• Environmental Engineering Research
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• 제19권3호
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• pp.261-268
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• 2014

Leachate quality and methane emission from pilot-scale lysimeters operated under semi-aerobic and anaerobic conditions were monitored for 650 days. Two semi-aerobic lysimeters were filled with un-compacted and compacted municipal solid wastes whereas two anaerobic lysimeters containing compacted wastes were operated with leachate storage at 50% and 100% of waste height, respectively. Despite having high moisture in wastes and operating under tropical rainfall events, leachate stabilization in semi-aerobic lysimeters took place much faster resulting in BOD reduction by 90% within 60 days, significantly shorter than 180-210 days observed in anaerobic lysimeters. Nitrogen concentration in leachate from semi-aerobic lysimeter could be reduced by 90%. In term of gas emission, semi-aerobic lysimeter with un-compacted wastes had much lower methane emission rate of $2.8g/m^2/day$ compare to anaerobic lysimeters ($62.6g/m^2/day$) through seasonal fluctuation was observed. Nevertheless, semi-aerobic lysimeter with waste compaction has similar performance to anaerobic lysimeter.

• 상하수도학회지
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• 제8권1호
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• pp.27-33
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• 1994

With the rapid industrialization, an ever-increasing quantity and kind of new organic compounds pose environmental problems due to their toxicity and physiological effect. However, research on the biodegradation of these compounds under anaerobic condition is very limited inspite of its efficiency and economical advantage. In this research, the pH effect on the ring cleavage of phenol under anaerobic condition was investigated, and the theory of phase separation was applied to the degradation of phenol for investigating the role of acidogenic bacteria. Results, obtained from biochemical methane potential(BMP) assay for 15.5 days of incubation, showed that acidic condition was more desirable for phenol degradation than alkaline condition. By both unacclimated methanogenic granular sludge and two mixed cultures, phenol was completely removed within six weeks of incubation with a gas conversion rate of over 86% of theoretical one. However, phenol was not degraded by unacclimated acidogenic culture, and thus it is considered as a syntrophic substrate. In case of phase separated biochemical methane potential(PSBMP) assay, in which acidogenic and methanogenic culture were seeded separately and consecutively, those that had been subjected to normal acidogens for 3 to 4 weeks showed higher gas production than those seeded with sterile or frozen culture.

• 에너지공학
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• 제23권1호
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• pp.33-39
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• 2014

본 연구에서는 하수슬러지의 소화가스 생산 효율향상을 위해 전기분해 처리방법을 수행하고 이를 소화가스 생산과 탈질실험 효과를 확인하였다. 전기분해 처리시간, 전류밀도가 증가함에 따라 가용화율은 증가하였으며 전극간격 4 mm에서 전류밀도 10 mA/cm2로 60분 처리 시 가용화율은 9.02%를 보였다. 이를 이용하여 BMP실험을 진행한 결과 0.49 L CH4/g VS의 메탄생산량을 보이며 대조군대비 88.4% 증가함을 보였다. 같은 조건으로 처리된 하수슬러지를 이용하여 탈질실험을 진행한 결과 $19.2mg\;NO_3{^{-}}N/g\;MLVSS{\cdot}hr$의 탈질율을 보였으며 이를 통해 전기분해 처리된 하수슬러지는 생분해성이 증대됨에 따라 혐기성소화와 탈질공정에도 적용이 가능한 것으로 확인되었다.

• 유기물자원화
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• 제23권1호
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• pp.23-28
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• 2015

본 연구는 회분식 실험을 통해 수거 형태에 따른 음식물류 폐기물의 혐기성 분해 특성을 평가하였다. 일반 종량제 봉투 내 음식물류 폐기물 (sample A)의 경우 최종 메탄 수율은 $285.6mL\;CH_4/g$ volatile solids (VS)로 가장 낮게 나타났으며 반응 속도는 $0.215d^{-1}$로 가장 높게 나타났다. RFID 기반의 폐기물 용기 내 음식물류 폐기물 (sample C)의 최종 메탄 수율 $493.4mL\;CH_4/g$ VS로 가장 높게 나타났으며 반응 속도는 $0.162d^{-1}$로 가장 낮게 나타났다. 모든 시료의 율속 단계 결정 계수는 양수로 나타나 메탄 생성 단계가 율속 단계인 것으로 나타났다.

• 유기물자원화
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• 제17권3호
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• pp.82-90
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• 2009

본 연구에서는 기계식 전처리에 의한 하수 슬러지의 가용화 효과를 회분식 실험을 통해 조사하였다. 기계식 전처리를 통한 하수슬러지의 가용화는 세포벽의 파괴로 통해 용존성 화학적 산소요구량, 단백질 및 탄수화물의 농도를 증가시키는 것으로 나타났다. 알칼리와 기계식 전처리를 병행하여 슬러지를 가용화한 결과 기계식 전처리만을 수행한 경우에 비해 용존성 화학적 산소요구량이 높은 것으로 나타났다. 혐기성 생분해도 측면에서 기계식 전처리는 메탄 발생량을 증가시키는 것으로 나타났다. 기계식과 알칼리 및 기계식 전처리를 동시에 수행한 경우 각각 24.1%와 44.5%의 생화학적 메탄 잠재능을 향상시키는 것으로 나타나 하수슬러지의 가용화는 혐기성 생분해도 향상에 효과적이다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.392-396
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• 2003

본 연구에서는 하수처리장 반송라인으로부터 얻은 혼합미생물을 사용하여 실험실에서 회분식 실험을 실행하였으며, 산소가 제한되는 유류 오염지역 내에서의 질산염 전자수용체를 이용한 탈질 박테리아의 질산염 이용 평가와 이에 따른, 현장 적용 타당성을 검토하는데 있다. 미생물은 톨루엔(toluene)을 탄소원으로 하고 질산염을 에너지원으로 이용하는 균주로 우점화한 혼합미생물(mixed culture)을 배양하여 실험에 사용하였다. 본 실험을 통해 유류에 의해 오염된 토양의 혐기성 지역에서의전자수용체로 질산염이 존재한다면, 토착미생물에 의한 분해가 느리지만, 발생될 수 있음을 추정할 수 있었다. 또한 질산염의 유무에 따른 BTEX와 MTBE의 혼합기질의 분해 특성 및 부산물을 살펴볼 수 있었다.

