• 한국환경농학회지
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• 제25권3호
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• pp.247-256
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• 2006

본 연구에서는 실험실 규모의 혐기성 소화 실험을 통하여 고온산발효를 거친 음식물찌꺼기 산발효액과 하수슬러지의 적정 혼합비와 유기물 부하율에 따른 반응조 운전특성을 분석하여 실제 플랜트에 적용가능성을 검토하여 얻은 결론은 다음과 같다. 음식물지꺼기 고온 산발효액과 하수슬러지를 혼합하여 반연속식으로 혐기성 소화실험을 실시한 결과 유기물 부하율 3.3 gVS/L.d(혼합비 1:1)에서 최적인 것으로 평가되었는데, 이때 SCOD 제거효율은 평균 74.2%, VS 제거효율은 73.6%, 주입된 VS당 생성된 가스량은 $0.440{\ell}/g\;Vs_{add}.d$였으며 평균 메탄 함량은 66.5%로 나타났다. 이는 기존에 음식물찌꺼기를 하수처리장의 중온 소화조에서 처리할 때의 유기물 부하보다 높아 효율성, 경제성에서 유리한 것으로 판단되었다.

• 환경위생공학
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• 제14권3호
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• pp.130-138
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• 1999

The feasibility of municipal sewage sludge digestion was investigated by using thermophilic anaerobic sequencing batch reactor(ASBR). One-day settle time was enough for the high performance of solid-liquid separation. The conversion of semi-continuous mode to sequencing batch mode is easily achieved without any adverse effects, although the large amount of sludge equal to the volume ratio of 0.3~06 to reactor volume was added in the feed step of the start-up. The ASBRs had higher conversion capability of organics to biogas than the control reactor. Gas yields of the ASBRs were increased by the average of 50% over the control reactor across a range of hydraulic retention time(HRT)s from 10days to 5days. The thermophilic reactors showed higher gas production than mesophilic reactor. Removal efficiencies of organic matter exceeded 80% on the basis of supernatants, except that at the reactor. Solid-liquid separation was essential in the performance of the ASBR, especially, at the lower HFT. The ASBRs were highly efficient in the retention of activated biomass within the reactor. thus compensating for increased equivalent organic loading rate through increased solids retention times followed by the increased solids, while maintaining shorter HRTs.

• 한국수소및신에너지학회논문집
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• 제27권2호
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• pp.135-143
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• 2016

Biogas is a renewable fuel from anaerobic digestion of organic matters such as sewage sludge, manure and food waste. Raw biogas consists mainly of methane, carbon dioxide, hydrogen sulfide, and water. Biogas may also contain other impurities such as siloxanes, halogenated hydrocarbons, aromatic hydrocarbons. Efficient power technologies such as fuel cell demand ultra-low concentration of containments in the biogas feed, imposing stringent requirements on fuel purification technology. Biogas is upgraded from pressure swing adsorption after biogas purification process which consists of water, $H_2S$ and siloxane removal. A polymer electrolyte membrane fuel cell power plant is designed to operate on reformate produced from upgraded biogas by steam reformer.

• 유기물자원화
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• 제16권2호
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• pp.57-65
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• 2008

일반적 중 저농도형 하수처리시설을 통해서는 처리가 힘든 고농도 유기성 폐수의 경우 재생에너지 생산이 가능한 혐기성 분해로 처리하는 것이 유리하다. 기존 호기성 처리에서 이미 그 실용성과 우수성이 입증된 E-PFR을 혐기성 처리에 적용하여 그 효용성과 재생에너지 생산 효율 증대 효과 등을 검증하고, 효율적인 재생에너지 생산을 위한 조건 등을 제시하기 위한 연구를 수행하였다. N 음식물쓰레기 처리시설에서 발생하는 탈리액을 대상으로 수행한 Pilot Plant 규모의 실험 연구에서 반응기의 구조적 특성으로 인해 혐기성 분해의 효율 향상 및 메탄가스 발생량이 증가함을 확인하였다. 이러한 처리 효율의 향상은 유체 이동관과 각단을 분리하는 격벽을 설치한 E-PFR의 구조적 특성에 기인한 원활한 혼합조건 형성과 스컴제어로 혐기성 처리에 있어서도 매우 이상적인 반응 조건을 형성시키기가 용이하였기 때문이다. E-PFR은 상향류식 폐수 유입과 각 단별로 분리된 다단형 처리로 인해 폐수 유입 구역에는 상대적으로 높은 MLSS가 유지될 수 있으므로 충격부하에 대한 내성이 강하고, 전체적으로 혐기성 최적 pH인 7.0~8.0 정도를 유지하여 상대적으로 높은 가스 발생량 및 메탄가스 함량을 유지하는 것이 가능하였다. 뿐만 아니라, 각 단별로 각기 다른 MLSS를 유지시키면서 SRT를 상대적으로 길게 유지함으로써 유기물 분해 및 가스 발생 효율을 증가시키는 효과가 있었다. 향후, 반응기의 구조적 개선과 발생가스를 이용한 교반 효과 개선 등을 통해 메탄가스 함량 70 % 수준의 안정적 혐기성 분해가 가능한 실증 플랜트 설계가 가능할 것으로 판단되며, 이를 통해 한층 향상된 재생에너지 획득 시스템 확보가 가능할 것이다.

