KR100520133B1 - Agent for Denitrification of Wastewater and method for preparing thereof - Google Patents

Abstract

The present invention relates to a nitrogen remover for removing inorganic nitrogen from waste water and a method for preparing the same, wherein the nitrogen remover composition comprises an organic solvent of N, N-dimethylacetamide (DMAc) and chlorinated active cellulose mercurized with sodium hydroxide. Nitrogen remover according to the present invention, characterized in that consisting of 70 to 95 parts by weight of the cellulose derivative treated with lithium (LiCl) as a catalyst and 5-30 parts by weight of zirconium hydroxide, the nitrogen removing agent according to the present invention is a cellulose and a plant fiber Zirconium hydroxide, which has strong ion exchange effect, is used as the main raw material, and shows excellent nitrogen removal effect only once in the waste water, and the amount used by nitrogen removal efficiency is inexpensive and economical compared to the conventional biological treatment cost, and storage and transportability There is a good advantage.

Description

Nitrogen remover for wastewater treatment and its manufacturing method {Agent for Denitrification of Wastewater and method for preparing

The present invention relates to a nitrogen remover for removing inorganic nitrogen from wastewater and a method for producing the same. Specifically, nitrate nitrogen and nitrite nitrogen dissolved in wastewater using cellulose as a main raw material for purifying various industrial wastewater and livestock wastewater. And an environmentally friendly nitrogen remover which effectively removes ammonia and the like by one treatment and does not require secondary additional treatment, and a method for producing the same.

Due to the development of industry, the harmfulness of pollution to humans and the environment surrounding human beings is getting serious day by day, and various environmental organizations and individuals are working on industrial activities together with efforts to reduce the occurrence of pollution to the natural environment and human environment. It is recognized as an important task or effort to effectively treat and reduce industrial wastes that occur.

There are many kinds of industrial wastes, such as waste acid, waste alkali, waste organic materials, waste oil, sludge, waste asbestos, waste pesticides, waste synthetic polymers, and the like. Required.

Nitrate and ammonia nitrogen compounds in various industrial wastewaters generate color and odor of wastewater, cause harmful gas and eutrophication, and increase the chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of wastewater. .

In addition, recently generated wastewater contains hardly degradable contaminants which are not easily decomposed and removed by conventional primary treatment. Accordingly, secondary, tertiary and quaternary additional treatments are performed according to the amount and type of contaminants. There are frequent cases that must be done.

In particular, the problem of nitrogen removal to remove harmful nitrogen compounds, ie, nitrate nitrogen, nitrite nitrogen, and ammonia nitrogen components, dissolved in various industrial wastewater, livestock wastewater, and untreated sewage requires expertise and facilities. Pay close attention to the device and operation.

Examples of such inorganic nitrogen removal methods include ion exchange resin methods, decomposition and removal methods using microbial strains, and separation by reverse osmosis.

Korean Patent Publication No. 276250 discloses phosphorus and nitrogen removing agents using hypochlorous acid, and Korean Patent Publication No. 98-61276 discloses chitosan-phthalocyanine-based compositions, and Korean Patent Publication No. 95-16788 discloses nitrogen using microbial strains. There is a known method of removal, and Korean Patent Publication No. 2002-24184 discloses a nitrogen scavenger composition containing sodium hypochlorite and sodium chlorite, sodium carbonate, sodium sulfate and the like. However, the inorganic nitrogen removal has a low efficiency to completely decompose and remove the contaminant, and there is a case that secondary pollution occurs due to the large amount of nitrogen remover added.

Nitrogen in untreated sewage or waste water is mainly in the form of dissolved and particulate ammonia or organic nitrogen, and dissolved organic nitrogen is mainly in the form of urea and amino acids. During biological treatment, most of the particulate organic nitrogen is converted to ammonium and other inorganic nitrogen forms, and some of the ammonium is assimilated into cellular material in vivo, but most of the nitrogen in the treated secondary effluent remains in the form of ammonium. Therefore, the processing process up to now, such as the conversion of ammonia nitrogen to nitrate nitrogen by biological nitrification and the nitrogen removal method by physicochemical method, should be carried out in multiple stages as the nitrogen conversion and its removal process.

Nitrifying bacteria are sensitive microorganisms, and they are particularly sensitive to various metabolic inhibitors, and high concentrations of organic and inorganic substances such as ammonia and nitrous acid can inhibit the growth and activity of these microorganisms. There is a limitation that the concentration or the like should be appropriate.

Conventional main physicochemical processes used to remove nitrogen include air stripping, breakpoint chlorination and selective ion exchange, which are temperature sensitive in the case of air degassing. And the solubility of ammonia and air requirements are variable, causing fog and ice in the winter season, air pollution may be caused by the reaction of ammonia and hydrogen sulfide, and there are problems such as deposition of carbonic acid scale and perfusion. .

 The breakdown point chlorine injection method increases the concentration of residual chlorine, which is toxic to aquatic organisms, and the formation of trihalomethane greatly affects the water quality of the constant source, and requires careful pH adjustment to prevent ammonia gas formation. There is a problem that an experienced driver is required.