• 청정기술
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• 제28권1호
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• pp.32-37
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• 2022

Food waste is produced from food factories, food services, and home kitchens. The generated mass reached 5.4 million tons/year in 2020. The basic management technology for such waste has been biological degradation under an anaerobic environment. However, the whole process is intrinsically slow and considerably affected by the inner physicochemical properties of the waste and other surrounding conditions, which makes optimization of the process difficult. The most promising options to counter this massive generation of waste are eco-friendly treatments or recycling. As a preliminary step for these options, attempts were made to evaluate the feasibility and usability of three simulative models based on reaction kinetics. Model (A) predicted relative changes over reaction time for reactant, intermediate, and product. Overall, an increased reaction rate produced less intermediate and more product, thereby leading to a shorter total reaction time. Particle diminishing model (B) predicted reduction of the total waste mass. The smaller particles diminished faster along with the dominant effect of microbial reaction. In Model (C), long-chain cellulose was predicted to transform into reducing sugar. At a standard condition, 48% of cellulose molecules having 10⁵ repeating units turned into reducing sugar after 100 h. Also it was found that the optimal enzyme concentration where the highest amount of remnant sugar was harvested was 1 mg L^-1.

• Journal of Microbiology
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• 제43권4호
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• pp.319-324
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• 2005

Estuarine sediments are frequently polluted with hydrocarbons from fuel spills and industrial wastes. Polycyclic aromatic hydrocarbons (PAHs) are components of these contaminants that tend to accumulate in the sediment due to their low aqueous solubility, low volatility, and high affinity for particulate matter. The toxic, recalcitrant, mutagenic, and carcinogenic nature of these compounds may require aggressive treatment to remediate polluted sites effectively. In petroleum-contaminated sediments near a petrochemical industry in Gwangyang Bay, Korea, in situ PAH concentrations ranged from 10 to 2,900 ${\mu}g/kg$ dry sediment. To enhance the biodegradation rate of PAHs under anaerobic conditions, sediment samples were amended with biostimulating agents alone or in combination: nitrogen and phosphorus in the form of slow-release fertilizer (SRF), lactate, yeast extract (YE), and Tween 80. When added to the sediment individually, all tested agents enhanced the degradation of PAHs, including naphthalene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene, pyrene, chrysene, and benzo [a] pyrene. Moreover, the combination of SRF, Tween 80, and lactate increased the PAH degradation rate 1.2-8.2 times above that of untreated sediment (0.01-10 ${\mu}g$ PAH/ kg dry sediment/day). Our results indicated that in situ contaminant PAHs in anoxic sediment, including high molecular weight PAHs, were degraded biologically and that the addition of stimulators increased the biodegradation potential of the intrinsic microbial populations. Our results will contribute to the development of new strategies for in situ treatment of PAH-contaminated anoxic sediments.

• 상하수도학회지
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• 제26권5호
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• pp.629-636
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• 2012

This study focuses on the feasibility of bio-gas production using anaerobic digestion by measuring methane generation and biodegradability through the BMP test of industrial organic wastes. Organic wastes consist of entrails of pigs and organic residues of rumen generated from slaughter houses, wastewater sludge from slaughter waste water, fish offal and residues of vegetables from public wholesale markets, and wastewater sludge from the process of wastewater treatment in paper mill. The cumulative methane production by BMP test ranges from 149.3 ml/g-VS to 406.6 ml/g-VS and this is similar to methane generation of the normal wastewater sludge and food waste. As a result of measurement of biodegradability, wastewater sludge (S1 ~ S4) is low, ranging from 27.1% to 58.9 % and organic residues of rumen (G1) is low at 49.6 %. In conclusion, it turned out that raising the hydrolysis by various pre-treatments is necessary in order to produce bio-gas by using industrial organic wastes.

• Journal of Microbiology
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• 제40권3호
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• pp.193-198
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• 2002

Several 2,4,6-trinitrotoluene (TNT) degrading bacteria were isolated from an activated sludge by an enrichment culture technique, and their TNT removal activities were examined. Among the isolates, strain C1 showed the highest degrading capability, and completely removed 100 or 200 mg I$\^$-1/ of TNT within 6 hours of incubation. This bacterium was identified as Klebsiella sp. The effects of different carbon sources on the removal of the parent TNT by Klebsiella sp. C1 were negligible, but the transformation rates of TNT metabolites such as amino-dinitrotoluenes and diamino-nitrotoluenes were higher with fructose addition compared to glucose addition. When nitrate was used as the nitrogen source, the degradation rates of TNT and hydroxylamino-dinitrotoluenes were higher than those with the ammonium addition. Although the TNT removal rate of Klebsiella sp. C1 was slightly higher in anaerobic conditions, the further transformations of TNT metabolites were more favorable in aerobic conditions.