• 한국환경과학회지
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• 제25권6호
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• pp.757-766
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• 2016

MTBE and other gasoline additives contained in gasoline are known to be a refractory substance resistant to biodegradation. As a method of removing these substances, a research of method using native microbes of polluted soil was progressed and among these, bio-degradation possibility under aerobic condition was evaluated. All of the experiments were progressed based on batch experiment of lab scale and analyzed by GC-FID using HS-SPME technique. The result of bio-degradation experiment based on MTBE and other additives(ETBE, TAME) was observed below 1 mg/L, which initial concentration were 100 mg/L for each method. And through production of by-product and CO2, partial mineralization was confirmed. Degradation velocity of each additive was promptly represented in the order of TBA>ETBE>MTBE>TAME. Through this study, bio-degradation possibility of native microbes of oil polluted soil, MTBE and other gasoline additives was confirmed and it was considered that the result could be used for basic experiment data in removing oil pollutants of soil.

• 수산해양기술연구
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• 제17권1호
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• pp.41-47
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• 1981

The characteristics of septic tank sludges were investigated and the kinetic coefficients in the aerobic biodegradation were evaluated from bach treatability tests. Using an unbiased statistical method, the estimated values, k (substrate removal rate coefficient) =0. 0175hr-1 at 17\ulcornerC, K. (Michaelis Menten constant) = 248mg/ e, a (cell yield coefficient)=0.625, and Kd (cell decay coefficient:' =0. 00192hr-1 were obtained based on biodegradable COD(mg/ \ulcorner) and volatile suspended solids(mg/\ulcorner). The relationship between COD and BOD, COD (mg/\ulcorner) =2. 1 BOD(mg/\ulcorner) +250, also was established for the septic tank sludges. Dilution was inevitable for the grit removal because of the high viscosity of the sludges. An aerobic activated sludge process rather than anaerobic processes was recommended for the removal of soluble organics after the removal of grit and suspended solids. A multi-stage activated sludge process was adapted for this highly concentrated and not easily-degradable waste. It was estimated that a four-stage activated sludge process would require 40 hours retention time compared to 92 hours for a single-stage process, 52 hours for a double-stage process, and 46 hours for a three stage process in order to achieve an effluent quality of 84mg/ e COD( 40mg/ e BOD) with about 4, OOOmg/ \ulcorner MLSS from an influent quality of I, 500mg/ t COD(714mg/.e BOD), while multi-stages beyond four stage would not save the required retention time significantly.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.221-225
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• 2005

A Staphylococcus sp. EY-3 with the capability of decolorizing Congo Red was isolated from soil at an effluent treatment plant of a textile and dyeing industry. This strain was able to almost completely decolorize a high concentration of Congo Red in 48 h under aerobic conditions. Optimal color removal (more than 96%) was achieved at 30- 40oC, and no noticeable effects of different pH values (5.5- 8.0) on decolorization were observed. This strain also exhibited a remarkable decolorization capability against azo dyes under aerobic conditions, even at a high concentration (dyes 1 g/l) of dye. The metabolic product of Congo Red degradation by this strain was identified by gas chromatography with mass selective detection (GC/MSD) to be an amine derivative benzidine.

• 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.

• 상하수도학회지
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• 제19권4호
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• pp.497-505
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• 2005

Domestic Sewage Treatment Plants are mostly based on biological treatment, in which large amounts of excess sludge are generated and occupy about 40 ~ 60% of the total sewage treatment costs. Several methods for sludge treatment has been so far reported as upgrading biodegradation of sludge; heat treatment, chemical treatment, including thermo-alkali and ozone, mechanical treatment including ultrasonic pulverization. But, it has a limitation in case of reducing the amount of excess sludge which are already producted. In this study, application of excess sludge reduction process using thermophilic aerobic bacteria for activated sludge was examined. The research was carried out two different stage. one for a biological wastewater treatment and the other for a thermophilic aerobic solubilization of the waste sludge. A portion of excess sludge from the wastewater treatment step was into the thermophilic aerobic sludge solubilization reactor, in which the injected sludge was solubilized by thermophilic aerobic bacteria. The solubilized sludge was returned to the aeration tank in the wastewater treatment step for its further degradation. Sludge solubilization reactor was operated at $63{\pm}2^{\circ}C$ with hydraulic retention time(HRT) of 1.5 ~ 1.7 day. Control group was operated with activated sludge process(AS) and experiment group was operated with three conditions(RUN 1, RUN 2, RUN3). RUN 1 was operated with AS without sludge solubilization reactor. RUN 2 were operated with AS with sludge solubilization reactor to examine correlation between sludge circulation ratio and sludge reduction ratio by setting up sludge circulation ratio to 3. RUN 3 was operated with sludge circulation ratio of 3 and MLSS concentration of 1,700~2,000mg/L to examine optimum operation condition. The quantity of excess sludge production was reduced sharply and in operation of RUN 3, sludge The quantity of excess sludge production was reduced sharply and in operation of RUN 3, sludge solubilization ratio and sludge reduction ratio were 53. 7%, 95.2% respectively. After steady state operation, average concentration of TBOD, SBOD, $TCOD_{Cr}$, $SCOD_{Cr}$, TSS, VSS, T-N, T-P of effluent were 4.5, 1.7, 27 .8, 13.8, 8.1, 6.2, 15.1, 1.8mg/L in the control group and were 5.6, 2.0, 28.6, 19.1, 9.7, 7.2, 16.1, 2.0mg/L in the experimental group respectively. They were appropriate to effluent standard of Sewage Treatment Plants.

