• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.859-865
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• 2005

The stimulatory effects of exogenous salicylate as a pathway inducer on phenanthrene biodegradation were investigated using Burkholderia cepacia PM07. The phenanthrene degradation rate was greatly enhanced by increasing the salicylate additions, and the maximum rate was 19.6 mg $I^{-1}\;d^{-1}$ with the addition of 200 mg $I^{-1}$ of salicylate, 3.5 times higher than that (5.6 mg $I^{-1}\;d^{-1}$) without the addition of salicylate. The degradation rate was decreased at higher concentrations of salicylate (above 500 mg$I^{-1}$), and cell growth was significantly inhibited. The phenanthrene degradation was not affected by increasing glucose up to 2 g $I^{-1}$, although dramatic microbial growth was obtained. The stimulatory effect of exogenous salicylate decreased in the presence of glucose. After the addition of 200 mg $I^{-1}$ of salicylate, approximately $60\%$ of the initial phenanthrene (50 mg $I^{-1}$) was degraded after 96 h. However, with extra addition of 200 mg $I^{-1}$ of glucose, the phenanthrene degradation rate decreased, and only $18.5\%$ of the initial phenanthrene was degraded.

• 대한환경공학회지
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• 제36권12호
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• pp.858-864
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• 2014

생물활성탄(BAC)과 안트라사이트 biofilter에서의 공탑 체류시간(EBCT) 및 수온의 변화에 따른 8종의 합성 향물질류의 생물분해 특성을 평가하였다. 수온 $7^{\circ}C$와 $18^{\circ}C$에서 EBCT를 5분~15분까지 변화시켜 실험하였다. 생물활성탄 공정에서 합성 향물질류 8종의 생물분해율은 EBCT와 수온에 따라 큰 영향을 받았으며 EBCT와 수온이 증가할수록 생물분해율이 증가하였으며, 합성 향물질류의 종류에 따른 생물활성탄 공정에서의 생물분해율은 대환 사향류인 pentalide와 ambrettolide가 가장 높았으며, 다환 사향류인 DPMI와 ADBI가 가장 낮았다. 합성 향물질류 8종에 대한 BAC 공정에서의 생물분해 속도상수($k_{bio}$)는 수온이 $7^{\circ}C$에서 $18^{\circ}C$로 상승하였을 경우, $0.1184{\sim}0.6545min^{-1}$에서 $0.3087{\sim}0.9173min^{-1}$로 증가하여 1.4~2.6배 정도 증가하였다.

• 대한환경공학회지
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• 제36권11호
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• pp.739-746
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• 2014

생물활성탄(BAC)과 안트라사이트 biofilter에서의 공탑 체류시간(EBCT) 및 수온의 변화에 따른 8종의 자외선 차단제들의 생물분해 특성을 평가하였다. 수온 $7^{\circ}C$와 $18^{\circ}C$에서 EBCT를 5분~15분까지 변화시켜 실험하였다. 생물활성탄 공정에서 자외선 차단제 8종의 생물분해율은 EBCT와 수온에 따라 큰 영향을 받았으며 EBCT와 수온이 증가할수록 생물분해율이 증가하였으며, 자외선 차단제들의 종류에 따른 생물활성탄 공정에서의 생물분해율은 EHMC와 BZC가 가장 높았으며, BP와 4-MBC가 가장 낮았다. 자외선 차단제 8종에 대한 BAC 공정에서의 생물분해 속도상수($k_{bio}$)는 수온이 $7^{\circ}C$에서 $18^{\circ}C$로 상승하였을 경우, $0.2730{\sim}0.6365min^{-1}$에서 $0.4824{\sim}0.8743min^{-1}$로 증가하여 1.5~2.1배 정도 증가하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권4호
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• pp.45-53
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• 2005

