실험실 규모 2상 혐기성 소화를 이용한 음식물 쓰레기 탈리액의 처리

허안희(Ahn Hee Heo),이은영(Eun Young Lee),김희준(Hee Jun Kim),배재호(Jae Ho Bae) 大韓環境工學會 2008 대한환경공학회지 Vol.30 No.12

본 연구에서는 실험실 규모 2상 혐기성 소화를 이용하여 음식물 쓰레기 탈리액의 처리성을 평가하였다. 이를 위해 산발효조의 적정 유입 pH 및 HRT를 도출하고, 산발효조로의 메탄조 유출수 반송 효과, 메탄발효조에서 고형물 내부반송 및 온도의 영향을 파악하였다. 산발효조에서는 유입 pH 6.0, HRT 2일인 조건에서 메탄조 유출수 반송 후 산생성 및 VS 제거효율은 30% 및 40%에서 안정적으로 유지되었다. 유기물 부하 7 g COD/L/d 이하의 조건에서 고형물 내부반송에 의해 중온 및 고온메탄발효조의 유출수 SCOD는 반송 이전보다 낮거나 같은 수준으로 유지되었고 유기물 부하 증가에 따른 비메탄생성량(specific methane production, SMP)의 감소폭이 줄어들었다. 고형물 내부반송 이후 동일한 유기물 부하에서 COD 제거효율과 SMP는 중온메탄발효조가 고온보다 우수하였으며 이는 중온메탄발효조의 MLVSS 농도가 고온보다 높기 때문인 것으로 판단되었다. 따라서 고온산발효-중온메탄발효로 구성된 시스템이 고온산발효-고온메탄발효보다 COD 제거와 메탄발생면에서 우수한 것으로 나타났다. This study was performed to evaluate the treatability of food waste leachate using lab-scale two-phase anaerobic digestion system. Effects of influent pH, hydraulic retention time (HRT), and recycle of methanogenic reactor effluent to the thermophilic acidogenic reactors were investigated. For methanogenic reactors, effects of internal solids recycle and temperature were studied. Performance of the acidogenic reactors was stable under the conditions of influent pH of 6.0 and HRT of 2 d with the recycle of methanogenic reactor effluent, and acidification and VS removal efficiency were about 30% and 40%, respectively. Up to the organic loading rate (OLR) of 7 g COD/L/d, effluent SCOD values of mesophilic and thermophilic methanogenic reactors either lower or kept the same with the internal solids recycle. Also, decreasing tendency in specific methane production (SMP) due to the organic loading increase became diminished with the internal solids recycle. Mesophilic methanogenic reactors showed higher TCOD removal efficiency and SMP than thermophilic condition under the same OLR as VSS was always higher under mesophilic condition. In sum, thermophilic acidogenesis-mesophilic methanogenesis system was found to be better than thermophilic-thermophilic system in terms of both organic removal and methane production.

Biotransformation of Eugenol via Protocatechuic Acid by Thermophilic Geobacillus sp. AY 946034 Strain

( Grazina Giedraityte ),( Lilija Kalediene ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.4

The metabolic pathway of eugenol degradation by thermophilic Geobacillus sp. AY 946034 strain was analyzed based on the lack of data about eugenol degradation by thermophiles. TLC, GC-MS, and biotransformation with resting cells showed that eugenol was oxidized through coniferyl alcohol, and ferulic and vanillic acids to protocatechuic acid before the aromatic ring was cleaved. The cell-free extract of Geobacillus sp. AY 946034 strain grown on eugenol showed a high activity of eugenol hydroxylase, feruloyl-CoA synthetase, vanillate-Odemethylase, and protocatechuate 3,4-dioxygenase. The key enzyme, protocatechuate 3,4- dioxygenase, which plays a crucial role in the degradation of various aromatic compounds, was purified 135-fold to homogeneity with a 34% overall recovery from Geobacillus sp. AY 946034. The relative molecular mass of the native enzyme was about 450 ± 10 kDa and was composed of the non-identical subunits. The pH and temperature optima for enzyme activity were 8 and 60oC, respectively. The half-life of protocatechuate 3,4-dioxygenase at the optimum temperature was 50 min.

