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.

Integrated system coupling non-thermal plasma and anaerobic digestion to reduce microalgae and microcystin

( Sol Yang ),( Sangjun Jeong ),( Hyun-woo Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 한국폐기물자원순환학회 심포지움 Vol.2019 No.1

Rising temperature in the summer and large amounts of nutrient loadings lead to serious algal blooms on the surface water. It is a problem because some microalgae can cause water quality deterioration and release ecological toxic substances such as microcystin thus continuous biomass harvesting should be done iteratively. Research on how to treat the harvested microalgae has been carried out and anaerobic biotechnology is getting special attention due to the advantage of being able to manufacture renewable energy in the form of biogas. However, the cell wall degradation of the harvested algae and the effect of certain cyanobacterial toxins on anaerobic microbial activity are obstacles to anaerobic digestion. In this study, biochemical methane potential (BMP) tests were conducted after the pretreatment of non-thermal plasma (NTP), a kind of advanced oxidation process, to enhance the potential for anaerobic biodegradation and toxicity reduction for harvested microalgae. We also investigated the inhibition effect of existing microcystin based on anaerobic digestion efficiencies. The BMP test was conducted with the initial substrate concentration of 1.0 ~ 2.0 gVS/L in a serum bottle (100 mL). Results show that the biogas yield was 124 mLCH₄/gVS in the NTP pretreated reactor, whereas the reactor without pretreatment showed about 20% lower yield. At the initial concentration of microcystin in 8,835 μg/L, about 50% of microcystin was removed during pretreatment. On the other hand, insufficient removal of microcystin seems to be associated with the release of microcystin from destroyed cyanobacteria. In summary, this study confirms that NTP pretreatment is effective in increasing the anaerobic digestion efficiency, but optimization on NTP application seems necessary due to microcystin release from the microalgae.

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.

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 2017 한국폐기물자원순환학회 학술대회 Vol.2017 No.11

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.

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.

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.

Leaching Characteristics of Heavy Metals from Plant Biomass from Phytoextraction Site during Anaerobic Digestion

( Jongkeun Lee ),( Jae Young Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 3RINCs초록집 Vol.2015 No.-

If biomass contains heavy metals, heavy metals may be released from biomass during biodegradation and inhibit the anaerobic digestion process. The objective of this study is to examine the leaching characteristics of heavy metals from biomass for prediction of heavy metal amounts in anaerobic digester. In this study, sunflower (i.e., Helianthus annuus) grown in heavy metal-contaminated soils was used as a substrate for anaerobic digestion. The released heavy metals in anaerobic digester can be classified as decomposition of biomass with microorganism activity and leaching themselves without microorganism activity. Lab-scale anaerobic batch digesters containing anaerobic sludge and autoclaved distilled water were set up to investigate the amount of heavy metals leached from biomass with and without microorganism activity. About 70% by wt. of Cu and Zn were leached from biomass with microorganism activity while about 50% by wt. of biomass was degraded for 28 days, whereas Cd, Pb, and Ni were barely leached. Only 14.3% by wt. of Cu and 21.6% by wt. of Zn were also partially leached from the biomass without microorganism activity while leaching of Cd, Pb, and Ni were hardly observed.

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.

돼지분뇨 처리를 위한 Farm-scale Two-phase Anaerobic Digester의 실증운영에 관한 연구

백인규,이상락,안정제,권윤정,맹원재 한국축산환경학회 2000 축산시설환경학회지 Vol.6 No.2

A two-phase anaerobic digestion system for the treatment of swine waste was constructed in a commercial hog farm. The digester system was composed of 4 major units; slurry storage pit, acidogenic digester, methanogenic digester and sedimentation pit. A biogas boiler unit was also attached to maintain the digester temperature of 37$^{\circ}C$. Substrate lading was made with 2hr-interval by pumping about 2.1$m^3$ of slurry type swine waste from the slurry pit into the acidogenic digester, which corresponds to hydraulic retention time of 4 days for the acidogenic digester and of 11 days for the methanogenic digester. Digester temperature were well maintained as the set temperature of 37$^{\circ}C$ in the methanogenic digester, while the temperature in the acidogenic digester showed around 34$^{\circ}C$. pH also showed a steady-state results of 7.3 in the acidogenic digester and of 7.6 in the methanogenic digester during the operation period. Average biogas production rate was 0.66$m^3$/$m^3$ digester volume. Reduction rate of total solid and volatile solid were 42.8% and 5.8%, respectively. Total nitrogen and ammonia nitrogen were not reduced during the anaerobic fermentation, however, most of VFAs seemed to be converted to the biogas,. These fermentation performance data may suggest that he newly developed a two-phase anaerobic digester for the swine waste treatment worked so successfully.