JP4934177B2 - Water purification apparatus and method - Google Patents

Description

  The present invention relates to a water purification apparatus and method used for advanced water purification treatment in the field of water treatment, particularly in waterworks.

Japan is endowed with clean and abundant tap water sources such as river water, lake water, and groundwater. Conventionally, the treatment flow as shown in FIG. This is for the purpose of turbidity and disinfection, and as water treatment agents, only flocculants such as aluminum sulfate and polyaluminum chloride and disinfectants such as chlorine and sodium hypochlorite have been used.
However, along with the increase of dam lakes for the purpose of securing tap water sources as a lifeline and the progress of eutrophication of water sources, Formium tenue, Anabaena that produces 2-methylisoborneol, geosmin, etc. that are musty odor substances spiroides var. Problems such as abnormal growth of algae such as crassa, Oscillatoria tenuis, Microcystis aeruginosa, and accompanying off-flavor generation occurred, making it difficult to deal with normal treatment.

As a countermeasure against this off-flavor, ozone treatment, biological treatment, activated carbon treatment, and the like have been performed in addition to the normal treatment flow. Activated carbon has fine pores with a large specific surface area of 1,000 m ² / g, and can remove organic substances such as mold odor substances. Activated carbon is classified into powdered activated carbon, granular molded activated carbon, and granular crushed activated carbon according to the difference in shape. The granular molded activated carbon is formed into a columnar shape or a spherical shape, and the granular crushed activated carbon is crushed into a granular crushed material. In addition, as a big difference in the usage mode of powdered activated carbon and granular activated carbon, powdered activated carbon is disposable only once, whereas granular activated carbon is periodically carbonized and steam activated at about 750 to 950 ° C. A reproduction process is performed, and reuse can be basically repeated. As a conventional technique, powdered activated carbon is a one-time disposable process as described above, and therefore, powdered activated carbon of all new coals is used. The regeneration of granular activated carbon is carried out regularly, but it is carried out as an individual operation for each water purification facility. Activated carbon is used.

As a countermeasure against bad odor, there are two types of flow in which activated carbon is used, as shown in Fig. 2 and Fig. 3. When the frequency of occurrence of bad odor is low, powder activated carbon is injected into the landing well only when the trouble occurs. If the frequency is high, a flow is selected in which an activated carbon adsorption pond laid with coconut shell granular crushed activated carbon is installed to perform permanent treatment.
Furthermore, in the 1970s, trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, and bromoform), which are carcinogenic substances, are produced by the reaction of organic substances such as humic acid in water and chlorine as a disinfectant. (Hereinafter referred to as THM), and other problems of disinfection by-products such as haloacetic acid and halal hydrate became apparent and became a major problem that shakes the safety of waterworks. Organic substances that produce disinfection by-products as described above by reaction with chlorine during chlorine disinfection are called disinfection by-product precursors, and the organic substances are efficiently removed and chlorine disinfection by-products are removed. Technology to reduce has come to be demanded.

Therefore, from the viewpoint of supplying safe and delicious water, advanced water purification for the purpose of suppressing chlorine disinfection by-products, such as reviewing the location of chlorinating agents and treating biological activated carbon (hereinafter referred to as BAC) Processing is now under full consideration.
The advanced water purification treatment is based on a combination of coagulation treatment + ozone treatment + BAC treatment + post-chlorine. First, turbidity removal by coagulation treatment and rough removal of organic substances, followed by ozone treatment, oxidative decomposition of residual organic substances and low molecular weight / biodegradable, removal of residual organic substances by BAC treatment and Biodegradation is performed, and organic substances that ultimately become disinfection by-product precursors are reduced as much as possible before disinfection with a chlorinating agent.

  As the processing flow of the advanced water purification treatment, three types of FIG. 4, FIG. 5, and FIG. 6 are representative depending on the method of using activated carbon, and granular crushed activated carbon having different particle diameters is used. The down-flow activated carbon adsorption pond (Fig. 4) placed in front of the sand filtration pond has a large particle diameter of 0.85mm to 2.0mm, an effective diameter of 1.1 to 1.3mm, and a uniformity coefficient of 1.3 or less. In the downward-flow activated carbon adsorption pond (FIG. 5), the coal-based granular crushed activated carbon having a diameter is placed after the sand filtration pond, the particle diameter is 0.5 mm to 2.0 mm, the average diameter is 0.9 to 1.1 mm, A coal-based granular pulverized activated carbon having a medium particle size with a uniformity coefficient of 1.5 to 1.9 has a particle size of 0.2 mm to 1.7 mm and an effective diameter of 0.8 mm in an upward flow fluidized bed activated carbon adsorption pond (FIG. 6). Coal-based granular crushed activated carbon having a small particle size of 35 to 0.45 and a uniformity coefficient of 1.4 or more is used. In addition to these, in the above processing flow, a system in which a biological oxidation treatment pond is combined in the previous stage of the coagulation sedimentation site, and a filter pond (including coagulation filtration) is further combined in the subsequent stage of the medium-size downflow activated carbon adsorption pond in FIG. There are also methods.

Even in this biological activated carbon, organic matter having no biodegradability is gradually accumulated, and therefore, the organic matter removal ability of activated carbon cannot be maintained unless periodic steam activation regeneration is performed.
However, in order to restore the ability of activated carbon to the same level as that of new charcoal, although it is said that regeneration every 3 years is preferable, it is practically carried out after 6 to 8 years have passed for financial reasons. In many cases, it is unavoidable. However, in the regeneration after 6 to 8 years, the regeneration yield decreases due to problems such as recovery of adsorption performance, reduction in hardness and particle size reduction, so used charcoal is discarded without being recycled. However, the number of local governments adopting a method of exchanging for new coal is increasing.

