibrio desulfuricans to generate hydrogen sulfide, and the hydrogen sulfide permeated through the bag and the selenite ion was insolubilized. Due to Although it was confirmed in Example 3 that the selenite ion concentration was 0 mg-Se / L 3 days after the bag C was immersed in the selenite-containing medium, the bag C was submerged. After 3 days of immersion in the selenate-containing phosphate buffer, the selenite ion concentration was almost unchanged from the beginning of the culture. The reason can be considered as follows. That is, the selenite-containing medium used in Example 3 contained iron, but the selenite-containing phosphate buffer used in this example did not contain iron, and the liquid to be treated The presence or absence of iron in the iron has some influence on the insolubilization treatment of selenite ions with hydrogen sulfide. For example, selenite ions are produced together with iron sulfide produced by the reaction of hydrogen sulfide with iron. It is conceivable that the oxidation-reduction potential of the liquid to be treated changes due to aggregation precipitation or the presence of iron, and the reaction rate of selenite ions and hydrogen sulfide changes. In addition, the culture medium in the bag C after 10 days from the start of the culture was black. This is considered to be due to the iron sulfide precipitation caused by the reaction between the iron component contained in the bag C and the hydrogen sulfide produced by the sulfate-reducing bacteria.

(Example 5)
30 ml of a medium having the same composition as in Table 1 with a selenite ion concentration of 50 mg-Se / L is placed in four 50 ml vials, and bags D, E, F and G are immersed in each vial. Then, the lid of the vial was closed, and culture was performed at 30 ° C. with shaking (100 rpm). Then, the selenite ion (SeO ₃ ²⁻ ) concentration, the sulfate ion (SO ₄ ²⁻ ) concentration, and the pH after culturing for 0 hour, 17 hours, 41 hours, 65 hours, 89 hours, 161 hours, and 233 hours. It was measured. The measurement of the selenite ion (SeO ₃ ²⁻ ) concentration and the sulfate ion (SO ₄ ²⁻ ) concentration was performed with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX). The pH was measured with a pH meter (model: HM-30V, manufactured by Toa Denpa Kogyo Co., Ltd.).

The results are shown in FIG. 4A is a graph showing selenite ion (SeO ₃ ²⁻ ) concentration, FIG. 4B is sulfate ion (SO ₄ ²⁻ ) concentration, and FIG. 4C is pH. In FIG. 4A, when bag F and bag G were immersed in the medium, it was confirmed that the selenite ion concentration hardly changed. On the other hand, when bag D and bag E were immersed, the selenite ion concentration became 0 mg-Se / L after 240 hours from the start of culture. Further, it was confirmed that the rate of decrease of the selenite ion concentration was faster when the bag E was immersed. Therefore, it was revealed that the rate of decrease in the selenite ion concentration can be increased by including iron in the medium sealed in the bag.

  Also, as shown in FIG. 4 (B), for sulfate ions, the sulfate ions in the bag were reduced and passed through the bag, so the bag D, Bag E, Bag F, Bag G Even when immersed in the medium, there was no change in the sulfate ion concentration in the medium. Furthermore, as shown in FIG. 4C, it was confirmed that the pH was kept neutral without touching acidity or alkalinity.

Next, 30 ml of the medium having the conditions shown in (a), (b), (c) and (d) below is put into a 50 ml vial, the vial is closed, and shaken at 30 ° C. (100 rpm). Culture was performed. Then, the selenite ion (SeO ₃ ²⁻ ) concentration, the sulfate ion (SO ₄ ²⁻ ) concentration, and the pH after culturing for 0 hour, 17 hours, 41 hours, 65 hours, 89 hours, 161 hours, and 233 hours. Measured and compared with the results of the above experiments using bags D, E, F and G. The measurement of the selenite ion (SeO ₃ ²⁻ ) concentration and the sulfate ion (SO ₄ ²⁻ ) concentration was performed with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX). The pH was measured with a pH meter (model: HM-30V, manufactured by Toa Denpa Kogyo Co., Ltd.).
(A) Medium of Table 1 with selenite ion concentration of 50 mg-Se / L (no sulfate-reducing bacteria added)
(A) Medium of Table 1 with selenite ion concentration of 50 mg-Se / L (with sulfate-reducing bacteria added)
(C) Iron-containing medium of Table 2 with selenite ion concentration of 50 mg-Se / L (no sulfate-reducing bacteria added)
(D) Iron-containing medium shown in Table 2 with selenite ion concentration of 50 mg-Se / L (with sulfate-reducing bacteria added)
The amount of sulfate-reducing bacteria added was adjusted so that the initial OD ₆₀₀ value in the medium was 0.01. The added sulfate-reducing bacteria was Desulfovibrio desulfuricans.

