KR100578408B1 - Method of Denitrification Using Anearobic Granule Sludge - Google Patents

Abstract

The present invention relates to a method for removing nitrogen from wastewater by the Anamox process using anaerobic granule sludge.

Nitrogen removal method according to the present invention is more economical by using the Anamox process, and can be used for anaerobic granule sludge of the waste water treatment tank of the beer factory as anaerobic granule sludge has the advantage that resources can be recycled.

Nitrogen Removal, Anamox Process, Anaerobic Granule Sludge

Description

Method of Denitrification Using Anearobic Granule Sludge}             

Figure 1 shows a schematic diagram of the Anamox process consisting of an upflow anaerobic sludge blanket (UASB) process filled with anaerobic granule sludge.

FIG. 2 is a graph showing the behavior of nitrogen in an upflow anaerobic sludge blanket (UASB) reactor.

The present invention relates to a method for removing nitrogen from wastewater by the Anamox process using anaerobic granule sludge.

In today's wastewater treatment, the removal of nitrogen is of great importance. Developed countries have long been concerned and regulated their emissions due to eutrophication, dissolved oxygen consumption, and direct toxicity to aquatic life when nitrogen is released into the water environment. The removal of nitrogen from the wastewater is mainly carried out by biological methods. The nitrogen removal process is more complicated than the existing organic removal process and the cost of energy and denitrification required for aeration are more complicated. Due to the high processing cost is a lot of economic burden. Therefore, much attention has been paid to improving existing nitrogen removal processes or developing new concepts.

Classically, the removal of ammonia nitrogen from waste water is characterized by the nitrification of ammonia to nitrite ions (NO2-) and nitrate ions (NO3-) by nitrifying microorganisms ( Nitrosomonas , Nitrobacter, etc.) and nitrate ions by heterotrophic microorganisms. Has been described as a denitrification (reduction) reaction to nitrogen gas (N2). Recently, however, many new biological nitrogen removal mechanisms that can occur in wastewater treatment plants have been announced. It can be summarized as anaerobic denitrification, heterotrophic nitrification, anaerobic ammonium oxidation, autotrophic denitrification, and the like. These new findings have complicated the assessment of nitrogen removal from activated sludge. Although the observations in the actual treatment system and the literature on the microbiological nitrogen metabolism conducted in the laboratory have reported the above-mentioned unusual nitrogen removal phenomenon, it is difficult to obtain the exact nitrogen balance (including gaseous N ₂ generation). It is not easy to prove this.

In the case of developed countries, the recent research on nitrogen removal, which is being carried out in practical terms, can be summarized into two categories. The first relates to a method of simultaneously causing nitrification and denitrification in one reactor, in which case ammonium is used as an electron donor, whereby nitric acid or nitrite ions can be denitrated without an external electron supply. The second is about nitrification and denitrification using the nitrite pathway without ammonium being oxidized to nitric acid. As shown in the following reaction path, ammonium is oxidized to nitrous acid and then directly reduced and denitrified in nitrous acid, so much research has been conducted in this field.

When ammonia is removed by the nitrous acid route, oxygen consumption of about 25% can be reduced in the aerobic nitrification step, and in the denitrification step, the required amount of electron donor, which is a carbon source, can be reduced by 40%, which is very economical. In addition, the use of nitrous acid reported that the denitrification rate is 1.5 to 2 times faster than that of nitric acid.

Currently, the method using biological nitrification / denitrification mechanism is most commonly applied in Korea than the physicochemical treatment method, and the research and technology development are very active, but most of the research and development methods adopt the technology of advanced countries and return rate It is a situation that the development of the degree of technology to increase the nitrification efficiency by increasing the additional or installing a reaction tank or by administering a carrier to the reaction tank. On the other hand, the process of nitrifying and denitrifying only nitrite nitrogen to wastewater with low C / N ratio, wastewater treatment using membrane, nitrogen / phosphor removal using Bacillus species, and nitrogen / phosphor removal using intermittent aeration were developed. Although it is commercially available, its mechanism has not been clearly identified. Therefore, it is urgent to develop a systematic and comprehensive treatment system capable of simultaneously removing organic matter, nitrogen and phosphorus for wastewater treatment.