  Activated carbon includes those made from coal, coconut shells, wood sawdust, etc., which are called coal-based activated carbon, coconut shell-based activated carbon, wood-based activated carbon, and the like, respectively. In the off-flavor countermeasure processing flow using powdered activated carbon, it is common to use wood-based powdered activated carbon made of wood sawdust from the characteristics of the shape of powder. In the processing flow for countermeasures against off-flavors using granular pulverized activated carbon, coconut shell-based granular pulverized activated carbon is generally used, but in the case of coconut shell-based activated carbon, micropores with a pore diameter of 2 nm or less have developed. Therefore, this is due to the feature that adsorption properties of off-flavor substances such as 2-methylisoborneol and geosmin with relatively small molecular weight are high.

  On the other hand, in advanced water purification treatment flow aimed at reducing chlorine disinfection by-products, coal-based granular crushed activated carbon is generally used. This is because mesopores with a pore diameter of 2 to 50 nm are developed. Therefore, this is due to the high adsorption characteristics of organic substances that are precursors of chlorine disinfection by-products.

Trees grow by using carbon dioxide in the atmosphere for photosynthesis, so it can be said that the trees have been fixed and transformed into trees. Therefore, when a tree is burned, the generated carbon dioxide was originally present in the atmosphere, so it does not become new exhausted carbon dioxide, but becomes so-called carbon neutral. On the other hand, the carbon contained in coal is the one in which carbon dioxide in the ancient atmosphere is fixed, so the carbon dioxide generated when burning coal is new to the current atmosphere. Treated as exhausted carbon dioxide. This is common to the production of coconut shell, wood and coal-based activated carbon, but not all carbon components in the raw material can be activated carbonized, and most of them are volatilized by combustion and gasification in the carbonization and activation processes. The final activated carbon is only about 10 to 20 parts by weight per 100 parts by weight of the raw material. The carbon dioxide derived from the raw material generated in this process is also carbon neutral with respect to activated carbon derived from plants such as coconut shells.
For this reason, there is a large difference in carbon dioxide emissions between plant-type activated carbon such as coconut shell-based activated carbon and wood-based activated carbon and coal-based activated carbon in the production process, and trial calculation considering utilities such as power consumption, fuel, and water. Then, about 3 to 5 times as much carbon dioxide as that at the time of producing the plant-based activated carbon is discharged during the production of the coal-based activated carbon.

In addition, since coal is an underground resource, it is easily affected by heavy metals contained in the buried formation and groundwater. For example, if coal mined from a formation containing a large amount of contaminants such as arsenic is used as a raw material, There is also concern about the safety of ash contained in activated carbon. On the other hand, since the plant-based activated carbon has a very small amount of ash, it can be said that the activated carbon is highly safe in that respect. Therefore, it is desirable to use plant activated carbon such as coconut shell activated carbon or wood activated carbon for both environmental and safety measures.
However, the coconut shell granular crushed activated carbon has been experimentally studied in Japan in the 1970s, but mesopores in the pore diameter region of 2 to 50 nm and the pore diameter of 50 nm which has a great influence on the material diffusion rate. The development of macropores in the above areas is inferior to that of coal, and the adsorption removal performance of organic substances that are precursors of disinfection by-products is inferior. In addition, there are cases where wood-based granular crushed activated carbon made from wood or other materials is used in advanced water treatment plants in Europe, which has been studied experimentally in Japan. Similarly, it has not been adopted in Japan's advanced water treatment facilities because of the low adsorption characteristics of the chlorine disinfection by-product precursors.

Moreover, as a prior art of granular shaping | molding activated carbon, for example, in Unexamined-Japanese-Patent No. 2002-29725, description (0006) is ".... (1) Water | moisture content in the mixture which mixed the binder with powdered activated carbon or crushed activated carbon. And after kneading and forming, a granulated product is prepared, subjected to thermosetting treatment and carbonization treatment, and a method of producing granulated activated carbon without activation treatment ... and so on.
JP 2002-29725 A

  Therefore, the present invention solves such problems of the prior art, adsorbs organic matter that becomes a precursor of disinfection by-products to a level comparable to that of coal-based granular crushed activated carbon, while using plant-based material that is carbon neutral as a raw material. It is an object of the present invention to provide a water purification apparatus and method using plant-based activated carbon having a high capacity and having developed mesopores having a pore diameter of 2 to 50 nm and macropores having a pore diameter of 50 nm or more and having a small carbon dioxide discharge load.

In order to solve the above problems, in the present invention, a water purification apparatus for water containing a disinfection by-product precursor organic substance that generates a disinfection by-product by chlorine disinfection, comprising a coagulation sedimentation treatment apparatus, a sand filtration apparatus, In addition, the ozone oxidation treatment device and the activated carbon adsorption treatment device are sequentially connected, and the activated carbon used in the activated carbon adsorption treatment device is activated carbon made from a coconut shell material and has a BET specific surface area of 1300 ± 200 m ^2. / G, a spherical volume having a pore volume of 0.15 ± 0.05 cm ³ / g in a mesopore region having a pore diameter of 2 to 50 nm and a pore volume of 0.40 ± 0.10 cm ³ / g in a macropore region of 50 nm or more. A water purification apparatus characterized by being formed activated carbon, or a water purification apparatus for water containing a disinfection by-product precursor organic substance that generates a disinfection by-product by chlorine disinfection, and a coagulation precipitation treatment , An ozone oxidation treatment device, an activated carbon adsorption treatment device, and a sand filtration device are connected in sequence, and the activated carbon used in the activated carbon adsorption treatment device is activated carbon made from coconut shell material, BET The specific surface area is 1300 ± 200 m ² / g, the pore volume of the mesopore region having a pore diameter of 2 to 50 nm is 0.15 ± 0.05 cm ³ / g, and the pore volume of the macropore region of 50 nm or more is 0.40 ± 0. The water purification apparatus is characterized by being spherically shaped activated carbon having a density of 10 cm ³ / g.

