젖소분뇨 반 건식 혐기소화 잔재물의 고체연료화 가능성 평가

정광화(Kwang Hwa Jeong),김중곤(Jung Kon Kim),이동준(Dong jun Lee),조원모(Won Mo Cho),B. Ravindran,곽정훈(Jung Hoon Kwag) 유기성자원학회 2016 유기물자원화 Vol.24 No.4

본 연구는 젖소분뇨를 원료로 하여 반 건식 혐기소화 방법을 적용하였을 경우의 혐기소화 가능성을 분석하고 혐기소화 과정에서 배출되는 젖소분뇨 혐기소화 잔재물의 고체연료로서의 가치를 평가하기 위하여 수행되었다. 젖소분뇨의 반 건식 혐기소화 가능성을 평가하기 위하여 950 mL 용량의 반응조를 제작하여 회분식 혐기소화를 실시하였다. 이와 동시에 젖소분뇨 혐기소화 원료를 가로 1,000 mm, 세로 450 mm 크기의 기밀형 아크릴 반응조에 투입하고 항온실에서 중온 혐기소화를 실시한 후에 배출되는 혐기소화 잔재물을 고체연료화 실험원료로 사용하였다. 혐기소화 기질로 사용된 젖소분뇨의 수분함량은 80.64%였으며 젖소분뇨에 첨가한 식종액의 수분함량은 96.83% 수준이었다. 젖소분뇨를 혐기소화하기 위하여 젖소분뇨와 식종액을 1:1 비율로 혼합하였을 때의 수분함량과 VS/TS(휘발성 고형물/총고형물) 함량은 89.74%와 83.35% 수준이었다. 이 젖소분뇨를 혐기소화 한 결과 식종액을 혼합하였을 때 바이오가스가 생성된 반면에 식종액을 혼합하지 않은 경우에는 바이오가스가 거의 발생되지 않았다. 반 건식 혐기소화를 거친 젖소분뇨 혐기소화 잔재물은 신선분에 비해 열량가가 약 20% 정도 감소하였다. 반면에 회분은 15%에서 18.4%로 증가하였다. 젖소분뇨 혐기소화 잔재물울 고체연료 형태로 펠릿화하였을 경우 크롬과 납, 카드뮴, 황 등의 농도가 규제 수준보다 낮았다. 따라서 젖소분뇨를 혐기소화 하여 바이오가스를 회수하고 난후 혐기소화 잔재물을 고체연료화하여 연료로 활용하는 방법을 적용할 수 있을 것으로 판단된다. The objective of this study was to investigate feasibility of semi-dry anaerobic digestion using dairy cattle manure and to evaluate solidified fuel value of semi-dry anaerobic digestate. To evaluate semi-dry anaerobic digestion using dairy cattle manure, 950 mL bottle type anaerobic reactor was set in the constant temperature room maintained at 35℃. To produce anaerobic digestate for making solidified fuel, acrylic cylindrical anaerobic digester(1,000 mm width × 450 mm height) was set in the constant room temperature to carry out batch test of semi-dry anaerobic digestion using same dairy cattle manure. Moisture content of dairy cattle manure and inoculum solution for anaerobic digestion were 80.64% and 96.83%, respectively. The dairy cattle manure and the inoculum solution was mixed by 1:1 ratio(v/v) for anaerobic digestion. Water content and VS/TS(Volatile Solids/Total Solids) of mixture of substrate and inoculum were 89.74% and 83.35%, respectively. In case of non-inoculated anaerobic digester, the biogas was not produced. By the semi-dry anaerobic digestion, the calorific value of the digestate was reduced by 20% compare to fresh dairy cattle manure. In other hand, ash content increased from 15% to 18.4%. The contents of Cr, Pb, Cd and S of pellet produced from anaerobically digested dairy cattle manure were not against the standard regulation for livestock manure solidified fuel. Therefore, it can be used as fuel that anaerobic digestate produced after semi-dry anaerobic digestion using dairy cattle manure.