The results are shown in FIG. FIG. 5A is a graph showing selenite ion (SeO ₃ ²⁻ ) concentration, FIG. 5B is a sulfate ion (SO ₄ ²⁻ ) concentration, and FIG. 5C is a diagram showing pH. In the case of the conditions (I), (U) and (E), it was confirmed that the selenite ion concentration decreased. In particular, when sulfate-reducing bacteria are added as in conditions (a) and (d), the rate of decrease in selenite ion concentration increases, and an iron-containing medium is used as in condition (d). Thus, the rate of decrease in the selenite ion concentration was further increased. This tendency was consistent with the results of the above experiment using bags D, E, F and G. In other words, it was found that adding iron in the presence of sulfate-reducing bacteria and sulfate ions increases the generation rate of hydrogen sulfide and increases the insolubilization rate of selenite ions. In FIG. 5 (B), when sulfate-reducing bacteria are added as in the conditions (A) and (D), it is confirmed that the sulfate ion concentration decreases, and by using an iron-containing medium, It was confirmed that the rate of decrease in the sulfate ion concentration was increased. Furthermore, as shown in FIG. 5C, it was confirmed that the pH was kept neutral without touching acidity or alkalinity. In addition, when the color of the culture medium after completion | finish of experiment was observed, in (I) and (U), the orange color was exhibited, and (I) was darker orange color. Therefore, it was confirmed that the selenite ion was insolubilized under the conditions (a) and (c). Moreover, the culture medium of the condition (d) exhibited a black color after the experiment was completed. Therefore, it was suggested that hydrogen sulfide reacts with iron contained in the medium to produce black sulfide iron sulfide.

  As described above, when hydrogen sulfide is generated inside the polyethylene bag and hydrogen sulfide is supplied to the periphery of the bag, and when hydrogen sulfide is generated and supplied with hydrogen sulfide in the liquid to be processed, It was revealed that there was no significant change in the treatment rate of selenite ion. In this example, the liquid to be treated contained only medium components and selenite ions. However, the liquid to be treated actually contains a microbial toxic substance. In addition, the amount of liquid to be treated is large, and it takes time and effort to continue to control the environment preferable for sulfate-reducing bacteria. However, by incubating microorganisms in a bag whose environment is easy to control, hydrogen sulfide is generated in sulfate-reducing bacteria at low cost and easily released locally around the bag, thereby insolubilizing heavy metals. It became clear that the processing can be performed efficiently.

(Example 6)
Pseudomonas sp. 4C-C (hereinafter referred to as selenate-reducing microorganism 4C-C), which is a selenate-reducing microorganism, was cultured using an NB medium as a medium. Table 3 shows the composition of the medium. After culturing at 30 ° C. with shaking (110 rpm), the cells are collected by centrifugation, and phosphate buffer (9 g / l Na ₂ HPO ₄ · 12H ₂ O, 1.5 g / l KH ₂ PO ₄ , pH = 7.5). ) For 3 times. The washed cells were 230 mg wet wt. / Ml was used in the experiment after suspending in phosphate buffer.

(Example 7)
Selenate-reducing microorganisms 4C-C were cultured in artificial wastewater, and the ability to treat selenate ions in the presence of nitrate ions was investigated using yeast extract as an energy source. Table 4 shows the composition of the artificial drainage. The initial selenate ion (SeO ₄ ²⁻ ) concentration of the artificial waste water was 100 mg-Se / L, and the nitrate ion (NO ₃ ⁻ ) concentration was 100 mg-N / L. The initial input amount of the selenate-reducing microorganism 4C-C into the artificial waste water is 1.38 mg wet wt. / Ml. 30 ml of this artificial waste water was placed in a 50 ml vial, covered, and cultured at 30 ° C. with shaking (100 rpm). Selenate ion (SeO ₄ ²⁻ ), selenite ion (SeO ₃ ²⁻ ), nitrate ion (NO ₃ ) when cultured for 1 hour, 2 hours, 4 hours, 18 hours, 22 hours, 46 hours, and 70 hours ^-), nitrite (NO ₂ ^-) concentrations were measured. The measurement was performed with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX).

The results are shown in FIG. (A) is a selenate ion (SeO ₄ ²⁻ ) concentration, selenite ion (SeO ₃ ²⁻ ) concentration, SeO ₄ ² + + SeO ₃ ²⁻ concentration, and (B) is a nitrate ion (NO ₃ ⁻ ) concentration. nitrite ions (NO ₂ ^-) _{concentration,} ^NO 3 ^- + ^NO ₂ - is a graph showing the concentration. The selenate ion concentration became 0 mg-Se / L after 18 hours of culture. On the other hand, the selenite ion concentration became 105 mg-Se / L, which was almost the same concentration as the initial selenate ion after 18 hours. Therefore, it was confirmed that the selenate-reducing microorganism 4C-C is a microorganism that reduces selenate ions to selenite ions using yeast extract as an energy source. The nitrate ion concentration became 0 mg-N / L after 4 hours from the culture. On the other hand, the nitrite ion concentration was 91 mg-N / L after 4 hours from the culture, but then decreased and became 70 mg-N / L after 70 hours. Therefore, the selenate-reducing microorganism 4C-C has the function of reducing nitrate ions and nitrite ions to harmless nitrogen gas using yeast extract as an energy source and simultaneously reducing selenate ions to selenite ions. confirmed.

