• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1221-1228
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• 2005

Carbon electrode was applied to a wastewater treatment system as biofilm media. The spatial distribution of heterotrophic bacteria in aerobic wastewater biofilm grown on carbon electrode was investigated by scanning electron microscopy, atomic force microscopy, and biomass measurement. Five volts of electric oxidation and reduction potential were charged to the carbon anode and cathode of the bioelectrochemical system, respectively, but were not charged to electrodes of a conventional system. To correlate the biofilm architecture of bacterial populations with their activity, the bacterial treatment efficiency of organic carbons was measured in the bioelectrochemical system and compared with that in the conventional system. In the SEM image, the biofilm on the anodic medium of the bioelectrochemical system looked intact and active; however, that on the carbon medium of the conventional system appeared to be shrinking or damaging. In the AFM image, the thickness of biofilm formed on the carbon medium was about two times of those on the anodic medium. The bacterial treatment efficiency of organic carbons in the bioelectrochemical system was about 1.5 times higher than that in the conventional system. Some denitrifying bacteria can metabolically oxidize $H_{2}$, coupled to reduction of $NO_{3}^{-}\;to\;N_{2}$. $H_{2}$ was produced from the cathode in the bioelectrochemical system by electrolysis of water but was not so in the conventional system. The denitrification efficiency was less than $22\%$ in the conventional system and more than $77\%$ in the bioelectrochemical system. From these results, we found that the electrochemical coupling reactions between aerobic and anaerobic reactors may be a useful tool for improvement of wastewater treatment and denitrification efficiency, without special manipulations such as bacterial growth condition control, C/N ratio (the ratio of carbon to nitrogen) control, MLSS returning, or biofilm refreshing.

• 상하수도학회지
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• 제11권4호
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• pp.63-70
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• 1997

The objectives of this study were to find out the optimum treatment conditions for removing nitrogen in a synthetic wastewater by using microorganisms immobilized with PVA-Freezing method. The samples used as influents to the laboratory scale treatment units were a synthetic wastewater. The experiments in this study were mainly directed to collect the data of nitrogen and organic matter removal efficiencies for the different hydraulic and internal recycle rates conditions, temperature and influent C/N ratios. The removal efficiencies of nitrogen and organic matters were investigated for the operating conditions of HRT 2~12hours, internal recycle rates 50~400%, temperatures $15{\sim}30^{\circ}C$ and C/N ratios 2.5~7.5. The adequate internal recycle rate for removing T-N and $BOD_5$ in the synthetic wastewater was found to be about 300% at the temperature of $30^{\circ}C$ when the ratio of carbon contents to the nitrogen (C/N) in the influent was around 5.5. Under these conditions, the final effluent concentrations of T-N and $BOD_5$ were 8.7 and 8.4 mg/l, respectively.

• 환경위생공학
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• 제17권1호
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• pp.69-74
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• 2002

This study explored for treatment processes by investigating the treatment efficiency and reaction mechanism through oxidation reaction using UV and $O_3$ as oxidant in compensate the wastewater containing nitrobenzene that is non biodegradable organic. Also by modeling these reactions, we try to step explanation of optimum reaction rate and reaction mechanism as the development of the computer program predictable the reaction rate by modeling the reaction. By using this model, after kinetic constant for each reaction from an experimental data is made an optimization and for hardly contribute to reaction rate in reaction kinetic equation is made an ignorance and suppose the simplified reaction mechanism, examined the propriety of computer simulation model and simplified reaction mechanism by comparing and inspecting the reaction kinetic constant and masstransfer coefficient. An investigation results for destructional treatment of nitrobenzene in the wastewater as non-biddegradable organic using UV, $O_3{\;}O_2{\;}H_2O_2-UV$ as oxidant.

• 환경위생공학
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• 제10권2호
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• pp.13-22
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• 1995

Most of small- scale livestock facility have difficulties to treat organic wastewater by activated sludge process as distinguished feces and urine. The organic wastewater discharged have characteristics of slurry, high concentration of BOD, 55 etc. This study was performed to estimate suitable condition for the application of packing materials, air flow, pollutant load and so on as important parameter to treat organic wastewater by thermopile oxlc process. As a result obtained at this experiments the most suitable condition for BOD load, air flow indicate 3.0kg · m$^{-3}$ day$^{-1}$,50 ∼ 100L· min$^{-1}$ m$^{-3}$, respectively, and we knew that it was necessary to add waste contained high calories to degrade about 80% of pollutant among waste- water. It showed that plastic material can be used as packing media because it can be provided as inhabitation for microorganism owing to intensity of material and characteristic of keeping moisture.