• KSBB Journal
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• 제25권6호
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• pp.547-552
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• 2010

The recent bloom of a very large jellyfish Nemopilema nomurai has caused a danger to sea fishery and sea bathers. Presently, Nemopilema nomurai is thrown away through a separator system in the sea. The objective of this work was to produce bio-gas from Nemopilema nomurai by using anaerobic digestion. The bio-gas includes the hydrogen or the methane gases. It relates that Nemopilema nomurai is effectually changed into the renewable energy. When the jellyfish biomass was used as an organic carbon source the bio-gases were evolved. The aim of this study was to determine the optimal conditions for hydrogen and methane gases production according to the substrate concentrations of Nemopilema nomurai, optimal culture condition and the sludge-pretreatment without pH control. The optimal culture condition was found to be $35^{\circ}C$ and the heat-treatments of jellyfish was done at $120^{\circ}C$ for 30 min. The production rate of hydrogen and methane gas were found to be 8.8 mL/L/h, 37.2 mL/L/h from 1.5 g of dry Nemopilema nomurai.

• 한국환경보건학회지
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• 제23권3호
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• pp.40-49
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• 1997

In Korea, naked barley and tapioca are main raw materials for the production of fermentation ethyl alcohol, and one million drums bf 95% fermentation ethyl alcohol is produced per year by use of them. Stillage of alcoholic fermentation is mostly digested by methane fermentation process, and methane gas occured if methane fermentation process is recovered and mixed with fuel to decrease 25-30% for total fuel used in factories. In the anaerobic digestion process of naked barley stillage, supplement of nutrients is necessary to slove the problems caused by inhibitory materials contained if stillage and deficiency of nutrients. Therefore, the objective of this study was to examine why the anaerobic digesters using the naked barley distillery wastewater have shown the poor digestability frequently and how to control it. As the poor digestion was supposed to be occurred by the lack of iron as trace nutrient, the experiments were carried out to find out the optimum dosage and the way of addition of iron and to assess the quantitative evaluation of the type of iron in digesters. Initially, bottle test as batch digesters and lab-scaled continuous flow digesters were used in order to determine the digestion characteristics with tapioca and naked barley distillery wastewater. According to the results of batch tests, the poor digestion was caused by volatile fatty acids and could be improved by adding of calcium. The activity of the methanogenic bacteria were increased remarkably when the iron was added to the digester in the form of mixture with substrates.

• Korean Chemical Engineering Research
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• 제48권1호
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• pp.103-109
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• 2010

하폐수 처리과정에서 발생되는 슬러지는 주로 혐기소화에 의해 처리되며 슬러지를 감량하고 메탄을 생산할 수 있어 많이 이용되고 있다. 슬러지의 전처리는 혐기소화의 율속단계인 가수분해를 높여 처리속도를 향상시키므로 많은 연구가 진행 중이다. 본 연구에서는 열, 초음파, 열-알칼리의 전처리 기술에 따른 슬러지의 가수분해(가용화) 효과와 전처리한 슬러지를 혐기소화하여 메탄 생산량과 슬러지의 감량 효과를 비교하였다. 하수와 폐수 슬러지 가용화율은 열-알칼리 동시 처리한 경우에는 67과 70%로 가장 높았고 다음으로 초음파 처리와 열처리가 40% 이상의 비슷한 가용화율을 보였다. 혐기소화 가스의 메탄 함량은 45~70% 범위로 유지되었고 전처리한 슬러지가 control에 비해 높게 나타났다. 메탄 생산량은 열처리, 초음파 처리, 열-알칼리를 같이 처리한 경우가 control에 비해 각각 하수슬러지는 2.6, 2.7, 3.5배, 폐수 슬러지는 3.5, 4.1, 4.2배 증가하였다. 혐기소화 슬러지의 감량효과는 전처리한 슬러지가 control에 비해 5~19% 포인트 높게 나타났으며 열-알칼리 처리한 경우가 초음파와 열처리에 비해 우수한 감량 효과를 보였다. 위의 결과로부터 전처리가 메탄 생산량에서 뿐만 아니라 슬러지 처리처분 비용 절감에 있어서도 중요한 역할을 함을 확인할 수 있었고 열-알칼리 동시 처리가 가장 우수한 성능을 보였다.