Further, in the present invention, a water purification method for water containing a disinfection by-product precursor organic material that generates a disinfection by-product by chlorine disinfection, wherein the treated water includes a coagulation precipitation step, a sand filtration step, In the treatment through the ozone oxidation process and the activated carbon adsorption process in sequence, the activated carbon used in the activated carbon adsorption process is activated carbon made from coconut shell material, and the BET specific surface area is 1300 ± 200 m ² / g pore diameter 2 Spherical shaped activated carbon having a pore volume of ˜50 nm mesopore region of 0.15 ± 0.05 cm ³ / g and a macropore region of 50 nm or more having a pore volume of 0.40 ± 0.10 cm ³ / g Or a water purification method for water containing a disinfection by-product precursor organic substance that produces a disinfection by-product by chlorine disinfection, wherein the treated water is subjected to an aggregation precipitation step, and ozone Of the process, the activated carbon adsorption step, upon sequentially through by treatment and sand filtration step, the activated carbon for use in the activated carbon adsorption step, with activated carbon for a coconut shell-based material as a raw material, BET specific surface area of 1300 ± 200 meters ² / G Spherical molding in which the pore volume of the mesopore region having a pore diameter of 2 to 50 nm is 0.15 ± 0.05 cm ³ / g and the pore volume of the macropore region having a pore size of 50 nm or more is 0.40 ± 0.10 cm ³ / g The water purification method is characterized by being activated carbon.
In the water purification apparatus and method, the sand filtration apparatus can be provided both between the coagulating sedimentation apparatus and the ozone oxidation apparatus, and at the subsequent stage of the activated carbon adsorption treatment apparatus, and the activated carbon has a washing turbidity of 20 It is preferable that the washing turbidity is 15 degrees or less.

The first effect of the present invention is that the amount of carbon dioxide emitted from the activated carbon used can be greatly reduced as compared with the existing advanced water purification apparatus. Activated carbon adsorption pond: Examples Large advanced water treatment facilities (activated carbon loading of 245m ³ × 24 ponds = 5,880m ^3), according to the conventional water treatment device and coconut shell-based spherical activated carbon according to existing coal-based granular crushed activated carbon Table 1 shows the case study results of the life cycle assessment (hereinafter referred to as LCA) of carbon dioxide emissions in the life cycle of activated carbon from fresh coal production to incineration disposal for the water purification apparatus of the present invention.

A 24-year operation comparison of the case of renewal replacement with new coal in the 8-year cycle and the case of renewal activation renewal in the 6-year cycle reveals that the case of the conventional coal-based granular crushed activated carbon 8-year cycle new coal renewal case When the total amount of carbon emissions is 1.00, the LCA for renewal of 8-year cycle activated carbon of the coconut shell-based spherical activated carbon of the present invention is 0.27, and the LCA of 6-year cycle activation regeneration for palm-shelled spherical activated carbon is 0.32. next, according to the present invention 154,000 _t-CO 2/24 years in coconut shell-based spherical activated carbon 8 year cycle new coal update, 165,000 t-CO is a coconut shell-based spherical activated carbon 6-year cycle activated reproducing update _2/24 years a significant carbon dioxide emissions reduction of.

The second effect is an effect of reducing the amount of washing water based on the fact that there is little generation of pulverized coal. In the activated carbon adsorption pond of the advanced water purification apparatus, the activated carbon adsorption pond is regularly cleaned by backwashing operation, but the backwashing process is generally performed in the following steps.
`` Water stoppage '' → `` Water level drop '' → `` Simultaneous cleaning with air and water '' → `` Washing '' → `` Discarding '' → `` Restarting water supply ''
In the case of a water purification apparatus using conventional coal-based granular pulverized activated carbon, activated carbon wear in the air / water simultaneous washing process was severe, and it was necessary to take a long water washing process and waste water treatment process. In the case of a water purification apparatus, since there is little generation | occurrence | production of pulverized coal, a water washing | cleaning process and a draining process can be shortened, and there exists an effect which can reduce the amount of washing water for this.

The third effect is an effect based on the small water flow resistance. Advanced water treatment apparatus water flow rate superficial velocity of the activated carbon adsorption pond (space velocity ^{[hr -1]:} hereinafter referred to as SV) is being passed through at about 3～8Hr ^-1 is generally, In the case of the water purification apparatus of the present invention, since the water flow resistance is small, the linear velocity (linear velocity [m / hr]: hereinafter referred to as LV) can be increased to increase the packed bed height. This means that the area of the apparatus is reduced, and there is a space-saving effect on the installation area of the water purification apparatus.
As described above, the present invention uses carbon-neutral plant-based materials as the main raw material, and has a level comparable to that of coal-based granular pulverized activated carbon. , A mesopore with a pore diameter of 2 to 50 nm, and a macropore with a pore diameter of 50 nm or more, which has a large effect on the material diffusion rate, have been developed. The present invention provides a water purification apparatus and can be said to be an invention that can greatly contribute to the environment.

The present invention is activated carbon made from plant-based materials, the BET specific surface area is 1300 ± 200 m ² / g, the pore volume of the mesopore region having a pore diameter of 2 to 50 nm is 0.15 ± 0.05 cm ³ / g, Moreover, it uses spherical shaped activated carbon with a pore volume of 0.40 ± 0.10 cm ³ / g in the macropore region of 50 nm or more, and carbon dioxide emissions that could not be achieved with conventional equipment using coal-based granular crushed activated carbon It is an invention of a water purification apparatus and method having a high suppression effect. The activated carbon is not particularly limited as long as it has a plant volume such as coconut shell or wood and has the above pore volume. For example, coconuts such as activated carbon A and activated carbon B shown in Table 2 are used. A shell system is preferred.