느타리버섯 배지로부터 느타리버섯 균사의 성장을 돕는 고온성 곰팡이의 분리 및 동정

이호용,현성희 한국미생물학회 2000 미생물학회지 Vol.36 No.1

버섯을 재배하는데 있어 버섯 균사의 성장은 고온성 곰팡이의 성장과 밀접한 연관이 있다. 느타리버섯 재배용 배지의 후발효 과정에서 느타리균사에 대하여 성장촉진 효과를 나타내는 7종의 thermophilic fungi를 순수분리 하였다. 각 7종의 thermophilic fungi모두 PDA(potato dextrose agar) 배지, $50^{\circ}C$에서 균사의 최적성장을 나타내었으며, 그 중 S-1, S-2 균주가 균사성장률이 가장 높았다. 또한 느타리버섯 폐면 배지에서도 좋은 성장을 나타내 우수한 고온성 후발효 균주로의 사용 가능성이 기대되었다. 액체배양 시 배지의 최초 pH는 pH 7.0- pH 10.0까지 다양한 구간에서 최적상태를 나타내었으나, pH 8.0또는 pH 9.0의 약알칼리 환경에서 잘 자랐으며, 배양 후 배지의 pH는 pH 5.5-6.0의 약산성을 띄었다. 이러한 최적환경에서 성장률을 측정한 결과 S-2 균주가 높은 성장률(0.47-0.50g/10 days)을 나타내었다. 형태적인 분류법에 따라 분류한 결과 S-1 균류는 Trichophyton sp.으로 동정되었으며, 이 외의 6 균주는 Sepedonium sp으로 분류되었다. 느타리버섯 후발효 과정에서 나타난 고온성 곰팡이들의 분포는 양송이 배지 숙성과정에 나타나는 고온성 곰팡이들의 분포와는 매우 달랐다. 이는 배지 성분 차이에 따른 생태적 차이로 판단되었다. Some of thermophilic fungi which has growth-promoting effect on Pleurotus ostreatus were isolated from compost during high temperature fermentation process. The temperature optima of 7 isolated thermophilic fungi were $50^{\circ}C$ on PDA media. Isolated strains S-1 and S-2 have the best mycelial growing rate, so these isolates were expected as excellent thermophilic fungi for high temperature composting and mycelial growing of oyster mushroom. In liquid culture, the optimal pH of thermophilic fungi observed variously, pH 7.0-10.0 but most of thermophilic fungi grow well in pH 8.0-pH 9.0 and the final pH of media after cultured was done pH 5.5-6.0. In liquid culture of thermophilic fungi on the optimal condition, S-2 have the best mycelial growing rate. The growing rate of thermophilic fungi S-1, S-2, S-5, and S-10 on lignocellulosic substrates was good but Humicola grisea var. thermoidea, well know thermophilic fungi which has growth-promoting effect on Agaricus bisporus, was poor and which was well grown on PDA at $50^{\circ}C$, pH 7.0. Isolated strain S-1 was identified as Trichophyton sp. and other 6 strains were identified as Sepedonium sp. by morphological characteristics.

Microbial Activity and Population Structure of Anaerobic Sludge Alternately Exposed to Mesophilic and Thermophilic Conditions

Young Chae Song,Jung Hui Woo,Sang Jo Kwon,Sung Cheol Koh 대한토목학회 2006 KSCE journal of civil engineering Vol.10 No.5

The microbial community structures of anaerobic sludge, alternately exposed to mesophilic and thermophilic condition, were investigated and their microbial activities under mesophilic and thermophilic conditions. PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) profiles for the eubacterial and archaebacterial communities from thermophilic sludge alternately exposed to mesophilic condition (TSEM) and mesophilic sludge alternately exposed to thermophilic condition (MSET) had a few populations in common, these are probably thermophilic microorganisms. The population profiles for archaebacterial communities of TSEM and MSET were quite different from each other. For TSEM under thermophilic condition, the specific methanogenic activity (SMA) was 159.6mL CH₄/g YSS/d, which was higher than 106.3mL CH₄/g VSS/d under mesophilic condition. The SMA for MSET under both temperature conditions was as much as those of TSEM. The lag phase period for MSET in the batch culture was around 2 times longer than TSEM, but the lag periods for both sludges under thermophilic condition were shorter than those under mesophilic condition. The acidogenic activity for both sludge types in MSET was slightly higher than TSEM under the thermophilic and mesophilic conditions. The specific hydrolytic activity for the two sludge types was higher under the mesophilic condition, and the hydrolysis potential of TSEM incubated under mesophilic condition was higher than other cases.