Pilot Scale Solid State Anaerobic Co-digestion of Dairy Manure and Milking Parlor Wastewater

Seunghun Lee,Eunjong Kim,Myeongseong Lee,Jisoo Wi,Heekwon Ahn 한국토양비료학회 2020 한국토양비료학회지 Vol.53 No.2

A pilot scale solid-state anaerobic co-digestion study was conducted to elucidate the feasibility of anaerobic digestion as an effective treatment method for dairy manure (DM) and milking parlor wastewater (MPW), and it focusing mainly on the stability of anaerobic digestion process and methane production potential. Dairy manure and milking parlor wastewater were co-digested (1/0.48, w/w) in 11m3 volume reactor for 63days at the mesophilic condition (36°C). In addition, pH, volatile fatty acids and ammonia were periodically analyzed to monitor anaerobic digestion inhibitions. The results showed that the co-digestion of DM and MPW was successfully performed without any inhibition caused by ammonia and volatile fatty acids accumulation. The potential methane production (P) from a modified Gompertz model was about 130.5 mL g-VS<SUP>-1</SUP>, and approximately 80% of the methane production was obtained during the 40 days digestion test and the lag phase was 14 days. The pilot scale SSAD (solid-state anaerobic digestion) system showed about 1.3-fold higher methane production than lab-scale system. The results of solid-state anaerobic co-digestion of bedded pack barn dairy manure and milking parlor wastewater using pilot-scale anaerobic digester can be used as a reference for the design of farm-scale anaerobic digester.

중온 혐기성소화 시 암모니아 독성 저해

박세용(Seyong Park),한성국(Seongkuk Han),송은혜(EunHye Song),김호(Ho Kim) 한국열환경공학회 2019 한국열환경공학회 학술대회지 Vol.2019 No.춘계

This study evaluated acute toxicity of ammonia in mesophilic anaerobic digestion of synthetic wastewater and thermally hydrolyzed waste sludge. The inhibition effects of ammonia, in terms of total ammonia nitrogen (TAN), under various pH values on mesophilic anaerobic microorganisms were investigated. Anaerobic batch feeding reactor (ABFR) operated at a chemical oxygen demand (COD) of 3.85, 7.5 and 15.0 g/L were subjected to free ammonia (FA) concentrations of 97.1, 225.5 and 362.4 mg/L. The reactor operations presented a case of chronic inhibition and it was observed that FA concentrations of 360 mg/L caused a drop in methane yield by as much as 60% with respect to FA concentrations of 97.1 mg/L. Batch anaerobic toxicity assays (ATA) were also performed to evaluate the acute toxicity effects of TAN and pH on anaerobic digestion at mesophilic condition. Modeling based on the results of ATA indicated that except parameter m, model parameter values (I*,Rm,and n) decreased with the increase of TAN concentration and the highest SMA for a given TAN level was observed over a pH range of pH 7.6-8.5. TAN concentration causing 70% inhibition occurred in the over 3.0 g/L in mesophilic anaerobic digestion. Results of bacterial community analyses, Chloroflexi and Synergistetes were the dominant communities at TAN less than 3.0 g/L and Firmicutes was the dominant community at TAN higher than 3.0 g/L. Even though the Phylum of Firmicutes dominated the gas production in anaerobic digestion at TAN concentration of above 3.0 g/L decreased due to the decrease of the Phylum of Chloroflexi and Synergistetes by high TAN concentration.

Comparative Analysis of Performance and Microbial Characteristics Between High-Solid and Low-Solid Anaerobic Digestion of Sewage Sludge Under Mesophilic Conditions

( Qin Lu ),( Jing Yi ),( Dian Hai Yang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.1

High-solid anaerobic digestion of sewage sludge achieves highly efficient volatile solid reduction, and production of volatile fatty acid (VFA) and methane compared with conventional low-solid anaerobic digestion. In this study, the potential mechanisms of the better performance in high-solid anaerobic digestion of sewage sludge were investigated by using 454 high-throughput pyrosequencing and real-time PCR to analyze the microbial characteristics in sewage sludge fermentation reactors. The results obtained by 454 highthroughput pyrosequencing revealed that the phyla Chloroflexi, Bacteroidetes, and Firmicutes were the dominant functional microorganisms in high-solid and low-solid anaerobic systems. Meanwhile, the real-time PCR assays showed that high-solid anaerobic digestion significantlyincreased the number of total bacteria, which enhanced the hydrolysis and acidification of sewage sludge. Further study indicated that the number of total archaea (dominated by Methanosarcina) in a high-solid anaerobic fermentation reactor was also higher than that in a low-solid reactor, resulting in higher VFA consumption and methane production. Hence, the increased key bacteria and methanogenic archaea involved in sewage sludge hydrolysis, acidification, and methanogenesis resulted in the better performance of high-solid anaerobic sewage sludge fermentation.

