CN110563134A - Anaerobic membrane bioreactor and its application in sewage treatment - Google Patents

Abstract

The invention discloses an anaerobic membrane bioreactor which comprises a shell, a hollow membrane body and an iron-based material, wherein the hollow membrane body and the iron-based material are arranged in an inner cavity of the shell, a sewage inlet and a purified water outlet are formed in the shell, the hollow membrane body comprises a membrane shell and a closed purified water cavity formed by surrounding of the membrane shell, the purified water cavity is communicated with the purified water outlet through a pipe body, the iron-based material is arranged outside the hollow membrane body, iron in the iron-based material is a zero-valent iron simple substance, and the iron-based material is a passive iron-based material. The invention also discloses an application of the anaerobic membrane bioreactor.

Description

Anaerobic membrane bioreactor and its application in sewage treatment

technical field

The invention relates to the technical field of sewage treatment, in particular to an anaerobic membrane bioreactor and its application in sewage treatment.

Background technique

Anaerobic membrane bioreactor is a water treatment process that combines high-efficiency anaerobic biological technology and membrane separation technology. It has the advantages of high effluent quality, small footprint, energy recovery, and less residual sludge. It has developed rapidly in recent years. . However, the application of this technology still faces some challenges.

First of all, membrane fouling is an important bottleneck limiting the application of anaerobic membrane bioreactor technology. During the membrane filtration process, the membrane pollutants in the reactor sludge mixture will gradually block the membrane pores and form membrane fouling. With the formation of membrane fouling, the water flux of the reactor decreases, and membrane cleaning is required to remove membrane fouling and restore flux. Therefore, membrane fouling can increase the running and operating costs of the system. The control of membrane fouling has become an urgent problem to be solved in the application of anaerobic membrane bioreactor technology. The property of the sludge mixture is an important factor affecting membrane fouling. A large number of existing technologies control the filterability of the sludge mixture by adding flocculants such as iron salts and aluminum salts to the reactor to control membrane fouling. However, the addition of flocculants will introduce some anions such as sulfate and chloride ions that are toxic to anaerobic microorganisms, thus causing the risk of anaerobic digestion inhibition. In addition, it is not easy to control the amount of flocculant added. If the amount added is too small, the flocculation effect will not be achieved. If the amount added is too large, the ferrous hydroxide and aluminum hydroxide formed may become new membrane pollutants.

In addition, especially for sulfur-containing sewage, the hydrogen sulfide contained in the gas produced by the anaerobic membrane bioreactor will affect the use of biogas, which is also a technical challenge for the anaerobic membrane bioreactor. Hydrogen sulphide is an acidic gas that corrodes combustion equipment when its content in biogas is too high. Therefore, biogas needs to be desulfurized before use to ensure safe combustion. Before the biogas enters the combustion equipment, the concentration of hydrogen sulfide in it generally needs to be controlled at least within 200ppm.

Contents of the invention

Based on this, it is necessary to provide an anaerobic membrane bioreactor and its application in sewage treatment in view of the difficulty in controlling the type and amount of traditional flocculants and the difficulty in treating sulfur-containing sewage.

An anaerobic membrane bioreactor, comprising a housing, a hollow membrane body and an iron-based material, the hollow membrane body and the iron-based material are arranged in the inner cavity of the housing, and the housing is provided with Sewage inlet and water purification outlet, the hollow membrane body includes a membrane casing and a closed water purification chamber surrounded by the membrane casing, the water purification chamber communicates with the water purification outlet through a pipe body, and the iron base The material is arranged outside the hollow membrane body, the iron in the iron-based material is zero-valent iron, and the iron-based material is a passive iron-based material.

In one embodiment, the iron-based material further includes an inert conductive material, and the inert conductive material and the zero-valent iron element are uniformly mixed in the iron-based material.

In one embodiment, the inert conductive material is selected from one or more of carbon, copper and lead.

In one of the embodiments, the mass percentage of the zero-valent iron elemental substance in the iron-based material is 80%-95%.

In one embodiment, the iron-based material in the housing is a plate-shaped iron-based material, a granular iron-based material, or a mixture of a plate-shaped iron-based material and a granular iron-based material.

In one of the embodiments, there are at least two plate-shaped iron-based materials in the housing, the hollow membrane body is cylindrical, and the length of the hollow membrane body is along the vertical direction of the inner cavity. extending in a direction, and along a direction perpendicular to the length of the hollow membrane body, the two plate-shaped iron-based materials are respectively arranged on both sides of the hollow membrane body.

