KR20040110352A - Preparation method of fine spherical granule for water treatment containing magnetite powder and adsorbent of eutrophicating substance and organic matters, and ultra-high speed water treatment process using fine spherical granule - Google Patents

Abstract

PURPOSE: To provide a preparation method of powder for ultra-high speed water treatment capable of separating the adsorbed phosphorus and nitrogen at a ultra-high speed by magnetic force after preparing spherical granule of which surface is modified by copper on the surface of magnetite powder, calcium hydroxide, activated carbon or activated carbon fiber and adsorbing phosphorus and nitrogen onto the spherical granule, and a water treatment process using the powder for ultra-high speed water treatment. CONSTITUTION: The preparation method of fine granule for ultra-high speed water treatment comprises the steps of preparing a mixture by mixing 15 to 60 wt.% of adsorbent which contains 10 to 80 wt.% of magnetic substance of magnetite, and in which 0.1 to 5.0 wt.% of copper is coated on activated carbon or activated carbon fiber, 4 to 29 wt.% of slaked lime, and less than 1.0 wt.% of one-pack polyurethane; preparing fine spherical granule having a granular size of 0.1 to 5.0 mm from the mixture; and forming solid fine granule by heating the fine spherical granule at a temperature of 135 deg.C or less for less than 30 minutes, wherein a specific surface area of the activated carbon or activated carbon fiber is 1,000 to 1,600 m¬2/g, 0.1 to 2.0 wt.% of Cu is coated on the activated carbon by electroless plating, and 0.5 to 5.0 wt.% of Cu is coated on the activated carbon fiber by electroplating.

Description

Water treatment microgranules manufacturing method and ultra-fast water treatment process in the form of microspherical granules containing magnetite powder, eutrophic material and organic adsorbent

The invention of the eutrophication of water contamination in _{^{NH 4 +, NO 3 -,}} PO 4 -3 , and a water-soluble organic compounds and hazardous substances activated carbon, activated carbon fibers, Ca (OH) ₂ and magnetite is mixed with the particles It can be easily adsorbed using fine spherical granules, and the adsorbed environmental harmful substances can be separated at a high speed by magnetite. More specifically, activated carbon is used to adsorb nonvolatile and volatile organic substances dissolved in water. It is a fine spherical powder in which magnetite (Fe ₃ O ₄ ) is mixed with activated carbon fiber, and the activated carbon or activated carbon carbon fiber with a large specific surface area is coated with copper as a catalyst to increase the adsorption rate and increase the convenience of work. It should be composed of a fine spherical powder and a material and material for applying magnetic force to separate the adsorbed material at high speed by applying magnetic force. In particular, in order to easily remove nitrogen, phosphorus and toxic substances, which are eutrophic substances, and to improve adsorptive power, magnetite powder surface-modified with copper as a catalyst on activated carbon or activated carbon fiber surface and ultrafast water treatment powder manufacturing method using magnetic force and water treatment process It is about.

Many of the substances contained in groundwater, wastewater or sewage have insufficient purification effect in general treatment operations and processes. Various inorganic wastewater advanced treatment is required to remove inorganic salts and various inorganic materials and complex organic synthetic materials. Among these, compounds containing nitrogen and phosphorus have been studied since the 1960's, which causes eutrophication by accelerating plant growth, and especially nitric acid, which causes blue cyanosis of infants. .

In general, high nitrate concentrations can be lowered by fossils from nitrate sources. However, if it is difficult to use a low nitric acid source, the nitric acid removal reaction is required. Techniques that have been used to remove nitric acid include ion exchange resins, biological nitrification and denitrification, chemical reduction, reverse osmosis, and dialysis. Among them, the most practical and available processes for large-scale water purification are ion exchange resin and biological denitrification.

However, both processes have serious disadvantages. Among them, the ion exchange resin method is the best in terms of cost, but it is limited to the treatment of concentrated by-products and is therefore only possible in coastal areas or areas where there is no possibility of eutrophication. In addition, since a large amount of salt must be added, the operating cost is high and the characteristics of the water quality itself have a disadvantage of large corrosiveness. In general, the biological denitrification process is known to be the most economical without worrying about by-products, but there are also many problems to be solved, such as post-treatment, causing problems with carbon sources or sensitive control.

Ion exchange resins are basically physicochemical processes that require regeneration of cyclic resins. Periodic regeneration of the consumed resin may be performed using sodium chloride or sodium bicarbonate, but as a result, it must be reprocessed or discarded with high concentrations of nitric acid, sodium chloride or sodium bicarbonate. However, increasing environmental concerns and regulations in recent years have made it difficult to cleanly dispose of recycled materials, making the widespread application of this process difficult.