(Example 8)
(A) Evaluation of 4C-C treatment capacity when ethanol is used as energy source Selenate-reducing microorganism 4C-C is cultured in artificial waste water, and the treatment capacity of selenate ions in the presence of nitrate ions is determined as ethanol as an energy source. It investigated using. The composition of the artificial waste water is shown in Table 5. The initial selenate ion (SeO ₄ ²⁻ ) concentration of the artificial waste water was 50 mg-Se / L, and the nitrate ion (NO ₃ ⁻ ) concentration was 50 mg-N / L. The initial input amount of the selenate-reducing microorganism 4C-C into the artificial waste water is 0.38 mg wet wt. / Ml. 30 ml of this artificial waste water was placed in a 50 ml vial, covered, and cultured at 30 ° C. with shaking (100 rpm). Moreover, 0.3 ml of ethanol was added. Selenate ion (SeO ₄ ²⁻ ), selenite ion (SeO ₃ ²⁻ ), nitrate ion (NO ₃ ⁻ ), nitrite ion (NO ₂ ) when cultured for 17 hours, 41 hours, 65 hours, and 137 hours ^- ) The concentration was measured. The measurement was performed with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX).

The results are shown in FIG. (A) is a selenate ion (SeO ₄ ²⁻ ) concentration, selenite ion (SeO ₃ ²⁻ ) concentration, SeO ₄ ² + + SeO ₃ ²⁻ concentration, and (B) is a nitrate ion (NO ₃ ⁻ ) concentration. nitrite ions (NO ₂ ^-) _{concentration,} ^NO 3 ^- + ^NO ₂ - is a graph showing the concentration. The selenate ion concentration became 0 mg-Se / L after 137 hours of culture. On the other hand, the selenite ion concentration was 53 mg-Se / L, which was almost the same as the initial selenate ion after 137 hours. Therefore, it was confirmed that the selenate-reducing microorganism 4C-C is a microorganism that reduces selenate ions to selenite ions using ethanol as an energy source. The nitrate ion concentration became 0 mg-N / L after 41 hours of culture. On the other hand, the nitrite ion concentration became 41 mg-N / L after 41 hours from the culture, but then decreased and became 0 mg-N / L after 137 hours. Therefore, it is confirmed that the selenate-reducing microorganism 4C-C has the function of reducing nitrate ions and nitrite ions to harmless nitrogen gas using ethanol as an energy source and simultaneously reducing selenate ions to selenite ions. It was done.

(B) Evaluation of 4C-C treatment capacity when methanol is used as the energy source Selenate-reducing microorganisms 4C-C are cultured in artificial waste water, and methanol is used as the energy source for the treatment capacity of selenate ions in the presence of nitrate ions. It investigated using. Table 6 shows the composition of the artificial waste water. The initial selenate ion (SeO ₄ ²⁻ ) concentration of the artificial waste water was 20 mg-Se / L, and the nitrate ion (NO ₃ ⁻ ) concentration was 500 mg-N / L. The initial input amount of the selenate-reducing microorganism 4C-C into the artificial waste water is 0.38 mg wet wt. / Ml. 30 ml of this artificial waste water was placed in a 50 ml vial, covered, and cultured at 30 ° C. with shaking (100 rpm). Further, 0.3 ml of methanol was added. Selenate ion (SeO ₄ ²⁻ ), selenite ion (SeO ₃ ²⁻ ), nitrate ion (NO ₃ ⁻ ), nitrite ion (NO ₂ ) when cultured for 17 hours, 41 hours, 65 hours, and 137 hours ^- ) The concentration was measured. The measurement was performed with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX).

