• Asian-Australasian Journal of Animal Sciences
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• 제12권4호
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• pp.607-628
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• 1999

The swine waste industry is growing rapidly along with the world human population. The trend is toward more concentrated piggeries with numbers of herds in the thousands. Associated with these increased herds are large quantities of wastes, including organic matter, inorganic nutrients, and gaseous emissions. The trend in swine waste management is toward treatment of these wastes to minimize negative impact on the health and comfort of workers and animals and the atmosphere, water, and soil environments. Treatment of these wastes has traditionally involved land application, lagoons, oxidation ditches, and conventional batch and continuously stirred reactor designs. More sophisticated treatment systems are being implemented, involving advanced anaerobic digester designs, integrated with solids separation, aerobic polishing of digester effluents, and biological nutrient removal. This review discusses the present and future role of anaerobic processes in piggery waste treatment with emphasis on reactor design, operating and performance parameters, and effluent processing.

• Asian-Australasian Journal of Animal Sciences
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• 제5권2호
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• pp.199-215
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• 1992

Sources of organic waste materials for aerobic and/or anaerobic degradation, or for composting of solid wastes in Germany were estimated. The basic microbiology and the energetics of these processes were compared with special emphasis on anaerobic degradation, for which a general degradation scheme of carbohydrates is presented. Advantages of anaerobic over aerobic treatment processes are pointed out and conditions for maintaining a highly stable anaerobic process as well as producing a sanitized, hygienic product are discussed. Reactor systems suitable for efficient treatment of wastes with a high or low proportion of suspended solids are principally compared and results of laboratory studies on the degradation of several wastes and animal manures summarized. Finally, a piggery slurry treatment factory for an ultimate slurry processing to obtain a dry fertilizer and a harmless, disposable liquid, as it is in operation in Helmond/Holland, is presented and preliminary process data are presented.

• Environmental Engineering Research
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• 제11권3호
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• pp.143-148
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• 2006

The ultrasonics is a new technology in waste activated sludge(WAS) treatment. Ultrasonic treatment is well known method for the break up of microbial cells to extract out a variety of intercellular materials inside microorganism cell. This study was done to investigate the effects of the ultrasonic frequency and power on disruption of biosolids in WAS and to examine the effect on methane production of WAS treated by ultrasonics. Biosolids disruption with ultrasound is more effective at ultrasonic frequency of 40 kHz and power of 0.3 watt/mL. In the digestion with WAS pretreated by sonication time for 10 minute at 40 kHz and 0.3 watt/mL, the total quantity of generated methane increased by 75%, as compared with experimental control(non-treatment).

• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1235-1243
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• 2020

The use of microalgal biomass as feedstock for biofuels has been discussed for decades as it provides a sustainable approach to producing fuels for the future. Nonetheless, its feasibility has not been established yet and various aspects of biomass applications such as CO₂ biofixation should also be explored. Therefore, in this study, the CO₂ biofixation and lipid/carbohydrate production potential of Chlorella sp. ABC-001 were examined under various nitrogen concentrations. The highest biomass productivity and CO₂ biofixation rate of 0.422 g/l/d and 0.683 g/l/d, respectively, were achieved under a nitrogen-rich condition (15 mM nitrate). Carbohydrate content was generally proportional to initial nitrate concentration and showed the highest value of 41.5% with 15 mM. However, lipid content showed an inverse relationship with nitrogen supplementation and showed the highest value of 47.4% with 2.5 mM. In consideration as feedstock for biofuels (bioethanol, biodiesel, and biogas), the sum of carbohydrate and lipid contents were examined and the highest value of 79.6% was achieved under low nitrogen condition (2.5 mM). For lipid-based biofuel production, low nitrogen supplementation should be pursued. However, considering the lower feasibility of biodiesel, pursuing CO₂ biofixation and the production of carbohydrate-based fuels under nitrogen-rich condition might be more rational. Thus, nitrogen status as a cultivation strategy must be optimized according to the objective, and this was confirmed with the promising alga Chlorella sp. ABC-001.

• 한국유기농업학회지
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• 제20권3호
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• pp.327-343
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• 2012

In order to develop a high cellulolytic direct-fed microorganism (DFM) for ruminant productivity improvement, this study isolated cellulolytic bacteria from the rumen of Holstein dairy cows, and compared their cellulolytic abilities via DM degradability, gas production and cellulolytic enzyme activities. Twenty six bacteria were isolated from colonies grown in Dehority's artificial (DA) medium with 2% agar and cultured in DA medium containing filter paper at $39^{\circ}C$ for 24h. 16s rDNA gene sequencing of four strains from isolated bacteria showed that H8, H20 and H25 strains identified as Ruminococcus flavefaciens, and H23 strain identified as Fibrobacter succinogenes. H20 strain had higher degradability of filter paper compared with others during the incubation. H8 (R. flavefaciens), H20 (R. flavefaciens), H23 (F. succinogenes), H25 (R. flavefaciens) and RF (R. flavefaciens sijpesteijn, ATCC 19208) were cultured in DA medium with filter paper as a single carbon source for 0, 1, 2, 3, 4 and 6 days without shaking at $39^{\circ}C$, respectively. Dry matter degradability rates of H20, H23 and H25 were relatively higher than those of H8 and RF since 2 d incubation. The cumulative gas production of isolated cellulolytic bacteria increased with incubation time. At every incubation time, the gas production was highest in H20 strain. The activities of carboxymethylcellulase (CMCase) and Avicelase in the culture supernatant were significantly higher in H20 strain compared with others at every incubation time (p<0.05). Therefore, although further researches are required, the present results suggest that H20 strain could be a candidate of DFM in animal feed due to high cellulolytic ability.

