• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제30권8호
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• pp.1198-1205
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• 2017

Objective: An experiment was conducted to isolate and identify new methanogens in Korea from an anaerobic digester that uses pig slurry. Methods: An anaerobic digestate sample was collected from an anaerobic digester using pig slurry. Pre-reduced media were used for the growth and isolation of methanogens. Growth temperature range, pH range, NaCl concentration range, substrate utilization, and antibiotic tolerance were investigated to determine the physiological characteristics of isolated methanogens. The isolates were also examined microscopically for their morphology and Gram-stained. Polymerase chain reaction of 16S rRNA and mcrA gene-based amplicons was used for identification purpose. Results: Four strains, designated KOR-3, -4, -5, and -6, were isolated and were non-motile, irregular coccoid, and 0.5 to $1.5{\mu}m$ in diameter. Moreover, the cell walls of isolated strains were Gram-negative. KOR-3 and KOR-4 strains used acetate for methane production but did not use $H_2+CO_2$, formate, or methanol as a growth substrate KOR-5 and KOR-6 strains utilized acetate, methanol, and trimethylamine for methanogenesis but did not use $H_2+CO_2$ or formate as a growth substrate. The optimum temperature and pH for growth of four strains were $39^{\circ}C$ and 6.8 to 7.2, respectively. The optimum concentration of NaCl for growth of KOR-3, KOR-5, and KOR-6 were 1.0% (w/v). The optimum NaCl concentration for KOR-4 was 0.5% (w/v). All of the strains tolerated ampicillin, penicillin G, kanamycin, streptomycin, and tetracycline; however, chloramphenicol inhibited cell growth. Phylogenetic analysis of 16S rRNA and mcrA genes demonstrated that strains KOR-3, -4, -5, and -6 are related to Methanosarcina mazei (M. mazei, 99% sequence similarity). Conclusion: On the basis of physiological and phylogenetic characteristics, strains KOR-3, -4, -5, and -6 are proposed to be new strains within the genus Methanosarcina, named M. mazei KOR-3, -4, -5, and -6.

• 한국토양비료학회지
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• 제45권6호
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• pp.1086-1093
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• 2012

본 연구는 유기성 바이오매스의 혐기소화율 평가에 주로 이용되는 VDI4630법에 대하여 소화액에 녹아 있는 탄산이온 ($CO_3{^{2-}}$)과 혐기소화 미생물 반응에 참여하는 수분 ($H_2O$)이 유기물의 혐기적 분해율에 미치는 영향을 분석하였으며, 이를 위해 탄산이온과 수분반응물에 의한 유기물의 혐기적 분해율 산출 보정식을 개발 하고자하였다. 돼지 혈액, 돼지 내장잔재물, 돼지 장내잔재물, 소 반추위잔재물의 화학조성식은 각각 $C_{3.78}H_{8.39}O_{1.46}N_1S_{0.01}$, $C_{9.69}H_{15.42}O_{2.85}N_1S_{0.03}$, $C_{25.17}H_{43.32}O_{15.04}N_1$, $C_{27.23}H_{42.38}O_{15.93}N_1S_{0.11}$으로 나타났으며, 돼지 혈액, 돼지 내장 잔재물, 돼지 장내잔재물, 소 반추위잔재물에서 이론적으로 1 mol의 유기물이 분해되는데, 0.336, 0.485, 0.227, 0.266 mol의 수분이 참여하였다. 혐기적 유기물 분해율에서 이론적 메탄생산퍼텐셜 대비 실험적 메탄생산퍼텐셜 ($B_u/B_{th}$)의 비율로 산출한 유기물 분해율은 돼지 혈액, 돼지 내장 잔재물, 돼지 장내잔재물, 소 반추위잔재물에서 각각 82.3, 81.5, 70.8, 66.1%이었으며, VDI4630에 근거한 유기물 분해율 (AB)은 각각 72.2, 87.8, 74.2, 62.0%를 보여 이론적 메탄생산퍼텐셜 대비 실험적 메탄생산퍼텐셜 ($B_u/B_{th}$)의 비율로 산출하는 유기물 분해율과는 전체 시험구에서 통계적으로 유의성 있는 차이를 보였다. VDI4630법에 소화액 중의 알칼리도를 보정한 유기물 분해율 (AB-I)은 돼지 혈액, 돼지 내장 잔재물, 돼지 장내잔재물, 소 반추위잔재물에서 각각 72.4, 88.1, 74.5, 62.1%를 보였으며, 알칼리도와 수분 반응물을 동시에 보정한 유기물 분해율 (AB-II)에서는 각각 72.5, 88.5, 74.5, 62.3%를 보여 본 연구에서 시험한 각각의 시료에서의 유기물 분해율 AB, AB-I, AB-II 간의 평균은 통계적으로 유의성 있는 차이를 보이지 않았다. 그러나 알칼리도, 수분 반응물의 보정식은 유기물의 혐기적 분해율의 측정에서 좀 더 높은 정확도를 보일 수 있을 것으로 판단된다.