하수슬러지 및 음식물류 폐기물의 혐기성소화 시 염화철 투입에 의한 Biogas 발생량 변화 및 안정화에 관한 연구

김대용 ( Dae-yong Kim ),김종모 ( Jong-mo Kim ),김정권 ( Jung-kwon Kim ) 한국환경기술학회 2012 한국환경기술학회지 Vol.13 No.3

본 연구는 음식물류 폐기물의 재활용 방안으로 음식물류 폐기물의 건식 단상 혐기성소화 공법으로 처리시 혐기성 소화조 내에 FeCl₂, 하수슬러지를 추가로 주입하여 혐기성 소화시 안정적이며 효율적인 음식물류 폐기물의 처리방안을 제시하고, 양질의 Biogas를 생산시킬 수 있는 운전조건을 제시하는데 그 목적이 있다. 유효용량 10 L의 반응조를 이용하여 음식물류 폐기물의 건식 단상 혐기성 소화를 실시한 결과 음식물류 폐기물만을 이용한 혐기성 소화보다 하수슬러지를 추가한 조건에서 높은 Biogas 발생률을 나타내었다. 또한 CH₄ 생성률의 경우 음식물류 폐기물의 단독 투입보다는 하수슬러지를 혼합하여 투입하였을 경우 더 높은 CH₄ 생산을 기대할 수 있게 되었다. H₂S농도의 경우 FeCl₂이 투입되지 않은 RN1 A 조건을 제외한 반응기내에서 300 ppm 이하로 유지되어 H₂S의 혐기성 소화의 독성작용을 억제해준 것으로 판단되며, NH₄-N의 경우 하수슬러지를 같이 투입해준 결과 혐기성 소화 효율이 상승되었다. 또한 첨가물의 병합처리에 의해 안정된 VFA와 pH 조절 효과도 나타났다. 연구결과 혐기성 소화효율이 좋아 질수록 Biogas 발생량, CH₄ 농도, 소화슬러지 pH는 증가하였으며, VFA, NH₄-N 농도는 감소하였다. 따라서 음식물류 폐기물 단독처리 보다 하수슬러지를 투입하게 되면 소화조의 안정화 및 고농도의 Biogas 발생량의 증가를 가져올 것으로 판단된다. The purposes of the present research are to suggest a stable and efficient treatment method for food waste in the anaerobic digester and to find good operating conditions for producing good-quality biogas by additionally injecting FeCl₂, sewage sludge inside the dry single-phase anaerobic digester. As a result of operating the anaerobic digester of food waste by using a reactor with the effective capacity of 10L, the higher biogas generation ratio appeared in conditions of adding sewage sludge than the anaerobic digester using food waste. Also, the methane generation ratio was the higher methane production can be expected. when adding the sewage sludge than that was mixed and putted into than input of food waste. It was appeared that as the concentration of H₂S was maintained in less than 300 ppm at a reactor excluding conditions of RN1 A that FeCl₂ was not put into, it inhibited toxic effects of anaerobic digestion of H₂S. The case of NH₄-N was shown that the anaerobic digestion efficiency increases as a result of putting sewage sludge into. Also, it showed the stable VFA and pH control effect by combining treatment of additives. As a result, the better the anaerobic digestion efficiency gets, the biogas generation, methane concentration and pH of digestion sludge increased, but the concentrations of VFA and NH₄-N were reduced. Accordingly, it was determined that if the sewage sludge was added in rather than single treatment of only food waste, it will bring better stabilization of the digester and increase high-concentration biogas generation amount.

Microbial communities change in an anaerobic digestion after application of microbial electrolysis cells

Lee, Beom,Park, Jun-Gyu,Shin, Won-Beom,Tian, Dong-Jie,Jun, Hang-Bae Elsevier 2017 Bioresource technology Vol.234 No.-

<P><B>Abstract</B></P> <P>Microbial electrolysis cells (MECs) are being studied to improve the efficiency of anaerobic digesters and biogas production. In the present study, we investigated the effects of electrochemical reactions in AD-MEC (anaerobic digester combined with MECs) on changes in the microbial communities of bulk sludge through 454-pyrosequencing analysis, as well as the effect of these changes on anaerobic digestion. <I>Methanobacterium beijingense</I> and <I>Methanobacterium petrolearium</I> were the dominant archaeal species in AD, while <I>Methanosarcina thermophila</I> and <I>Methanobacterium formicicum</I> were dominant in AD-MEC at steady-state. There were no substantial differences in dominant bacterial species. <I>Clostridia</I> class was more abundant than <I>Bacteroidia</I> class in both reactors. Compared to AD, AD-MEC showed a 40% increase in overall bacterial population, increasing the removal of organic matters and the conversion of volatile fatty acids (VFAs). Thus, the MEC reaction more effectively converts organic matters to VFAs and activates microbial communities favorable for methane production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Improving the generation of renewable sources of energy. </LI> <LI> Anaerobic digester and anaerobic digester combined with microbial electrolysis cells. </LI> <LI> Archaeal communities between the AD and AD-MEC. </LI> <LI> Increased methane production using activated microbial communities. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Changes in the structure of microbial communities were observed in the bulk sludge of conventional anaerobic digester and anaerobic digester combined with microbial electrolysis cells (MECs). According to the results, there was a difference in the dominant species of the two reactors, where anaerobic digester combined with a MECs activates microbial communities associated with acetoclastic methanogens, thereby resulting in increased methane production.</P> <P>[DISPLAY OMISSION]</P>

