• 유기물자원화
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• 제26권4호
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• pp.53-61
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• 2018

혐기성소화(AD)는 폐활성슬러지의 유기물함량을 바이오가스로 전환할 수 있는 가장 널리 이용되는 공정 중 하나이다. 그러나 현재 전통적인 혐기성소화에 의한 실제 메탄수율은 이론적인 최대 메탄수율에 미치지 못하기 때문에 메탄수율을 높일 수 있는 방안의 지속적인 연구가 필요하다. 따라서 본 연구에서는 폐활성슬러지로부터 메탄수율을 높이기 위해 생물전기화학 혐기성소화조를 이용하여 혐기성소화슬러지와 생슬러지의 혼합비율(3:7, 5:5)에 따른 메탄수율 및 유기물제거 효율에 미치는 영향에 관하였다. 그 결과 생물전기화학 혐기성소화 슬러지의 혼합비가 3:7과 비교하여 5:5일 때 가장 높은 메탄수율 294.2 mL $CH_4/L$(0.63배 증가)과 52.5%(7.5% 증가)로 유기물제거효율을 가지는 것으로 나타났으며 pH, 알칼리도와 VFAs의 농도도 안정적으로 유지되었다. 이러한 결과는 혐기성소화 슬러지의 혼합비의 증가는 생물전기화학 혐기성소화조의 안정적인 성능유지를 위해 효과적인 것으로 나타났다.

• 한국토양비료학회지
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• 제44권1호
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• pp.104-111
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• 2011

In order to assess the performance of co-digester using pig slurry and food waste at the farm scale biogas production facility, the anaerobic facility that adopts the one-stage CSTR of 5 $m^3\;day^{-1}$ input scale was designed and installed under the conditions of the OLR of 2.33 kg $m^3\;day^{-1}$ and HRT of 30 days in an pig farmhouse. Several operation parameters were monitored for assessment of the process performance. The anaerobic facility was operated in three stages to compare the performance of the anaerobic co-digester. In the Stage I, that was fed with a mix of pig slurry to food waste ratio of 7:3 in the input volume, where input TS content was 4.7 (${\pm}0.8$) %, and OLR was 0.837-1.668 kg-VS $m^3\;day^{-1}$. An average biogas yield observed was 252 $Nm^3\;day^{-1}$ with methane content 67.9%. This facility was capable of producing an electricity of 626 kWh $day^{-1}$ and a heat recovery of 689 Mcal day-1. In Stage II, that was fed with a mixture of pig slurry and food waste at the ratio of 6:4 in the input volume, where input TS content was 6.9 (${\pm}1.9$) %, and OLR was 1.220-3.524 kg-VS $m^3\;day^{-1}$. The TS content of digestate was increased to 3.0 (${\pm}0.3$) %. In Stage III, that was fed with only pig slurry, input TS content was 3.6 (${\pm}2.0$) %, and OLR was 0.182-2.187 kg-VS $m^3\;day^{-1}$. In stage III, TS and volatile solid contents in the input pig slurry were highly variable, and input VFAs and alkalinity values that affect the performance of anaerobic digester were also more variable and sensitive to the variation of input organic loading during the digester operation. The biogas produced in the stage III, ranged from 11.3 to 170.0 $m^3\;day^{-1}$, which was lower than 222.5-330.2 $m^3\;day^{-1}$ produced in the stage II.

• 대한환경공학회지
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• 제38권4호
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• pp.201-209
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• 2016