Chemical removal of nitric acid using iron hydroxide has been studied mainly in the United States. It is known that ferrous sulfate forms are the most economical among various reducing materials. Reduction of nitric acid with ferrous metals requires the use of 1 to 5 ppm copper or silver catalysts, with the best results at pH 8.0, but these conditions can be adjusted with lime or soda. Approximately 70% of the reactants are usually obtained with a gas of nitrogen or nitrogen oxides, the remainder being reduced to ammonia. This reaction has the disadvantage that it is difficult to reduce to complete nitrogen gas, and the use amount of ferrous metal is too large.

Biological denitrification is most widely used for the purification of waste water and septic tank effluents. Denitrifying bacteria reduce nitric acid to nitrogen gas when organic substrates are present. The most widely used substrates are methanol, which is inexpensive and effective. Biological denitrification using various types of filtration baths with bacterial supports has been studied. In particular, the time required for the growth of bacteria and the temperature of the reaction tank have a great effect on the efficiency, and there are control difficulties such as careful supply of methanol for sufficient consumption, and the blockage caused by the growth of microorganisms is periodic. It has the disadvantage that it can occur.

The main causes of phosphorus generation include domestic wastewater and agricultural return water. Phosphorus promotes the growth of aquatic plants, leading to eutrophication. Phosphorus in wastewater can be removed by 10% from conventional biological treatment as a primary treatment, but for further treatment only by precipitation of chemicals with insoluble chemicals. However, such drug additions result in an increase in dissolved solids.

In order to adsorb harmful organic substances known to the past in drinking water or wastewater, adsorption treatment should be generally performed by using activated carbon or activated carbon fiber having a large specific surface area after primary and secondary treatments. As described above, in the case of using the conventional method mentioned above, if the treatment period takes a long time, separation between the treated water and the adsorbent cannot be easily separated. When dealing with the technology developed so far, it is not only economically burdensome to have a large facility and a lot of manpower involved, but also has a disadvantage of not very high processing efficiency. In addition, in order to remove the water-soluble organics dissolved in water, most of the methods other than activated carbon or activated carbon fibers are rare, and even if there is a treatment method, the treatment efficiency is very low. Therefore, to remove harmful substances dissolved in water by using activated carbon or activated carbon fiber, it is sprayed in water and then adsorbed organic matter and separated to collect the activated carbon or activated carbon fiber dispersed in water. And the separation time also requires a considerable time.

In case of using such a conventional method, in order to treat huge contaminated water, not only a large amount of equipment cost and labor cost, but also a long processing time, and a large amount of material cost, are required to separate adsorbents and treated water such as activated carbon and activated carbon fiber. It takes a lot of time and has many problems economically.

Accordingly, an object of the present invention is to overcome the disadvantages of the water treatment adsorbents used up to now, to improve the adsorption capacity of volatile or non-volatile organic compounds in drinking water or wastewater, and to separate the adsorbed material at high speed, magnetite and specific surface area The surface of the activated carbon or activated carbon fiber is surface-modified and the catalyst of Cu is mixed with magnetite and binder to form spherical powder to improve the adsorption rate of nitrogen and phosphorus as well as water-soluble organic substances as well as adsorbed organic substances. By applying the magnetic force to the ultra-high speed to clean the contaminated water cleanly, and to process the separation of the adsorbed material by the magnetic material of magnetite very quickly, to overcome the disadvantage of the long-term treatment of wastewater treatment by the conventional method, clear water treatment To protect the health and natural environment of the people It can relieve lining.

Therefore, the present invention produces magnetite powder, calcium hydroxide powder and spherical granules surface-modified with copper on the surface of activated carbon or activated carbon fiber to adsorb the phosphorus and nitrogen, which is an eutrophic substance dissolved in aqueous solution, higher than the conventional method. It is characterized by consisting of a water treatment powder production method and a process that can be separated at a high speed by.

The purpose of the present invention overcome the disadvantages of the method for water treatment that use so far, and NH ₄ ⁺ in eutrophic substance, NO ₃ ^-, and PO ₄ ^-3, while increasing the efficiency of the adsorption process of the water-soluble organic compounds and hazardous substances so It is achieved by ultra-high-speed water treatment powder production method using surface modified adsorbent and magnetic force on fine spherical granules containing magnetite powder which can separate suspended solids in a short time.

Hereinafter, the present invention will be described in detail.

Example 1 (copper electroless plating on activated carbon surface)

The activated carbon powder of the present invention was purchased from Zeocarbon in Korea having a specific surface area (BET) of 1,000 m 2 / g on average, and electroless plating of copper (Cu) as a catalyst was used to improve the adsorption rate of ammonia nitrogen and phosphate. 0.1, 0.5, 2.0% by weight was coated on the surface of the activated carbon powder. Electroless copper plating for the present invention was carried out in accordance with Scheme 1, electrolytic plating according to Table 7. In the case of electroless plating, monobasic potassium-sodium copper complex salt and EDTA copper complex salt were used, and formalin was used as a reducing agent. Electroless copper plating may vary the plating amount and plating time according to the concentration of potassium / sodium copper complex and EDTA copper complex salts and the concentration of the reducing agent.