고농도 유기성 폐수 처리를 위한 고온호기법에서의 미생물상 특성

조경숙 이화여자대학교 생명과학연구소 1995 생명과학연구논문집 Vol.6 No.-

많은 SS를 포함하는 고농도 유기성 폐수인 주정폐수를 고온호기법(TOP)에 의해 처리하는 과정에서의 미생물상의 변화에 대하여 조사하였다. BOD부하량을 4㎏ BOD·m_-3·d_-1, 통기량을 200ℓ·m_-3·min_-1의 조건으로 2일에 한번 폐수를 투입하면서 30일간 연속적으로 주정폐수를 처리한 결과, 96%의 유기탄소화합물이 CO_2로 무기물화됨을 알 수 있었다. 이 처리 과정동안에 수분은 유기물의 분해시 생성된 열과 전열기에 의해 가해진 열에 의하여 모두 증발 되었고, 잉여슬러지의 생성은 매우 적었다. TOP에 의해 주정폐수를 분해하는 동안, 반응기 내부 온도가 증가함에 따라, 고온성 세균의 밀도가 증가하는 것이 관찰되었으나, 4일 이후로는 고온성 세균수가 거의 일정해져 평균 세균수는 6.65×10^8c.f.u/g-day charocoals 이었다. 고온성 방선균과 곰팡이는 거의 관찰되지 않았는데, 이들의 미생물은 고온호기법에서는 유기물의 분해에 거의 관여하지 않는 것으로 사료되었다. TOP 반응기에 주정폐수를 최초로 투입했을 때와 20일간 우전한 후의 반응기내의 quinone profiel을 비교해보면, menaquinone-7성분이 현저하게 증가하였고, 전체 quinone의 42mole%를 차지하였다. 이들의 결과로부터 고온호기법에 의하여 주정폐수를 처리하는 데에 있어서 menaquione-7을 주성분으로 가진 고온성 세균이 유기물 분해에 관여하는 중요 미생물인 것을 알 수 있었다. Thermophilic oxic process was applied to treat the liquor processed wastewater which contained hogh amounts of organic matters and suspended solids, and the microbial population was charaterized during the treatment of wastewater. When Bod load and aeration rate were 4 ㎏ BOD·m_-3·d_-1 and 200ℓ·m_-3·min_-1, respectively, 96 % of organic carbon compounds in the wastewater were decomposed to CO_2. Due to evaporation of water, darin water wsa not detected. Extremely little amount of exess sludge was formed. With increasing the temperature in the reator the density of thermophilic bacteria gradually grew at the initial stage, and then the constancy of the number of thermophilic bacteria was observed after 4 days. The average number of therophilic bacteria was 6.65×10^8c.f.u/g-day charocoals. Little appearance of therophilic actinomycetes and fungi indicated that their contribution was insignificant in the decomposition of orgnic matters in this process. Comparing to the quione profiels in the reactor after the treatment of liquor processed wastewater by TOP for ! and 20 days, remarkable increase of menquinone-7 was observed, and the concentration of menaquinone-7 in total quinone was 42 mole% after 20days. This result indicated that thermophilic bacteria containing menaquinone were responsible for the decomposition of liquor processed wastewater in thermophilic oxic process.

Dry semi-continuous anaerobic digestion of food waste in the mesophilic and thermophilic modes: New aspects of sustainable management and energy recovery in South Korea

Nguyen, Dinh Duc,Chang, Soon Woong,Cha, Jae Hun,Jeong, Seong Yeob,Yoon, Yong Soo,Lee, Sin Jin,Tran, Minh Chi,Ngo, Huu Hao Elsevier 2017 Energy conversion and management Vol.135 No.-