Glucose ($C_6H_{12}O_6$)의 이론적인 최대 메탄수율은 표준상태(1 atm, $0^{\circ}C$)를 기준으로 0.35 L $CH_4/g$ COD이지만, 전통적인 혐기성소화조에서 유기물이 메탄으로 전환되는 양은 연구의 방법이나 유기물의 종류에 따라 매우 다양하게 보고되고 있으며, 대부분의 연구실 규모 실험에서 안정화 후 메탄 수율은 0.35 L $CH_4/g$ COD 이하로 나타난다. 최근, 미생물 전기화학 기술(Microbial Electrochemical Technology, MET)은 지속가능한 신재생에너지 생산 기술로서 큰 주목을 받고 있으며, MET를 혐기성소화조에 적용할 경우 고농도의 유기성폐기물의 빠른 분해가 가능할 뿐만 아니라 전기화학적인 반응에 의해 휘발성지방산(VFAs)이나 독성물질, 생분해 불가능한 물질까지도 분해가 가능하며, 소화조 내 미생물의 활성을 높이고 바이오가스의 생산량을 극대화 할 수 있다고 알려져 있다. 본 연구에서는 MET가 혐기성소화의 메탄발생에 미치는 영향에 대하여 연구하기 위해 음식물 탈리액과 하수슬러지의 원소조성에 따른 이론적인 최대 메탄수율을 분석하였으며, BMP (Biochemical Methane Potential) 실험과 연속식 실험을 통한 메탄수율의 특성을 평가하였다. 그 결과, MET가 적용된 혐기성소화에서의 메탄수율은 일반적인 혐기성소화조에 비하여 기질에 따라 2-3배 정도 높았으며, 이론적인 최대 메탄수율에 미치지는 못하였으나 일부는 거의 근접한 결과가 도출되었다. 또한, 일반적인 혐기성소화조와 MET가 적용된 혐기성소화조의 안정화 후 바이오가스의 조성은 거의 유사하게 나타났다. 결과적으로, MET가 혐기성소화조의 유기물 제거효율을 향상시켜 메탄발생량을 증가시킨 것으로 나타났으며, 향후 추가적인 연구를 통하여 MET에서 메탄발생 메카니즘이 명확히 규명되어야 할 것이다.

• 한국물환경학회지
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• 제22권3호
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• pp.540-545
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• 2006

The anaerobic digester supernatant (ADS) with high $NH_4-N$ concentration often results in a $NH_4-N$ overloading to the mainstream process of municipal wastewater treatment plant (MWTP). The nitrogen removal from the ADS is therefore important in order to achieve a stable mainstream process performance as well as to prevent $NH_4-N$ overloading due to ADS. Recently because of several advantages compared to the full nitrification, many works have shown interests in controlling the build-up of $NO_2-N$ in nitritation processes. The application of nitritation could save the aeration power compared to the full nitrification processes. In addition, the denitrification of $NO_2-N$ could reduce organic carbon requirements compared to the $NO_3-N$ denitrification. The purpose of this research was to find out the characteristics of the ADS nitritation and $NO_2-N$ accumulating factors from the laboratory reactor study. As a result based on the long-term laboratory experiment, it can be concluded that the degree of nitritation was closely related with the availability of alkalinity, free ammonia (FA), solid retention time (SRT) and solid concentration in the nitritation reactor.

• 한국물환경학회지
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• 제27권5호
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• pp.563-571
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• 2011

The purpose of this study is to investigate the high strength ammonia oxidation of piggery wastewater. Laboratory scale reactors was operated using influent of piggery wastewater and effluent of anaerobic digester from piggery wastewater at $35^{\circ}C$ and $20^{\circ}C$. Results of various operating conditions were compared and analyzed. After analyzing the results, effluent of anaerobic digester from piggery wastewater required shorter Solid retention time (SRT) than influent of piggery wastewater. In terms of the temperature, stable ammonia removal and denitrification was achieved on the both of the condition. At the temperature of $35^{\circ}C$, nitrite conversion rate was better than $20^{\circ}C$. It can be concluded that treating the piggery wastewater using anaerobic digester on the condition of the temperature at $35^{\circ}C$ is more efficient on the nitritation of the piggery wastewater.

• 상하수도학회지
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• 제29권2호
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• pp.203-209
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• 2015

The purpose of this study is to estimate the applicability of a stable anaerobic digester using a separator membrane to the preprocessing thickening process. The results of the experiments showed about a 47.16% weight loss rate for the sludge under anaerobic condition, and about 41.17% under intermittent aeration condition. The concentrations of rejection water were $SCOD_{Cr}$ 25 mg/L, T-N 16.6 mg/L, and T-P 1.4 mg/L on the average under the intermittent aeration condition, which were lower than the concentrations of rejection water under an anaerobic condition. As for the factors affecting the reduction of the flux, correlation analyses of TTF, MLSS, $SCOD_{Cr}$, and $EPS_{Protein}$, $EPS_{Polysacchride}$ resulted in -0.97, -0.95, -0.84 and -0.86, -0.95, respectively, which showed that TTF had the highest correlation to the reduction of the flux. In addition, it was concluded that MLSS, $SCOD_{Cr}$ and $EPS_{Protein}$, $EPS_{Polysacchride}$ also have close correlations. The results are considered to show that, in the case of the process using a tubular membrane in the preprocessing process of an anaerobic digester, an intermittent aeration condition of the thickener considering the contamination of the membrane and load of rejection water is appropriate for the stable preprocessing process.