The results are shown in FIG. (A) is a selenate ion (SeO ₄ ²⁻ ) concentration, selenite ion (SeO ₃ ²⁻ ) concentration, SeO ₄ ² + + SeO ₃ ²⁻ concentration, and (B) is a nitrate ion (NO ₃ ⁻ ) concentration. nitrite ions (NO ₂ ^-) _{concentration,} ^NO 3 ^- + ^NO ₂ - is a graph showing the concentration. The selenate ion concentration became 0 mg-Se / L after 137 hours of culture. On the other hand, the selenite ion concentration became 18 mg-Se / L, which was almost the same as the initial selenate ion after 137 hours. The nitrate ion concentration reached 446 mg-N / L after 137 hours from the culture. On the other hand, the nitrite ion concentration became 70 mg-N / L after 137 hours from the culture. Accordingly, the selenate-reducing microorganism 4C-C has a function of reducing selenate ions to selenite ions using methanol as an energy source, and this reduction function has a high initial nitrate ion concentration of 500 mg-N / L. However, it became clear that it did not decrease. In addition, since the nitrate ion concentration decreased and the nitrite ion increased, it was confirmed that the nitrate ion was reduced but not the nitrite ion. This is because the initial nitrate ion concentration is high. That is, when the treatment time is further increased and the energy source is further supplied, the reduction reaction of nitrite ions also occurs.

(C) Evaluation of 4C-C treatment capacity when propanol is used as the energy source The selenate-reducing microorganism 4C-C is cultured in artificial waste water, and the treatment capacity of selenate ions in the presence of nitrate ions is determined by using propanol as an energy source. It investigated using. The composition of the artificial waste water is the same as in Table 6. The initial selenate ion (SeO ₄ ²⁻ ) concentration of the artificial waste water was 20 mg-Se / L, and the nitrate ion (NO ₃ ⁻ ) concentration was 500 mg-N / L. The initial input amount of the selenate-reducing microorganism 4C-C into the artificial waste water is 0.38 mg wet wt. / Ml. 30 ml of this artificial waste water was placed in a 50 ml vial, covered, and cultured at 30 ° C. with shaking (100 rpm). In addition, 0.3 ml of propanol was added. Selenate ion (SeO ₄ ²⁻ ), selenite ion (SeO ₃ ²⁻ ), nitrate ion (NO ₃ ⁻ ), nitrite ion (NO ₂ ) when cultured for 17 hours, 41 hours, 65 hours, and 137 hours ^- ) The concentration was measured. The measurement was performed with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX).

The results are shown in FIG. (A) is a selenate ion (SeO ₄ ²⁻ ) concentration, selenite ion (SeO ₃ ²⁻ ) concentration, SeO ₄ ² + + SeO ₃ ²⁻ concentration, and (B) is a nitrate ion (NO ₃ ⁻ ) concentration. nitrite ions (NO ₂ ^-) _{concentration,} ^NO 3 ^- + ^NO ₂ - is a graph showing the concentration. The selenate ion concentration became 0 mg-Se / L after 17 hours of culture. On the other hand, the selenite ion concentration became 18 mg-Se / L, which was almost the same as the initial selenate ion after 17 hours. The nitrate ion concentration became 359 mg-N / L after 137 hours of culture. On the other hand, the nitrite ion concentration became 119 mg-N / L after 137 hours from the culture. Therefore, the selenate-reducing microorganism 4C-C has a function of reducing selenate ions to selenite ions using propanol as an energy source, and this reduction function has a high initial nitrate ion concentration of 500 mg-N / L. It became clear that even if it was a case, it did not fall. In addition, since the nitrate ion concentration decreased and the nitrite ion increased, it was confirmed that the nitrate ion was reduced but not the nitrite ion. This is because the initial nitrate ion concentration is high. That is, when the treatment time is further increased and the energy source is further supplied, the reduction reaction of nitrite ions also occurs.

  In addition, in the artificial waste water used in Examples 7 and 8, as shown in Tables 4 to 6, various compounds other than nitrates, such as sulfates, chlorides, phosphates, carbonates, boric acid, etc. The selenate-reducing microorganism 4C-C reduced selenate ions to selenite ions and reduced nitrate nitrogen. That is, it has been clarified that the selenate-reducing microorganism 4C-C functions sufficiently even in wastewater containing such a compound, for example, in desulfurization wastewater such as a thermal power plant.

Example 9
30 ml of a medium having the same composition as in Table 1 with a selenate ion concentration of 50 mg-Se / L was placed in four 50 ml vials, and the following operations were performed on each vial.
(I) No microorganism added (ii) Selenate-reducing microorganism 4C-C added (iii) Sulfate-reducing bacteria Desulfovibrio desulfuricans added (iv) Selenate-reducing microorganism 4C-C + Sulfate-reducing bacteria Desulfovibrio desulfuricans added Selenate-reducing microorganism 4C- The initial OD ₆₀₀ value in the C medium was 0.01. The initial OD ₆₀₀ value of the sulfate-reducing bacterium Desulfovibrio desulfuricans was 0.003. Cultivation was performed by closing the lid of the vial and shaking at 100 ° C. (100 rpm). Then, the selenate ion (SeO ₄ ²⁻ ) concentration, selenite ion (SeO ₃ ²⁻ ) concentration, and sulfate ion (SO ₄ ²⁻ ) concentration after culture for 0 hours, 42 hours, and 96 hours were measured. The selenate ion (SeO ₄ ²⁻ ) concentration, selenite ion (SeO ₃ ²⁻ ) concentration, and sulfate ion (SO ₄ ²⁻ ) concentration were measured with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX).