In one of the embodiments, in the vertical direction of the inner cavity, the top of the iron-based material is closer to the top of the inner cavity than the top of the hollow membrane body, and the top of the iron-based material The bottom end is closer to the bottom of the inner chamber than the bottom end of the hollow membrane body.

In one of the embodiments, the anaerobic membrane bioreactor further includes a deflector, and the deflector is arranged on the side of the iron-based material close to the inner surface of the shell, and the inner In the vertical direction of the cavity, the top of the deflector is closer to the top of the inner cavity than the top of the iron-based material, and the bottom of the deflector is closer to the top of the inner cavity than the bottom of the iron-based material. closer to the bottom of the lumen.

In one of the embodiments, the sewage inlet and the purified water outlet are respectively arranged at the bottom and the top of the housing, and the anaerobic membrane bioreactor also includes an aeration assembly, and the aeration assembly is arranged at the bottom of the cavity.

An application of the anaerobic membrane bioreactor in sewage treatment.

In one of the embodiments, the sewage is sulfur-containing sewage.

In one of the embodiments, the method of sewage treatment includes:

inoculating anaerobic sludge in the inner cavity of the anaerobic membrane bioreactor without the iron-based material;

acclimatizing the anaerobic sludge; and

The iron-based material is arranged in the inner cavity, and the sewage is passed into the inner cavity of the anaerobic membrane reactor under the control condition that the iron-based material is not energized for sewage treatment.

When the anaerobic membrane bioreactor of the present invention is carrying out sewage, volatile fatty acids will be released during anaerobic digestion and degradation of organic matter in the sewage, and zero-valent iron in the anaerobic membrane bioreactor will react with volatile fatty acids to form sub Ferrous ions and ferrous ions will be hydrolyzed in the anaerobic sludge and sewage mixture to produce Fe(OH _{) 2 with} flocculation. Remove the dissolved or colloidal organic matter of membrane fouling in the sludge mixture, promote the growth of sludge floc particle size, and then improve the filterability of the sludge-sewage mixture, slow down the occurrence of membrane fouling, and prolong membrane fouling. cycle. The elemental zero-valent iron used in the anaerobic membrane bioreactor of the present invention is a green and economical material. Compared with traditional industrial flocculants, the elemental zero-valent iron will not introduce anions that are potentially toxic to anaerobic digestion, It also does not introduce too many inorganic impurities. In addition, traditional industrial flocculants consume alkalinity in the process of flocculation, but the zero-valent iron element used in the present invention not only does not consume alkalinity, but also consumes acidity to resist the occurrence of acidification in anaerobic systems, and is beneficial to anaerobic digestion There are also certain potential benefits.

In addition, if the zero-valent iron element is oxidized to form ferrous ions when it is energized as an anode, too much ferrous ions will form a large amount of Fe(OH) ₂ flocs. At this time, a large amount of Fe(OH) ) ₂ The flocs will become new pollutants of the hollow membrane body, which is not conducive to reducing membrane fouling. The iron-based material of the present invention is a passive iron-based material. When the reactor is used, the iron-based material is not connected to electricity, and the zero-valent iron is converted into ferrous ions by using the acid generated in the sewage or the anaerobic digestion and degradation process of organic matter. Therefore, the amount of ferrous ions formed is moderate, which can play a role in reducing membrane fouling.

Further, the anaerobic membrane bioreactor of the present invention is especially suitable for treating sulfur-containing sewage. Hydrogen sulfide will be generated during the anaerobic digestion and degradation process in sulfur-containing sewage. As an acidic substance, hydrogen sulfide will undergo a redox reaction with zero-valent iron Zero-valent iron is transformed into ferrous ions with flocculation. On the one hand, ferrous ions can reduce membrane fouling through flocculation, and on the other hand, they can react with sulfur ions in hydrogen sulfide to form FeS precipitation, thereby reducing The concentration of hydrogen sulfide in the biogas collected anaerobically can protect and improve the life of anaerobic membrane bioreactor and improve the quality of biogas.

