• 상하수도학회지
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• 제26권1호
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• pp.21-27
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• 2012

This study evaluated the performance of a thermophilic two-phase anaerobic digestion (TTPAD) coupled with membrane process treating garbage leachate. The pilot-scale treatment system is consisted of thermophilic acidogenic reactor (TAR) and thermophilic methanogenic reactor (TMR) coupled with an ultrafiltration (UF) membrane unit. The hydraulic retention time of TAR and TMR were 4 and 20 days, respectively. Effluent TCOD and SCOD of the TTPAD were $25\;{\pm}\;6\;and\;12\;{\pm}\;3$ g/L, respectively, and the corresponding TCOD and SCOD removal efficiencies were 77% and 81%, respectively. Propionate was major acids as 75% in the effluent. Scum formation was not observed in TTPAD, which might be resulted from complete lipid degradation. However, TTPAD was appeared to be sensitive to free ammonia toxicity. The UF membrane was operated with constant pressure filtration at average TMP 1.3 atm. Permeate flux had a range of 15-30 $L/m^2/hr$. With UF membrane, TCOD removal increased from 77% to 93%, and this SS free effluent would be beneficial to subsequent processes such as ammonia stripping.

• 대한환경공학회지
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• 제22권3호
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• pp.523-533
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• 2000

본 연구는 재래식 혐기성 공법에 비해 메탄회수율과 처리효율이 우수한 막분리형 이상 혐기성 반응시스템을 개발하여 산생성 반응조의 미생물 체류시간을 증대시키고 시스템 운전효율을 향상시키기 위해 수행하였다. Pilot plant 운전에 사용된 막은 셀룰로오스 계통으로 $0.5{\mu}m$의 막공경과 $0.8m^2$의 유효 표면적을 가졌으며 메탄발효조는 UASB와 AF로 구성되어 있다. 혐기성 침지형 반응조를 운전한 결과 COD 제거율은 70~80%, 생성가스 중 메탄함율은 90%까지 향상시킬 수 있었다. Pilot plant 운전동안 막의 케이크 저항이 중요한 막오염원으로 나타남에 따라 이를 최소화하기 위해 세가지 공경 (40, 53, $63{\mu}m$)을 가진 전처리 필터로 적용하였다. 적용된 prefilter중 $63{\mu}m$ 전처리 필터의 경우가 가장 효과적으로 케이크 저항을 줄이고 막 유속을 증가시켜 50일 이상 장기운전을 가능케 하였다. 또한 장기 운전으로 인한 막 오염물질은 산과 알카리 세척용액에 의해 연속적으로 세척함으로써 최초 막유속의 89% 까지 회복할 수 있었다.

• Environmental Engineering Research
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• 제19권4호
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• pp.355-361
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• 2014

The wastewater treatment with a two-phase expanded granular sludge bed (EGSB) system for anaerobic degradation of acetate, benzoate, terephtalate and p-toluate from purified terephtalic acid (PTA) production was studied. The feasibility and effectiveness of the system was evaluated in terms of organic oxidation by chemical oxygen demand (COD), gas production, bacterial adaptability and stability in the granular sludge. Average removal efficiencies 93.5% and 72.7% were achieved in the EGSB reactors under volumetric loading rates of $1.0-15kg-COD/m^3/day$ and terephtalate and p-toluate of 351-526 mg/L, respectively. Gas production reached total methane production rate of 0.30 L/g-COD under these conditions in the sequential EGSB reactor system. Higher strength influent COD concentration above 4.8 g-COD/L related to field conditions was fed to observe the disturbance of the EGSB reactors.

• Journal of Microbiology and Biotechnology
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• 제22권8호
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• pp.1148-1154
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• 2012

A novel two-phase anaerobic treatment technology was developed to treat high-concentration organic cassava bioethanol wastewater. The start-up process and contribution of organics (COD, total nitrogen, and $NH_4^+$-N) removal in spatial succession of the whole process and spatial microbial diversity changing when sampling were analyzed. The results of the start-up phase showed that the organic loading rate could reach up to $10kg\;COD/m^3d$, with the COD removal rate remaining over 90% after 25 days. The sample results indicated that the contribution of COD removal in the pre-anaerobic and anaerobic phases was 40% and 60%, respectively, with the highest efficiency of 98.5%; TN and $NH_4^+$-N had decreased to 0.05 g/l and 0.90 g/l, respectively, and the mineralization rate of total nitrogen was 94.8%, 76.56% of which was attributed to the anaerobic part. The microbial diversity changed remarkably among different sample points depending on the physiological characteristics of identified strains. Moraxellaceae, Planococcaceae, and Prevotellaceae were dominant in the pre-anaerobic phase and Bacteroidetes, Campylobacterales, Acinetobacter, Lactobacillus, Clostridium, and Bacillus for the anaerobic phase. Methanosarcinaceae and Methanosaeta were the two main phylotypes in the anaerobic reactor.

