• 상하수도학회지
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• 제10권4호
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• pp.45-54
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• 1996

Effects of temperature on the efficiency of the Upflow Anaerobic Sludge Blanket(UASB) process for treatment of wastewater from a starch and related products manufacturing industry were investigated using laboratory scale reactors equipped with two types of Gas-Solid Separator(GSS). Both fresh digested sludge and granular sludge stored nearly for one year at room temperature were good as a seeding material. The reactors seeded with aged granular sludge showed slow start-up, however, lowered activity at the initial period was recovered gradually. The GSS with an inner cylinder was proved to be effective in liquid-solid separation compared to the conventional type. Although the rate of organic removal and gas production per unit volatile suspended solids in the reactor reduced significantly as the temperature varied from 35 to $20^{\circ}C$, possibility of operation at low temperatures was shown as a result of gradual buildup of volatile suspended solids in the bed. Stable operation with a reduced efficiency was possible at a COD loading of $5-8kg/m^3/day$ at a temperature as low as $20^{\circ}C$.

• 상하수도학회지
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• 제10권4호
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• pp.119-126
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• 1996

Influence factors and efficiency characteristics for treatment of wastewater containing phenol were studied with using Pseudomonas sp. B3. It took 130 hours to remove phenol, when only activated sludge of terminal disposal palnt of sewage was innoculated in batch culture, but it was required just 36 hours, when bacteria degrading phenol and activated sludge were simultaneously innoculated. If only phenol an carbon source was used, it necessary 36 hours for biodegradation of phenol, while glucose was added to medium, it took 73 hours. It was revealed as excellent effluent and SVI, when the F/M ratio, COD and phenol concentration were 53mg/l and 1.2mg/l, respectively, and optimum F/M ratio was revealed 0.31. The reactor were seriously shocked as reducing hydraulic retention time at constant phenol concentration more than increasing phenol concentration at constant hydraulic retention time, when volumetric loading rate was increased to $0.8kg\;phenol/m^3{\codt}d$ from $1.6kg\;phenol/m^3{\codt}d$. And also the effluent phenol concentration was 34mg/l after starting 12 hours of shocking and reactor was recovered as steady state after 65 hours of changing in the former test. Although the effluent phenol concentration was maximum value with 12mg/l after starting 20 hours of shocking and reactor was recovered as steady state after 54 hours of changing in the later test.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제2권2호
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• pp.99-108
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• 1998

Results obtained from this research showed that the anaerobic contact process was applicable to pear waste with COD removal efficiencies of up to $95\%$ depending on conditions, provided ammonium and phosphate salts were added as well as other nutrients, present in the commercial fertilizer, Milorganite or in yeast extract. These latter materials were required in minimum concentrations of 5 and 1.5 g/L, respectively, in the feed independent of HRT and volatile solids loading rate, with part of the effect due to the mineral fraction. Digestion was satisfactory over the whole range of volatile solids loading rates and liquid retention time of 30 to 0.5 days tested, although treatment efficiency dropped off noticeably between 1 and 0.5 day liquid retention time because of poorer flocculation and separation of anaerobic bacteria. Settling of anaerobic bacteria including methane producing bacteria was related to settling of mixed liquor suspended solids only at 1 to 5 days liquid retention times, at other liquid retention times anaerobic microorganism settled markedly less efficiently than mixed liquor suspended solids. Further studies are being made to provide information of practical and basic interest. Data on the composition of the active fraction of yeast extract might solve many practical nutrient problems encountered with the anaerobic contact process and improve its economics. Further improvement in the flocculation and settling of anaerobic bacteria as well as other bacteria would improve overall performance and allow the use of shorter liquid retention times with dilute waste. Knowledge about the numbers of methane formers present would allow a degree of understanding and control of the process not presently attainable.