Description of drawings

Fig. 1 is the structural representation of the anaerobic membrane bioreactor of an embodiment of the present invention;

Fig. 2 is the structural representation of the anaerobic membrane bioreactor of another embodiment of the present invention;

Fig. 3 is the schematic diagram of the transmembrane pressure difference development situation of embodiment and comparative example;

Fig. 4 is the schematic diagram of dissolved organic matter content and composition situation in the sludge mixed liquid of embodiment and comparative example;

Fig. 5 A, Fig. 5 B are respectively the situation schematic diagram of the reactor sludge floc particle size of embodiment and comparative example;

Fig. 6 is the situation schematic diagram of the filterability of the sludge mixed liquor of embodiment and comparative example;

Fig. 7 is a schematic diagram of the concentration of hydrogen sulfide in the biogas of the embodiment and the comparative example.

Detailed ways

In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the associated drawings. Preferred embodiments of the invention are shown in the accompanying drawings. However, the present invention can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure of the present invention more thorough and comprehensive.

It should be noted that when an element is referred to as being “fixed” to another element, it can be directly on the other element or there can also be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements may also be present.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Please refer to Fig. 1, an embodiment of the present invention provides an anaerobic membrane bioreactor, including a housing 100, a hollow membrane body 200 and an iron-based material 300, and the hollow membrane body 200 and the iron-based material 300 are arranged on the In the inner cavity of the housing 100, the housing 100 is provided with a sewage inlet 110 and a water purification outlet 122, and the hollow membrane body 200 includes a membrane housing 210 and a sealed water purification chamber surrounded by the membrane housing. 220, the water purification chamber 220 communicates with the water purification outlet 122 through a pipe body, the iron-based material is arranged outside the hollow membrane body 200, and the iron in the iron-based material 300 is zero-valent iron , the iron-based material 300 is a passive iron-based material.

When the anaerobic membrane bioreactor of the embodiment of the present invention is carrying out sewage, volatile fatty acids will be released during the anaerobic digestion and degradation process of organic matter in the sewage, and the zero-valent iron in the anaerobic membrane bioreactor will react with volatile fatty acids Ferrous ions are formed, and ferrous ions will be hydrolyzed in the anaerobic sludge-sewage mixture to produce Fe(OH _{) 2 with} flocculation. Destabilization and other functions remove the dissolved or colloidal organic matter of membrane fouling in the sludge mixture, promote the growth of sludge floc particle size, and then improve the filterability of the sludge-sewage mixture, slow down the occurrence of membrane fouling, and prolong Membrane fouling cycle. The zero-valent iron element used in the anaerobic membrane bioreactor of the embodiment of the present invention is a green and economical material. Compared with traditional industrial flocculants, the zero-valent iron element will not introduce potential toxicity to anaerobic digestion. anion, and will not introduce too many inorganic impurities. In addition, traditional industrial flocculants consume alkalinity during the flocculation process, but the zero-valent iron element used in the present invention not only does not consume alkalinity, but also consumes acidity to resist the occurrence of acidification in anaerobic systems. There are also certain potential benefits.

In addition, if the zero-valent iron element is oxidized to form ferrous ions when it is energized as an anode, too much ferrous ions will form a large amount of Fe(OH) ₂ flocs. At this time, a large amount of Fe(OH) ) ₂ flocs will become new pollutants of the hollow membrane body 200, which is not conducive to reducing membrane fouling. The iron-based material 300 of the embodiment of the present invention is a passive iron-based material. The iron-based material is not connected to electricity when the reactor is in use, and the zero-valent iron element is converted into sub- Iron ions, so that the amount of ferrous ions formed is moderate, which can play a role in reducing membrane fouling.

Further, the anaerobic membrane bioreactor of the embodiment of the present invention is especially suitable for treating sulfur-containing sewage. Hydrogen sulfide will be generated during anaerobic digestion and degradation in sulfur-containing sewage. As an acidic substance, hydrogen sulfide will undergo redox with zero-valent iron The reaction converts zero-valent iron into ferrous ions with flocculation. On the one hand, ferrous ions can reduce membrane fouling through flocculation, and on the other hand, they can react with sulfur ions in hydrogen sulfide to form FeS precipitation to reduce the anaerobic membrane biological reaction. The hydrogen sulfide concentration in the reactor and in the anaerobically collected biogas plays a role in protecting and improving the life of the anaerobic membrane bioreactor and improving the quality of biogas.

The reaction principle of the anaerobic membrane reactor in the embodiment of the present invention for treating sewage is as follows: sewage enters the inner cavity from the sewage inlet 110, anaerobic sludge is inoculated in the inner cavity and arranged outside the hollow membrane body 200, and the anaerobic sludge is used to Anaerobic microorganisms in the sewage decompose the organic matter in the sewage into inorganic matter and remove it. The water after the anaerobic sludge treatment passes through the membrane housing 210 of the hollow membrane body 200 and enters the water purification chamber 220 to become purified water, which is further collected through the pipe body through the purified water outlet.

