• 한국물환경학회지
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• 제30권5호
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• pp.559-567
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• 2014

Since the ocean dumping of organic wastes is prohibited under the London Convention, the need for land treatment of food waste leachate (FWL) has significantly been growing in recent years. This study was conducted to use thermal solubilization to turn FWL into a form that can easily be degraded during the anaerobic digestion process, thereby reducing the percentage of solids and increasing the production of methane. To derive the optimal operating conditions of thermal solubilization, a laboratory-scale reactor was built and operated. The optimal reaction temperature and time turned out to be $190^{\circ}C$ and 90 min, respectively. The BMP test showed a methane production of 465 mL $CH_4/g$ $COD_{Cr}$ and a biodegradation rate of 90.1%. The production of methane rose by about 15%, compared with no the application of thermal solubilization. To reduce the solid content of FWL and improve the methane production, therefore, it may be helpful to apply thermal solubilization to pre-treatment facilities for anaerobic digestion.

• 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.

• 상하수도학회지
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• 제7권1호
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• pp.5-12
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• 1993

The objectives of this paper are to present data to illustrate how an advanced digestion process, two-phase digestion, can provide superior performance in terms of waste stabilization efficiency and net energy recovery. As the result, it is possible to separate enrichment cultures of acidogenic and methanogenic organisms in isolated environments by kinetic control involving manipulation of dilution rates. In single-phase digestion process, HRT and COD loading for effective operation were 14.29 days and 2.33kg $COD/m^3$ day, but two-phase digestion may be conducted efficiently at 7 days of HRT and 5.71kg $COD/m^3$ day of loading. Data from this studies showed that the two-phase process is better than single-phase digestion under all test conditions when compared on the bases of gas yield and production rate, reductions of COD and VS, buffer capacity, and unconverted volatile acids in the effluent.

• 한국물환경학회지
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• 제22권4호
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• pp.711-719
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• 2006

The effluent from anaerobic digestion process of slurry-type piggery waste has a characteristic of very low C/N ratio. Because of high nitrogen content, it is necessary to evaluate nitrogen removal alternative rather than conventional nitrification-denitrification scheme. In this study, two parallel treatment schemes of SBR-like partial nitritation reactor coupled with anaerobic ammonium oxidation (ANAMMOX) reactor, and a nitritation reactor followed by nitrite denitrification process were evaluated with a slurry-type piggery waste. The feed to reactors adjusted with various $NH_4-N$ and organics concentration. The nitrite accumulation was successfully accomplished at the loading rate of about $1.0kgNH_4-N/m^3-day$. The $NO_2-N/NH_4-N$ ratio 1~2.6 in nitritated effluent that operated at HRT of 1 day indicated that SBR-like partial nitritation was applicable to ANAMMOX operation. Meanwhile, the nitrite accumulation of 87% was achieved at SBR operated with HRT of 3 days and $0.4mgO_2/L$ for denitritation. Experimental results further suggested that HRT (SRT) and free ammonia(FA) rather than DO are an effective control parameter for nitrite accumulation in piggery waste.

• 대한환경공학회지
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• 제36권12호
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• pp.865-872
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• 2014

본 연구는 수소가스 생산을 위한 brown water(소변을 제외한 대변 + 대변세척수 6 L)의 혐기성 소화 시, 음식물쓰레기 혼합 효과를 평가하기 위해 실시하였다. brown water와 음식물쓰레기의 적절한 혼합 비율을 찾기 위해 회분식 실험이 수행되었고, 도출된 결과는 연속운전 세미파일럿 규모 brown water의 혐기성 소화장치의 실험에 적용되었다. 회분식 실험에서 70%의 음식물쓰레기와 30%의 brown water을 혼합하였을 때 $6.92mmol\;H_2/g\;COD_{removed}$의 최대 수소생산수율을 나타내었다. 동일한 혼합비율로 투입한 음식물쓰레기 및 brown water의 세미파일럿 규모 혐기성 소화조를 운전하였을 때, 반응조 내부에서 수소생산의 중간산물인 butyric acid의 현저한 증가를 보였다. 이 때 수소 생산의 지표인 B/P (butyrate/propionate) 비는 52.64로 나타났고, 수소생산수율은 최대 $25.03mmol\;H_2/g\;COD_{removed}$로 나타났다. 이상의 실험적 연구결과 brown water의 혐기성 수소발효에서 음식물쓰레기의 혼합은 수소발생을 촉진하기 위한 좋은 대안임을 확인하였다.

• 상하수도학회지
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• 제10권2호
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• pp.104-116
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• 1996

Anaerobic digestion is generally used for the treatment of volatile organic solids such as manure and sludge from waste water treatment plants. However, the reaction rate of anaerobic process is slow, and thus it requires a large reactor volume. To minimize such a disadvantage, physical and chemical pre-treatment is generally considered. Another method to reduce the reactor size is to adopt different reactor system other than CSTR. In this paper, the effects of heat pre-treatment and reactor configurations on the anaerobic treatability of volatile solids was studied. Carrot, kale, primary sludge, and waste activated sludge was chosen as the test materials, and the BMP method was used to evaluate the maximum methane production and first order rate constants from each sample. After the heat treatment at $130^{\circ}C$ for 30min., the measured increase in SCOD per gram VS was up to 394 mg/L for the waste activated sludge. However, the methane production potential per gram VS was increased for only primary and waste activated sludge by 17-23%, remaining the same for carrot and kale. The overall methane production process for the tested solids can be described by first order reactions. The increased in reaction constant after heat pre-treatment was also more significant for the primary and waste activated sludge than that for carrot and kale. therefore, the heat pre-treatment appeared to be effective for the solids with high protein contents rather than for the solids with high carbohydrate contents. Among the four reactor systems studied, CSTR, PFR, CSTR followed by PFR, and PFR with recycle, CSTR followed by PFR appeared to be the best choice considering methane conversion rate and the operational stability.