• 한국습지학회지
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• 제16권4호
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• pp.433-441
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• 2014

고농도 질소를 함유하고 있는 하수는 하수처리장 처리 효율에 악영향을 미치는 것으로 알려져 있다. 따라서 고농도 질소를 함유한 하수를 처리하기 위한 다양한 연구가 이루어지고 있다. 본 연구에서는 대표적인 고농도 질소를 함유한 하수인 혐기 소화 상징액과 가축분뇨를 대상으로 유기물 분석, foaming 실험 및 실험실 규모 아질산화 반응조 운전을 실시하였다. 유기물 분석 결과 혐기 소화 상징액은 용존성 불활성한 성분, 가축분뇨는 입자성 생물학적 분해가능한 성분이 가장 큰 부분을 차지하는 것으로 나타났다. 아질산화 반응에 적합한 체류시간은 혐기소화 상징액 2일과 가축분뇨 6일이였으며, 이와 같은 적정 체류시간에 차이는 암모니아성 질소 농도 및 유기물 성상차이에 의한 것으로 보인다. 또한 가축 분뇨 반응조 foam은 혐기 소화 상징액 반응조 foam과 비교하여 발생량은 많지만 빠르게 제거되는 특성을 보였다. 본 연구의 결과는 향후 아질산화 반응의 하수처리장 적용 시 기초 자료로 이용할 수 있을 것으로 보인다.

• 상하수도학회지
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• 제26권6호
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• pp.825-831
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• 2012

The retrofitting of a thickening unit process is widely considered in municipal wastewater treatment plants in Korea to enhance the anaerobic digestion efficiency. The authors examined the effect of feed concentration (2-34.1 g VS/L) and feed to microorganism (F/M) ratio (0.50-1.35 g VS/g VS) on anaerobic batch digestion of sewage sludge. Methane yield over 90 mL $CH_4/g$ $VS_{feed}$ was found at a feed concentration in the range of 12-26 g VS/L and a F/M ratio below 0.6 g VS/g VS. A high F/M ratio decreased methane yield and rate with oragnic acid accumulation. As sudden increase of sewage sludge concentration prior to anaerobic digestion would jeopardize the digester performance due to the rasied F/M ratio, gradual increase of the sludge feed concentration or an additional biomass retention in the digester is recommended.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1995년도 한국생물과학협회 학술발표대회
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• pp.158.2-158
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• 1995

• Journal of Microbiology and Biotechnology
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• 제22권7호
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• pp.1005-1014
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• 2012

The understanding of the relationship between ammonia-oxidizing bacteria (AOB) communities in activated sludge and the operational treatment parameters supports the control of the treatment of ammonia-rich wastewater. The modifications of treatment parameters by alteration of the number and length of aerobic and anaerobic stages in the sequencing batch reactor (SBR) working cycle may influence the efficiency of ammonium oxidation and induce changes in the AOB community. Therefore, in the research, the impact of an SBR cycle mode with alternating aeration/mixing conditions (7 h/1 h vs. 4 h/5.5 h) and volumetric exchange rate (n) on AOB abundance and diversity in activated sludge during the treatment of anaerobic sludge digester supernatant at limited oxygen concentration in the aeration stage (0.7 mg $O_2/l$) was assessed. AOB diversity expressed by the Shannon-Wiener index (H') was determined by the cycle mode. At aeration/mixing stage lengths of 7 h/1 h, H' averaged $2.48{\pm}0.17$, while at 4 h/5.5 h it was $2.35{\pm}0.16$. At the given mode, AOB diversity decreased with increasing n. The cycle mode did not affect AOB abundance; however, a higher AOB abundance in activated sludge was promoted by decreasing the volumetric exchange rate. The sequences clustering with Nitrosospira sp. NpAV revealed the uniqueness of the AOB community and the simultaneously lower ability of adaptation of Nitrosospira sp. to the operational parameters applied in comparison with Nitrosomonas sp.