• 한국환경과학회지
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• 제1권2호
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• pp.125-136
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• 1992

Digestion of a municipal wastewater sludge by the anaerobic sequencing batch reactor (ASBR) was investigated to evaluate the performance of the ASBR process at a critical condition of high-solids-content fined. The reactors were operated at an HRT of 10 days with an equivalent loading rate of 0.8-1.5 gVS/L/d at 35$^{\circ}C$ The main conclusions drawn from this study were as follows: 1. Digestion of a municipal wastewater sludge was possible using the ASBR in spite of high concentration of settleable solids in the sludge. The ASBRS with 3- and 4-day cycle period showed almost identical high digestion performances. 2. No adverse effect on digestion stability was observed In the ASBRS in spite of withdrawal and replenishment of 30% or 40% of liquid contents. A conventional anaerobic digester could be easily converted to the ASBR without any stability problem. 3. Flotation thickening occurred in thicken step of the ASBRS throughout steady state, and floating bed volume at the end of thicken period occupied about 70% of the working volume of the reactor Efficiency of flotation thickening in the ASBRS could be comparable to that of additional gravity thickening of a completely mixed digester. 4. Solids were accumulated rapidly in the ASBR during start-up period. Solids concentrations in the ASBRS were 2.6 times higher than that in the completely mixed control reactor at steady state. Dehydrogenase activity had a strong correlation with the solids concentration. Dehydrogenase activity of the digested flu형e in the ASBR was 2.9 times higher than that of the flu형e in the control reactor, and about 25 times higher than that of the subnatant in the ASBR. 5. Remarkable increase in equivalent gas production of 52% was observed at the ASBRS compared with the control reactor in spite of similar quality of clarified effluent from the ASBRS and control reactor. The increase in gas production from the ASBRS was believed to be combined results of accumulation of microorganisms, higher driving force applied, and additional long-term degradation of organics continuously accumulated.

• 한국환경보건학회지
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• 제25권3호
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• pp.29-35
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• 1999

Quantity and composition of biogas from semi-continuous anaerobic digestion of straw were obtained experimentally in laboratory scale digesters fed with 1 liter of 5% straw-water mixture and maintained at 35$^{\circ}C$. Experiments were carried out for hydraulic retention time(HRT) of 8, 10 and 15days, respectively. The amount and composition of biogas produced were measured until steady-state was achieved for each run. The amount of biogas and methane percent go through a maximum and decrease continuously towards the steady-state after three times operation of hydraulic retention time(HRT). Methane gas production rates at steady-state increase with the increasing of HRT. Biogas production of 0.45 liter/day with 25% methane, 0.42 liter/day with 33.7% methane and 0.492 liter/day with 31.7% methane were obtained for 8, 10 and 15days of HRT, respectively. The high proportion of soluble carbohydrates present in straw makes the volatile fatty acids to build up within the digester causing a drop in pH that inhibits digestion. Regular control of pH is therefore necessary by adding alkalinity. Reductions in COD increase with increase in HRT. The stratification of plant material within the digester is different from that of manure, and modifications in design and operation of digesters may be necessary if they are fed with plant matter.

• KSBB Journal
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• 제6권2호
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• pp.135-141
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• 1991

This study thus looks into two treatment processess : i) Anaerobic digester coupled with hollow fibre membrane unit. Treatment of starch waste with anaerobic digester-membrane system was studied. $0.17\m^2$ area of hollow fibre membrane unit of known pore size was immersed into laboratory-scale anaerobic digestion system. The pore size of membrane was varied from 0.03 to $\0.15mu$m. The hydraulic retention time of anaerobic digester was varied from 1.5 to 10 days. The effect of hydraulic retention time on treatment efficiency was significant while effect of membrane size was not significant. The gas production was about 0.74㎥/kg COD treated. The COD removal efficient was about 80-95% depending on the hydraulic retention time. ii ) Crossflow ultrafiltration as post treatment to anaerobic filter. The effluent from anaerobic filter, which had a total COD in the range of 4,500-5,200 mg/L was treated by crossflow ultrafiltration units. The study conducted with different membrane pore size indicated that membrace with 1,000,000 molecular weight cut-off size gave a higher COD removal efficiency in the range of 83-87% while giving a study flux of $120-130 L/\m^2$.h. A study was conducted to see the long term clogging effect of membrane also.