• Applied Biological Chemistry
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• 제27권
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• pp.3-17
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• 1984

Anaerobic digestion has recently attracted all over the world and Korea also shows no exception. The major benefits of anaerobic digestion are energy production, water pollution control, pathogen reduction and effective manure production. In Korea it was recognized in late sixties that there was a positive need to find alternative energy for farmers household. The main traditional energy sources in rural area were crop residues and forestry products. Therefore Office of Rural Development through its Rural Guidance Bureau disseminated about 29,000 household biogas units from 1969 to 1975 to provide cooking fuel for farmers household and to improve the mode of farmers living standards. The units were welcomed by farmers at that time. Now, however, most of them are not using due to a number of reasons associated with cold winter and some techno-economical problems (in those day, fossil fuel was quite expensive to compare with other prices and since then farmers income was quickly increased). The author studied on bag type household biogas plant to solve some technical problems of existing household biogas plants, but this also has little appeal for the farmers. From 1977 author studied on village scale biogas plant with two pilot plants. From the viewpoint of energy production, COD removal, kill rate of pathogen and fertilizer value, the results obtained from the experiments were quite promising, but the construction cost of the village scale biogas plant was too high for the farmers in Korea. To find most suitable biogas plant for farmers in Korea through the simplifying the biogas digester, the author developed batch-load biogas plant. By feeding coarse crop residues and manures, total solids concentrations of the batch-load biogas plant are about 28 percent which is much higher than continous digester of 5-8 percent. The batch-load biogas plant was welcomed by many farmers in Korea when it was reported on TV and newspapers. The plant was disseminated 154 units in 1982, 766 units in 1983 and 812 units in 1984 as a promissing project. Besides these biogas plant experiments, studies were also conducted 1) to determine gas production rate with agricultural wastes, 2) to evaluate the effect of loading rate, dilution, retention time on biogas production, 3) to project the amount of potencial energy from agricultural wastes.

• KSBB Journal
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• 제10권3호
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• pp.241-248
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• 1995

염색가공 폐수 중 난분해성 물질이 PYA를 처리 하기 위하여, 한천-acrylamide를 이용한 bead를 제 조한 후 air-lift 반응기에서 연속실험을 행하였다. 합성폐수의 PYA놓도가 $3,100mg/\ell$. 체류시간 24hr일 때 유출수의 농도는 $4500mg/\ell$ 이며, 제거효율은 85% 이상을 나타내었다. 실제 호발폐수의 경우 PYA 및 COD농도가 $3,253mg/\ell$, $4,500mg/\ell$일 때, 체류시간 24hr에서 유출수의 농도는 $840mg/\ell, 480mg/\ell$이며, 제거효 율은 81.3%와 85.2%로 각각 나타났다. bead의 지름이 lmm일 때는 내부의 미생물 성장 이 양호하였으나 bead의 지름이 2mm일 때는 기질 과 산소전달저항에 의하여 반지름의 48% 이상은 미 생물의 성장이 저해를 받았다. 고정화 반응기에서 전체 기질 제거속도 중 bead 내 고정화 cell의 제거 분율은 평균 70%로 나타났다. 현탁 반응기에서 희석율 $0.083hr^{-1}$ 이상에서는 기질 이용속도가 감소하였으나 고정화 반응기에서는 희석율 $0.125hr^{-1}$까지 거의 선형척으로 증가하였다. PYA 제거속도식에서 포화상수 $K_s=6.60(g PVA/\ell)$와 최대 비기질 이용속도 k=0.175(g PVA/g cell.hr)를 얻었다.