<P><B>Abstract</B></P> <P>In this study, parallel, bench-scale, mesophilic and thermophilic, dry, semi-continuous anaerobic digestion (DScAD) of Korea food waste (FW, containing 22% total solids (TS) and 20% volatile solids (VS)) was investigated thoroughly under varying operational conditions, including hydraulic retention times (HRTs) and organic loading rates (OLRs). The aim was to evaluate the start-up, stability, overall removal efficiency, and inhibitory effects of toxic compounds on process performance over a long-term operation lasting 100days. The results from both digesters indicate that the simultaneous reduction of VS and the production of gas improved as the HRT decreased or the OLR increased. The highest average rates of VS reduction (79.67%) and biogas production (162.14m<SUP>3</SUP> biogas/ton of FW, 61.89% CH<SUB>4</SUB>), at an OLR of 8.62±0.34kgVS/m<SUP>3</SUP> day (25days of HRT), were achieved under thermophilic DScAD. In addition, the average rates of reduction of VS and the production of biogas in thermophilic DScAD were higher by 6.88% and 16.4%, respectively, than were those in mesophilic DScAD. The inhibitory effects of ammonia, H<SUB>2</SUB>S, and volatile fatty acids (VFAs) on methane production was not clear from either of the digesters, although, apparently, their concentrations did fluctuate. This fluctuation could be attributed to the self-adaptation of the microbial well. However, digestion that was more stable and faster was observed under thermophilic conditions compared with that under mesophilic conditions. Based on our results, the optimum operational parameters to improve FW treatment and achieve higher energy yields could be determined, expanding the application of DScAD in treating organic wastes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> DScAD remained stable even at a high rate of organic loading. </LI> <LI> Higher OLR led to the more reduction of VS and the production of biogas. </LI> <LI> Thermophilic digesters had higher reduction of VS and the generation of biogas. </LI> <LI> Stable with faster digestion and higher OLR was achieved in the thermophilic operation. </LI> <LI> Acetic and propionic acids were the most prominent in the TVFA. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

고온 및 중온에서 유기물 부하에 따른 음폐수의 이상 혐기성소화

박혜린,박준규,홍의환,전항배 한국수처리학회 2019 한국수처리학회지 Vol.27 No.4

This study demonstrates effects of temperature and organic loading rate (OLR) on performance of anaerobic digestion of food waste leachate. Thermophilic and mesophilic two-phase anaerobic digestion reactors were constructed to compare performance by increasing OLR. Thermophilic two-phase anaerobic digestion reactor shows a higher solubilization efficiency and operational stability than those of mesophilic two-phase anaerobic digestion reactor. Methane was efficiently produced in thermophilic two-phase anaerobic digestion reactor by high hydrolysis and acidogenesis efficiencies. At run 3 (OLR 10kg/m3·d), specific methane production (SMP) was decreased in both of thermophilic and mesophilic two-phase anaerobic digestion reactors because ammonium ion concentration was sharply increased in reactors. However, operational stability of thermophilic reactor was higher than that of mesophilic one. These results show that the thermophilic reactor is advantageous in operation at high OLR.

Anaerobic Digestion of Food Waste: Meshophilic vs Thermophilic Regime

( Gopalakrishnan Kumar ),( Hyun Jun Ju ),( Sang-hyuon Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2014 한국폐기물자원순환학회 심포지움 Vol.2014 No.1

Food waste generation around the globe is a serious issue that needs to be concerned. Developing suitable treatment methods along with the generation of energy (methane) is a common practice to make the world sustainable. In this study, methane generation of food waste has been reported in mesophilic and thermophilic regimes at various hydraulic retention times (HRT) and organic loading rates (OLR). Different reactor configurations were used for mesophilic and thermophilic operations. The influent concentrations were ranged from 30 to 110 g COD/L corresponding to the OLR of 1.0 to 5.5 Kg COD/m³*d, respectively. Three different HRTs evaluated were 30, 24 and 20 days in both regimes. The production performances showed that an increase in biogas and methane production while increasing the substrate concentration in both temperatures. However, better results were obtained from thermophilic temperature due to the hydrolysis of the complex polymers at higher temperatures. Peak methane productivities attained at mesophilic and thermophilic regimes were 1.30 and 0.95 m³/m³*d, respectively. However, the maximal yield achieved were at 50 g CODL and at HRT of 24 d in both the cases and the values were 264 and 221 m3/ton COD, respectively. The COD removal rate was ranged from 54-86% in case of thermophilic and 61-87% in case of mesophilic, respectively. The results of this study could aid in the development of sustainable methane production technologies using food waste as carbon source.