In one embodiment, the sewage inlet 110 and the purified water outlet 122 are respectively disposed at the bottom and the top of the housing 100 . The sewage inlet 110 is arranged at the bottom, so that the sewage and anaerobic sludge can enter the central control membrane body after fully contacting from bottom to top, so as to improve the degradation rate of sewage. The inside of the hollow membrane body 200 can communicate with the clean water outlet 122 through the first pipe body 124, and the first pipe body 124 can extend to the water purification collection device outside the shell 100 of the anaerobic membrane bioreactor. The first pipe body 124 A membrane suction pump 126 may be provided on the top, and the clean water inside the hollow membrane body 200 may be sucked into the first pipe body 124 by the membrane suction pump 126 .

In one embodiment, the top of the housing 100 is provided with a first biogas outlet 132, the first biogas outlet 132 communicates with the gas collection device 134 outside the housing 100, and the anaerobic sludge and the organic matter in the sewage are formed by the reaction of The biogas is collected in a gas collection device 134 via the first biogas outlet 132 . The anaerobic membrane bioreactor can also include an aeration assembly, and the aeration assembly can include an aeration pipe 146 arranged at the bottom of the inner chamber, a second pipe body 144 connected to the aeration pipe 146 and an aeration pump 148, and the housing The top of 100 can also be provided with a second biogas outlet 142, the second biogas outlet 142 can communicate with the second pipe body 144, a part of the reactor formed in the inner cavity can be collected by the gas collection device 134, and a part can enter the aeration A gas source for aeration in the module. The aeration at the bottom of the inner cavity by the aeration component realizes the flow of anaerobic sludge and sewage inside the casing 100, improves mass transfer efficiency, and improves sewage degradation efficiency.

In an embodiment, the iron-based material 300 in the housing 100 is a plate-shaped iron-based material, a granular iron-based material, or a mixture of a plate-shaped iron-based material and a granular iron-based material. Preferably, the iron-based material 300 is fixed in the inner cavity of the casing 100 . In one embodiment, the iron-based material 300 is in the shape of a plate, and the plate-shaped iron-based material 300 can be fixed at a specific position in the inner cavity through a slot. In another embodiment, the iron-based material 300 is granular, and the granular iron-based material 300 can be arranged in a screen frame, and the screen frame can be fixed at a specific position in the inner cavity. Preferably, the iron-based material 300 may have a porous structure, and the contact area between the iron-based material 300 and the sewage is increased by setting the porous structure, which is beneficial to flocculation and improves the treatment efficiency of sewage.

In one embodiment, there are at least two plate-shaped iron-based materials 300 in the casing 100, the hollow membrane body 200 is cylindrical, and the length of the hollow membrane body 200 is along the length of the inner cavity. The vertical direction extends, that is to say, the length of the water purification chamber extends along the vertical direction of the inner chamber. Along the direction perpendicular to the length of the hollow membrane body 200 , that is, along the horizontal direction of the inner cavity, the two plate-shaped iron-based materials 300 are respectively disposed on both sides of the hollow membrane body 200 . The plate-shaped iron-based material 300 is arranged on both sides of the hollow membrane body 200 to play the role of diversion. Under the action of the aeration component, the anaerobic sludge in the shell 100 can flow around the plate-shaped iron-based material 300 Carry out circulation flow, promote the mixing of anaerobic sludge and sewage, and speed up sewage treatment. The columnar shape of the hollow membrane body can be a square column, a cylinder or an irregular column. Here, the vertical direction of the inner cavity is the direction from the bottom of the inner cavity to the top of the inner cavity.

In an embodiment, the length of the plate-shaped iron-based material 300 extends along the vertical direction of the inner cavity, and the length of the plate-shaped iron-based material 300 may be greater than the length of the hollow membrane body 200 . In the vertical direction of the inner cavity, the top end of the iron-based material 300 is closer to the top of the inner cavity than the top end of the hollow membrane body 200, and the bottom end of the iron-based material 300 is closer to the top of the inner cavity than the top end of the hollow membrane body 200. The bottom end of the hollow membrane body 200 is closer to the bottom of the inner cavity. That is, both ends of the iron-based material protrude from both ends of the hollow membrane body 200, so that the anaerobic sludge can strengthen the disturbance at the top and bottom of the plate-shaped iron-based material 300, so that the anaerobic sludge The circulation flow is stronger.