단상 고온 및 중온 혐기성 하수 슬러지의 소화 공정 비교

장현민 ( Hyun Min Jang ),최석순 ( Suk Soon Choi ),하정협 ( Jeong Hyub Ha ) 한국공업화학회 2016 공업화학 Vol.27 No.5

본 연구에서는 하수 슬러지를 대상으로 단상 고온(55 ℃)과 중온(35 ℃) 혐기성 소화조의 안정성, 고형물 제거 및 메탄 생성을 관찰하였다. 실험 결과 별도의 pH 조절 없이 고온(RTAD, reactor of thermophilic anaerobic digestion) 및 중온 (RMAD, reactor of mesophilic anaerobic digestion) 소화조 내 pH의 경우 혐기 소화 시 안정적인 미생물 활성을 나타낸다고 알려진 6.5-8.0 사이의 값을 소화 기간 내내 유지하는 것을 관찰할 수 있었다. 또한, total alkalinity (TA)의 경우 RTAD 및 RMAD 모두 3-4 g CaCO₃/L의 높은 값을 안정적으로 유지하였다. 고형물 제거의 경우 순응 기간 후 RTAD에서 43.3%, RMAD에서 33.6%의 VS 제거율을 보이며 RTAD에서 약 10% 높은 VS 제거율은 제거율을 보였다. 유기산의 경우 RTAD 및 RMAD에서 순응 기간 직후 검출되지 않았다. RTAD 및 RMAD 모두 순응 기간 후 안정적인 메탄 생성을 보였으며, RTAD 에서 RMAD에 비해 31.4% 향상된 메탄 생성률이 관찰되었다(RTAD<; 243 mL CH4/L/d; RMAD : 185 mL CH₄L/d). 반면, 두 소화조 RTAD 및 RMAD에서의 메탄 수율은 유사한 값을 보였다. In this study, single-stage continuous anaerobic reactors to treat sewage sludge were operated under different temperature (55 and 35 ℃; RTADand RMAD) to evaluate the reactor stability and performance of the thermophilic and mesophilic anaerobic digestion. During the overall digestion, both anaerobic reactors maintained quite stable and constant pH and total alkalinity (TA) values in the range of 6.5-8.0 and 3-4 g CaCO₃/L, respectively. After the start-up period, RTADshowed 10% higher VS removal efficiency than that of RMAD (RTAD; 43.3%; RMAD : 33.6%). Although organic acids such as acetic and propionic acid were detected in both anaerobic reactors at the start-up period, all organic acids in RTADand RMAD were consumed at the steady state condition. Also RTADshowed 31.4 % higher methane production rate (MPR) than that of RMAD at the steady state condition (RTAD; 243 mL CH₄/L/d; RMAD : 185 mL CH₄/L/d). Meanwhile, the experimental results indicated similar methane yield between RTADand RMAD.

혐기 소화 시 식물체 잔사 및 투입량에 따른 메탄 생산량 예측

신중두(JoungDu Shin),홍승길(Seung-Gil Hong),박상원(SangWon Park),김현욱(HyunWook Kim) 유기성자원학회 2016 유기물자원화 Vol.24 No.3

