• Journal of Korean Society for Atmospheric Environment
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• 제21권E2호
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• pp.57-65
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• 2005

An experimental study was performed on the decomposition of gaseous ammonia and two selected volatile organic compounds (VOCs: toluene and acetone) in a combined nonthermal plasma reactor with corona and glow discharges. A lab pilot scale reactor (206 liter) equipped with a high electric power pack was used to determine the decomposition efficiency in relation with the inlet concentration and applied voltage. Three different types of discharging electrode such as wired rack, wire strings for corona discharge, and thin plate for glow discharge were put in order in the reactor. While decomposition of ammonia decreased with an increase in the initial concentration, acetone showed an opposite result. In the case of toluene however no explicit tendency was found in toluene and aceton. Negative discharge resulted in high decomposition efficiency than the positive one for all gases. A better removal of gas phase element could be achieved when fume dust were present simultaneously.

• 한국초전도ㆍ저온공학회논문지
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• 제23권3호
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• pp.20-25
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• 2021

Milking parlor wastewater contains high concentration suspended solid (SS), nitrogen, and/or phosphate as well as organic compounds. A new biological wastewater process by magnetic separation, magnetic activated sludge (MAS) process, was applied to milking parlor wastewater treatment process. A three step wastewater treatment process of coagulation sedimentation / ammonia stripping (C/S), magnetic activated sludge process and contact oxidation (CO) was proposed for removal of these pollutants. First step, C/S process recovered 96% TN and 96% PO₄^3--P as resource for fertilizer from the wastewater. 81% biochemical oxygen demand (BOD) in wastewater was removed after MAS process. As a results, all pollutant concentrations satisfied Japanese effluent standards. Most of residual BOD and SS were removed by the CO process. It was estimated that the proposed process could reduce the process space to 1/7.

• Environmental Engineering Research
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• 제14권4호
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• pp.238-242
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• 2009

This study investigated the effects of organic loading rates on simultaneous carbon and nitrogen removal in an innovative fixed-film aerobic bioreactor. The fixed-film bioreactor (FFB) was composed of a two-compartment aeration tank, in which a synthetic filamentous carrier was submerged as biofilm support media, and a settling tank which polyvinylidene media (Saran) was used as settling aid for suspended solids. Three different organic loading rates, ranging from 0.92-2.02 kg chemical oxygen demand/$m^3$/day were applied by varying hydraulic retention time (HRT). The total soluble organic carbon removal efficiencies were in the range of 90-97%. The removal efficiency of ammonia was found to be in the range of 70-84%. Total nitrogen removal efficiency was found to be in the range of 40-45%, which indicates that denitrification reactions occurred simultaneously in the attached biofilm on the fibrous media in the aeration tank. The settling performance of suspended solids was significantly improved due to the presence of Saran media in the settling compartment, even for a short HRT. The fixed-film aerobic bioreactor used in this study demonstrated efficient treatment efficiency even at higher organic loading rates and at short HRTs.

• Environmental Engineering Research
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• 제25권1호
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• pp.80-87
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• 2020

Landfill waste decomposition generates a dark effluent named, leachate which is characterized by high organic matter content. To minimize these polluting effects, it becomes necessary to develop an effective landfill leachate treatment process. The objective of this study was to evaluate the performance of an innovative approach based on air stripping, anaerobic digestion (AD) and aerobic activated sludge treatment. A reduction of 80% of ammonia and an increase of carbon to nitrogen ratio to 25 were obtained, which is a suitable ratio for AD. This latter AD was performed in fixed bed reactor with progressive loading rate that reached 2 and 3.2 g COD/L/d for the raw and diluted leachate (1:2), respectively. The anaerobic treatment led to significant removal of chemical oxygen demand (COD) and biogas production, especially for the diluted leachate. The COD removal was of 78% for the raw leachate and a biogas production of 4 L/d with 70% methane content. The use of the diluted leachate led to 81% of COD removal and 7 L/d biogas with 75% methane content. It allowed a removal of 77% COD and more than 97% of the organic compounds present in the initial leachate sample.