• KSBB Journal
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• 제23권3호
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• pp.245-250
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• 2008

퀴놀린은 생물학적으로 거의 산화 분해되지 않았으나, 250$^{\circ}C$ 습식산화에서 니코틴산과 초산 등으로 산화 분해되었다. 퀴놀린 습식산화는 균일촉매 $CuSO_4$ 또는 쉽게 습식산화 분해되는 페놀에 의해 반응조건이 완화되었다. 퀴놀린 습식산화 반응의 주 생성물 중 하나인 니코틴산은 호기성 Bacillus 종균에 의해 산화 분해되었다. 촉매를 사용하지 않은 고온에서의 퀴놀린 습식산화 생성물의 생물학적 산화는 저온에서 진행된 균일 촉매 ($CuSO_4$) 습식산화와 퀴놀린-페놀 혼합용액 습식산화 반응 생성물의 생물학적 산화에 비하여 늦게 진행되었다. 반면에, 호기성 균주의 습식산화 생성물에의 적응은 생물학적 처리에서의 니코틴산 산화 분해 반응의 지체기를 크게 단축시켰다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.175-178
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• 2000

Biodegradability of the $poly({\beta}-hydroxybutyrate-co-3 -hydroxyvalerate)$ [PHB/V] containing 0, 10 and 15mol% hydroxyvalerate [HV] was studied. Bioderadability of PHB/V was evaluated at $30^{\circ}C$ for 58 days and $55^{\circ}C$ for 33 days by monitoring the time-dependent changes in weight loss(erosion) of aerobic conditions in a temperature-controlled microcosms containing the earthworm cast($30^{\circ}C$) and compost ($55^{\circ}C$). It was found that PHB/V biodegradability occurred with increasing HV monomer concentration from 0 mol% to 15 mol%.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.454-457
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• 2003

A new approach for groundwater treatment combines a permeable Fe(0) barrier to breakdown higher chlorinated solvents like PCE and TCE with a downgradient aerobic biological treatment system to biotransform less chlorinated solvents, such as DCE and vinyl chloride (VC). The expected bacterial performance downgradient of an Fe(0) barrier was evaluated through laboratory batch experiments with a toluene-degrading mixed culture that cometabolically transforms cis-1,2-DCE and VC. The amount of cis-1,2-DCE (initially at 2,000 ppb) and VC (initially at 2,000 ppb) transformed was controlled by the initial toluene (20,000 ppb) concentration. VC was removed much more effectively than Cis-1,2-DCE, and a higher toluene concentration in comparison to the co-substrate concentrations was needed for complete co-substrate removal. Overall, the coupling of an Fe(0) barrier and subsequent biodegradation appears feasible for remediation of complex mixtures of chlorinated solvents and petroleum hydrocarbons in groundwater

• 한국농공학회지
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• 제42권
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• pp.61-67
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• 2000

Composting of hog manure amended with sawdust trials lasted three weeks and used pilot-scale in bin composting system. Results showed that the rise temperature and carbon dioxide evolution in compost during the composting decomposition process were affected by the aeration method, pH, C/N, moisture content, bulk density and particle size distribution. No significant differences existed in biophysical properties of the composit produced from the continuous and intermittent aeration method. The intermittent aeration was very successful in compost odor control and required less time to reach stability than the continuous aeration.

• 한국환경보건학회지
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• 제36권3호
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• pp.222-228
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• 2010

Biological degradation of nitrogen-containing aromatic compounds was investigated in activated sludge previously adapted to mineralize low concentrations of nitrogen-containing aromatic compounds. Normally, the time required for 95% degradation of 10 mg/l dinitrophenol (DNP) under aerobic conditions was less than 4 hours without any lag, and with mixed liquor suspended solid (MLSS) levels from 600 to 1,000 mg/l. However, when the initial DNP concentration was increased to 75 mg/l, lags and even complete inhibition of DNP degradation were observed. The length of the lag was found to increase proportionally with decreasing MLSS levels. When dilute activated sludge was incubated for extended periods (192 hours), degradation of 75 mg/l DNP did eventually occur after lag periods of 37 to 144 hours, depending on the MLSS concentration. DNP was degradable in high concentrations if MLSS concentrations were sufficiently high to allow growth of bacteria resistant to the toxic effects of DNP.