• 한국해양환경ㆍ에너지학회지
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• 제4권3호
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• pp.28-39
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• 2001

광양만의 수질현황을 파악하고 환경변동에 따른 수질을 예측해서 부영양화를 억제하고 수질 환경회복을 위한 적절한 수질관리대책을 제시하기 위해서 생태ㆍ유체역학 수치모델을 이용하였다 광양만에 대한 점원 오염부하량의 약 90%가 폐수배출부하량이 차지하는 것으로 나타났으며, 부영양화 기준인 Chl. α 10㎍/L이하와 해역수질환경기준 II등급인 COD 2㎎/L이하를 지속적으로 유지하기 위해서는 현재의 점원 오염부하량의 약 35%이상 저감하는 대책이 요구되는 것으로 예측되었다.

• Environmental Engineering Research
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• 제22권2호
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• pp.157-161
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• 2017

Simultaneous treatment of food waste leachate and power generation was investigated in an air-cathode microbial fuel cell. A TCOD removal efficiency of $95.4{\pm}0.3%$ was achieved for an initial COD concentration of 2,860 mg/L. Maximum power density ranged was maximized at $1.86W/m^3$, when COD concentration varied between 60 mg/L and 2,860 mg/L. Meanwhile, columbic efficiency was determined between 1.76% and 11.07% for different COD concentrations. Cyclic voltammetric data revealed that the oxidation peak voltage occurred at -0.20 V, shifted to about -0.25 V. Moreover, a reduction peak voltage at -0.45 V appeared when organic matters were exhausted, indicating that reducible matters were produced during the decomposition of organic matters. The results showed that it was feasible to use food waste leachate as a fuel for power generation in a microbial fuel cell, and the treatment efficiency of the wastewater was satisfied.

• Environmental Engineering Research
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• 제22권2호
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• pp.210-215
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• 2017

Produced water is the largest wastestream of oil and gas exploration. It consists of various organic and inorganic compounds that hinder its beneficial use. This study compared the treatment of produced water in a batch suspended and biofilm activated sludge process. The biofilm carrier material was made from Gardenia Carinata shell. COD, $NH_4{^+}-N$ and $NO_3-N$ removal was monitored in both the suspended (control) and floating carrier bioreactors. The results show a rapid reduction of produced water constituents in the floating carrier bioreactor. COD, $NH_4{^+}-N$ and $NO_3-N$ removal was in the range of 99%, 98% and 97% for the floating carrier bioreactor whereas it was 88%, 84% and 83% for the control bioreactor. The rapid reduction of COD, $NH_4{^+}-N$ and $NO_3-N$ clearly indicate that the floating carrier materials served as an attached growth medium for microorganisms, improved the breakdown of produced water constituents and reduced inhibition of microbial metabolic activities.

• KSBB Journal
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• 제17권3호
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• pp.241-246
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• 2002

오늘날 섬유 염색공정에서 발생하는 염색폐수로 인해 많은 문제점들을 야기한다. 염색폐수에는 난분해성의 EG, PVA, TPA, 여러 종류의 계면활성제가 포함되어 있어 완전하게 처리하기가 어렵다. 현재 일반적으로 사용하고 있는 물리화학적 처리와 활성오니공정의 처리성을 향상하기 위하여 jet-loop reactor (JLR)와 물리화학적 처리를 결합한 새로운 공정을 개발하였다. JLR의 부피산소전달계수는 air-lift 반응기에 비해 아주 우수하였다. 또한 좀더 효율적인 처리를 위하여 JLR에 활성탄 담체를 적용하여 (JLRAS) 실험하였다. 체류시간이 8시간일 때 BOD, $COD_{Mn}$, $COD_{Cr}$, 색도 제거율은 각각 99, 86, 84, 83%로 우수하였다. JLRAS 성능은 $COD_{Mn}$의 부하 변동에도 아주 빠르게 회복되었다. 2차 물리화학적 응집처리의 최적 응집제로는 폴리황산제2철이며 130 mg/L 투입하였을때 $COD_{Mn}$과 색도의 제거율은 자각 85, 73%였다. 결론적으로 이 공정으로 난분해성의 많은 유기물을 효율적으로 처리할 수 있으며 운전비용도 감소시킬 수 있었다.

• 한국응용과학기술학회지
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• 제34권3호
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• pp.436-442
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• 2017

합성폐수 내의 유기물(COD), 질산성 질소, 인산이온을 제거하기 위한 폐수처리 시스템 개발을 위한 연구를 수행하였다. 먼저 COD는 HClO의 산화 반응에 의해 거의 100 % 제거되었으며 전기화학적 처리에 의해 질산성 질소가 암모니아성 질소로 환원되지만, 암모니아성 질소는 HClO 처리에 의해 질산성 질소로 재 산화 되었다. 암모니아성 질소는 가열 증발 처리에 의하여 거의 100% 제거 되었으며 HClO 처리를 하여도 재 산화되는 암모니아성 질소는 나타나지 않았다. 인산 이온은 pH에 따라 금속 착염을 형성함으로써 침전 처리에 의해 제거할 수 있었으며 전기화학적 처리와 HClO 처리를 통하여 COD 99.5 % 이상, 질소 97.3 %, 인 91.5 %의 제거 효율을 얻을 수 있었다.