Please refer to Fig. 2, in an embodiment, the described anaerobic membrane bioreactor can also comprise deflector 400, the length of deflector 400 is arranged along the vertical direction of inner cavity, and the length of deflector 400 is It may be longer than the length of the iron-based material 300 , and the deflector 400 may be disposed on a side of the iron-based material 300 close to the inner surface of the casing 100 . In the vertical direction of the cavity, the top of the deflector 400 is closer to the top of the cavity than the top of the iron-based material 300, and the bottom of the deflector 400 is closer to the top of the cavity than the top of the iron-based material 300. The bottom end of the iron-based material 300 is closer to the bottom of the cavity. That is, both ends of the deflector 400 protrude from both ends of the iron-based material 300. Since the iron-based material 300 will be consumed to a certain extent during the sewage treatment process, the ability of the iron-based material 300 to resist fluid impact may be reduced. It will be affected to a certain extent. In order to reduce the load of the iron-based material 300, a separate deflector 400 is provided. The deflector 400 can be a material with high mechanical strength and does not participate in the degradation of sewage. The length of the deflector 400 is longer than the iron-based material 300, the top of the deflector 400 can be set higher than the top of the iron-based material 300, and the bottom of the deflector 400 can be set lower than the bottom of the iron-based material 300, Most of the impact force of anaerobic sludge and sewage can be shared on the deflector 400 , reducing the load on the iron-based material 300 . Moreover, the iron-based material 300 and the deflector 400 form a stepped diversion structure, which can increase the disturbance of anaerobic sludge and sewage, promote the circulation of anaerobic sludge in the inner cavity and the mixing of anaerobic sludge and sewage .

In an embodiment, the iron-based material 300 may further include an inert conductive material, and the inert conductive material and the zero-valent iron element are evenly mixed in the iron-based material 300 . The inert conductive material itself does not participate in the oxidation-reduction reaction, but plays the role of transferring electrons. In order to increase the potential difference and promote the release of ferrous ions, a certain proportion of inert conductive material is added to the iron-based material 300. Under the condition of no electricity, the zero-valent iron elemental iron with low potential becomes the anode, and the inert conductive material with high potential As a cathode, an electrochemical reaction occurs under acidic conditions to promote the oxidation of zero-valent iron to form ferrous ions, thereby promoting the release of ferrous ions into sewage. In an embodiment, the mass percentage of the zero-valent iron elemental substance in the iron-based material 300 may be 80%-95%. The inert conductive material plays a role in assisting the release of ferrous ions.

In one embodiment, the inert conductive material may be selected from one or more of carbon, copper, lead and platinum. Preferably, the inert conductive material is mainly carbon, which has high stability and low price, and is more suitable for industrial applications. The inert conductive material may include small amounts of copper or lead when carbon is predominant.

In one embodiment, the iron-based material 300 is a pre-treated material, and the pre-treatment may include removing impurities on the surface of the iron-based material 300, such as oil stains, rust, and the like. The pretreatment step may be to carry out alkaline cleaning on the iron-based material 300, and then carry out acid cleaning. The reagent for alkali washing can be sodium hydroxide with a mass fraction of 0.08% to 0.12%. The reagent for pickling can be hydrochloric acid with a mass fraction of 4% to 6%. The step of rinsing with water may also be included after alkali washing and pickling.

The material of the hollow membrane body 200 may be polyolefin membrane material, which has high mechanical strength, long service life and good corrosion resistance. The polyolefin film material can be selected from one or more of polyethylene film, polypropylene film and polyvinylidene fluoride film. Preferably, the material of the hollow membrane body 200 may be a polyvinylidene fluoride membrane. The hollow membrane body 200 may be a flat membrane module. The membrane pore diameter of the hollow membrane body 200 may be 0.05 μm˜0.15 μm.

The embodiment of the present invention also provides a kind of sewage treatment method, utilizes described anaerobic membrane bioreactor, and comprises:

S20, inoculating anaerobic sludge in the inner chamber of the anaerobic membrane bioreactor without the iron-based material 300;

S40, acclimating the anaerobic sludge; and

S60, disposing the iron-based material 300 in the inner cavity, and controlling the condition that the iron-based material 300 is not energized, passing sewage to be treated into the inner cavity of the anaerobic membrane reactor for sewage treatment .