본 연구의 목적은 농업에서 발생하는 식물체 잔사 종류별 투입비율에 따른 메탄 잠재 발생량을 예측하는 것이다. 바이오가스를 생산하기 위하여 보릿짚 및 유채대 등의 식물체 잔사를 다양한 투입율로 사용하여 세륨병에서 실험을 수행하였다. 표면 방법론의 운동방법을 통하여 메탄 생산은 Gomperz 수식에 적합한 것으로 나타났다. 중온소화 시 식물체 잔사별 바이오가스 생산에 있어, 최대생산량은 보릿짚 및 유채대 투입율 1%로 혐기소화 후 각각 6.8일에 37.2 mL/g과 7.5일에 28.0 mL/g로 나타났다. 중온소화 시 메탄 함량은 보릿짚 및 유채대 투입율 5%로 혐기소화 후 각각 5.5일에 61.7%와 3.4일에 75.0%로 가장 높게 관측되었다. 중온 소화시 최대 메탄 잠재발생량은 1% 보릿짚 투입율에서 159.59 mL/g 와 3% 유채대 투입율에서 156.62 mL/g로 산정되었다. 전반적으로 중온소화 시 바이오매스 투입율은 유채대 3% 및 보릿짚 1%를 투입하는 것이 적정 비율인 것으로 나타났다. Objective of this experiment was to predict the potential methane production with crop residues at different loading rates. Anaerobic digestion of barley and rapeseed straw substrates for biogas production was performed in Duran bottles at various biomass loading rates with crop residues. Through kinetic model of surface methodology, the methane production was fitted to a Gompertz equation. For the biogas production at mesophilic digestion with crop residues, it was observed that maximum yield was 37.2 and 28.0 mL/g at 6.8 and 7.5 days after digestion with 1% biomass loading rates of barley and rapeseed straws, respectively. For the methane content of mesophilic digestion, there were highest at 61.7% after 5.5 days and 75.0% after 3.4 days of digestion with barley and rapeseed straw on both 5% biomass loading rates, respectively. The maximum methane production potentials were 159.59 mL/g for 1% barley straw and 156.62 mL/g for 3% rapeseed straw at mesophilic digestion. Overall, it would be strongly recommended that biomass loading rate was an optimum rate at mesophilic digestion for using 1% barley and 3% rapeseed straws for feed stocks.

Seasonal and locational effects of anaerobic process performance on microbial communities in full scale digesters

( Chang Hyun Jeon ),( Sang Ho Lee ),( Min Ju Song ),( Woong Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2017 한국폐기물자원순환학회 추계학술발표논문집 Vol.2017 No.-

There is a rising interest of depletion of deposited fossil fuel and environmental pollution, inducing extensive studies to find new alternative sustainable energy sources to replace current petroleum based energy usage. As one of solutions, anaerobic digestion (AD) treating organic wastes has been considered one of the most promising processes owing to its sustainability, low production of sludge, unnecessariness of aeration, and biogas generation. Swine wastewater is characterized by high strength of organic matter contents, so it is regarded as a potential feedstock to produce methane through AD process. To investigate the functional relationship between the microbial communities and anaerobic process performance, regular seasonal sampling was done at four full scale anaerobic digesters treating swine wastewater in South Korea for two years. As results of process and microbial community analyses, chemical oxygen demand (COD) removal efficiency was monitored to proportional to those of carbohydrates, proteins and lipids. Methanogenic and bacterial populations were also positively related to the removal efficiencies of carbohydrates and lipids. However, proteins removal efficiency was independent of microbial population. It means that microbial communities in full scale anaerobic digesters are most likely to be mainly associated with carbohydrates and/or lipids metabolisms, indicating that proteins may be putative recalcitrant contents in wastewater. The microbial population tends to be more affected by places rather than seasons; however, with respect to seasons, the highest species abundances were observed mainly at winter. This implied that rising temperature in the anaerobic digesters in summer would be not suitable for the growth of mesophilic microorganisms, known to be predominant in anaerobic process. Actually, this speculation is supported by the fact that the highest removal efficiency of COD was measured at winter samples. The marked information in this study must provide a real insight into the effective field operation of anaerobic digestion.

폭기량과 고액분리에 따른 혐기소화폐액의 액비화 특성에 관한 연구

한성국,정희숙,송형운,안대현 한국폐기물자원순환학회 2015 한국폐기물자원순환학회지 Vol.32 No.6

Recently, it is increase in the processing of organic waste using anaerobic digestion. Therefore, the studies on the processing method for increasing the anaerobic digestion waste water. Among them, purification treatment and liquid fertilizer have been issues. But, efficiency of the ways is very insufficient. While increasing the anaerobic digestion process, increasing study for the treatment of anaerobic digestion waste water. In this study, It was evaluate the characteristic of liquid fertilizer of anaerobic digestion waste water as affected by aeration rate and solid-liquid separation. Also, we review liquid fertilizer degree using maturity assessment indicators of liquid fertilizer by national institute of animal science. As a result, insertion of air (3.5 L/min) sample after solid-liquid separation appeared was the highest. pH and color was difficult to understanding correlation with liquid fertilizer among maturity assessment indicators (seed germination, ammonia (NH3), hydrogen sulfide (H2S), electrical conductivity (EC), pH, color, etc).