종균 첨가가 음식물 쓰레기 퇴비화 미생물에 미치는 영향

최민호(Min-Ho Choi),정윤진(Yoon-Jin Chung),박연희(Yun-Hee Park) 유기성자원학회 1996 유기물자원화 Vol.4 No.1

음식물 쓰레기의 고온 퇴비화 과정에서 종균 첨가가 미생물의 변화에 미치는 영향을 조사하였다. 실험실용 소형 퇴비화 장치에 선발한 고옹성 세균,효모 및 고온성 세균,효모 복합종균을 첨가하여 50.C 에서 분해시키면서 고온성 세균과 효모의 생육 및 pH 의 변화를 측정한 결과,모든 실험구에서 효모가 우선적으로 생육하였으며 고온성 세균은 그보다 l 일 또는 2 일 후에 생육하였다. 종균으로 고온성 세균만 사용한 경우는 효과가 거의 없었으나 고온성 세균과 효모의 복합 종균을 첨가한 경우에는 고온성 세균의 생육이 현저히 촉진되었다. 특히 효모 종균을 단독으로 첨가한 경우에도 고온성 세균의 수가 반응 시작부터 급속히 증가하였다. 이러한 결과는 음식물 쓰레기의 분해시 고옹성 세균의 증식에는 효모의 역할이 필수적인 것으로 나타났으며 그 이유는 효모가 세균의 생육을 저해하는 유기산을 제거하기 때문으로 밝혀졌다. The effect of seeding on the thermophilic composting of food waste was investigated with selected strains of yeast, thermophi\ic bacteria and the mixed strains of yeast and bacteria in the lab-scale composter at 50.C. The results demonstrated that in all case the growth of yeasts preceded the growth of thermophilic bacteria by one or two days. The seeding of bacteria alone was ineffective for thermophilic bacterial development and the rapid increase of total thermophilic bacterial count was obtained by mixed seeding of yeasts and bacteria. Moreover, the bacterial growth was accelerated by the addition of yeasts alone. It was revealed that the yeasts removed organic acids from the food waste at the initial period and consequently induced the growth of thermophilic bacteria. The results presented in this paper indicate the indis pensable role of yeasts for thermophilic process of food waste composting.

Effect of feed to microbe ratios on anaerobic digestion of Chinese cabbage waste under mesophilic and thermophilic conditions: Biogas potential and kinetic study

Kafle, G.K.,Bhattarai, S.,Kim, S.H.,Chen, L. Academic Press 2014 Journal of environmental management Vol.133 No.-

The objective of this study was to investigate the effect of the feed-to-microbe (F/M) ratios on anaerobic digestion of Chinese cabbage waste (CCW) generated from a kimchi factory. The batch test was conducted for 96 days under mesophilic (36.5 <SUP>o</SUP>C) (Experiment I) and thermophilic (55 <SUP>o</SUP>C) conditions (Experiment II) at F/M ratios of 0.5, 1.0 and 2.0. The first-order kinetic model was evaluated for methane yield. The biogas yield in terms of volatile solids (VS) added increased from 591 to 677 mL/g VS under mesophilic conditions and 434 to 639 mL/g VS under thermophilic conditions when the F/M ratio increased from 0.5 to 2.0. Similarly, the volumetric biogas production increased from 1.479 to 6.771 L/L under mesophilic conditions and from 1.086 to 6.384 L/L under thermophilic conditions when F/M ratio increased from 0.5 to 2.0. The VS removal increased from 59.4 to 75.6% under mesophilic conditions and from 63.5 to 78.3% under thermophilic conditions when the F/M ratio increased from 0.5 to 2.0. The first-order kinetic constant (k, 1/day) decreased under the mesophilic temperature conditions and increased under thermophilic conditions when the F/M ratio increased from 0.5 to 2.0. The difference between the experimental and predicted methane yield was in the range of 3.4-14.5% under mesophilic conditions and in the range of 1.1-3.0% under thermophilic conditions. The predicted methane yield derived from the first-order kinetic model was in good agreement with the experimental results.