본 연구의 목적은 실제 디젤유로 오염된 불포화 토양을 복원하기 위해 수행되었던 고온공기 주입 파일롯 테스트에서 토양온도 변화가 생분해 속도에 미치는 영향을 알아보고자 히는 것이었고, 이것을 토대로 현장 생분해 속도, 최적의 생분해 온도 및 1차 분해 속도 상수를 도출하고 총복원기간을 예측해 보았다. 실험은 과거 디젤유 누출 사고가 있었던 고농도 오염지역에 대해 토양의 온도별 현장 호흡률(in-situ respiration)을 약 10일 간격으로 측정하는 식으로 진행되었다. 적용된 복원공법은 고온공기를 주입/추출하여 1차적으로 오염된 디젤 성분을 휘발, 추출하고 이어서 토양의 잔열과 미생물 생분해를 이용하여 토양내 잔류 디젤을 제거하는 후속공정으로 이루어졌다. 토양온도 $26\sim60^{\circ}C$ 범위에서 산소소비속도는 $2.2\sim46.3%/day$ 값을 보였고 $32^{\circ}C$에서 가장 빠른 46.3%/day를 나타냈다. 산소소비속도를 기준으로 하여 계산한 0차반응 생분해 속도(biodegradation rate)는 $6.5\sim21.3mg/kg-day$ 이었고 역시 토양온도 $ 32^{\circ}C$ 에서 최대값을 보였고 그 이전과 이후는 각각 감소된 값을 나타냈다. 주기적으로 측정된 현장호흡률을 바탕으로 계산한 1차 분해속도 k는 몇가지 온도 범위에서 즉, $0.0027\;d^{-1}(@32.8^{\circ}C),\;0.0013\;d^{-1}(@41.1^{\circ}C)$ 그리고 $0.0006\;d^{-1}(@52.7^{\circ}C)$ 이었다. 토양의 초기 TPH 농도 대비목표 농도를 870 mg/kg으로 가정했을 경우 소요 복원기간은 $2\mu9$년 정도 소요되는 것으로 예측되었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.340-343
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• 2003

Soils contaminated by hazardous hydrophobic organic compounds, such as polycyclic aromatic hydrocarbons (PAHs), have become a major environmental issue due to toxic and carcinogenic properties of those compounds. In this work, we investigated effects of various metabolic inducers on phenanthrene biodegradation. Biodegradation tests were peformed with two different Pseudomonads: Pseudononrdia hydrocarboxydans (Gram positive) and Pseudomonas putida (Gram negative). Intermediates of phenanthrene metabolism (1-hydroxy-2-naphthoate, salicylate, catechol, phthalate and protocatechuate) were selected as inducers. The tests indicated that 1-hydroxy-2-naphthoate was the most effective inducer and enhanced the phenanthrene degradation rate up to 5.7 times, even though all the others also had induction ability to some extent. The effective induction could be achieved even at a low concentration of 1-hydroxy-2-naphthoate. Addition of metabolic inducers would be an attractive trick for the successful bioremediation of PAH-contaminated soil.

• Environmental Analysis Health and Toxicology
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• 제30권sup호
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• pp.8.1-8.5
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• 2015

Objectives The objective of this study was to evaluate the biodegradation potential of four perfluorooctane sulfonic acid (PFOS) alternatives that were developed at Changwon National University. While PFOS has been used widely in industrial and consumer products, it is known to be a persistent organic pollutant. Therefore, greener alternatives are highly desirable. Methods Biodegradation tests were run for 28 days using standard test protocols. The biochemical oxygen demand was measured daily throughout the experimental period, and the data were used to calculate the biodegradation rates. Microorganisms were isolated from the some of the tests that showed evidence of biodegradation. Results $C_8H_8F_9KO_3S$, which has the same number of carbons as the parent compound PFOS but a reduced number of fluorines, showed the highest biodegradation rate followed by $C_{10}H_8F_{13}KO_3S$. Chemical alternatives with lower number of carbons did not biodegrade readily in the experiments. Conclusions Together, these results suggest that it may be advantageous to develop PFOS alternatives with 8 carbons, the same as PFOS, but a reduced number of fluorines; as such, chemicals are more susceptible to biodegradation than the parent compound.

