• KSBB Journal
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• v.10 no.2
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• pp.170-175
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• 1995

The effect of nitrogen source on production of a high viscosity exopolysaccharide, methylan, from methanol by Mentylobacterium organophilum was investigated in fed-batch culture. During the fermentation, cells continued to grow even after the nitrogen source added to the medium was depleted and methylan production was stimulated under the condition which ammonium ion was depleted. Cell growth increased proportionally to the initial concentration of ammonium ion in the medium, but methylan production was significantly inhibited at the high concentration of ammonium ion. As the initial concentration of ammonium ion increased, the specific growth rate, the specific product formation rate and the specific substrate consumption rate decreased due to the inhibitory effect of excess ammonium ions. In order to reduce the inhibitory effect by high concentration of ammonium ion. The control of ammonium ion concentration within the desired level(usually $0.45g/\ell$) was necessary. When ammonium ion concentration was maintained below $0.15g/\ell$ by exponential feeding, methylan production could be increased up to $12.5g/\ell$.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.45-52
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• 2013

In this study, we had analyzed the ammonia removal efficiency in sea animal-culturing aquarium water using hypochlorous acid (HOCl) which is very reactive, no harm to human, and with no formation of toxic trihalomethane. The amount of hypochlorous acid for the removal of ammonia varied with the concentration of ammonia in samples, with 90% of removal efficiency for 30 minute reaction time in the sea water where the ratio of hypochloous acid to ammonia (w/w) is about 8.5 ~ 9.0, and 100% removal in the sample with the ratio of 9.8 ~ 10.1. The removal efficiency with the time was shown to be 90% within 10 minute in the ratio of 9.0 ~ 10.0. These results will effectively be used for the proper management and protection of sea animals in large aquarium through water clarification with hypochlorous acid by calculating the right amount and reaction time.

• Clean Technology
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• v.13 no.1 s.36
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• pp.16-21
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• 2007

This study estimated the effect of hydraulic residence time(HRT), influent total ammonia nitrogen(TAN) concentration, temperature and pH in the packed-bed bioreactor using immobilized nitrifiers. Removal rate of ammonia nitrogen was increased with decreasing HRT and the optimum HRT was 0.2 hour when influent TAN was $2g/m^3$. At this point, removal rate was $226.1\;g/m^3{\cdot}day$ and removal efficiency was 88.8%. Removal rate of ammonia nitrogen was Increased with increasing TAN concentration. Removal rate and efficiency of ammonia nitrogen were kept constant at $20{\sim}35^{\circ}C$ and pH $8{\sim}9$ value.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.05a
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• pp.183-187
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• 2003

신천에 금호강물을 혼합한 이후의 수질개선에 대한 효과를 알아보기 위해 수질조사를 하였다. 3월부터 9 개월 동안 신천의 물을 측정한 결과 부유물질의 농도는 1.2mg/$\ell$~18.7mg/$\ell$의 범위로 나타났으며, 상동교 지점에서 금호강물 유입이 시작된 5월 말부터 측정한 부유물질의 농도는 2.8mg/$\ell$~8.6mg/$\ell$의 범위로 나타내었다. 생화학적산소요구량의 농도는 0.6mg/$\ell$~7.9mg/$\ell$의 범위로 나타났으며, 상동교 지점에서 5월 말부터 측정한 생화학적산소요구량의 농도는 2.9mg/$\ell$~7.2mg/$\ell$의 범위로 나타났다. 무태교 지점에서 생화학적산소요구량의 농도는 3.6mg/$\ell$~5.6mg/$\ell$의 범위로 높았다. 암모니아태 질소의 농도는 0.12mg/$\ell$~0.79mg/$\ell$~의 범위로 나타났으며, 상동교 지점에서 5월 말부터 측정한 암모니아태 질소는 0.15mg/$\ell$~0.67mg/$\ell$~의 범위로 나타났다. 무태교 지점에서의 암모니아태 질소의 농도는 0.43mg/$\ell$~0.79mg/$\ell$의 범위이었다. 총인의 농도는 0.16mg/$\ell$~l.12mg/$\ell$의 범위로 나타났으며, 상동교 지점에서 5월 말부터 측정한 암모니아태 질소의 농도는 0.33mg/$\ell$~0.88mg/$\ell$~의 범위로 나타났다. 무태교 지점에서의 총인의 농도는 0.52mg/$\ell$~0.99mg/$\ell$~의 범위이었다. 신천에 금호강물을 혼합한 이후에도 부유물질, 생화학적산소요구량, 암모니아태 질소, 총인 등의 농도가 개선되지 않았다. 즉 금호강물의 혼합은 신천수질환경사업소에서 배출되는 방류수에 함유되어 있을 2차 오염물질의 희석이라는 이점외의 수질개선효과는 확인되지 않았다.