The results are shown in FIGS. FIG. 10 (A) shows the selenate ion (SeO ₄ ²⁻ ) concentration, (B) shows the selenite ion (SeO ₃ ²⁻ ) concentration, and (C) shows the SeO ₄ ² + SeO ₃ ²⁻ concentration. is there. FIG. 11 is a diagram showing the sulfate ion concentration. In the case of operation (ii), that is, when only the selenate-reducing microorganism was added, a decrease in the selenate ion concentration was observed, but no decrease in the selenite ion concentration was observed. Although the reaction to reduce to acid ions occurred, insolubilization of selenite ions did not occur. In the cases of operations (i) and (iii), that is, when no microorganism was added and when only sulfate-reducing bacteria were added, a decrease in the selenate ion concentration was hardly observed. In the case of operation (iv), that is, when both selenate-reducing microorganisms and sulfate-reducing bacteria are added, a decrease in the selenate ion concentration is observed, and the selenite ion concentration is 0 mg-Se / L during the culture period. Met. That is, during the culture period, all of the selenite ion produced by the reduction of the selenate ion was insolubilized. As shown in FIG. 11, the sulfate ion concentration decreased only in the case of operation (iv), that is, when both selenate-reducing microorganisms and sulfate-reducing bacteria were added.

Next, 30 ml of a medium having the same composition as in Table 1 with a selenate ion concentration of 50 mg-Se / L and a nitrate ion concentration of 50 mg-N / L was placed in four 50 ml vials. The same operations as in the above (i), (ii), (iii) and (iv) were performed. The initial OD ₆₀₀ value in the medium of the selenate-reducing microorganism 4C-C was 0.01. The initial OD ₆₀₀ value of the sulfate-reducing bacterium Desulfovibrio desulfuricans was 0.003. Cultivation was performed by closing the lid of the vial and shaking at 100 ° C. (100 rpm). Then, selenate ion (SeO ₄ ²⁻ ) concentration, selenite ion (SeO ₃ ²⁻ ) concentration, nitrate ion (NO ₃ ⁻ ) concentration, nitrite ion (NO) after culturing for 0 hours, 42 hours, and 96 hours ₂ ^-) concentrations were measured sulfate ion _(SO ^{4 2-)} concentration. Selenate ion (SeO ₄ ²⁻ ) concentration, selenite ion (SeO ₃ ²⁻ ) concentration, nitrate ion (NO ₃ ⁻ ) concentration, nitrite ion (NO ₂ ⁻ ) concentration, sulfate ion (SO ₄ ²⁻ ) The concentration was measured with an ion chromatograph analyzer (ICS-1500, manufactured by DIONEX).

The results are shown in FIG. 12, FIG. 13 and FIG. FIG. 12A shows the selenate ion (SeO ₄ ²⁻ ) concentration, FIG. 12B shows the selenite ion (SeO ₃ ²⁻ ) concentration, and FIG. 12C shows SeO ₄ ² + + SeO ₃ ²⁻ concentration. is there. FIG. 13A is a diagram showing nitrate ion (NO ₃ ⁻ ) concentration, (B) is nitrite ion (NO ₂ ⁻ ) concentration, and (C) is NO ₃ ⁻ + NO ₂ ⁻ concentration. In the case of operation (ii), that is, when only the selenate-reducing microorganism was added, a decrease in the selenate ion concentration was observed, but no decrease in the selenite ion concentration was observed. Although the reaction to reduce to acid ions occurred, insolubilization of selenite ions did not occur. In the cases of operations (i) and (iii), that is, when no microorganism was added and when only sulfate-reducing bacteria were added, the selenate ion concentration was hardly decreased. In the case of operation (iv), that is, when both selenate-reducing microorganisms and sulfate-reducing bacteria are added, a decrease in the selenate ion concentration is observed, and the selenite ion concentration increases until 42 hours from the start of culture. After that, it decreased and became 0 mg-Se / L after 96 hours from the start of the culture. Therefore, it was revealed that all selenate ions can be insolubilized when both selenate-reducing microorganisms and sulfate-reducing bacteria are added. The nitrate ion concentration decreased in all conditions except for the operation (i), that is, when no microorganism was added. However, in the case of operation (iii), that is, when only sulfate-reducing bacteria are added, the nitrite ion concentration does not decrease, and when only sulfate-reducing bacteria are added, nitrate ions are converted into nitrite ions. It was confirmed that it can only be reduced. In the case of operations (ii) and (iv), that is, when only selenate-reducing microorganisms are added and when both selenate-reducing microorganisms and sulfate-reducing bacteria are added, the nitrite ion concentration is 0 mg during the culture period. -N / L. That is, during the culture period, all of the nitrite ions produced by the reduction of nitrate ions were reduced to nitrogen gas. Regarding sulfate ion, it decreased only in the case of operation (iv), that is, when both selenate-reducing microorganisms and sulfate-reducing bacteria were added. The rate of decrease of the selenate ion concentration and sulfate ion concentration was greater when there was no nitrate ion. This is considered to be due to the fact that the reduction of sulfate ions was likely to occur as much as nitrate reduction was not performed.