Activated carbon A and activated carbon B were kneaded with 100 parts by weight of coconut powder activated carbon, 20 parts by weight of a novolac-type powdered phenol resin, and 90 parts by weight of water, and after being granulated and formed into a spherical shape with a spherical molding machine, the gelation treatment was performed at 170 ° C. Carbonized for 30 minutes at a reducing atmosphere of 900 ° C. to obtain a carbonized product, and further manufactured by performing a steam activation treatment for 3 hours or more under the conditions of a reducing atmosphere of 900 ° C. and a water vapor concentration of 40% as mol. Has a particle size of 0.85 to 2.0 mm, an effective diameter of 1.1 to 1.3 mm, and a particle size adjusted to a uniformity coefficient of 1.3 or less. Activated carbon B has a particle size of 0.5 to 2.0 mm and an average diameter of 0.8. The particle size is adjusted to 9 to 1.1 mm and the uniformity coefficient 1.5 to 1.9. Table 2 shows product specification examples of activated carbon A and activated carbon B together with specification examples of conventional coal-based granular crushed activated carbon and coconut shell-based granular crushed activated carbon.
Here, the BET specific surface area and the pore volume of the mesopore are measured by the specific surface area / pore distribution measuring device ASAP2010 manufactured by Micrometrics (sales: Shimadzu Corporation), and the pore volume of the macropore is manufactured by Shimadzu Corporation. It is measured by a mercury porosimeter device Autopore IV9500 type.

Furthermore, in the present invention, the activated carbon preferably has a washing turbidity of 20 degrees or less, more preferably a washing turbidity of 15 degrees or less.
The washing turbidity is a test item described in the JWWA A 103 water filter test method, which is a standard of the Japan Water Works Association, and is the following test.

(Washing turbidity measurement method)
Take 30 g of an air-dried sample in a 500 mL stoppered reagent bottle, add 300 mL of purified water, seal tightly, shake at a rate of 150 times per minute, shake for 1 minute with a swinging width of about 15 cm, and leave for 3 minutes. Next, about 150 mL of the upper liquid is collected by inclining and the turbidity is measured.
The washing turbidity is originally a test for filter sand, and is not applicable to filter media such as anthracite and manganese sand, which easily generate chromaticity. The manufacturing method of coal-based granular pulverized activated carbon used in Japan's advanced water purification treatment is to finely pulverize bituminous coal and subbituminous coal, remove ash, knead and add binder, crush and adjust the particle size Thereafter, carbonization and steam activation were performed. Therefore, since the external appearance has an angular shape, the existing advanced water purification apparatus has a drawback that fine powder due to wear is easily generated during the backwashing process, and the washing time is long.

The present invention comprises a coagulation sedimentation treatment device, an ozone oxidation treatment device connected to the coagulation precipitation treatment device, and an activated carbon adsorption treatment device connected to the ozone oxidation treatment device, which produces a disinfection by-product by chlorine disinfection. A water purification apparatus for water containing a by-product precursor organic substance, wherein the activated carbon adsorption treatment apparatus is activated carbon using a coconut shell material as a raw material, and has a BET specific surface area of 1300 ± 200 m ² / g and a pore diameter of 2 Spherical shaped activated carbon having a pore volume of ˜50 nm mesopore region of 0.15 ± 0.05 cm ³ / g and a macropore region of 50 nm or more having a pore volume of 0.40 ± 0.10 cm ³ / g is used. Further, between the coagulation precipitation treatment device and the ozone oxidation treatment device, or after the activated carbon adsorption treatment device, or between the coagulation precipitation treatment device and the ozone oxidation treatment device, and the activated carbon adsorption treatment device. The apparatus which connected the sand filtration apparatus to both the back | latter stages may be sufficient. Accordingly, the water purification apparatus of the present invention also includes an embodiment configured with the processing flows shown in FIGS. 4, 5, and 6.

In addition, if ammonia nitrogen is present in the raw water in the water treatment, it is inevitable that various amines (monochloramine NH ₂ CL, dichloroamine NHCL ₂ , trichloramine NHCL ₃ ) are generated by chlorine disinfection. Of these, dichloramine and trichloramine have odors, and the latter is particularly strong, and these are called odors. Chalk odor has been repelled by water users for a long time along with the malodor produced by algae in eutrophic water sources, and reducing these odors in the supply water This is an important issue for administrators.
Moreover, in order to completely decompose chloramine, so-called discontinuous point chlorination is necessary, but the amount of chlorine consumed for this purpose is empirically about 8 to 10 times that of ammonia nitrogen, Ammonia nitrogen removal is also important to reduce the amount of chlorine used.

  Nitrification is said to be performed by nitrite production by nitrite bacteria that oxidize ammonia and nitric acid production by nitrite bacteria that oxidize nitrite. In the activated carbon adsorption pond, ammonia nitrogen, inorganic soluble carbon and dissolved oxygen are supplied from the ozone contact area, and microorganisms that live and carry the activated carbon in the activated carbon adsorption pond perform nitrification. It is desired that the activated carbon in the adsorption pond functions well as a carrier for the microorganism group that performs nitrification. In other words, the nitrification reaction is quick after onset of new charcoal, the nitrification rate is not easily lowered even at low water temperatures, and the nitrification rate is required to follow the fluctuation of the inflowing ammonia nitrogen concentration well. The activated carbon of the present invention sufficiently satisfies these required characteristics.

The activated carbon used in the present invention has a BET specific surface area of 1,100 m ² / g or more, preferably 1,200 m ² / g or more, more preferably 1,300 m ² / g or more. In the pore volume of the mesopore region of pore size of 2 to 50 nm 0.10 cm ³ / g or more, preferably 0.12 cm ³ / g or more, more preferably it is 0.15 cm ³ / g or more. The pore volume of more macropore region 50nm at 0.30 cm ³ / g or more, preferably 0.35 cm ³ / g or more, more preferably is 0.40 cm ³ / g or more. Moreover, it is preferable that the washing | cleaning turbidity by the filter medium test method for JWWA A103 water supply is 20 degrees or less, Furthermore, it is preferable that it is 15 degrees or less.