• 한국물환경학회지
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• 제23권1호
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• pp.155-160
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• 2007

Constructed wetland has been widely used for the treatment of sewage, stormwater runoff, industrial wastewater, agricultural runoff, acid mine drainage and landfill leachate. For the removal of nitrogen and phosphorus, uptake by plants and adsorption to media material are the major processes, and, therefore, the selection of media with specific adsorption capacity is the critical factor for the optimal design of wetland along with the selection of appropriate plant species. In this study, two media materials (loess bead and mixed media) possessing different adsorption characteristics for ammonium and phosphate were selected, and their adsorption characteristics were evaluated. In addition, the performance of subsurface-flow wetland systems employing these media was evaluated in both batch and continuous flow systems. With LB medium, beter phosphorus removal was observed, while better ammonia removal was obtained with MM medium. In addition, enhanced removal efficiencies were observed in the wetland systems employing both media and aquatic plants, mainly due to the better environment for microbial growth. As a result, appropriate selection or combination of media with respect to the inflow water quality maybe important factors for the successful design and operation of wetland systems.

• 공업화학
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• 제22권1호
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• pp.48-55
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• 2011

아민계열 화학흡수제와 다른 화합물과의 혼합용액이 중화반응을 통해 악취가스를 제거하는 사실이 알려져 왔다. 이러한 혼합용액 중 식물추출물의 식물정유 성분은 그 자체로 만으로도 악취가스 20~40% 이상 제거능을 가지며 0.2% 아민계열 흡수제와의 혼합용액은 악취가스의 98% 이상의 제거효율을 갖는 것으로 나타났다. 악취가스인 암모니아가스와 황화수소가스를 제거하기 위해 온도와 pH 운전조건에 따라 식물정유물질과 아민계열의 화학흡수제 등을 이용하여 적정운전조건을 위한 실험을 수행하였다. 식물정유 성분 중 모노테르펜의 성분을 분석하기 위하여 GC-MS분석방법을 사용하였으며 그들의 반응메카니즘의 일부가 규명되었다.

• 한국입자에어로졸학회지
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• 제7권3호
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• pp.87-97
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• 2011

In this study, we organized the test results obtained from the performance tests for the CA certificated air cleaners which had been commercially available in Korea since 2003, and analyzed the correlation among the test parameters such as flow rate, particle collection efficiency, clean air delivery rate (CADR), ozone emission, odor removal efficiency and noise level etc. The noise level of 267 air cleaners were increased as concentrated at the 45, 50, 55 dB, which are the required noise level for CA certification according to flow rate, and ozone emissions from the CA air cleaners were significantly lower than the requirement limit, 50 ppb for 24 hour operation. The average particle collection efficiency and odor removal efficiency were 89.3 and 80.8%, approximately 20% higher than the requirement of CA certification, regardless of flow rates. The particle removal performance of an air cleaner was clearly discriminated by its CADR, and the CADR was obtained with a simple calculation: 0.79 x flow rate. The low differentiation of gas removal performance of air cleaners by the current CA gas test method was improved by 3.2, 751.3, 13.4 times for ammonia, acetic acid, respectively, by adopting the CADR concept and the real time measurement method, FTIR, for gas removal performance test.

• 대한토목학회논문집
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• 제6권2호
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• pp.35-44
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• 1986

본(本) 연구(硏究)는 정화조(淨化槽) 유출수(流出水)의 질소분석(窒素分析) 제거(除去)에 관한 기초적(基礎的)인 연구(硏究)로서 주(主)로 암모니아성(性) 질소제거(窒素除去)를 위한 실험적(實驗的) 결과(結果)에 관한 내용(內容)이다. 실험(實驗)에 사용(使用)한 시료(試料)는 정화조(淨化槽) 유출수(流出水)와 유이(類以)한 합성폐수(合成廢水)를 사용하여 그 처리가능성(處理可能性)을 규명(糾明)한 후 실제(實際) 정화조(淨化槽) 유출수(流出水)를 사용(使用)하여 처리효율(處理效率)을 비교(比較)하였고, 질산화(窒酸化) 반응(反應)이 단계적(段階的)으로 일어날 것을 고려(考慮)하여 4 단계(段階) 생물학적(生物學的) 유동층(流動層)을 고안(考案)하였으며, 이 반응기(反應器)를 이용(利用)하여 질소제거(窒素除去) 가능성(可能性)을 검토(檢討)하였다. 그 결과(結果) 순환비(循環比) 변화(變化)에 의한 유기물(有機物) 제거(除去)는 초기단계(初期段階)에서 80% 정도(程度)였으며 질산화(窒酸化) 반응(反應)은 후기단계(後期段階)에서 90% 이상(以上)의 암모니아성 질소(窒素)가 제거(除去)되었다. 체류시간(滯留時間)에 따른 유기물(有機物) l단계(段階)에서 대부분(大部分) 진행(進行)되어 85% 이상(以上) 제거(除去)되었으며 질산화(窒酸化) 반응(反應)은 3, 4 단계(段階)에서 90% 이상(以上)의 암모니아성(性) 질소(窒素)가 제거(除去)되었으며, 이 때 적정순환비(適正循環比) 및 체류시간(滯留時間)은 각각 30과 7 시간(時間)이었다. 합성폐수(合成廢水)와 실제(實際) 정화조(淨化槽) 유출수(流出水)의 $NH_4{^+}-N$ 제거(除去)와 $NO_3{^-}-N$ 생성(生成) 효율(效率)을 얻기 위한 실험(實驗)에서 $NH_4{^+}-N$ $1mg/{\ell}$ 제거(除去)에 합성폐수(合成廢水)는 $NO_3{^-}-N$ $0.95mg/{\ell}$가 생성(生成)되었고 실제(實際) 정화조(淨化槽) 유출수(流出水)는 $0.82mg/{\ell}$ $NO_3{^-}-N$이 생성(生成)되었다. 또한 유동층(流動層)에서 반응기(反應器)에서 질산화(窒酸化) 반응(反應)의 동력학적(動力學的) 계수(係數)를 구(求)하였다.