  As described above, by using a combination of the selenate-reducing microorganism 4C-C and the sulfate-reducing bacterium Desulfovibrio desulfuricans, it is possible to insolubilize selenate ions that are difficult to insolubilize with hydrogen sulfide, and to convert nitrate ions in the liquid to be treated into nitrogen gas. It became clear that it can be rendered harmless. Therefore, it is possible to insolubilize selenate ions by using the selenate-reducing microorganism 4C-C in combination with the hydrogen sulfide supply device of the present invention.

(Example 10)
A bag was formed using a polyethylene film as a non-porous film, and the amount of organic matter permeated when methanol and ethanol were sealed therein was measured to investigate the permeability of methanol and ethanol from the polyethylene film.
A polyethylene film (trade name: Mipolon film, manufactured by Mitsuwa Co., Ltd.) having a thickness of 0.05 mm, 0.1 mm, 0.3 mm, and 0.5 mm is formed into a bag shape, and methanol (manufactured by Wako Pure Chemical Industries, 99.8%) and ethanol (Wako Pure Chemical Industries, 99.5%) were sealed. The sealed solution volume was 5 mL. This was immersed in water, and the permeation amount of methanol and ethanol was evaluated by measuring the molecular permeation amount with respect to the elapsed days and the TOC concentration. The TOC concentration was measured by a combustion-infrared total organic carbon analyzer (TOC-650, manufactured by Toray Engineering). The results are shown in FIGS. 22A and 22B. In the figure, B is background, MeOH is methanol, EtOH is ethanol, and numerical values such as 0.05, 0.1, 0.3, and 0.5 represent polyethylene film thickness (unit: mm). From this experiment, both methanol and ethanol increase the TOC concentration as the polyethylene film thickness decreases. Therefore, the supply amount of alcohol such as methanol and ethanol can be controlled by the film thickness of the polyethylene film. Was confirmed.

It is a figure which shows a time-dependent change of the selenate ion and selenite ion density | concentration at the time of immersing the polyethylene bag which sealed the hydrogen sulfide production | generation raw material in a to-be-processed liquid. It is a figure which shows the secular selenite ion concentration at the time of culture | cultivating a sulfate reduction bacterium on various conditions in a selenite containing medium, and a time-dependent change of a sulfate ion concentration. It is a figure which shows the time-dependent change of a selenite ion density | concentration at the time of culture | cultivating a sulfate reduction bacterium on various conditions in the selenite containing phosphate buffer. It is a figure which shows the time-dependent change of a selenite ion concentration, a sulfate ion concentration, and pH at the time of immersing the polyethylene bag of various conditions in a selenite containing medium. It is a figure which shows the time-dependent change of a selenite ion concentration, a sulfate ion concentration, and pH at the time of culture | cultivating a sulfate reduction bacterium in the selenite containing medium of various conditions. It is a figure which shows the time-dependent change of various ion density | concentrations when culture | cultivating selenate reducing microorganisms 4C-C by making an energy source a yeast extract with the artificial waste_water | drain containing a nitrate ion and a selenate ion. It is a figure which shows the time-dependent change of various ion density | concentrations when culture | cultivating selenate reducing microorganisms 4C-C by making the energy source ethanol with the artificial waste water containing a nitrate ion and a selenate ion. It is a figure which shows the time-dependent change of various ion density | concentrations when culture | cultivating selenate reducing microorganisms 4C-C by using the artificial effluent containing nitrate ion and a selenate ion as an energy source methanol. It is a figure which shows the time-dependent change of various ion density | concentrations when culture | cultivating the selenate reducing microorganisms 4C-C by propanol as an energy source with the artificial waste water containing a nitrate ion and a selenate ion. It is a figure which shows a time-dependent change of the selenate ion and selenite ion density | concentration at the time of culturing various microorganisms in the culture medium containing a selenate ion. It is a figure which shows a time-dependent change of a sulfate ion concentration when various microorganisms are cultured with the culture medium containing a selenate ion. It is a figure which shows the time-dependent change of the selenate ion and selenite ion density | concentration at the time of culture | cultivating various microorganisms with the culture medium containing a nitrate ion and a selenate ion. It is a figure which shows a time-dependent change of the nitrate ion and the nitrite ion density | concentration at the time of culture | cultivating various microorganisms with the culture medium containing a nitrate ion and a selenate ion. It is a figure which shows a time-dependent change of a sulfate ion density | concentration at the time of culture | cultivating various microorganisms with the culture medium containing a nitrate ion and a selenate ion. It is a figure which shows the example of the sealing type which is one Embodiment of the hydrogen sulfide supply apparatus of this invention, (A) is a perspective view, (B) is a longitudinal cross-sectional view. It is a figure which shows the example of the replenishment type which is other embodiment of the hydrogen sulfide supply apparatus of this invention, (A) is a perspective view, (B) is a longitudinal cross-sectional view. It is a schematic explanatory drawing which shows the whole structure of the hydrogen sulfide supply apparatus of embodiment of FIG. It is a longitudinal cross-sectional view which shows other embodiment of the hydrogen sulfide supply apparatus of this invention. It is a figure which shows the example of the sealing type which is one Embodiment of an electron donor supply apparatus, (A) is a perspective view, (B) is a longitudinal cross-sectional view. It is a figure which shows the example of the replenishment type which is other embodiment of an electron donor supply apparatus, (A) is a perspective view, (B) is a longitudinal cross-sectional view. It is a schematic explanatory drawing which shows the whole structure of the electron donor supply apparatus of embodiment of FIG. It is a figure which shows the permeation | transmission amount measurement result of the lower alcohol from a polyethylene film, (A) is methanol, (B) is a measurement result of ethanol.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrogen sulfide supply apparatus 2 Non-porous membrane 3, 3 '' Hydrogen sulfide production raw material 3 'Hydrogen sulfide 4 Container 5 Supply part 12, 12' Lower alcohol