Activated carbon is also used as a material for dechlorination in the production process of water used for products and utilities in the production of beer and soft drinks.
For example, in the 1970s, the process flow is the same as that of a water purification plant.
It was based on water intake ⇒ coagulation sedimentation ⇒ sand filtration ⇒ activated carbon adsorption ⇒ disinfection ⇒ dechlorination ⇒ treated water. In this case, the manufacturer defines management standards different from tap water for pH, acid consumption, dissolved salt concentration, residual chlorine concentration, and the like. In recent years, membrane separation technology has been adopted for water treatment, taking into account the need to respond to diversification of products, high quality requirements from consumers, security and security, and deterioration of water quality of raw water intake sources. is increasing. As an example of recently installed equipment processing flow,
Water intake ⇒ RO membrane treatment ⇒ Disinfection ⇒ Dechlorination ⇒ MF membrane ⇒ Treated water.
Whatever the treatment, old or new, sodium hypochlorite is commonly used as a disinfectant because it is important to remove unwanted substances and prevent contamination caused by the growth of organisms in the water production process. Is done. On the other hand, in the manufacturing process in which water is processed into products, it is necessary to manage residual chlorine below a certain level in order to maintain product quality, so activated carbon is used to dechlorinate water before the commercialization. .

As described above, in the dechlorination, granular activated carbon using a plant-based raw material having a low content of heavy metals or the like is often selected in order to ensure food safety. Normally, activated carbon is filled in a fixed bed and water is passed through to dechlorinate. One of the technical issues here is the response to the activated carbon fine powder generated in the backwashing process of the packed tower. Fine powder generated by scouring activated carbon by backwashing cannot be completely removed in the water washing process, so it is inevitable that fine powder leakage will be tailed and drained into the treated water at the beginning of the water flow process. . Since the spilled fine powder is supplemented by the MF membrane after dechlorination in the above flow, the frequency of backwashing of the MF membrane, the amount of backwashing water increases, or if the membrane is damaged, There will be danger. For these reasons, it has been desired to develop activated carbon for dechlorination that does not generate fine powder during backwashing or generates a small amount.
The activated carbon (coconut shell-based spherical coal) used in the present invention is characterized by having a smaller washing turbidity than either coal-based or coconut shell-based granular crushed coal. Utilizing this in a food-based irrigation process is an effective means for solving or improving the above problems.

Example 1
About the organic substance removal performance by the processing apparatus of the flow of FIG. 4, the conventional apparatus (coal crushed coal: mesopore volume 0.28 cm ³ / g, macropore volume 0.40 cm ³ / g, BET specific surface area 1,070 m ² / g) And the present invention (coconut shell-based spherical coal A: steam activation conditions are 900 ° C., steam concentration 40% as mol for 3 hours, mesopore volume 0.12 cm ³ / g, macropore volume 0.35 cm ³ / g, BET Specific surface area 1,320 m ² / g), comparative apparatus 1 (coconut shell-based spherical coal A-1: steam activation condition is 850 ° C., steam concentration 30% as mol for 3 hours, mesopore volume 0.14 cm ³ / g, macropore Volume 0.23 cm ³ / g, BET specific surface area 1,070 m ² / g), comparative device 2 (coconut shell-based spherical coal A-2: steam activation condition is 850 ° C., steam concentration 40% as mol for 5 hours, mesopore volume 0.08 cm ³ / g, macropore volume 0.39 cm ³ / g, BET specific surface area 1,080 m ² / g), comparison device 3 (coconut shell spherical coal A-3: steam activation The conditions were 950 ° C., water vapor concentration 40% as mol for 2 hours, mesopore volume 0.07 cm ³ / g, macropore volume 0.21 cm ³ / g, BET specific surface area 1,240 m ² / g). 7 and 8 show a comparison of the transition of the water absorption multiple and removal rate of the ultraviolet absorbance E260, which is an indicator of organic substances, and the total trihalomethane production ability (THMFP).

While the E260 removal rate of the present invention device 1 (coconut shell-based spherical coal A) at a water flow rate of 11,808 times and 35,617 times is 48% and 28%, respectively, the comparison device 1 (coconut shell-based spherical coal A) 33% and 15% for charcoal A-1), 28% and 14% for comparative device 2 (coconut shell-based spherical coal A-2), and 23% for comparative device 3 (coconut-shell spherical carbon A-3), respectively. %, 9%, 42% and 27% for the conventional apparatus (coal-based crushing), respectively, and 44% and 32% of the THMFP removal rate at the water flow rate of 14,876 times and 34,987 times of the apparatus 1 of the present invention, respectively. On the other hand, the comparison device 1 has 34% and 16%, the comparison device 2 has 31% and 14%, the comparison device 3 has 26% and 10%, and the conventional device has 44% and 29%. The removal performance of the device of the present invention (coconut shell sphere (Table 2 specifications)) for both UV absorbance E260 and THMFP is equivalent to that of the conventional device (coal crushing), and compared to the comparative device (coconut shell spheres (outside of Table 2 specifications)). Confirmed that there is an advantage.
Treatment conditions / activated carbon layer height: 2500 mm
Activated carbon particle size: effective diameter -1.2 mm, uniformity coefficient -1.3
Space velocity [SV]: 5.2 / h (linear velocity [LV] 13 m / h)
Activated carbon influent water quality: UV absorbance E260-0.029-0.082 Abs.
Total trihalomethane production capacity THMFP-0.017-0.035 mg / L

Example 2
About the organic substance removal performance by the processing apparatus of the flow of FIG. 4, the conventional apparatus (coal crushed coal: mesopore volume 0.28 cm ³ / g, macropore volume 0.40 cm ³ / g, BET specific surface area 1,070 m ² / g) And apparatus of the present invention (coconut shell-based spherical coal A: steam activation condition is 900 ° C., steam concentration 40% as mol for 3 hours, mesopore volume 0.12 cm ³ / g, macropore volume 0.35 cm ³ / g, BET specific surface area 1,320 m ² / g), and comparison apparatus (coconut shell crushed charcoal: mesopore volume 0.05 cm ³ / g, macropore volume 0.15 cm ³ / g, BET specific surface area 1,240 m ² / g) . 9 and 10 show a comparison of the transition of the water absorption multiple and the removal rate of the ultraviolet absorbance E260, which is an indicator of organic substances, and the total trihalomethane production ability (THMFP).