• 유기물자원화
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• 제14권3호
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• pp.110-116
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• 2006

본 연구에서는 재조합 대장균으로 부터 Organophosphorus Hydrolase (OPH)를 이용하여 유기인 살충제 화합물인 paraoxon의 생분해 속도를 향상시켰다. OPH의 비 활성도 (Specific whole cell OPH Activity)를 증가시키기 위한 배지의 최적 조건은 초기 pH 8.5의 조절과 5.0 % acetone 첨가가 필요하다는 것을 알 수 있었다. 또한, 이 최적의 조건에서 498 Unit/L의 OPH가 생산될 때, 275 mg/L paraoxon은 반응 10분 동안 98% 생분해 효율을 나타내었고, 그 결과 생분해 속도를 $29.2mg/g{\cdot}min$까지 향상시킬 수 있었다. 이러한 실험 결과들은 지하수 또는 토양에 잔류하는 유기인 살충제를 빠른 시간 안에 효과적으로 생분해시키는 실질적인 생물 복원 기술로 사용될 수 있을 것이다.

• 상하수도학회지
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• 제24권4호
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• pp.387-394
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• 2010

The influent COD of municipal wastewater has been divided into 4 fractions; readily soluble biodegradable, slowly particulate biodegradable, soluble and particulate unbiodegradable COD. The mathematical modeling of biological wastewater treatment processes and the design and operation of nutrient removal plants require a reliable and accurate estimate of the composition of influent wastewater COD. COD utilization rate is proportional to the oxygen uptake rate(OUR), so a batch biodegradation test with OUR measurement has been effectively used for the determination of COD fractionation. But the mathematical model of COD utilization and heterotrophs synthesis is essential to interpret the OUR measurement. Mamais method is another method for determining readily biodegradable soluble COD. Like the OUR test method, batch biodegradation test is necessary but it does not require mathematical model. These two methods for determining COD fractionation are introduced here in detail. Experimental results showed that COD composition by Mamais method is not different to that by OUR test method so, either of them can be used.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권5호
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• pp.42-54
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• 2019

Biodegradation of an explosive compound, glyceryl trinitrate (GTN), was studied with a denitrifying microbial culture grown in a sequencing batch reactor and a GTN acclimated denitrifying culture. The GTN acclimated culture, which were fed on GTN for 1 month, degraded GTN regioselectively via denitration on C1 position as compared to C2 position denitration by denitrifying culture that has never been exposed to GTN. Accumulation of two isomeric glyceryl dinitrates (GDNs) in both culture medium suggests that GDN denitration is the rate-limiting step in GTN biodegradation. The first order GTN degradation rate normalized to cell concentration of the acclimated culture was calculated to be 0.045 (${\pm}0.002$) L/g-hr. Increasing concentration of electron acceptor(nitrate) resulted in discouraged GTN degradation. According to microbial community analysis, prolonged GTN exposure resulted in 25% increase in the genus level of the GTN acclimated culture with the disappearance of two dominating denitrifying microbial species of Methyloversatilis universalis and Hyphomicrobium zavarzinii in the denitrifying culture.

• 한국환경보건학회지
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• 제23권3호
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• pp.85-90
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• 1997

The objective of this study was to investigate biodegradation of TPA(terephthalic acid) and EG (ethylene glycol), treatment efficiency of polyester weight loss wastewater and microbial characteristics by aerated submerged biolfilm(ASB) p.rocess. In a batch reactor, pH increased from 7.0 to 8. 5 in the biodegradation of TPA. Whereas, in case of EG, decreased from 7.0 to 5.2. COD concentration rapidly decreased within 24hr in the biodegradation of TPA and EG. COD removal velocity constant(k) were 0.065-0.088 hr$^{-1}$. The biodegradation velocity of TPA was 1.4 times faster than that of EG. The ratio of suspended biomass to the total biomass in the reactor was 18.3-33.3%, increased as a high ratio of EG content. Biofilm thickness, biofilm dry density and attached biomass were 346-432 $\mu$m, 41.8-61.9 mg/cm$^3$, 1.45-2.67 mg/cm$^2$, respectively. There values increased as a high ratio of TPA content. In the hydraulic retention time of 36 hr, organic loading rate of 4 kgCOD/m$^3\cdot$ day and packing ratio of 70%, the effluent concentrations of TCOD, SCOD in a continuous flow reator were 1,388 mg/l, 147 mg/l and removal efficiencies were 77%, 97.6%, respectively.