• Environmental Engineering Research
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• 제24권4호
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• pp.662-669
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• 2019

Anaerobic digestion is a popular sewage sludge (Ss) treatment method as it provides significant pollution control and energy recovery. However, the low C/N ratio and poor biodegradability of Ss necessitate pretreatment methods that improve solubilization under anaerobic conditions in addition to anaerobic co-digestion with other substrates to improve the process efficiency. In this study, three pretreatment methods, namely microwave irradiation, ultrasonication, and heat treatment, were investigated, and the corresponding improvement in methane production was assessed. Additionally, the simplex centroid design method was utilized to determine the optimum mixture ratio of food waste (Fw), livestock manure (Lm), and Ss for maximum methane yield. Microwave irradiation at 700 W for 6 min yielded the highest biodegradability (62.0%), solubilization efficiency (59.7%), and methane production (329 mL/g VS). The optimum mixture ratio following pretreatment was 61.3% pretreated Ss, 28.6% Fw, and 10.1% Lm. The optimum mixture ratio without pretreatment was 33.6% un-pretreated Ss, 46.0% Fw, and 20.4% Lm. These results indicate that the choice of pretreatment method plays an important role in efficient anaerobic digestion and can be applied in operational plants to enhance methane production. Co-digestion of Ss with Fw and Lm was also beneficial.

• 한국물환경학회지
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• 제35권4호
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• pp.362-369
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• 2019

In this study, biodegradation efficiency improvement of mixed sludge for the anaerobic digestion process in wastewater treatment plant was investigated. In order to release the organic material contained in the sludge cell and promote the hydrolysis step, mixed sludge of 7% TS (Total Solids) was physically shear-treated at a shear strength of 1,000 ~ 4,000 rpm and a maximum of 120 mins. As a result of the comparison between mixed sludge before and after the treatment, the concentration of $SCOD_{Cr}$(Soluble Chemical Oxygen Demand-chromium method) was increased through the conversion of granular organic matter into dissolved organic matter as shear strength and treatment time increases. The solubilization efficiency increased rapidly after 30 min of solubilization application time, and they were 11.23 %, 20.10 %, 22.52 % and 25.43% at 120 min for each shear strength conditions, respectively. Additionally, the BMP(Biochemical Methane Potential) test was conducted with the optimized samples to determine the increase of methane production by the shear pre-treatment. Consequently, methane production of each samples were 0.275, 0.310, 0.323 and $0.335m^3/kg\;VS_{add}$, which indicates that methane production was increased to a maximum of 21.28% compared to the control without the solubilization process ($0.262m^3/kg\;VS_{add}$). As a result, the physical shear-treatment is a promising process for sewage sludge pre-treatment to reduce the organic waste and increase the energy production.

• 대한환경공학회지
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• 제33권9호
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• pp.662-669
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• 2011

본 연구에서는 메탄의 생물학적 메탄올 전환에 관한 연구를 수행하였다. 바이오가스 중의 메탄은 메탄산화균의 methane monooxygenase (MMO)의 생물학적 촉매반응에 의해 산화되었으며, 인산염, NaCl, $NH_4Cl$, EDTA와 같은 methanol dehydrogenase (MDH)의 활성 저해제를 이용하여 MDH의 활성도를 저해함으로써 메탄올의 전환이 이루어졌다. 메탄산화균은 $35^{\circ}C$, pH 7, 인공 바이오가스($CH_4$ 50%, $CO_2$ 50%) / Air의 부피비가 0.4인 조건에서 메탄 산화 정도가 0.56 mmol로 최대로 나타났다. 인산염 40 mM, NaCl 50 mM, $NH_4Cl$ 40 mM, EDTA $150{\mu}m$ 이하일 때 저해제의 종류에 상관없이 메탄 산화율은 80% 이상을 달성하였다. 한편, 인산염 40 mM, NaCl 100 mM, $NH_4Cl$ 40 mM, EDTA $50{\mu}m$ 주입 시 각각 1.30, 0.67, 0.74, 1.30 mmol의 메탄이 산화되는 동시에 각각 0.71, 0.60, 0.66, 0.66 mmol의 메탄올이 최대로 생성되었다. 이때의 메탄올 전환율은 각각 54.7, 89.9, 89.6 및 47.8%였으며 최대 메탄올 생성 속도는 $7.4{\mu}mol/mg{\cdot}h$였다. 이로부터 대상 저해제로 MDH 활성도를 일반적으로 35% 저해 시에 메탄올 생산량이 최대인 89.9%까지 나타남을 알 수 있었다.