• 상하수도학회지
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• 제28권1호
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• pp.13-23
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• 2014

A lab-scale Anaerobic Baffled Reactor (ABR) was applied to treat a primary sludge taken from a municipal wastewater treatment plant. In this experiment, acidogenic reaction was promoted by operating the ABR with short hydraulic retention time (HRT) to produce sufficient volatile fatty acids (VFA) instead of production of methane. The performance of ABR on the VFA production and total solids reduction was observed with different operating conditions with 2, 4, 6, and 8 days of HRT. Corresponding organic loading rates were 6.7, 3.4, 2.2, and $1.6kgCOD_{cr}/m^3{\cdot}day$. As HRT increased the removal rate of TCOD was also increased (82.5, 84.2, 96.9, and 95.9 % in average for HRT of 2, 4, 6, and 8 days, respectively) because the settlement of solids was enhanced in the baffle by the decrease of upflow velocity. At HRT of 2 days the average concentration of VFA in the effluent was measured at $1,306{\pm}552$ mgCOD/L corresponding to 107 % increment as compared to the VFA concentration in the influent. However, as HRT increased VFA concentraiotn was decreased to $143{\pm}552$ mgCOD/L at HRT of 8 days. The reduction rates of total solids were 12.2, 26.5, 24.8, and 43.0 % for HRT of 2, 4, 6, and 8 days. As HRT increased the hydrolysis of organic particulate matters in the reactor was enhanced due to the increasing of solids retention time in the baffle zone with low upflow velocity in long HRT condition. Consequently, we found that a primary sludge became a good source of VFA production by the application of ABR process with HRT less than 4 days and the 12-26 % of total solids reduction was expected at these conditions.

• 대한환경공학회지
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• 제31권11호
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• pp.997-1006
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• 2009

본 연구에서는 음폐수를 대상으로 5 톤/일 처리규모의 막결합형 2상 혐기성 소화(TPADUF) 플랜트를 운영하며 유기물 제거효율 및 메탄 발생량을 파악하고, 소화가스를 이용한 발전 가능성 및 분리막 적정 운영방안을 검토하였다. 고온 산발효조, 중온 메탄조 및 UF 막으로 구성된 처리 시스템에서 평균 TCOD가 150 g/L인 음폐수를 유기물 부하 11.1 g COD/L/d까지 증가시키며 처리한 결과 최종 유출수의 TCOD는 6 g/L 이하이었으며, TCOD 및 SCOD 제거효율은 모두 95% 이상이었다. 소화 가스의 메탄 구성비는 65%이었으며, 회수된 메탄량은 시스템에서 일부 가스가 누출되었음에도 39 $m^3/m^3$ 음폐수 주입량, 260 $m^3$/톤 COD유입량, 또는 270 $m^3$/톤 COD제거량 이었다. 소모된 가스량 당 발전량은 0.96 kWh/$m^3$ 가스, 또는 1.49 kWh/$m^3$ 메탄으로 다소 낮았으나 이는 소용량 발전기(15 kW급)의 저효율에 기인한 것이다. 분리막은 평균 flux 10 L/$m^2$/hr에서 운전하였으며, 운전 중 flux가 감소하였을 때는 물 또는 화학적(NaOCl)세정을 실시하여 회복시킬 수 있었다. TPADUF 플랜트에서는 메탄조 내액 또는 분리막 농축액을 산발효조로 반송함으로써 산발효조의 pH를 별도의 약품 주입 없이 적정 수준을 유지할 수 있었으며, 산발효조에서 부분적인 메탄생성을 통해 메탄조의 유기물 부하를 낮추는 효과도 있었다.

• 한국토양비료학회지
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• 제44권2호
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• pp.278-284
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• 2011