• 한국환경농학회지
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• 제24권4호
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• pp.386-390
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• 2005

국내에서 구입이 용이한 부숙수피와 펄라이트를 부피비 7:3으로 혼합하여 혼합충전재에 암모니아 산화균 Rhodococcus equi A3와 황 산화균 Alcaligenes sp. S5-5.2를 접종한 후, 개발한 양압식 상향류 방식의 바이오필터에 혼합충전재를 충전하여 돈사에서 발생하는 암모니아 및 황화수소에 대한 악취가스 제거성능을 실험을 실시하였다. 혼합충전재에 미생물을 접종한 후 72시간동안 순치하였을 때의 미생물 생균수와 24시간 간격으로 측정하였을 때의 미생물 생균수가 거의 같은 것으로 나타났다. 이는 개발한 바이오필터가 미생물의 생육조건을 유지하는데 성공했다고 판단된다. 또한 암모니아 가스의 유입농도는 평균 $22.8{\pm}5.2mgL^{-1}$이었고, 배출농도는 평균 $2.1{\pm}0.3mgL^{-1}$, 제거율은 90.8%이었다. 흐리고 황화수소의 유입농도는 평균 $2.7{\pm}1.2mgL^{-1}$이었고, 배출농도는 $0.5{\pm}0.2mgL^{-1}$, 제거율은 81.5%로 비교적 높았다. 이와 같이 부숙수피와 펄라이트를 혼합하여 만든 혼합충전재를 충전한 바이오필터가 악취가스 제거율이 비교적 높고 가격이 저렴한 것을 고려해 볼 때, 기존의 다른 충전재을 이용한 바이오필터보다 개발한 바이오필터가 양돈가에서 이용하는데 유리한 것으로 판단된다.

• Environmental Engineering Research
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• 제23권1호
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• pp.28-35
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• 2018

$17{\alpha}-ethinylestradiol$ (EE2), a synthetic estrogen which interfere the endocrine and reproductive function in living organisms, has been found extensively to be deposited into municipal wastewater treatment plants and the environment via human excretion. EE2 has long been known to be efficiently cometabolized by ammonia-oxidizing bacteria (AOB) during ammonia ($NH_3$) oxidation. Current study aims to investigate the effect of culture history on the biotransformation of EE2 by nitrifying sludge which was enriched under different ammonia loading rates in continuous flow reactors. Result showed that past growth condition largely affected not only the metabolic rate of $NH_3$ oxidation but also EE2 cometabolism. Sludge previously acclimated with higher $NH_3$ loads as well as sludge dominated with AOB belong to high growth cluster (Nitrosomonas europaea-Nitrosococcus mobilis) showed higher rate of EE2 biotransformation than those one being acclimated with lower $NH_3$ loads because of its ability to provide more reducing power from $NH_3$ oxidation. Moreover, the correlation between the degradation rates of $NH_3$ and EE2 was higher in sludge being acclimated with higher load of $NH_3$ in comparison with other sludge. Implication of the findings emphasized the role of volumetric $NH_3$ loading rate in determining EE2 removal in wastewater treatment system.