The E260 removal rate at the water flow rate of 12,316 times and 29,681 times of the comparison device (coconut shell crushing) is 21% and 14%, respectively, whereas the device of the present invention (coconut shell sphere) is 43%, Compared to 27% for the conventional equipment (coal crushing), 42% and 27%, respectively, the THMf removal rates of the comparative equipment at 10,018 times and 27,847 times are 25% and 17%, respectively. Inventive devices are 45% and 29%, respectively, and conventional devices are 45% and 28%, respectively. Both the ultraviolet absorbance E260 and THMFP have the removal performance of the present device (coconut shell sphere) compared to the conventional device (coal crushing). And superiority to the comparative device (coconut shell crushing).
・ Activated carbon layer height: 2500mm
Activated carbon particle size: effective diameter -1.2 mm, uniformity coefficient -1.3
Space velocity [SV]: 5.2 / h (linear velocity [LV] 13 m / h)
Activated carbon influent water quality: UV absorbance E260-0.037-0.095 Abs.
Total trihalomethane production capacity THMFP-0.016-0.038mg / L

Example 3
About the organic substance removal performance by the processing apparatus of the flow of FIG. 5, conventional apparatus (coal-based crushed coal: mesopore volume 0.26 cm ³ / g, macropore volume 0.38 cm ³ / g, BET specific surface area 1,050 m ² / g) And apparatus of the present invention (coconut shell-based spherical coal B: mesopore volume 0.12 cm ³ / g, macropore volume 0.32 cm ³ / g, BET specific surface area 1,280 m ² / g), comparison device (coconut shell crushed coal: mesopore Comparison was made with a volume of 0.06 cm ³ / g, a macropore volume of 0.16 cm ³ / g, and a BET specific surface area of 1,220 m ² / g). 11 and 12 show a comparison of the transition of the water absorption multiple and the removal rate of the ultraviolet absorbance E260, which is an indicator of organic substances, and the total trihalomethane production ability (THMFP).

The E260 removal rate at the water flow rate of 9,131 times and 35,917 times of the comparison device (coconut shell crushing) is 34% and 18%, respectively, whereas the device of the present invention (coconut shell sphere) is 59%, 34%, 56% and 35% for the conventional device (coal crushing), respectively, and the THMf removal rate of the comparison device at 12,021 times and 35,521 times is 29% and 18%, respectively. Inventive devices are 49% and 33%, respectively, and the conventional devices are 47% and 30%, respectively. Both the ultraviolet absorbance E260 and THMFP have the removal performance of the present device (coconut shell sphere) compared to the conventional device (coal crushing). And superiority to the comparative device (coconut shell crushing).
Treatment conditions / activated carbon layer height: 2700mm
Activated carbon particle size: average diameter -1.0 mm, uniformity coefficient -1.7
Space velocity [SV]: 5.8 / h (linear velocity [LV] 15.7 m / h)
Activated carbon influent water quality: UV absorbance E260-0.016-0.034 Abs.
Total trihalomethane production capacity THMFP-0.009-0.023mg / L

Example 4
About the organic substance removal performance by the processing apparatus of the flow of FIG. 6, conventional apparatus (coal-based crushed coal: mesopore volume 0.25 cm ³ / g, macropore volume 0.33 cm ³ / g, BET specific surface area 1,030 m ² / g) And apparatus of the present invention (coconut shell-based spherical carbon C: mesopore volume 0.13 cm ³ / g, macropore volume 0.35 cm ³ / g, BET specific surface area 1,300 m ² / g), comparison device (coconut shell crushed charcoal: mesopore volume 0.04 cm ³ / g, the macropore volume of 0.11 cm ³ / g, compared with the BET specific surface area of 1,250 m ² / g) was carried out. 13 and 14 show a comparison of the transition of the water absorption multiple and removal rate of the ultraviolet absorbance E260, which is an indicator of organic substances, and the total trihalomethane production ability (THMFP).

The E260 removal rate at the water flow rate of 12,424 times and 38,152 times of the comparison device (coconut shell crushing) is 39% and 17%, respectively, whereas the device of the present invention (coconut shell sphere) is 53%, Compared to 35%, the conventional equipment (coal crushing) has 50% and 37%, respectively, and the THM removal rate of the comparison equipment at 14,426, 38, and 429 times is 35% and 20%, respectively. The inventive device is 54% and 37%, respectively, and the conventional device is 55% and 36%, respectively. Both the ultraviolet absorbance E260 and THMFP have the removal performance of the present device (coconut shell sphere) compared to the conventional device (coal crushing). And superiority to the comparative device (coconut shell crushing).
Treatment conditions / Activated carbon layer height: 2100mm
Activated carbon particle size: effective diameter -0.4mm, uniformity coefficient -1.4
Space velocity [SV]: 7.1 / h (Linear velocity [LV] 14.9 m / h)
Activated carbon influent water quality: UV absorbance E260-0.036 to 0.068 Abs.
Total trihalomethane production capacity THMFP-0.014-0.031mg / L

Example 5
About the organic substance removal performance by the processing apparatus of the flow of FIG. 4, the conventional apparatus (coal crushed coal: mesopore volume 0.28 cm ³ / g, macropore volume 0.40 cm ³ / g, BET specific surface area 1,070 m ² / g) And apparatus of the present invention (coconut shell-based spherical charcoal A: mesopore volume 0.12 cm ³ / g, macropore volume 0.35 cm ³ / g, BET specific surface area 1,320 m ² / g), comparison apparatus 1 (coconut shell / wood mixed) Spherical coal A: Mesopore volume 0.08 cm ³ / g, Macropore volume 0.33 cm ³ / g, BET specific surface area 1,160 m ² / g), Comparative device 2 (woody spherical coal A: Mesopore volume 0.12 cm ³ / G, macropore volume 0.33 cm ³ / g, and BET specific surface area 1,060 m ² / g). 15 and 16 show a comparison of the transition of the water passage multiple and removal rate of the ultraviolet absorbance E260, which is an indicator of organic substances, and the total trihalomethane production ability (THMFP).