• 상하수도학회지
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• 제12권3호
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• pp.30-40
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• 1998

Increasing water consumption produced sludge problems of the water treatment plants. The objective of this study is to investigate aluminium coagulants recovery n acidic and alkaline conditions. Water treatment plant sludge produced in Pusan Metropolitan City were tested for the aluminium extraction process. Experiment samples were obtained in summer from water treatment plants of Deoksan and Myongjang. Aluminium coagulants used in these plants during the test period were polyaluminium chloride(PAC), polyaluminium sulfate organic(PSO), polyaluminium sulfate silicate(PASS). Aluminium contents of water treatment sludge were in the range of 7.2~10.9% of the total solids. The recovery percentages for aluminium and iron by acidic extraction method was evaluated to 88% and 42% respectively. Extracted mass variation for other materials such as iron, manganese, total organic carbon was observed during the extraction operation. Alkaline extraction produced more than two times amount of total organic carbon than that in the acidic extraction process.

• 생명과학회지
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• 제30권2호
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• pp.129-136
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• 2020

암모니아성 질소(NH₄-N) 함유폐수의 효과적인 처리를 위하여 암모니아성 질소가 함유되어있는 식품폐수처리장의 폭기조 활성오니에 우점적으로 존재하는 미생물 중 TOC (total organic carbon) 제거율이 높은 AT2, AT9, AT12 균주와 암모니아성 질소 제거능이 우수한 FN47을 분리, 동정하였다. 이들 분리균주의 균체를 탈지강을 담체로하여 산업폐수처리용 미생물제제 FIW-1 을 제조하였다. 폭기조 분리균주들의 대상으로 폐수자체를 배양기질로 하여 배양학적 특성을 조사하였을 때 분리균주들의 기질친화성이 매우 높은 것으로 나타났으며, 분리균주 중 AT12 균주(Alcaligenes sp. AT12)가 가장 높은 기질친화성을 나타내었다. 식품폐수 중의 암모니아성 질소 제거효율은 분리균주 FN47 (Microbacterium sp. FN47)의 처리구에서 71%의 제거율을 나타내었다. 실험실규모의 반응조에서 식품폐수를 이용한 연속배양 실험에서 활성슬러지만을 첨가한 경우 63% TOC제거효율을 나타내었으며, 폐수처리용 미생물제제 FIW-1을 첨가 시에는 92%의 제거효율을 나타내었다. 또한 폐수처리용 미생물제제 FIW-1의 폐수처리장 현장실험에서는 미생물제제 FIW-1을 투입한 초기 3일간의 유출수COD (chemical oxygen demand) 값은 43% 내외의 처리율을 나타내었으나, 5일이 경과하였을 때 유출수의 COD값은 62%의 처리효율을 나타내었다.

• 환경위생공학
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• 제16권3호
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• pp.28-33
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• 2001

Photosynthetic bacteria (PSB), strains IP-4 and IP-6-7 were isolated from nature, and were studied for swine wastewater treatment. It was confirmed that these PSB were very effective for the COD treatment. Growth of those PSB were increased to 4.5 fold in organic-acids (acetate, propionate and butyrate) added medium than cultivation in Lascelles basal medium and the amount of bacteriochlorophyll a were increased to 5 folds. The COD removal rate in swine wastewater using PSB, strains IP-4 and IP6-7 were obtained 91% and 85%, respectively.