• 상하수도학회지
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• 제24권1호
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• pp.51-62
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• 2010

The high concentration of N in the wastewater from livestock farming generally renders the efficiency of the wastewater treatment. Therefore, removal of N in livestock wastewater is crucial for successful treatment. The current study was conducted to investigate the optimum conditions for partial nitrification under anaerobic condition following nitritation in TPAD-BNR(two-phase anaerobic digestion-biological nitrogen removal) operating system. Sequential operating test to stimulate partial nitrification in reactor showed that partial nitrification occurred at a ratio of 1.24 in $NO_2{^-}$-N:$NH_4{^+}$-N. With this result, a wide range of factors affecting stable nitritation were examined through regression analysis. In the livestock wastewater treatment procedure, the hydraulic retention time (HRT) and pH range for optimum nitrite accumulation in the reactor were 1-1.5 days and 7-8, respectively. It was appeared that accumulation of $NO_2{^-}$-N in the reactor is due to inhibition of the $NO_2{^-}$-N oxidizer by free ammonia (FA) while the effect of free nitrous acid was minimal. Nitrification was not influenced by DO concentration at a range of 2.0-3.0 mg/L and the difference in the growth rate between $NH_4{^+}$-N oxidizer and $NO_2{^-}$-N oxidizer was dependent on the temperature in the reactor.

• 대한토목학회논문집
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• 제10권4호
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• pp.185-192
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• 1990

본 연구에서는 주정폐액의 고율처리를 위하여 이상 UASB 공정을 시험하였다. 상분리는 반응조의 pH를 조절하므로써 가능하였다. 유입폐수의 SS 농도가 4.1g/l일 때 산형성조는 유기부하 16.5kg $COD/m^3.day$까지 운전이 가능하였고, 이때 산생성율은 3.9g HAc/l.day를 나타내었다. 메탄형성조는 유기부하 44kg $COD/m^3.day$까지 운전이 가능하였으며, 이때 COD 제거율은 80%이었고 비가스 생성율은 16.51/l.day이었다. 두 반응조에서 입상슬러지가 형성된 이후에는 알칼리도의 주입없이 메탄조유출수의 재순환으로 산형성조의 pH를 적절하게 유지할 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.465-469
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• 2006

Two mesophilic trickling bed bioreactors filled with two different types of media, hydrophilic- and hydrophobic-cubes, were designed and tested for hydrogen production via anaerobic fermentation of sucrose. Each reactor consisted of a column packed with polymeric cubes and inoculated with heat-treated sludge obtained from anaerobic digestion tank. A defined medium containing sucrose was fed with changing flow rate into the capped reactor, hydraulic retention time and recycle rate. Hydrogen concentrations in gas-phase were constant, averaging 40% for all conditions tested. Hydrogen production rates increased up to $10.5 L{\cdot};h^{-1}{\cdot}L^{-1}$ of reactor when influent sucrose concentrations and recycle rates were varied. Hydrophobic media provided higher value of hydrogen production rate than hydrophilic media at the same operation conditions. No methane was detected when the reactor was under a normal operation. The major fermentation by-products in the liquid effluent of the both trickling biofilters were acetate and butyrate. The reactor filled with hydrophilic media became clogged with biomass and bio gas, requiring manual cleaning of the system, while no clogging occurred in the reactor with hydrophobic media. In order to make long-term operation of the reactor filled with hydrophilic media feasible, biofilm accumulation inside the media in the reactor with hydrophilic media and biogas produced from the reactor will need to be controlled through some process such as periodical backwashing or gas-purging. These tests using trickling bed biofilter with hydrophobic media demonstrate the feasibility of the process to produce hydrogen gas in a trickle-bed type of reactor. A likely application of this reactor technology could be hydrogen gas recovery from pre-treatment of high carbohydrate-containing wastewaters.

