• Clean Technology
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• v.9 no.1
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• pp.23-28
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• 2003

The generation of food waste in Korea amounts to 4.10 million per year, which corresponds to 820,000 dry ton of organic waste. This has been used traditionally as animal feed or soil conditioner, but its efficacy has remained doubtful in recent years. In this study as an alternative we considered methane production by anaerobic treatment, which has an advantage of 200 million US dollars over aerobic methods. The production of methane amounts to $4.40{\times}10^8m^3$, 3.43% of $1.28{\times}10^8m^3$, total natural gas used in Korea. Furthermore the methane from household kitchen food waste amounts to 28.9% of the total gas used in the kitchen.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.4
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• pp.151-160
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• 2006

Anaerobic treatment of landfill leachate was studied to investigate the behaviors of pollutant and the characteristics of microorganism for 10 months. The upflow anaerobic sludge blanket (UASB) reactor achieved about 90% chemical oxygen demand (COD) removal at organic loading rates(OLR) up to $20kgCOD/m^3.d$. At higher OLR ($8-20kgCOD/m^3.d$), the propionate concentration increased, indicating that converting propionate to acetate was the rate-limiting step. Nevertheless, increase in the precipitate inside and on the surface of granules as well as on the wall of the reactor resulted in operational problems. The main inorganic precipitate in the granule was calcium compound. Although specific methanogenic activity (SMA) was not affected seriously in this study, metals had to be removed prior to anaerobic treatment so as to be free from the excessive inorganic accumulation that resulted in operational problems.

• Journal of Conservation Science
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• v.33 no.3
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• pp.167-179
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• 2017

In this study, Sangpyeontongbo excavated at Bigyeongdo, Seosan, were investigated to determine the components of the corrosion products that were formed while they were buried underwater in an anaerobic environment. The causes of corrosion product formation were also determined. Microstructure observation, element mapping, principle component analysis for each year, and the detection of corrosion products were carried out. Results indicate that the concretions of corrosion products on the surface are needle-, hexahedral-, and octahedral-shaped; Pb, Cu, and S were among the elements detected. The Cu-S layer was clearly verified using element mapping. An analysis of major elements for each layer showed that Cu, S, and Pb were present and that most Zn was eliminated. The corrosion products detected were $PbCO_3$ (concretion) and $Cu_{1.96}S$ (metal). Accordingly, the anaerobic corrosion properties of Sangpyeongtongbo are summarized as follows: dezincification, copper sulfide, and lead compound.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.660-665
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• 2013

To find out the major cause of scale formation in digestion facility, a componential analysis of scale and a digestion experiment for food wastewater were conducted. The analysis indicated that grease in food wastewater was closely connected to the organic component of scale. It is also indicated that grease-removed food wastewater showed 58.9% level compared to unprocessed one in crystal generation quantity in this study. The experiment provided insight that grease is one of the important causes of scale formation. Additionally, pre-removal of grease from food wastewater did not show negative effect on digestion gas production, as 68.7 L-gas/kg-COD for grease-removed food wastewater and 67.7 L-gas/kg-COD for unprocessed one.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.293-303
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• 1987

A $C_{1}$ enriched cellulase fraction was separated from culture filtrate of anaerobic Clostridium thermocellum by hydroxyapatite column chromatography. The separated fraction showed strong synergistic action with $C_{x}$ component (endo-$\beta$-1, 4-glucanase) in digestion of crystalline cellulose, similar to the other aerobic cellulolytic microorganisms. Unlike the $C_{x}$ component the $C_{1}$ enriched fraction was rapidly inactivated by oxidation at the atmospheric condition. The enzyme activity was significantly enhanced by the addition of reducing agents, especially $\beta$-mercaptoethanol, which indicates that a $C_{1}$ component has a lot of sulfhydryl groups essential for the enzyme activity. The effect of metal ions on $C_{1}$ activity was also investigated. The $C_{1}$ fraction was found to be thermally stable compare to endo-$\beta$-1,4-glucanase. Optimal temperature and pH were found to be $60^{\circ}C$ and 6.0, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.93-101
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• 2000

The objective of this study was to evaluate the possibility of co-digestion of food waste and sewage sludge mixture using anaerobic system. The Biochemical methane Potentials of cabbage and food waste were $297ml\;CH_4/g$ VS and $306.7ml\;CH_4/g$ VS, respectively. The biodegradability of food waste was 60%. The concentrations of acetate, propionate, and isobutyrate produced during the aerobic acidogenesis of food waste for 36 hours were 7,000~7,200 ppm, 260~280 ppm, 380~400 ppm, and 40~50 ppm, respectively, of which acetate was over 85%. The concentrations of acetate, propionate, and isobutyrate produced during the anaerobic acidogenesis for 36 hours were 1,400~1,600 ppm, 30~40 ppm, 220~250 ppm, and 260~300 ppm, respectively, of which acetate was over 70%. The biodegradabilities of aerobic and anaerobic acidogenesis were 30% and 25%, respectively. Methanogensis could be activated under 1 % of NaCl and 1,000 ppm of volatile fatty acids at the range of pH 6.8~7.2. The maximum mixture ratio of food waste and sewage sludge in the present study was 2:8 by the result of VS removal rate and Methane production.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.9
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• pp.542-549
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• 2015