In the case of selective ion exchange, pretreatment by filtration is usually required to prevent excessive head loss due to accumulation of suspended solids, high concentrations of other cations reduce the ability to remove ammonia, and additional unit processes during resin regeneration and recovery, ie The disadvantage is the need for a gas stripping process.

Therefore, there has been a need for a nitrogen removing agent capable of treating nitrogen more simply and reliably, overcoming the problems of the conventional technology as a nitrogen removing technology requiring a high degree of expertise and attention as compared to a general wastewater treatment process. The present inventors have completed the present invention as a result of repeated studies on the nitrogen removing agent in response to these demands.

Accordingly, it is an object of the present invention to provide a nitrogen scavenger composition and a method for producing the nitrogen scavenger which exhibits an excellent effect of nitrogen removal with only a single administration with strong ion exchange.

In detail, the object of the present invention is to eliminate the nitrogen by flocculation and sludge by only one administration, so that no special management is required, and the water quality management of the treated wastewater is easy and the process management and the operation of the wastewater treatment system are convenient. The present invention provides a new nitrogen scavenger composition and a method of manufacturing the same, and the product properties are gray brown fine powder, which is easy to transport and has excellent long-term integrity, and is easy to distribute. To provide.

In addition, another object of the present invention is a complex reaction of ion exchange reaction and selective adsorption reaction is excellent in the removal effect of nitrogen, clean water properties of the waste water is clean, clean, high TDS removal is essential for water treatment engineering Expected effect is large, nitrogen removal agent composition and its manufacturing method which is expected to have a great effect in the animal industry or environmental pollution prevention by simply removing nitrogen from high concentration and organic nitrogen wastewater such as livestock wastewater and manure wastewater with high cost To provide.

Hereinafter will be described in detail with respect to the nitrogen-removing agent composition of the present invention and its preparation method for achieving the object as described above.

Nitrogen scavenger composition of the present invention is a cellulose derivative 70 to 95 treated by treating active cellulose mercerized with sodium hydroxide using an organic solvent of N, N-dimethylacetamide (DMAc) and lithium chloride (LiCl) as a catalyst It is characterized in that the nitrogen removal agent composition composition for wastewater treatment, characterized in that consisting of 5 parts by weight and 5-30 parts by weight of zirconium hydroxide.

Cellulose, which is a major component of the nitrogen scavenger composition of the present invention, is an industrially important resource as an organic compound present in a large amount following coal in nature. In particular, unlike the conventional chemical physical nitrogen treatment agent itself was a secondary pollutant, cellulose is a plant fiber, because it does not itself become a pollutant, secondary processing is unnecessary.

The cellulose derivative, which is a main component used in the present invention, reacts the active cellulose mercurized with sodium hydroxide with an organic solvent of N, N-dimethylacetamide (DMAc) using lithium chloride (LiCl) as a catalyst, followed by vaporization and condensation. It is prepared by making. In this process, mercurized cellulose is hardly dissolved in an organic solvent, but is dissolved by adding lithium chloride as a catalyst together with N, N-dimethylacetamide (DMAc) and stirring for 10 hours or more.

The nitrogen scavenging agent according to the present invention is composed of 70 to 95 parts by weight of the cellulose derivative and 5 to 30 parts by weight of zirconium hydroxide (ZrO (OH)) having excellent ion exchange efficiency, and preferably 80 to 95 parts by weight of the cellulose derivative. Part and 5 to 20 parts by weight of zirconium hydroxide (ZrO (OH)), 90 parts by weight of the cellulose derivative and 10 parts by weight of zirconium hydroxide (ZrO (OH)) is most preferred.

Nitrogen remover of the present invention is prepared by the following method.

1) 5 to 10 parts by weight of mercerized active cellulose powder is placed in a reactor, and 0.1 to 0.3 parts by weight of lithium chloride as a catalyst is added to the reactor together with 300 to 500 parts by weight of DMAc as an organic solvent, maintaining the temperature of the reactor at 90 ° C. The reaction was carried out for 12 hours to prepare a cellulose derivative solution.

2) 70 to 95 parts by weight of the cellulose derivative and 5 to 30 parts by weight of zirconium hydroxide powder are added to a reaction tank, heated to about 40 ° C. for reaction for about 3 hours, and left for a predetermined time.

3) 5 to 20 parts by weight of ethyl alcohol is added to the prepared reaction mixture, the mixture is stirred at 50 to 60 rpm at room temperature, gelled, and selectively pulverized wet or dry to prepare the nitrogen scavenger composition of the present invention.

Nitrogen remover according to the present invention can be used in a similar manner to the method of adding the wastewater treatment agent in a conventional wastewater treatment method.

The amount of nitrogen removal agent varies depending on the wastewater, but the effective nitrogen removal effect can be obtained by a single dose of about 0.05 to 1g per liter of wastewater to be treated based on the conventional wastewater. Due to the flocculation effect of the nitrogen removing agent after the addition to the wastewater, the wastewater is separated into the supernatant and the sediment, and the sediment can be separated by a conventional method.