Claims (25)

  Hydrogen sulfide is filled in a container having a sealed structure including at least a part of the non-porous film, the container is immersed in a liquid to be treated, and molecules of the non-porous film are formed from the non-porous film part of the container. A step of supplying the hydrogen sulfide to the periphery of the container at a speed governed by permeation performance to insolubilize heavy metals contained in the liquid to be treated; and insolubilizing in the vicinity of the non-porous film. A method for treating a heavy metal-containing liquid, wherein a carrier capable of supporting heavy metal is disposed.   A hydrogen sulfide generating raw material is filled in a sealed structure container provided with at least a part of the non-porous film, the container is immersed in a liquid to be treated, and the non-porous film from the non-porous film portion of the container Supplying the hydrogen sulfide produced by the hydrogen sulfide production raw material to the periphery of the vessel at a speed governed by the molecular permeation performance of the container, and insolubilizing heavy metals contained in the liquid to be treated, A method for treating a heavy metal-containing liquid, wherein a carrier capable of supporting an insolubilized heavy metal is disposed in the vicinity of the porous membrane. A selenate-reducing microorganism that reduces selenate ions (SeO ₄ ²⁻ ) to selenite ions (SeO ₃ ²⁻ ) is supported on the carrier capable of supporting the insolubilized heavy metal, and the non-porous membrane The processing method of the heavy metal containing liquid of Claim 1 or 2 arrange | positioned in the vicinity. Hydrogen sulfide is filled in a container having a sealed structure including at least a part of the non-porous film, the container is immersed in a liquid to be treated, and molecules of the non-porous film are formed from the non-porous film part of the container. Including supplying the hydrogen sulfide to the periphery of the container at a speed governed by permeation performance to insolubilize heavy metals contained in the liquid to be treated, and performing the process before or after performing the process. Simultaneously, a selenate-reducing microorganism that reduces selenate ion (SeO ₄ ²⁻ ) to selenite ion (SeO ₃ ²⁻ ) and the liquid to be treated are brought into contact under anaerobic conditions. Liquid processing method. A hydrogen sulfide generating raw material is filled in a sealed structure container provided with at least a part of the non-porous film, the container is immersed in a liquid to be treated, and the non-porous film from the non-porous film portion of the container Supplying the hydrogen sulfide produced by the hydrogen sulfide production raw material to the periphery of the vessel at a speed governed by the molecular permeation performance of the vessel, and insolubilizing heavy metals contained in the liquid to be treated, Before or simultaneously with the above step, the selenate-reducing microorganism that reduces selenate ions (SeO ₄ ²⁻ ) to selenite ions (SeO ₃ ²⁻ ) and the liquid to be treated are subjected to anaerobic conditions. The processing method of the heavy metal containing liquid characterized by making it contact with.   The method for treating a heavy metal-containing liquid according to claim 4 or 5, wherein a carrier capable of supporting an insolubilized heavy metal is disposed in the vicinity of the non-porous film. The selenate-reducing microorganism is a selenate-reducing microorganism that uses a lower alcohol having 1 to 3 carbon atoms as an energy source, and the lower alcohol is supplied to the selenate-reducing microorganism according to any one of claims 3 to 6. The processing method of the heavy metal containing liquid of description. The method for treating a heavy metal-containing liquid according to claim 7 , wherein the selenate-reducing microorganism is Pseudomonas sp. 4C-C (Pseudomonas sp. 4C-C, FERM P-20840) . The lower alcohol having 1 to 3 carbon atoms seals the lower alcohol or waste alcohol having 1 to 3 carbon atoms in a container having at least a part of the nonporous film, and the nonporous film portion of the container The method for treating a heavy metal-containing liquid according to claim 7 or 8 , wherein the liquid