The bioelectrochemical anaerobic digestion for sewage sludge was attempted at different applied voltages ranged from 0.2 V to 0.4 V. At 0.3 V of the applied voltage, pH and VFAs were at 7.32 and 760 mg COD/L, respectively, which were quite stable. The methane production rate was $1.32L\;CH_4/L.d$, and the methane content in biogas was 73.8%, indicating that the performance of the bioelectrochemical anaerobic digestion could be considerably improved by applying a low voltage. At 0.4 V of the applied voltage, however, the contents of the minor VFA components including formic acid and propionic acid were increased. The methane production rate was reduced to $1.24L\;CH_4/L.d$ and the biogas methane content was also reduced to 72.4%. At 0.2 V of the applied voltage, the pH was decreased to 6.3, and VFAs was accumulated to 5,684 mg COD/L. The contents of propionic acid and butyric acid in the VFAs were considerably increased, The performances in terms of the methane production rate and the biogas methane content were deteriorated. The poor performance of the bioelectrochemical reactor at 0.2 V of the applied voltage was ascribed to the thermodynamic potential lack for the driving of the carbon dioxide reduction into methane at cathode.

• Korean Journal of Medicinal Crop Science
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• v.9 no.4
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• pp.275-279
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• 2001

The contents of chemical components such as total nitrogen, total amino acid, chlorophyll, vitamin C and free sugar were somewhat higher in $CO_2$ and $N_2$ gas treatment than those of other treatment. However, the contents of tannin and caffeine did not show any different in the 5 treatments. ${\gamma}-aminobutyric$ acid(GABA) and alanine accumulated in tea leaves under anaerovic condition. The content of GABA acid with ${CO_2\;and\;N_2}$ gas treatment was higher 8-6 times with values of ${264{\sim}215mg/100g}$ than in control (35mg/100g). The scores of sensory test was not different between anaerobic treatment and control. Consequently, tea mading within ${N_2\;and\;CO_2}$ gas treatment after plucking was considered to be the best green tea in terms of functional nature as well as taste nature.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.325-326
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• 2003

매립지 내부에서 진행되는 혐기성 분해로 인한 폐기물의 부패현상은 일반적으로 악취와 관련한 직접적인 대기오염문제에서부터 메탄과 이산화탄소와 같은 온실기체의 발생 등과 같이 기후환경변화와 관련된 문제에 이르기까지 매우 심각한 오염원으로 인식되고 있다. 특히 매립지 내부의 가스상 오염물질들의 누적을 억제하기 위하여 설치하는 배출공에서는 이산화탄소나 메탄과 같은 온실기체 이외에도 약 80여 종에 이르는 다양한 휘발성유기화합물질 (Volatile Organic Compound, 이하 VOC) 성분들이 검출되기도 하였다 (Young and Parker, 1983). (중략)

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.57-65
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• 2008

Wastewater containing strong organic matter is very difficult to treat by utilizing general sewage treatment plant. but the wastewater is adequate to generate biomass energy (bio-gas; methane gas) by utilizing anaerobic digestion. EcoDays Plug Flow Reactor (E-PFR), which was already proved as an excellent aerobic wastewater treatment reactor, was adapted for anaerobic food wastewater digestion. This research was performed to improve the efficiency of bio-gas production and to optimize anaerobic wastewater treatment system. Food wastewater from N food waste treatment plant was applied for the pilot scale experiments. The results indicated that the efficiency of anaerobic wastewater treatment and the volume of bio-gas were increased by applying E-PFR to anaerobic digestion. The structural characteristics of E-PFR can cause the high efficiency of anaerobic treatment processes. The unique structure of E-PFR is a diaphragm dividing vertical hydraulic multi-stages and the inversely protruded fluid transfer tubes on each diaphragm. The unique structure of E-PFR can make gas hold-up space at the top part of each stage in the reactor. Also, E-PFR can contain relatively high MLSS concentration in lower stage by vertical up-flow of wastewater. This hydraulic flow can cause high buffering capacity against shock load from the wastewater in the reactor, resulting in stable pH (7.0~8.0), relatively higher wastewater treatment efficiency, and larger volume of bio-gas generation. In addition, relatively longer solid retention time (SRT) in the reactor can increase organic matter degradation and bio-gas production efficiency. These characteristics in the reactor can be regarded as "ideal" anaerobic wastewater treatment conditions. Anaerobic wastewater treatment plant design factor can be assessed for having 70 % of methane gas content, and better bio-gas yielding and stable treatment efficiency based on the results of this research. For example, inner circulation with generated bio-gas in the reactor and better mixing conditions by improving fluid transfer tube structure can be used for achieving better bio-gas yielding efficiency. This research results can be used for acquiring better improved regenerated energy system.