[Equation 1]

Cu ²⁺ -complex (copper ions) + 2HCHO (formalin) + 2NaOH →

Cu + 2HCOONa (sodium formate) + H ₂ + complex

Using sodium nitrate (1.3708 g / 1 L) and ammonium chloride (2.9712 g / 1 L) as nitric acid, make 1 liter at a concentration of exactly 1,000 ppm as ammonia, dilute to 1/10 and exactly 100 ml in a 250 ml Erlenmeyer flask. Were each aliquoted. 2 g of activated carbon coated on the surface of the activated carbon by electroless plating was added thereto, and then the lid was closed and shaken up and down ten times, and the supernatant was analyzed after standing. The adsorption rate of ammonia nitrogen was better than that of nitrate nitrogen, and the higher the plating amount of copper, the better the adsorption rate. The results are shown in Table 1.

Example 2 (copper electroplating on activated carbon fiber surface)

Activated carbon fiber was purchased from Degussa (foreign), and the specific surface area was 1,600 m 2 / g. In order to improve the adsorption rate of ammonia nitrogen and nitrate nitrogen, copper, which is a catalyst, was plated at 0.5, 2.0, and 5.0 wt% with electroplating in the case of activated carbon fiber. The conditions for electroplating are shown in Table 7. In the case of electroplating, the coating amount of copper may be varied according to the amount of copper sulfate, current density and plating time. Electron micrographs of Cu electroplated with activated carbon fibers are shown in photographs 1 and 2.

Using sodium nitrate (1.3708 g / 1 L) and ammonium chloride (2.9712 g / 1 L) as nitric acid, make 1 liter at a concentration of exactly 1,000 ppm as ammonia, dilute to 1/10 and exactly 100 ml in a 250 ml Erlenmeyer flask. Were each aliquoted. 2 g of activated carbon fibers coated on the surface of the activated carbon by electroplating were added thereto, and then the lid was closed, shaken up and down vigorously 10 times, and the supernatant was analyzed after standing. As in Example 1, the adsorption rate of ammonia nitrogen was better than that of nitrate nitrogen, and the higher the plating amount of copper, the higher the adsorption rate, and the higher the adsorption rate of copper coated on activated carbon fibers than the activated carbon. Indicated. This shows that the specific surface area of activated carbon fibers is higher than that of activated carbon, resulting in good adsorption rate. The results are shown in Table 2.

Example 3 (Phosphate Removal Experiment)

40, 65, 90 g of magnetite (Fe ₃ O ₄ ) and 60, 35, 10 g of calcium hydroxide were measured, respectively, and a mixed solution containing a solvent of one-component polyurethane and ethyl acetate (including 1 g of polyurethane). And then mixed uniformly, fine spherical granules were prepared using a tilted rotating plate of 0.1, 1.0, 2.0, 5.0 mm. The prepared spherical granules were heated in an oven at 135 ° C. for 30 minutes and then cooled slowly. The magnetite used was purchased by using Fe ₃ O ₄ for Merck having an average size of 1.0 μm.

Dissolve 1.2629 g of sodium hydrogen phosphate (NaH ₂ PO ₄ ) in 1 liter to make 1,000 ppm as PO ₄ , dilute to 1/10 and aliquot exactly 100 ml into a 250 ml Erlenmeyer flask. After adding 2 g of granulated fine particles of magnetite and calcium hydroxide to each other, the lid was closed, shaken up and down vigorously 10 times, and left to stand at high speed by accessing the permanent magnet to the lower part of the vitreous and analyzed for supernatant. The higher the content of magnetite, the faster the separation of layers by magnetic force, the higher the amount of calcium hydroxide, and the finer the granule size, the higher the removal rate of the phosphoric acid (PO ₄ ^-3 ) group. This can be explained by the easy formation of apatite by reaction with calcium hydroxide, the results are shown in Table 3. The concentrations of nitrate nitrogen, ammonia nitrogen, and phosphate were checked for adsorption rate using Metrohm Ion Liquid Chromatograph (ILC).