• 한국물환경학회지
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• 제22권2호
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• pp.203-208
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• 2006

A continuous feed and cyclic draw SBR process was developed to overcome flow rate fluctuation and to maximize organic matters utilization efficiency for nitrogen and phosphorus removal. The developed SBR process was operated with two parallel reactors. Influent was supplied to one reactor which was not obligately aerated. At the same time, the other reactor was just aerated without supplying influent. In addition this mode was changed periodically. Cycle time was 6hr and aeration time ratio($t_{aer}/t_{total}$) was 0.33, respectively. $COD_{cr}$ and SS removal efficiencies of 95% or higher were achieved. Nitrogen removal was so greatly influenced by influent $COD_{cr}/T-N$ ratio. At influent $COD_{cr}/T-N$ ratio of 5.7, removal efficiencies of ammonia-N, T-N and T-P were 96%, 78% and 55%, respectively. Influent $COD_{cr}/T-N$ of 4 or higher ratio was necessary to achieve 60% or higher nitrogen removal. Organic matters of influent was efficiently utilized in denitrification reaction and consumed COD has a good correlation with removed T-N(about 6.5 mgCOD/mgTN). Continuous feed and cyclic draw SBR process could be one of alternative processes for the removal of nutrients in rural area where $COD_{cr}/T-N$ ratio was low and fluctuation of flow rate was severe.

• 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.

• 상하수도학회지
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• 제13권2호
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• pp.47-54
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• 1999

SRB(Sulfate Reducing Bacteria) converts sulfate into sulfide using an organic carbon source as the electron donor. The sulfide formed precipitates the various metals present in the AMD (Acid Mine Drainage). This study is the fundamental research on heavy metal removal from AMD using SRB. Two completely mixed anaerobic reactors were operated for cultivation of SRB at the temperature of $30^{\circ}C$ and anaerobic batch reactors were used to evaluate the effects of carbon source, COD/sulfate($SO_4^=$) ratio and alkalinity on sulfate reduction rate and heavy metal removal efficiency. AMD used in this study was characterized by low pH 3.0 and 1000mg/l of sulfate and dissolved high concentration of heavy metals such as iron, cadmium, copper, zinc and lead. It was found that glucose was an organic carbon source better than acetate as the electron donor of SRB for sulfate reduction in AMD. Amount of sulfate reduction maximized at the COD(glucose)/sulfate ratio of 0.5 in the influent and then removal efficiencies of heavy metals were 97.5% of Cu, 100% of Pb, 100% of Cr, 49% of Mn, 98% of Zn, 100% Cd and 92.4% of Fe. Although sulfate reduction results in an increase in the alkalinity of the reactor, alkalinity of 1000mg/1 (as $CaCo_3$) should be should be added continuously to the anaerobic reactor in order to remove heavy metals from AMD.

• 상하수도학회지
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• 제7권1호
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• pp.20-28
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• 1993

The Wastewater from the weight reduction process of polyester is more difficult to be treated biologically than the general wastewater from dyeing and finishing processes in textile industries. Above wastewater shows high pH, high organic strength and wide variation of organic loading. These characteristics are due to TPA and EG resulting from alkaline weight-reduction process and make trouble in the operation of activated sludge process. Therefore, the objective of this study is to develop the pretreatment method for the successful operation of treatment process. For the successful pretreatment process, the wastewater from weight-reduction process should be segregated from other wastewater stream and then acidified with concentrated sulfuric acid to precipitate out TPA from DST solution. At the optimum pH of 2. 2, the initial $COD_{cr}$ 60,000mg/l is reduced to 11,500mg/l and the removal efficiency of $COD_{cr}$ is 81.1%. The required amount of sulfuric acid for pretreatment is not greater than the amount for the the existing neutralization process. Moreover, the supernatant of pretreatment process can be reused in acidification of wastewater.

• Journal of Microbiology and Biotechnology
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• 제5권2호
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• pp.114-116
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• 1995

Concentrated Brazillian sugar cane stillage was used as a substrate for the yeast biomass production using Candida rugosa isolated from East Africa. At the optimum stillage concentration of 10% dry matter, biomass production was 20.4 g/l and COD reduction rate was 41%. The specific growth rate of the yeast was 0.17 $h^{-1}$ and the corresponding productivity 0.91 g $l{-1} h^{-1}$ in the batch fermentation was observed at $40{\circ}^C$.