In step S20, the inoculum amount of the anaerobic sludge and the source of the anaerobic sludge can be determined according to the type of sewage to be treated.

In step S40, the purpose of acclimating the sludge is to increase the biological activity of the sludge. When dealing with easily degradable low-concentration organic sewage, sludge domestication can directly use the sewage to be treated for domestication. When dealing with toxic, non-biodegradable or high-concentration organic industrial wastewater, the domestication method can be asynchronous or synchronous. The steps of asynchronous domestication of the anaerobic sludge include: injecting domestic sewage or feces water into the anaerobic membrane bioreactor to cultivate and mature the anaerobic sludge; and gradually increasing the proportion of the sewage to be treated. The steps of synchronous domestication of the anaerobic sludge include: while cultivating the anaerobic sludge with domestic sewage or feces water, adding a certain amount of sewage to be treated; and then gradually increasing the proportion of the sewage to be treated. The long-term domesticated sludge can stably degrade organic matter and produce methane.

The hydraulic retention time when acclimating anaerobic sludge can be 8h-12h. The temperature of the anaerobic membrane bioreactor is about 30°C to 35°C, and the flow rate can be 8L/(m ² /h) to 20L/(m ² /h).

In step S60, the iron-based material is not energized, and only uses the reaction with sewage to release ferrous ions. An appropriate amount of ferrous ions plays a role of flocculation, which is beneficial to reduce membrane fouling.

Example

(1) Prepare two zero-priced iron plates, 90cm long, 5cm wide, and 0.3cm thick. Soak in 0.1% NaOH first, then pickle with 5% hydrochloric acid, then rinse with water to remove surface oil, rust and other impurities, and dry it for later use.

(2) Prepare the anaerobic membrane bioreactor device. The reactor adopts a flat membrane module, the membrane material is polyvinylidene fluoride, and the membrane pore size is 0.1 μm.

(3) No zero-valent iron plate is set in the anaerobic membrane bioreactor, and anaerobic sludge is inoculated in the anaerobic membrane bioreactor device, and domesticated. During the domestication process, simulated domestic sewage was used, and the hydraulic retention time was 10 hours. The temperature of the reactor was controlled to about 35°C with an insulating belt, and the constant flux mode was adopted during the operation process, with a flux of 15L/(m ² /h). Monitor gas production, effluent chemical oxygen demand, and transmembrane pressure difference indicators during the acclimation process.

(4) After 20 days, the acclimation process is completed. At this time, place the zero-valent iron plate in the slot of the inner cavity of the anaerobic membrane bioreactor device and fix it. The machine continues to operate. The reactor stopped running when the transmembrane pressure difference rose to 20kPa.

comparative example

The comparative example is basically the same as the examples and the difference is that no zero-valent iron plate is set in the anaerobic membrane bioreactor.

The development of the transmembrane pressure difference in this embodiment and the comparative example, the content and composition of dissolved organic matter in the sludge mixed solution, the particle size of the reactor sludge floc, the filterability of the sludge mixed solution and the hydrogen sulfide in the biogas concentrations were tested. The experimental results are shown in Fig. 3-7 respectively.

Figure 3 illustrates that the development speed of the transmembrane pressure difference in the example with zero-valent iron added is significantly slower than that in the comparative example without zero-valent iron added. The transmembrane pressure difference of the comparative example reached 20 kPa on the 80th day, while the transmembrane pressure difference of the example reached 20 kPa on the 95th day. After deducting the acclimation time of Example and Comparative Example for 20 days, the development speed of membrane fouling in Example is nearly 20% slower than that of Comparative Example, which shows that the use of zero-valent iron can obviously slow down the development of membrane fouling.

Figure 4 illustrates that the concentrations of dissolved and colloidal organic matter in the examples added with zero-valent iron are significantly lower than those in the comparative example without added zero-valent iron. The total concentration of dissolved and colloidal organic matter and the concentration of protein and polysaccharide in it were 6.6mg/L, 7.2mg/L, and 9.6mg/L, respectively, but the three indicators in the comparative example were 11.1mg/L and 11.5mg/L respectively. L, 12.6mg/L. The results indicated that the flocculation induced by the addition of zero-valent iron removed part of the dissolved and colloidal organic matter.