• Clean Technology
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• v.29 no.4
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• pp.297-304
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• 2023

The rapid advancement of the high-tech electronics industry has led to a significant increase in high-concentration ammonia wastewater. Various methods have been attempted to reliably treat wastewater containing high concentrations of ammonia, but no successful technology has yet been developed and applied. In this study, the removal efficiency and characteristics of ammonia nitrogen was evaluated according to changes in temperature, air loading rate, and liquid loading rate using a closed circulation countercurrent packed tower type demonstration facility for wastewater containing high concentrations of ammonia generated in the high-tech electronics industry. The temperature was varied while maintaining operating conditions of a wastewater flowrate of 20.8 m³ h^-1 and an air flow rate of 18,000 Nm³ h^-1. The results showed that at temperatures of 45,50,55, and 60℃, the removal efficiencies of ammonia nitrogen (NH₃-N) were 87.5%, 93.4%, 96.8%, and 98.7%, respectively. It was observed that temperature had the most significant impact on the removal efficiency of NH₃-N under these conditions. As the air loading rate increases, the removal rate also increases, but the increase in removal efficiency is not significant because droplets from the absorption tower flow into the stripping tower. Even if the liquid loading rate was changed by ±30%, the removal rate did not change significantly. This does not mean that the removal rate was unaffected, but was believed to be due to the relatively high air load rate. Through demonstration research, it was confirmed that ammonia stripping is a reliable technology that can stably treat high-concentration ammonia wastewater generated in the high-tech electronics industry.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.363-366
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• 2003

본 연구는 membrane bioreactor (MBR)을 질산화 위주로 운영하면서 질소폐수 처리 과정에서 나타나는 MBR의 운전특성 및 처리효율을 검토하고, 아울러 경제적인 질소처리 방법인 아질산화를 유도하기 위한 조건을 탐색하는 것이다. 반응기의 유효부피 8 L, 체류시간을 12시간으로 고정하고 유입폐수 중의 암모니아 농도를 증가시키는 방법으로 암모니아 부하를 $2\;kg/m^3{\cdot}day$까지 증가시켜 보았다. 운전 중반부에 이유를 명확히 알 수 없는 슬러지의 활성 저하 기간을 제외하고는 거의 98% 이상의 질산화 효율을 나타냈으며, 2 kg 이상의 암모니아 부하에서는 효율이 감소하였다. pH 조절, 유입수의 암모니아 농도 및 부하 조절에 의해 MBR 내의 free ammonia (FA) 농도를 변화시켜, FA 저해에 의한 유도한 아질산화는 매우 불안정하게 이루어졌다. 반면에, 공기 공급량을 변화시켜 반응기 내의 DO를 낮추는 방법으로 유도한 아질산 축적은 안정적인 경향을 보여 MBR에서 적절한 운전전략으로 판단된다.

• Plant Journal
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• v.11 no.2
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• pp.32-38
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• 2015

This study was conducted on combined cycle power plant consisting of HRSG with integral deaerator type to avoid tube failures of low pressure evaporator tubes. Based on the observation of pH variation at the discharge of boiler feed water pump by continuous pH measurement for a period of time, it was identified that pH of feed water is getting reduced as ammonia is distributed into vapor and liquid depending on the distribution ratio of ammonia in the LP drum after the deaerator. To solve this problem, the counterplan was prepared by reexamination of ammonia injection point and quantity. In conclusion, it was accomplished that 9.2~9.6 is the optimized pH range for boiler feed water by arranging additional piping for ammonia to inject directly to LP drum.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.221-222
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• 2002

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1893-1904
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• 2000

Nitrogen compounds are one of the major pollutants which cause eutrophication problems of the river or lake and red tides problems of the ocean. Currently available technologies for the removal of nitrogen compounds are mostly biological treatment. However, biological treatment is only effective for the wastewater which contains low concentration of nitrogen compounds. Leachate from solid waste landfill or industrial wastewater which contains high concentration of nitrogen can not be effectively treated by most of the currently available biological treatment technologies. With this connection. the objective of this study is to examine the applicability of ammonia stripping technology for the removal of high concentration of ammonia nitrogen compounds of the leachate from solid waste landfill. It can be concluded that ammonia stripping technology which was placed before the biological treatment process was very effective for the removal of high concentration of ammonium compounds. The chemical cost for the ammonia stripping was 16 percent higher than MLE process, so other methods like sludge recycling are needed for the reduction of operation cost. Further details are discussed in this paper.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.4
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• pp.35-41
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• 2020

The immobilization of the hydroxylamine-oxidoreductase on the water channel surface was performed to investigate the efficacy of ammonia removal in turbulent flow. The reaction by this enzyme proceeds rapidly by converting hydroxylamine into nitrous acid. For the analysis of the effect, a dimensionless mass transfer governing equation was established with the physical properties based on room temperature. The ammonia diffusion coefficient in water and the kinematic viscosity coefficient of water were 2.45×10-9 ㎡/s and 1×10-6 ㎡/s, respectively. The distribution of ammonia concentration in the water was calculated with respect to the distance from the point at which exposure to ammonia began. The quantitative distribution with respect to the mixing depth was also found. Such a quantitative analysis can provide insight into whether the enzyme immobilized on the water channel surface can be effectively used for ammonia removal.