Example 4 (Adsorption Rate Experiment of Ammonia Nitrogen According to Adsorbent Size, Type of Activated Carbon, Addition of Calcium Hydroxide and Addition of Activated Carbon)

In order to confirm the availability of the industrial water treatment formulation, a solution of ammonia nitrogen, nitrate nitrogen, and 1,000 ppm of phosphate was diluted 1/10 to 100 ml each. Here, the adsorption rate of the spherical average size of the adsorbent, the type of activated carbon, the addition of calcium hydroxide, and the amount of activated carbon added was checked for ammonia nitrogen (Table 4), nitrate nitrogen (Table 5), and phosphate (Table 6). Other methods were carried out by similar methods from Examples 1 to 3. As a result of the experiment, the adsorption rate of activated carbon or activated carbon fiber coated with copper was better than that of activated carbon or activated carbon fiber not coated with copper, and the adsorption rate increased as the particle size was smaller and the addition amount was increased. It showed in 4-6.

Example 5 (Field Test)

Field tests were performed at the sewage treatment plant of Taeyoung Construction Co., Ltd. located in Gyeryong University, using the fine granules prepared in Example 3. 10 kg of the granulated granules were added to a 1.0 ton storage tank, and rotation mixing was performed for 1 minute using a mechanical rotating rod. After standing, magnets corresponding to 1,000, 2,000, and 3,000 gauss were used for permanent magnets, and layers were separated using electromagnets corresponding to 3,000, 5,000, and 10,000 gauss for electromagnets. In the case of permanent magnets, they were attached to the storage tank and separated, and the higher the magnetic force, the higher the separation rate. In the case of an electromagnet, it was mounted on a rotating rod and applied magnetic force whenever necessary. Electromagnets, like permanent magnets, were layered in tens of seconds at a very high rate of magnetic force. In the case of permanent magnets, it was easy to attach and detach them to the storage tank, but the separation of the layers took about 4 minutes due to the lack of magnetic force.

Until now, although various chemical and physical methods are used to remove environmental harmful substances and eutrophic substances, nitrogen or phosphorus dissolved in water, the treatment efficiency is insufficient and the processing time is required for a long time. As the facilities increase, so does the economic burden. Therefore, the surface-modified activated carbon or activated carbon fibers are used to adsorb and remove organic substances dissolved in water, but much time is required to separate the activated carbon or activated carbon fibers and the treated water contained in the water. As a result, water treatment costs are being greatly affected. In order to make the waste water quality below the environmental standard, the adsorption rate is low and the chemical and biological treatment is time-consuming due to the influence of the medium contained in the aqueous solution. In particular, organic substances in water should be extracted using an adsorbent with good adsorption rate because it can cause an increase in chemical oxygen demand (COD). In addition, in order to treat a large amount of water, such as a plant or a sewage treatment plant, a large amount of storage and a large amount of time are required for the conventional methods. It is causing trouble.

As described above, the present invention contains activated carbon or activated carbon fiber, calcined lime, magnetite powder of water-soluble organic substance contained in aqueous solution of nitrogen, phosphorus as well as eutrophic material, and the surface-modified with copper catalyst is prepared as microspherical granules. The present invention relates to a manufacturing method and a process for easily separating and removing treated water and water treatment powder at high speed using magnetic force, and through surface modification of Cu on the surface of the powder, ammonia nitrogen, nitrate nitrogen, phosphate, and water-soluble harmful substances. By increasing the adsorption rate of substances, it is possible to reduce the chemical oxygen demand and to reduce the fatal damage to the human body. By using magnetic material of magnetite, it is possible to treat harmful substances adsorbed on spherical granules in a very short time. This reduces the possibility of downsizing and waste of manpower, creating a cleaner environment, The cost is very effective in reducing chemical oxygen demand and reducing algae.

Claims (4)

It contains 10 to 80% by weight of magnetic material of magnetite, 15 to 60% by weight of adsorbent coated with activated carbon or activated carbon fiber in 0.1 to 5.0% by weight, and 4 to 29% by weight of slaked lime, A one-component polyurethane contains less than 1.0%, forms a size of 0.1 to 5.0 mm, it is heated at a temperature of 135 ℃ or less within 30 minutes to form a solid microgranules, ultra-fast water treatment microgranules manufacturing method. In claim 1, the specific surface area of the activated carbon or activated carbon fiber has 1,000 to 1,600 m 2 / g, and in the case of activated carbon, 0.1 to 2.0% by weight of Cu by electroless plating, and Cu by electroplating when activated carbon fiber is 0.5 to 5.0% by weight of the ultrafast water treatment fine granules manufacturing method. Eutrophication material of NH ₄ ^+, NO ₃ ^- a water treatment process in which, PO ₄ ^-3 naejineun remove the water-soluble fine powder, the fine granules adsorbed organic material by applying magnetic force absorption speed. The water treatment process of claim 3 in the case of permanent magnets 1,000 to 3,000 gauss, electromagnets to apply a magnetic force of 3,000 to 10,000 gauss to separate the adsorbed fine powder at high speed.