is supplied to the selenate-reducing microorganism around the container at a speed governed by the molecular permeation performance of the non-porous membrane . The heavy metal to be insolubilized exists in the form of selenium (Se) present in the form of selenite ion (SeO ₃ ²⁻ ) in the liquid to be treated and in the form of a cation in the liquid to be treated. Copper (Cu), silver (Ag), lead (Pb), cadmium (Cd), mercury (Hg), tin (Sn), nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn), The method for treating a heavy metal-containing liquid according to any one of claims 1 to 9, wherein the treatment method is one or more of manganese (Mn) and aluminum (Al) . The method for treating a heavy metal-containing liquid according to claim 2 or 5 , wherein the hydrogen sulfide generating raw material is an electron donor substance that serves as an energy source for sulfate-reducing bacteria, sulfate ions (SO ₄ ²⁻ ), and the sulfate-reducing bacteria . The method for treating a heavy metal-containing liquid according to claim 11 , wherein iron is further used as the hydrogen sulfide production raw material . The method for treating a heavy metal-containing liquid according to claim 2, wherein the hydrogen sulfide production raw material is iron sulfide and an acid . The method for treating a heavy metal-containing liquid according to claim 2 or 5 , wherein the hydrogen sulfide generating raw material is one or more of sodium thiosulfate, sodium sulfide, and sodium hydrogen sulfide . The method for treating a heavy metal-containing liquid according to claim 1, wherein the non-porous film is a polyethylene film or a polypropylene film .   A container having a sealed structure including at least a part of a non-porous membrane that transmits hydrogen sulfide; and hydrogen sulfide or a hydrogen sulfide generating raw material, the container being filled with hydrogen sulfide or a hydrogen sulfide generating raw material, A hydrogen sulfide supply apparatus for treating a heavy metal-containing liquid, wherein a support capable of supporting an insolubilized heavy metal is provided on at least a part of the surface of the conductive film. The supply of hydrogen sulfide for heavy metal-containing liquid treatment according to claim 16, wherein the hydrogen sulfide generating raw material is an electron donor material that serves as an energy source for sulfate reducing bacteria, sulfate ions (SO ₄ ²⁻ ), and the sulfate reducing bacteria. apparatus.   The hydrogen sulfide supply apparatus for heavy metal-containing liquid treatment according to claim 17, further comprising iron as the hydrogen sulfide production raw material.   The hydrogen sulfide supply apparatus for heavy metal-containing liquid treatment according to claim 16, wherein the hydrogen sulfide production raw material is iron sulfide and an acid.   The hydrogen sulfide supply device for heavy metal-containing liquid treatment according to claim 16, wherein the hydrogen sulfide generation raw material is one or more of sodium thiosulfate, sodium sulfide, and sodium hydrogen sulfide.   21. The hydrogen sulfide supply apparatus for heavy metal containing liquid treatment according to any one of claims 16 to 20, wherein the non-porous film is a polyethylene film or a polypropylene film.   The said container is provided with the supply part which replenishes the said hydrogen sulfide or the said hydrogen sulfide production | generation raw material, The hydrogen sulfide supply apparatus for heavy metal containing liquid processing as described in any one of Claims 16-21. 23. The selenate-reducing microorganism that reduces selenate ions (SeO ₄ ²⁻ ) to selenite ions (SeO ₃ ²⁻ ) is supported on the carrier. Hydrogen sulfide supply device for processing heavy metal-containing liquids.   The hydrogen sulfide supply apparatus for heavy metal-containing liquid treatment according to claim 23, wherein the selenate-reducing microorganism is a selenate-reducing microorganism that uses a lower alcohol having 1 to 3 carbon atoms as an energy source.   The hydrogen sulfide supply apparatus for heavy metal containing liquid treatment according to claim 24, wherein the selenate-reducing microorganism is Pseudomonas sp. 4C-C (Pseudomonas sp. 4C-C, FERM P-20840).

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