축산농가에서 소규모로 발생하는 축산폐수를 인공습지에서 효율적으로 처리하기 위한 최적 조합방법 및 부하량을 조사하기 위해 호기성조, 혐기성조 및 무산소조를 구분하여 9개 시스템의 소형 축산폐수처리장치를 설계 및 제작한 다음 조합방법별 및 부하량별에 따른 수처리 효율을 조사하였다. 축산폐수처리장치의 조합방법에 따른 처리효율을 조사한 결과 COD 처리효율은 호기-호기 조합형과 호기-혐기 조합형이 다른 조합방법에 비해 높았으며, T-N 처리효율은 호기성조-혐기성조 조합형이 다른 조합방법에 비해 높은 처리효율을 보였다. 또한 조합방법에 따른 SS 및 T-P 처리효율은 큰 차이가 없었다. 소형 축산폐수 처리장치에서 부하량에 따른 처리효율을 조사한 결과 SS를 제외한 COD, T-N 및 T-P 처리효율은 축산폐수 부하량 $100L\;m^{-2}\;day^{-1}$까지 안정적이었으나, $100L\;m^{-2}\;day^{-1}$ 이상의 부하량에서는 처리효율이 약간 감소하였다. 소형 축산페수처리장치에서 SS처리의 경우 부하량 $200L\;m^{-2}\;day^{-1}$까지 안정적인 처리효율을 보였으며, 그 이상의 부하량도 처리가 가능할 것으로 판단된다. 이상의 결과 미루어 볼 때, 축산폐수를 처리하기 위한 소형 축산폐수처리장치의 최적조합방법은 호기-혐기 조합이었으며, 부하량은 $100L\;m^{-2}\;day^{-1}$이었다.

• 대한환경공학회지
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• 제32권6호
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• pp.563-580
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• 2010

2009년 환경부는 '농어촌지역 하수도정비 종합계획'을 발표하면서 도시지역과 농촌지역의 하수도 서비스 격차를 줄이고 농어촌지역의 생활환경을 개선하기 위하여 2015년까지 약 4조 7천억 원의 예산을 투입하여 농어촌지역의 하수도 보급률을 75%까지 향상하겠다고 밝혔다. 하지만 이번 종합계획은 소규모하수도의 문제점을 정확히 파악하지 못하고 있어 하수도 보급률 증가에 따른 수질개선 효과는 기대하기 어려울 것이다. 따라서 본 연구에서는 경기도의 2개 지역 마을하수도 정비 사례를 중심으로 마을하수도의 문제점과 해결방안에 대해서 알아보고, 종합계획을 추진하는데 고려되어야 할 사항들에 대해서 논의하고자 한다. 현장조사를 통하여 하수의 불균등 유입, 저유량, 저부하 등의 문제가 공통적으로 발생하고 있는 것을 파악하였다. 유입되는 부하량에 맞게 처리시설의 운전 방법을 개선해야 하지만 대부분의 시설들이 설계시 제시된 운전인자로 운전되고 있어 처리효율이 저하되는 것으로 조사되었다. 정밀진단에서는 문제점에 대한 해결방안으로 유량균등화, 포기/ 비포기 비율 조절 등을 검토하여 현장에 적용하였으며, 그 결과 유기물 및 탈질산화 반응에 의한 T-N의 처리효율 개선되는 것을 확인할 수 있었다.

• 대한환경공학회지
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• 제36권4호
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• pp.258-264
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• 2014

본 연구는 낙동강 중류수계의 강정고령보와 달성보의 수질특성을 조사하였다. 조사결과 강정고령보와 달성보에서 COD 3.5~6.8 mg/L, TOC 3.4~6.5 mg/L, T-N 1.8~4.0 mg/L, T-P 0.08~0.12 mg/L의 농도로 조사되었으며, 달성보에서 다소 높은 농도로 조사되어 금호강 유입의 영향이 큰 것으로 판단된다. 침전물 조사결과 강정고령보와 달성보에서 모두 심층의 SS, T-N, T-P 수질지표의 농도가 표층의 1.6~2.4배로 높게 조사되었으며, 침전율(%/d)은 표층에서 7.14~9.76 %/d, 심층에서 1.68~2.42 %/d로 다소 낮게 침전되는 것으로 조사되어 심층의 SS가 쉽게 가라앉지 않고 부유하고 있는 경향을 나타냈다. 용출조사에서는 시간이 지날수록 용출농도가 증가하여 나타났으며 수온과 DO농도와 밀접한 관계가 있는 용출 특성에 의해 하계의 높은 수온과 낮은 DO농도의 조건이 용출에 용이 했을 것으로 판단된다.