• 유기물자원화
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• 제24권2호
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• pp.51-58
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• 2016

일체형 2상 혐기성소화 방식은 기존 분리형 2상 혐기성소화의 단점을 보완할 수 있는 기술로 산발효조와 메탄발효조가 병합된 형태의 일체형으로 구성되어 유기물 부하변동 대처 용이, 설치부지면적 감소 등의 이점이 있다. 본 연구는 음폐수를 기질로 일체형 2상 혐기성소화의 유기물 분해효율 및 바이오가스 생산량 등에 대한 실험을 실시하여 기존 분리형 2상 혐기성소화와의 효율 비교를 통해 대규모 플랜트 설치의 타당성 여부를 검토하였다. 5ton/일 규모의 Pilot Plant를 구성하여 약 130일 간 소화조 내 유기물 변화, 바이오가스 생산량 및 메탄함량 등의 실험을 실시하였다. 실험 결과, 평균 음폐수 투입량은 $4.1m^3$/일이었으며, 이때 VS 제거효율은 약 77%로 나타났다. 바이오가스는 평균적으로 투입 음폐수 ton당 약 $63.0m^3$($0.724m^3/kg-VS_{added}$)가 발생되었으며, 메탄함량은 약 61.3%로 분석되었다. 일체형 2상 혐기성소화는 기존 산발효조와 메탄발효조가 분리된 소화방식과 유기물 제거 측면에서 다소 높게 나타났다. 결과적으로 일체형 2상 혐기성소화 방식은 충분히 고농도 유기성 폐수인 음폐수 처리에 있어서 상용화가 가능하다는 결론을 내릴 수 있었다.

• 대한환경공학회지
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• 제30권6호
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• pp.628-636
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• 2008

축산폐수를 처리하기 위한 2상 혐기성소화(TPAD)공정을 생물학적 질소제거공정(BNR)과 결합하여 운전하였다. 질산화된 유출수를 TPAD 공정의 산생성 반응조로 반송할 경우 탈질반응이 산생성 반응에 미치는 영향과 효율을 관찰하였다. 질산화된 유출수의 반송은 유입된 COD의 VFA로의 전환율을 향상시켰다. 질산화된 유출수에 적응된 산생성 슬러지의 산생성 속도는 적응되지 않은 슬러지보다 6배 빠른 것으로 관찰되었다. 탈질반응은 생성된 VFA를 탄소기질로써 사용하였지만 산생성 활성도를 향상시킬 수 있었다. 탈질속도는 COD/N비에 영향을 받았지만, 질산성 질소에 대한 산생성 슬러지의 적응여부에 더욱 지배적인 영향을 받는 것으로 나타났다. 산생성 슬러지에 의한 탈질반응은 0차 반응을 보였으며 탈질속도는 1.31$\sim$1.90 mg/L$\cdot$h이었다. 반면, 질산화된 유출수에 적응된 산생성 슬러지의 탈질속도는 3.30 mg/L$\cdot$h로 거의 2배가 빠른 것으로 나타났다. COD/N비 10에서 1g의 질산성 질소를 탈질반응에 의해 제거하는데 소비된 COD의 양론비는 5.1$\sim$6.4 범위이었다.

• Environmental Engineering Research
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• 제12권1호
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• pp.8-15
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• 2007

Two phase UASB reactors for treating wastewater with sulfate were operated to assess the performance and competition of organics between sulfate reducing bacteria(SRB) and methane producing bacteria(MPB), and the change of characteristics of microorganisms. The reactors were fed in parallel with a synthetic wastewater of 4,000-5,000 mgCOD/L and sulfate concentration of $800-1,000\;mgSO_4/L$. In the MPR(methane producing reactor) and CR(control reactor), COD removal efficiencies were 90% and 60%, respectively, at the OLR(organic loading rate) of 6 gCOD/L, while the amount of biogas and methane content were 6.5 L/day and 80%, and 3 L/day and 50%, respectively. However, the portion of electron flow used by SRB at the OLR of 6 gCOD/L day in MPR and CR was 3% and 26%, respectively. This indicated that the increase of OLR of wastewater containing high sulfate like CR resulted in activity decrease and cell decay of MPB, while SRB was adapted immediately to new environment. The MPB activities in MPR and CR were 2 and $0.38\;kgCH_4-COD$/gVSS day at the OLR of 6 gCOD/L. This indicated hat SRB dominated gradually over MPB during long-term operation with wastewater containing sulfate as a consequence of outcompeting of SRB over MPB. In addition, the solution within AFR was maintained around pH 5.0, the MPB such as Methanothrix spp. which was very important to formation of granules was detached from the surface of granules due to the decrease of activity by limitation of substrate transportation into MPB. Therefore, a significant amount of sludge was washed out from the reactor.