• 미생물학회지
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• 제37권4호
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• pp.317-324
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• 2001

본 연구실에서 개발한 3단계 메탄발효시스템을 이용하여 음식폐기물을 소화하고 배출되는 고농도 유기성 폐수를 미생물막 반응조와 조류, 물벼룩을 이용한 생택학적 수처리 시스템으로 처리하였다. 미생물막 반응조에서 유출되는 폐수에 두 종의 조류를 처리하였을 때 Chlorella sp. 보다 Selenastrum capricornutum이 더 잘 성장하였고, 질소제거 효과도 높았다. 고농도의 $Mg^{2+}$과 $Ca^{2+}$을 주입하고 유출수의 질소와 인 농도 비율을 10 : 1이 되도록 인위적으로 인농도를 조절하였을 때에는 더욱 높은 질소 제거와 조류 성장을 나타내었다. 시험관에서 조류와 물벼룩 두 종의 개체 수 변화를 관찰했을 때, 초기 조류 개체수는 물벼룩 개체수의 증가에 따라 감소하다가 물벼룩의 개체수가 최대치에 이른 후 환경저항에 의해 감소하기 시작하는 시점부터 점차적으로 증가하는 양상을 나타냈다. 본 연구에서 제시하는 생태학적 수처리 시스템은 유기성 폐수내 질소 및 인 처리에 매우 효율적이며, 시스템내의 최종 섭식자인 물벼룩을 대량 사육함으로써 이를 어류의 사료로 쓸수 있는 가능성을 확인할 수 있었다.

• 한국축산시설환경학회지
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• 제10권1호
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• pp.29-36
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• 2004

양돈폐수의 원수, 활성오니정화처리, 오존 처리 및 $TiO_2$처리 등 각 정화처리단계별 유기물질의 성분특성 및 분자량의 분포의 변화를 알아보기 위하여 시험을 수행하였으며 그 결과는 다음과 같다. 1. 양돈폐수 원수 중에는 acetic acid, 2-butanone, hexane, chloroform, propionic acid, butanoic acid 등 33종의 유기물질이 포함되어 있었으며 phenol 28.7%, benzoic acid 9.9%, benzeneacetic acid 13.3% 등으로 고른 분포를 보였다. 2. 오존처리 후 ethene, pentane, 2-methyl-propanal, hexane, furan 등 13종의 유기물질이 존재하였으며, hexane이 67.8%로 대부분을 차지하는 것으로 나타났다. 3. $TiO_2$ 처리를 한 후에는 ethene, hexane, chloroform, 1-decene, silane 등 12종의 유기물질이 존재하였으며, ethene 8.8%, hexane 16.2%, 1-dodecene 8.0%, 1-tetradecene 10.8%, cyclo-trisiloxane 12.6% 등의 분포를 보였다. 4. 양돈폐수 원수는 500Da 이하의 분자량이 15%, 500-1,000Da 분자량이 14% 1,000∼3,000Da 분자량인 물질은 21%를 차지하였다. 5. 활성오니처리 후 분자량 500Da 이하는 7%, 500∼1,000Da 12%, 1,000∼3,000Da 10%이었으며 난분해성 물질인 분자량 3,000∼10,000Da 24%, 10,000Da 이상 26%로 고분자 물질의 분포가 높아졌다. 6. $TiO_2$ 처리 후 분자량 3,000∼10,000Da 5%, 분자량 10,000Da 이상 5%로 급격히 감소한 반면 분자량 500Da 이하 31%, 분자량 500∼1,000Da 54%를 차지였다.

• 한국지반환경공학회 논문집
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• 제9권2호
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• pp.23-29
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• 2008

고농도 입자성 유기 폐수를 대상으로 기존 혐기성 공정인 CSTR과 UASB공정으로 처리 시 불량한 상징수질, 불안정한 운전 특성과 같은 문제점이 제시되었다. 이에 본 연구는 새로운 개념의 ADEPT(Anaerobic Digestion Elutriated Phased Treatment) 공정을 주정폐수에 적용하여 처리 가능성을 평가하였다. CSTR과 ADEPT의 성능 비교 결과 ADEPT공정에서 gas 발생량은 약 2배였으며, 유기물 제거 효율과 고형물 제거 효율 역시 더 높은 효율을 보여주었다. 또한 ADPET는 비교적 짧은 HRT에서도 휘발성 지방산 생성으로 인한 pH 저하의 영향을 받지 않았으며, 안정적으로 pH를 유지하였다. ADEPT의 recycle ratio를 6Qin과 2Qin으로 변화를 주어 운전 시 6Qin의 운전 기간 동안 높은 처리 효율을 보여주었다. 따라서 ADEPT는 짧은 HRT로 인한 경제성 향상과 메탄 발생을 이용한 에너지 회수, 또한 산 생성조에서 생성되는 유기산을 최대로 생산, BNR 공정의 유기 탄소원으로 활용 가치가 있다고 판단된다.