Accordingly, the present inventors have made diligent efforts to develop a more economical and efficient method for removing nitrogen. As a result, the present inventors have confirmed that the Anamox process using anaerobic granule sludge of a wastewater treatment tank of beer factory can remove nitrogen efficiently and effectively. It was completed.

It is an object of the present invention to provide a method for removing nitrogen from wastewater by an anamok process using anaerobic granule sludge.

In order to achieve the above object, the present invention (a) 10 ~ 200mg NH ₄ ⁺ -N obtained in the anaerobic treatment tank of beer factory wastewater, and filled with anaerobic granule sludge containing Brocadia anammoxidans and / or Kuenenia stuttgartiensis A first step of introducing a wastewater containing ammonia at a concentration of / L and a nitrite at a concentration of 10 to 500 mg NO ₂ ^-- N / L, while maintaining a hydraulic residence time of about 1 day, (b) containing ammonia and nitrite sikidoe introducing the waste water, the reactor within the COD / nO ₂ ^- and the second step without ammonia and (c) the supply of carbon to the proportion of -N supplying the carbon source to be about 1, maintaining the hydraulic retention time of about 5 days The present invention provides a method for removing nitrogen from wastewater using an anoxix process, wherein the wastewater containing nitrous acid is introduced, and the third step of maintaining the hydraulic residence time is about 3.5 days.

In the present invention, the reactor may be characterized as an anaerobic baffled reactor (ABR), an upflow anaerobic sludge blanket (UASB), or a variant thereof.

delete

 The present invention fills the anaerobic granule sludge developed well in the anaerobic treatment tank of the beer manufacturing plant in the UASB (upflow anaerobic sludge blanket) reactor, the wastewater with high ammonia nitrogen and nitrate nitrogen concentration flows into the reactor, the organic matter is The present invention relates to a technique for inducing denitrification in a deficient state. The present invention relates to a wastewater treatment process for maximizing organic matter reduction and denitrification, and to a method for smoothly operating a biological treatment process in a wastewater treatment plant, ensuring stable water quality, and preventing water pollution in public waters.

As described above , the discovery of anamorphic bacteria ( Brocadia anammoxidans, Kuenenia stuttgartiensis ) , a denitrifying microorganism that removes nitrogen in the presence of ammonia nitrogen and nitrate nitrogen, without the use of organic matter , has resulted in a worldwide shift around Europe. It is spurring process development using bacteria. However, due to the low growth rate of anoxix bacteria and the sensitivity of nitrite nitrogen, it is difficult to cultivate pure animox bacteria and it is difficult to selectively isolate and cultivate this strain from existing activated sludge. Except for European countries, it is difficult to develop technology based on this strain.

Therefore, the present inventors have developed a method for finding an indigenous Anamox bacteria of Korea and applied it to the process. As a result, we discovered the presence of Anamox strain in well-developed anaerobic granule sludge in the anaerobic treatment tank of beer factory and studied the technology for culturing the granule sludge.

The denitrification of the wastewater by the Anamox process using the Anamox strain was carried out in the existing advanced bioprocessing process (by shearing the reactor according to the division of the biological treatment tank or by splitting and supplying the influent and external carbon source to each reactor). Reasons superior to denitrification are as follows. In the existing process, even if the calculated amount of organic matter required for denitrification is introduced into the biological treatment tank according to the operation method and characteristics of the reactor, the denitrification rate is affected by the change in influent properties, making it difficult to secure operational stability. In the Anamox process, residual organic matter in the biological treatment tank of the front end is almost consumed, and excess nitrogen nitrate and residual ammonia nitrogen are contained, so that denitrification can be stably performed without supplying organic matter. According to the present invention, it is possible to stably cultivate the anamok strain showing the anamoks phenomenon from anaerobic sludge which can be easily obtained, and thus it is expected to enable economic treatment of wastewater containing nitrogen.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not to be construed as being limited by these examples.