Figure 5 illustrates that the addition of zero-valent iron increases the particle size of sludge flocs. In the example, after adding zero-valent iron on the 20th day, the particle size of the sludge flocs gradually increased from 51.3 μm to 88.9 μm, while the particle size of the sludge flocs in the comparative example remained basically unchanged.

Fig. 6 shows that the specific resistance of the sludge mixture in the embodiment added with zero-valent iron is significantly smaller than that of the comparative example without added zero-valent iron. The filtration specific resistance of the embodiment is 0.23×10 ⁶ m/(kg MLSS), while the filtration specific resistance of the comparative example is 2.3×10 ⁶ m/(kg MLSS). The results show that the addition of zero-valent iron improves the sludge mixture. Filterability.

Fig. 7 illustrates that the concentration of hydrogen sulfide in the example with zero-valent iron added is significantly lower than that of the comparative example without zero-valent iron added. The concentration of hydrogen sulfide in the biogas of the comparative example is 541ppm, while the concentration of hydrogen sulfide in the biogas of the embodiment is only 55ppm, which shows that the hydrogen sulfide in the biogas can be effectively removed by using zero-valent iron.

The various technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (12)

1. The utility model provides an anaerobic membrane bioreactor, its characterized in that, includes casing, the cavity membrane body and iron-based material, the cavity membrane body with iron-based material set up in the inner chamber of casing, be provided with sewage inlet and water purification export on the casing, the cavity membrane body include the membrane shell and by the inclosed water purification chamber that the membrane shell surrounds the formation, the water purification chamber pass through the body with water purification export intercommunication, iron-based material set up in the outside of the cavity membrane body, iron among the iron-based material is the zero-valent iron simple substance, iron-based material is passive iron-based material.

2. The anaerobic membrane bioreactor as claimed in claim 1, wherein the iron-based material further comprises an inert conductive material, and the inert conductive material and the zero-valent iron are uniformly mixed in the iron-based material.

3. The anaerobic membrane bioreactor of claim 2, wherein the inert conductive material is selected from one or more of carbon, copper and lead.

4. The anaerobic membrane bioreactor of claim 3, wherein the mass percentage of the zero-valent iron in the iron-based material is 80-95%.

5. The anaerobic membrane bioreactor of any one of claims 1-4, wherein said ferrous material in said housing is a plate-like ferrous material, a granular ferrous material or a mixture of plate-like and granular ferrous materials.

6. The anaerobic membrane bioreactor as claimed in claim 5, wherein the housing has at least two of said plates of said iron-based material, said hollow membrane body is cylindrical, the length of said hollow membrane body extends along the vertical direction of said inner cavity, and said two plates of said iron-based material are disposed on the two sides of said hollow membrane body respectively along the direction perpendicular to the length of said hollow membrane body.

7. the anaerobic membrane bioreactor of claim 6, wherein in the vertical direction of the inner chamber, the top end of the ferrous material is closer to the top of the inner chamber than the top end of the hollow membrane body, and the bottom end of the ferrous material is closer to the bottom of the inner chamber than the bottom end of the hollow membrane body.

8. The anaerobic membrane bioreactor as claimed in any one of claims 6 to 7, further comprising a baffle plate disposed on a side of the iron-based material adjacent to the inner surface of the housing, wherein in the vertical direction of the inner chamber, a top end of the baffle plate is closer to a top of the inner chamber than a top end of the iron-based material, and a bottom end of the baffle plate is closer to a bottom of the inner chamber than a bottom end of the iron-based material.

9. The anaerobic membrane bioreactor as claimed in any one of claims 1-4 and 6-7, wherein the sewage inlet and the clean water outlet are respectively disposed at the bottom and the top of the housing, and the anaerobic membrane bioreactor further comprises an aeration component disposed at the bottom of the inner chamber.

10. Use of an anaerobic membrane bioreactor according to any one of claims 1 to 9 in the treatment of wastewater.

11. the use of an anaerobic membrane bioreactor according to claim 10 in the treatment of wastewater, wherein the wastewater is sour wastewater.

12. Use of an anaerobic membrane bioreactor according to claim 10 or 11 for the treatment of wastewater, wherein the method of wastewater treatment comprises:

Inoculating anaerobic sludge in the inner cavity of the anaerobic membrane bioreactor without the iron-based material;

Domesticating the anaerobic sludge; and

And arranging the iron-based material in the inner cavity, and introducing the sewage into the inner cavity of the anaerobic membrane reactor to perform sewage treatment under the condition that the iron-based material is controlled not to be electrified.