• 한국토양비료학회지
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• 제44권6호
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• pp.1245-1251
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• 2011

본 연구는 축산부문에서 주요한 가축종인 돼지의 사육과 정과 도축 가공과정에서 발생하는 양돈 바이오매스의 발생특성을 조사 분석하고, 전과정 평가 기법을 활용하여 물질(퇴 액비) 및 에너지 (바이오가스) 자원화 잠재량을 평가함으로써 지역단위 바이오매스 순환단지 조성을 위한 기초자료를 확립하고자 하였으며, 이를 위해 양돈 바이오매스의 발생 단계를 사양단계와 도축 가공단계로 구분하여 각각의 단계에서 발생하는 양돈바이오매스의 물질 및 에너지 자원화 잠재량을 평가하였다. 사양단계는 성장단계(사육기간, 평균체중)에 따라 자돈 (1~9주, 23.4 kg), 육성돈 1기 (10~15주, 50 kg), 육성돈 2기 (16~21주, 80 kg), 비육돈 (22~26주, 110 kg)의 단계로 분류하고 도축 가공단계에서 발생하는 혈액과 폐내장류, 장내 잔재물로 구분하여 생산량을 산정하여 양돈 바이오매스의 물질 및 에너지 자원 잠재량을 평가한 결과 돼지 1두에서 발생하는 바이오매스의 총량은 542.02 kg로 나타났다. 양돈 바이오매스는 분 $210.68kg\;head^{-1}$, 뇨 $315.78kg\;head^{-1}$가 발생하는 것으로 평가되었으며, 분뇨 발생량은 성장단계별로 자돈 14.2%, 육성돈 1기 19.6%, 육성돈 2기 30.9%, 비육돈 35.2%를 차지하는 것으로 나타났다. 양돈 바이오매스에서 기인하는 매탄 생산 잠재량은 $24.56Nm^3\;head^{-1}$이였으며, 사양 단계에서 기인하는 메탄 생산 잠재량이 92.9%를 차지하는 것으로 나타났다. BMP 시험에 의한 최대 메탄생산량은 $16.58Nm^3\;head^{-1}$로 나타나 매탄 생산 잠재량의 67.5%가 에너지로 전환 가능하였으며, 94.4%가 사양 단계에서 기인하는 것으로 나타났다.

• 한국환경농학회지
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• 제30권3호
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• pp.295-303
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• 2011

혐기성 소화 반응조에서 항생항균물질의 영향을 평가하기 위해서 회분식 및 연속식 실험을 통하여 biogas 발생량, 유기산 생성, 유기물 제거 거동 등을 관찰하였다. 회분식 조건에서 단일항생항균물질 1~10 mg/L에서는 저해 영향이 관찰되지 않았으며, 50 mg/L에서 일부 VFAs가 축적되었고 16~30%의 유기물 제거효율이 감소되었지만, 일시적 저해 영향 후 점차 안정되었다. 그러나 항생항균물질 100 mg/L에서 바이오가스 발생량이 48~58% 감소하였으며, VFAs가 메탄으로 전환되지 않고 축적되었다. 연속식 반응기에서 4종의 혼합항생항균물질을 1~10 mg/L 주입시 미생물에 대한 저해영향은 없었으며, 50 mg/L 주입시 30~40%의 메탄가스 발생량이 감소하였고, 이는 이론적 메탄발생량의 60~65% 수준이었다. 항생항균물질 100 mg/L 주입시 85% 감소한 약 2.2 L/day의 바이오가스가 발생하였으며, 서서히 회복하여 7.2 L/day까지 바이오가스가 발생하였으나 대조군 대비 52% 수준이상은 회복되지 않았다. 항생항균물질 50 mg/L에서는 독성 저해 후 반응조 체류시간의 3배인 약 30일 정도 후 유기물 제거효율 및 바이오가스 회수가 가능하였으나, 100 mg/L 주입 후 40일 후에도 유기물 제거효율 및 바이오가스 발생량은 낮은 수준이었다. 따라서 혐기성 소화조에 고농도 항생항균물질이 유입되어 저해영향이 관찰되었을 경우 소화슬러지의 일부 또는 전체를 교체해야 할 것으로 판단된다. 혼합항생항균물질을 10~100 mg/L까지 주입하였을 경우 잔류항생항균물질 농도는 주입 6시간 후 CTC 80~90%, OTC 50~70%, SMZ 80~90%, TLS 20~40%가 반응조내에서 독성으로 작용한 후 입자성 유기물이나 EPS 등에 흡착되거나 소화온도에 의하여 감소한 것으로 판단된다. 따라서 혐기성 처리를 이용한 공정에 고농도 항생항균물질이 포함된 유기성폐수가 유입되었을 경우 공정의 유지관리에 어려움을 줄 수 있으며, 혐기소화조 유출수내 잔류항생항 균물질이 자연수계로 유입될 경우 2차 오염을 야기할 수 있기 때문에 항생항균물질의 사용의 적절한 관리가 요구되어 진다.