The present invention can be easily understood and practiced by those skilled in the art without a separate embodiment, but as an example for illustrating the present invention described through the following examples, the present invention is as follows. Of course, it is not limited to only.

Example 1

Preparation of Cellulose Derivative Solution

8.0 kg of mercured activated cellulose powder of 150 mesh was weighed into a reactor, and 160 g of lithium chloride as a catalyst and 400 kg of DMAc as an organic solvent were weighed and reacted for 12 hours while maintaining the temperature at 90 ° C. Was prepared.

Preparation of Nitrogen Scavenger

9Kg of the cellulose derivative solution prepared by the above method and 1 kg of zirconium hydroxide powder were placed in a reactor, heated to about 40 ° C. for reaction for about 3 hours, and the reaction solution was vaporized and condensed. This was allowed to stand for a certain time, and then 10 kg of ethyl alcohol was added thereto, followed by gelation by stirring at 50 to 60 rpm with a mixer at room temperature. The nitrogen-removing composition mainly composed of cellulose and zirconium hydroxide thus obtained was pulverized dry and passed through a 150-mesh sieve to obtain a nitrogen-removing composition of the present invention in the form of grey-brown fine powder.

Example 2

A nitrogen scavenger composition was prepared in the same manner as in Example 1 except that the cellulose derivative solution prepared in Example 1 and the zirconium hydroxide powder were used in a weight ratio of 8.5: 1.5.

Example 3

Example of Wastewater Treatment Using Nitrogen Remover According to the Present Invention

In order to evaluate the performance of the nitrogen scavenger compositions prepared in Examples 1 and 2, 1 L of a wastewater stock solution containing 372.4 ppm of nitrate nitrogen was placed in a 2 L beaker, and 500 mg of the compositions prepared in Examples 1 and 2 were added. After stirring for 1 hour at 40 rpm with a stirrer, the supernatant and sediment were separated, the supernatant was taken, and the total nitrogen remaining before and after treatment was measured by an elemental analyzer.

The total nitrogen removal rate before and after treatment of the wastewater by the addition of the nitrogen scavenger composition prepared in Example 1 was removed about 96.6% from 372.4 ppm to 12.5 ppm after 1 hour, and the nitrogen scavenger composition prepared in Example 2 was added. The total nitrogen removal rate before and after the treatment of the wastewater was removed by 96.2% from 372.4 ppm to 14.2 ppm.

As a result, it was found that the nitrogen remover according to the present invention has a very effective nitrogen removal effect on organic nitrogen and nitrified nitrogen compounds by strong ion exchange and selective adsorption reaction. It has been shown to have an excellent effect of removing significant amounts of nitrogen.

As described above, the nitrogen removing agent composition according to the present invention, unlike the conventional nitrogen treatment agent by using cellulose which is a plant fiber as a main raw material, does not cause pollution by itself, and thus no additional treatment is required after treatment. There is an advantage to clean the waste water environmentally friendly.

In addition, the nitrogen remover composition of the present invention can effectively remove nitrogen from various industrial wastewater by using zirconium hydroxide as a main raw material, with a strong ion exchange effect, and shows an excellent nitrogen removal effect with only one input, so the amount used for each nitrogen removal efficiency is high. Inexpensive and economical compared to conventional biological treatment costs.

In addition, the nitrogen remover composition of the present invention is a high source of pollution and solves the problems of high cost and refractory livestock wastewater, which has a great effect in terms of preventing livestock industry or environmental pollution, and the water quality management of the treated water facilitates process management and wastewater. The operation of the treatment system becomes convenient, and coagulation and sludgeization proceed in one dose, so that there is no effect of requiring special management in the nitrogen removal process.

In addition, the nitrogen-removing composition of the present invention has the advantage that it is easy to store and transport in the form of grey-brown fine powder, and easy to store and distribute because of excellent long-term storage.

Claims (4)

70 to 95 parts by weight of a cellulose derivative treated with an organic solvent of N, N-dimethylacetamide (DMAc) and lithium chloride (LiCl) as a catalyst and 5-30 parts by weight of zirconium hydroxide Nitrogen remover for wastewater treatment, characterized in that made. The nitrogen removal agent for wastewater treatment according to claim 1, which is 80-95 parts by weight of the cellulose derivative and 5-20 parts by weight of zirconium hydroxide powder. a) adding 5 to 10 parts by weight of mercured active cellulose powder into a reactor and adding 0.1 to 0.3 parts by weight of lithium chloride as a catalyst to the reactor together with 300 to 500 parts by weight of DMAc as an organic solvent to prepare a cellulose derivative solution; b) adding 70 to 95 parts by weight of the cellulose derivative solution and 5 to 30 parts by weight of zirconium hydroxide powder to a reactor and then heating the reaction; c) adding to 5 to 20 parts by weight of ethyl alcohol to the prepared reaction mixture, stirred at room temperature with a mixer, gelled, and pulverized in a wet or dry manner. 4. The method of claim 3, wherein in step b), 80-95 parts by weight of the cellulose derivative and 5-20 parts by weight of zirconium hydroxide powder are added.