The E260 removal rate of the present invention device 1 (coconut shell sphere) at a water flow rate of 12,136 times and 29,681 times is 43% and 27%, respectively, while the comparison device 1 (coconut shell / wood mixed sphere) Are 35% and 20%, respectively, 34% and 16% for the comparison device 2 (woody spherical), 42% and 27% for the conventional device (coal-based crushing), respectively, and 10,018 times the water flow rate of the device 1 of the present invention , 27,847 times, the THMFP removal rates are 45% and 29%, respectively, while the comparison device 1 is 36% and 21%, the comparison device 2 is 33% and 19%, and the conventional device is 45%. , 28%. Both UV absorbance E260 and THMFP have the removal performance of the device of the present invention (coconut shell sphere) equivalent to the conventional device (coal crushing) and superior to the comparative device (coconut shell / woody sphere and woody sphere). confirmed.
Treatment conditions / activated carbon layer height: 2500 mm
Activated carbon particle size: effective diameter -1.2 mm, uniformity coefficient -1.3
Space velocity [SV]: 5.2 / h (linear velocity [LV] 13 m / h)
Activated carbon influent water quality: UV absorbance E260-0.037-0.095 Abs.
Total trihalomethane production capacity THMFP-0.016-0.038mg / L

Example 6
Coconut shell spherical activated carbon A of the present invention (mesopore volume 0.12 cm ³ / g, macropore volume 0.35 cm ³ / g, BET specific surface area 1,320 m ² / g, effective diameter 1.2 mm, uniformity coefficient 1.3), Coconut shell spherical activated carbon B of the present invention (mesopore volume 0.12 cm ³ / g, macropore volume 0.32 cm ³ / g, BET specific surface area 1,280 m ² / g, average diameter 1.0 mm, uniformity coefficient 1.7) Washing turbidity of conventional coal-based crushed coal (mesopore volume 0.28 cm ³ / g, macropore volume 0.40 cm ³ / g, BET specific surface area 1,070 m ² / g, effective diameter 1.2 mm, uniformity coefficient 1.3) A degree measurement example is shown in FIG. The backwashing process at the activated carbon adsorption facility at the water purification plant follows the procedures of draining / mixing water / air washing / washing / disposal, but the following data can be said to mimic the situation at the time of backwashing with fresh coal filling. . As a result of this test, the activated carbon of the present invention has reduced the turbidity discharge amount to about 1/3 in six accumulations compared to coal-based crushed coal. In addition, in the test method described in JWWA A 103 water filter medium test method, the turbidity is determined by a visual method compared with the turbidity standard sequence, but in the examples of the present invention, Using an integrating sphere turbidimeter, which is a more precise measurement method, measurement was performed by an optical method.

(Measurement method: JWWA A 103)

Example 7
FIG. 4 shows a conventional apparatus (coal-based granular crushed coal: mesopore volume 0.28 cm ³ / g, macropore volume 0.40 cm ³ / g, BET specific surface area 1,070 m ² / g, effective diameter 1.2 mm. , Uniformity coefficient 1.3) and apparatus of the present invention (coconut shell-based spherical coal A: mesopore volume 0.12 cm ³ / g, macropore volume 0.35 cm ³ / g, BET specific surface area 1,320 m ² / g, effective diameter 1 A comparison of backwashing at .2 mm, uniformity coefficient 1.3) is shown in FIG.
As shown in FIG. 18, the conventional apparatus (coal-based granular pulverized coal) required a water drainage time of 30 minutes until the turbidity became 0.1 degrees or less. Occurrence was low and reached in 20 minutes. Thereby, it was confirmed that the device of the present invention (coconut shell-based spherical coal A) can reduce the amount of backwash water to about 2/3 compared with the conventional device (coal-based granular crushed coal).

Example 8
FIG. 5 shows a conventional apparatus (coal-based granular crushed coal: mesopore volume 0.26 cm ³ / g, macropore volume 0.38 cm ³ / g, BET specific surface area 1,050 m ² / g, average diameter 1.0 mm). , Uniformity coefficient 1.7) and device of the present invention (coconut shell-based spherical charcoal B: mesopore volume 0.12 cm ³ / g, macropore volume 0.32 cm ³ / g, BET specific surface area 1,280 m ² / g, average diameter 1 Comparison of backwashing at 0.0 mm, uniformity coefficient 1.7) is shown in FIG.
As shown in FIG. 19, the conventional apparatus (coal-based granular pulverized coal) required a water drainage time of 30 minutes until the turbidity became 0.1 ° C. or less. Occurrence was low and reached in 20 minutes. Thereby, it was confirmed that the device of the present invention (coconut shell-based spherical coal B) can reduce the amount of backwash water to about 2/3 compared with the conventional device (coal-based granular crushed coal).

Example 9
FIG. 20 shows the result of comparing the nitrification performance of ammoniacal nitrogen for the spherical activated carbon of the present invention and the conventional commercial coal-based granular crushed coal in the processing flow of FIG. The water temperature during the test is room temperature.
Table 4 shows the properties of each activated carbon.
As a result of the comparative test, it was confirmed that the nitrification reaction of the plant-based spherical activated carbon started earlier than the coal-based crushed coal, and that the coconut shell-based spherical coal started nitrification earlier.

Example 10
Table 5 shows the results of evaluating the dechlorination ability of four of the coconut shell spherical coals A and B of the present invention, the coconut shell crushed coal, and the coal-based granular crushed coal. The evaluation of the dechlorination capacity was carried out according to the German standard DIN 19603 with a half-layer thickness of chlorine concentration. The activated carbon layer thickness (Gg) was measured in order to halve the chlorine concentration at the inlet of the water flow column by the following procedure. The thinner the layer thickness, the higher the chlorine resolution.
1) The granular activated carbon is boiled with distilled water and cut off from contact with the outside air in a wet state.
m glass column to a height of about 10 cm.
2) Add sodium hypochlorite to distilled water that does not contain chlorine compounds and ammonia nitrogen, and adjust the effective chlorine concentration to about 5 mg / l. The pH is 7.0-7.5.
3) Pass the prepared chlorine solution to the packed column at room temperature for 30 minutes at a linear velocity of 36 m / h.
4) Simultaneously measure the chlorine concentration of treated water and influent water at 29 minutes.
Gg = 0.301 × t / log (u / V)
Gg: Half width of dechlorination of granular activated carbon (half layer thickness) cm
t: Activated carbon layer thickness cm
u: Chlorine concentration in influent water mg / l
V: Chlorine concentration in treated water at the 29th minute mg / l