• 펄프종이기술
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• 제46권3호
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• pp.58-64
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• 2014

Management of organic waste such as livestock manure has been considered as very important issue in terms of the environment. The anaerobic digestion of livestock manure become more attractive treatment method and has been widely applied. In this work, the properties of the residue after the anaerobic digestion of livestock manure was evaluated for providing the basic data to develop new application. The lignin and the ash contents of the residue were much higher than those of other biomass such as wood. The components of the residue were also analyzed with SEM-EDS and Elemental Analyzer. The addition of the residue into the handsheet paper resulted in the higher bulk and he higher air permeability with the loss of the strength properties. The water holding capacity of the handsheet were increased until the 40 % addition of the residue.

• 한국물환경학회지
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• 제36권1호
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• pp.55-68
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• 2020

Because of the intensified environmental problems such as climate change and resource depletion, sewage treatment technology focused on energy management has recently attracted attention. The conversion of primary sludge from the primary sedimentation tank and excessive sludge from the secondary sedimentation tank into biogas is the key to energy-positive sewage treatment. In particular, the primary sedimentation tanks recover enriched biodegradable organic matter and anaerobic digestion process produces methane from the organic wastes for energy production. Such technologies for minimizing oxygen demand are leading the innovation regarding sewage treatment plants. However, sewage treatment facilities in Korea lack core technology and operational know-how. Actually, the energy potential of sewage is higher than sewage treatment energy consumption in the sewage treatment, but current processes are not adequately efficient in energy recovery. To improve this, it is possible to apply chemically enhanced primary treatment (CEPT), high-rate activated sludge (HRAS), and anaerobic membrane bioreactor (AnMBR) to the primary sedimentation tank. To maximize the methane production of sewage treatment plants, organic wastes such as food waste and livestock manure can be digested. Additionally, mechanical pretreatment, thermal hydrolysis, and chemical pretreatment would enhance the methane conversion of organic waste. Power generation systems based on internal combustion engines are susceptible to heat source losses, requiring breakthrough energy conversion systems such as fuel cells. To realize the energy positive sewage treatment plant, primary organic matter recovery from sewage, biogas pretreatment, and co-digestion should be optimized in the energy management system based on the knowledge-based operation.

• 상하수도학회지
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• 제26권4호
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• pp.497-502
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• 2012

Anaerobic Digestion Process is evaluated as efficient wastewater treatment process with the removal of high concentrations of organic waste and production of biogas. This study was performed using hybrid anaerobic hybrid reactor (AHR) which consists of anaerobic sludge blanket (UASB) and biofilm-coated filter media was applied for Palm Oil Mill Effluent (POME) for 80 days to know optimum removal efficiency and production of biogas by comparing each part which divided changing Organic Loading Rate (OLR). As a result of this study, the removal efficiency was 90.4 % when the organic loading rate of influent was 15 kg COD/$m^3$/day. Since organic loading rate was up to 20 kg COD/$m^3$/day, the removal rate declined 80.7%. Over loading of influent caused sludge expansion and overproduction of microorganism. Amount of biogas was collected 82.3 L/day and pH was remained 6.9 constantly with balance of alkalinity.

• 한국환경농학회지
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• 제21권4호
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• pp.248-254
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• 2002

가축분뇨를 혐기성소화하여 메탄가스를 생산하고 난 다음 혐기성 소화액비를 비료자원으로 활용하기 위하여 농가포장에서 액비의 시용적량을 구명하였다. 벼 생육상황은 액비 100%+화학비료구가 전 시기를 통해 가장 양호하였으며, 그 다음으로 표준시비구가 분얼기에만 양호하였으나 그 이후에는 표준시비구 액비 100%구 및 액비 150%구 간에는 서로 차이가 없었다. 시기별 식물체중 전질소함량은 분얼기 및 출수기에는 추비의 영향으로 표준시비구가, 유수형성기에는 액비 100%+화학비료구가 높았다. 벼 수량은 액비 100% 및 150%구들이 표준시비구와 비슷하거나 약간 증수되었으며, 액비 100%+화학비료구는 고중의 증가 및 도복으로 인하여 표준시비구보다 수량이 오히려 약간 낮았다. 수확기 질소흡수량은 표준시비구가 가장 높았고, 시비질소 효율은 액비 100%구에서, 시비질소 이용율은 액비 100%+화학비료구에서 높았다. 시기별 토양중 $NH_4-N$ 및 $NO_3-N$함량 변화는 액비 100%+화학비료구가 타 처리구보다 높았다. 시기별 관개수 중 $NH_4-N$ 및 $NO_3-N$함량 변화는 분얼비의 영향으로 급격히 증가하였다가 급격히 감소하였는데, 증가한 시기에는 표준시비구 및 액비 100%+화학비료구가 가장 높았다. 시기별 침투수 중 $NH_4-N$함량 변화는 액비 150%구들에서 많이 용탈되었고, $NO_3-N$ 함량은 액비에 화학비료를 추비한 구들에서 많이 용탈되었다. 혐기성 소화액비는 액비 중의 질소성분을 분석하여서 표준시비량의 질소성분에 맞추어 시용하여야 한다.