Example

(1) The composition of artificial wastewater

Table 1 shows the composition of the artificial wastewater used in the present invention.

Characteristics of the artificial wastewater of the present invention (unit: mg / L, pH is not a unit) ingredient range pH 7.4-8.2 (NH ₄ ) ₂ SO ₄ 235.75 NaNO ₂ 246.5-739.5 KHCO ₃ 500 KHPO ₄ 27.2 CaCl ₂ 2H ₂ O 180 MgSO ₄ 7H ₂ O 120 Fe solution One Trace metal solution One

(2) UASB process operation filled with anaerobic granules

Experimental apparatus used in the present invention was made of 6L stainless steel, the schematic is as shown in FIG. The experimental apparatus was configured by filling anaerobic granules taken from the treatment plant of a beer factory in a UASB reactor including an inlet, an outlet, an internal return port, a gas and a sampling port. The temperature of the reactor was maintained at 35 ° C., and the return was maintained at three times the rate of influent to prevent deactivation of microorganisms by high concentration of nitrous acid.

Three different conditions were applied to the anamorphic strain expression in anaerobic granule sludge. In the first stage, the concentration of ammonia in the influent was 50 mg NH ₄ ⁺ -N / l and the concentration of nitrite was 50-150 mg NO. _The reactor was maintained at ₂ ^-- N / l and the hydraulic residence time of the reactor was maintained at 1 day.In the second stage, the carbon source was supplied at the ratio of COD / NO ₂ ^-- N = 1 while maintaining the concentration of the nitrogen source as in the first stage. The hydraulic residence time was maintained at 5 days, and the third stage was operated at 3.5 days, excluding the supply of carbon sources, while maintaining the concentration of nitrogen sources such as stage 1,2.

(3) operation performance

Figure 2 shows the behavior of nitrogen in the UASB reactor during the operation period. In the initial period of operation, the concentration of ammonia in the reactor rose to 130 mg / l, but this was probably due to the release of ammonia nitrogen present in the anaerobic granule sludge. It was lowered to the same level as the concentration of. The concentration of ammonia nitrogen began to drop significantly after 186 days of reactor operation, and it was confirmed that nitrous acid nitrogen began to drop at the same time as the reduction of ammonia nitrogen occurred.

In order to check on Ana Comox phenomenon was used for sampling, (Fluorescence in situ hybridization) FISH method for the strain in the reactor, test results, micro-organisms involved in Ana Comox phenomenon was confirmed by Brocadia anammoxidans, Kuenenia stuttgartiensis turned out in Europe.

Having described the specific part of the present invention in detail, it is obvious to those skilled in the art that such a specific description is only a preferred embodiment, thereby not limiting the scope of the present invention. something to do. Therefore, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

The present invention has the effect of providing a method for efficiently removing nitrogen from the wastewater by the Anamox process using anaerobic granule sludge.

Nitrogen removal method according to the present invention is more economical by using the Anamox process, and can be used for anaerobic granule sludge of the waste water treatment tank of the beer factory as anaerobic granule sludge has the advantage that resources can be recycled.

Claims (5)

A method for removing nitrogen from wastewater using the Anamox process, characterized by the following steps: (a) 10-200 mg NH ₄ ⁺ -N / L ammonia and 10-500 mg NO in a reactor filled with anaerobic granule sludge obtained from an anaerobic treatment tank of brewery wastewater and containing Brocadia anammoxidans and / or Kuenenia stuttgartiensis Introducing a wastewater containing ₂ ^-- N / L nitrous acid at a concentration of about 1 day; (b) the reactor within the COD / NO ₂ sikidoe introducing the wastewater containing ammonia and nitrite, ^- a second step of supplying a carbon source such that the ratio of -N about 1 and maintains the hydraulic residence time of about 5 days; And (c) a third step of maintaining the hydraulic residence time at about 3.5 days, while introducing wastewater containing ammonia and nitrous acid without supplying a carbon source; delete The method of claim 1, wherein the reactor is an anaerobic baffled reactor (ABR), an upflow anaerobic sludge blanket (UASB), or a variant thereof. delete delete

Images