* DIN19603

As shown in Table 5, it was confirmed that the coconut shell-based spherical activated carbon of the present invention had the same or higher chlorine decomposition ability as the conventional product.
Table 6 is an example of washing turbidity measurement of the above four brands of activated carbon. The occurrence of washing turbidity of the present spherical coal was significantly less than that of crushed coal.
By applying the spherical coal of the present invention, which generates a small amount of fine powder in the backwashing process, to dechlorination treatment of water production for food production, it can contribute to improvement, simplification, and cost reduction of facility operation management.

The normal process flow figure of a water purification apparatus. Odor odor countermeasure processing flow diagram using powdered activated carbon of a water purification apparatus. The off-flavor countermeasure processing flow diagram using the granular pulverized activated carbon of the water purification apparatus. The advanced water purification process flow figure which uses the large particle-size granular activated carbon of a water purification apparatus. Advanced water purification treatment flow diagram using medium-sized granular activated carbon in water purification equipment. The advanced water purification process flow figure which uses the small particle-size granular activated carbon of a water purification apparatus. The ultraviolet part light absorbency E260 which shows the comparison result of Example 1 is a graph of transition of a water passage multiple and a removal rate. The graph of the transition of the total trihalomethane production | generation capability THMFP water passage multiple and removal rate which shows the comparison result of Example 1. FIG. The ultraviolet part light absorbency E260 which shows the comparison result of Example 2 is a graph of transition of a water passage multiple and a removal rate. The graph of transition of the total trihalomethane production | generation capability THMFP water passage multiple and removal rate which shows the comparison result of Example 2. FIG. The ultraviolet part light absorbency E260 which shows the comparison result of Example 3 is a graph of transition of a water passage multiple and a removal rate. The graph of the transition of the total trihalomethane production | generation capability THMFP water passage multiple and removal rate which shows the comparison result of Example 3. FIG. The ultraviolet part light absorbency E260 which shows the comparison result of Example 4 is a graph of transition of a water passage multiple and a removal rate. The graph of the transition of the total trihalomethane production | generation capability THMFP water passage multiple and removal rate which shows the comparison result of Example 4. FIG. The ultraviolet part absorbance E260 which shows the comparison result of Example 5 is a graph of a transition of a water flow rate multiple and a removal rate. The graph of the transition of the total trihalomethane production | generation capability THMFP water passage multiple and removal rate which shows the comparison result of Example 5. FIG. The comparison graph of the washing | cleaning turbidity which shows the result of Example 6. FIG. The comparative graph of the turbidity change in the water-washing process at the time of backwashing which shows the result of Example 7. The comparative graph of the turbidity change in the water-washing process at the time of backwashing which shows the result of Example 8. 10 is a comparative graph of rising of nitrification reaction of ammoniacal nitrogen showing the results of Example 9. FIG.

Claims (4)

A water purification apparatus for water containing a disinfection by-product precursor organic substance that generates disinfection by-products by chlorine disinfection, a coagulation sedimentation treatment apparatus, a sand filtration apparatus, an ozone oxidation treatment apparatus, an activated carbon adsorption treatment apparatus, The activated carbon used in the activated carbon adsorption treatment apparatus is activated carbon made from coconut shell material, and has a BET specific surface area of 1300 ± 200 m ² / g and a mesopore region with a pore diameter of 2 to 50 nm. A water purification apparatus characterized by being a spherical activated carbon having a pore volume of 0.15 ± 0.05 cm ³ / g and a pore volume of a macropore region of 50 nm or more of 0.40 ± 0.10 cm ³ / g . A water purification apparatus for water containing a disinfection by-product precursor organic material that generates disinfection by-products by chlorine disinfection, a coagulation precipitation treatment apparatus, an ozone oxidation treatment apparatus, an activated carbon adsorption treatment apparatus, a sand filtration apparatus, The activated carbon used in the activated carbon adsorption treatment apparatus is activated carbon made from coconut shell material, and has a BET specific surface area of 1300 ± 200 m ² / g and a mesopore region with a pore diameter of 2 to 50 nm. A water purification apparatus characterized by being a spherical activated carbon having a pore volume of 0.15 ± 0.05 cm ³ / g and a pore volume of a macropore region of 50 nm or more of 0.40 ± 0.10 cm ³ / g . A water purification method for water containing a disinfection by-product precursor organic material that generates a disinfection by-product by chlorine disinfection, the treated water comprising a coagulation precipitation step, a sand filtration step, an ozone oxidation step, and activated carbon When processing through the adsorption step sequentially, the activated carbon used in the activated carbon adsorption step is activated carbon made from coconut shell material, and has a BET specific surface area of 1300 ± 200 m ² / g in a mesopore region having a pore diameter of 2 to 50 nm. Purified water treatment characterized by being a spherical shaped activated carbon having a pore volume of 0.15 ± 0.05 cm ³ / g and a macropore region having a pore size of 50 nm or more of 0.40 ± 0.10 cm ³ / g Method. A water purification method for water containing a disinfection by-product precursor organic material that generates a disinfection by-product by chlorine disinfection, wherein the treated water includes a coagulation precipitation step, an ozone oxidation step, an activated carbon adsorption step, a sand When processing through the filtration step sequentially, the activated carbon used in the activated carbon adsorption step is activated carbon made from coconut shell material, and has a BET specific surface area of 1300 ± 200 m ² / g in a mesopore region having a pore diameter of 2 to 50 nm. Purified water treatment characterized by being a spherical shaped activated carbon having a pore volume of 0.15 ± 0.05 cm ³ / g and a macropore region having a pore size of 50 nm or more of 0.40 ± 0.10 cm ³ / g Method.