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RISS 인기검색어
- 검색키워드
- 저자 : Heekwon Ahn (검색결과 22 건)
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Heekwon Ahn,Seunghun Lee,Eunjong Kim,Jaehee Lee,Yongjoo Sung 한국토양비료학회 2014 한국토양비료학회지 Vol.47 No.2
The effect of thermal pretreatment conditions on hydrolysis characteristics of dairy manure and sawdust mixtures has been evaluated. Thermal pretreatment temperature varied between 35 and 120°Cand the period of the treatment changed between 30 and 1440min (24h). As thermal pretreatment temperature and duration increased, organic material solublization rates were improved. Maximum solubilizations of chemical oxygen demand (SCOD), carbohydrates, and volatile fatty acids(VFAs) were observed when dairy manure treated for one day at 120°C. Although one day treatment duration at 120°Cshowed the highest SCOD, soluble carbohydrates, and VFAs concentration, its hydrolysis rate was only about 12%. The results reveal that the thermal pretreatment conditions tried in this study are not enough to solubilize the organic matter contained in dairy manure and sawdust mixtures. In order to maximize hydrolysis performance, the further research needs to determine the factors influences on organic material solubilization in addition to thermal pretreatment temperature and duration.
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Ahn, Heekwon,Lee, Seunghun,Kim, Eunjong,Lee, Jaehee,Sung, Yongjoo 한국토양비료학회 2014 한국토양비료학회지 Vol.47 No.2
The effect of thermal pretreatment conditions on hydrolysis characteristics of dairy manure and sawdust mixtures has been evaluated. Thermal pretreatment temperature varied between 35 and $120^{\circ}C$ and the period of the treatment changed between 30 and 1440min (24h). As thermal pretreatment temperature and duration increased, organic material solublization rates were improved. Maximum solubilizations of chemical oxygen demand (SCOD), carbohydrates, and volatile fatty acids(VFAs) were observed when dairy manure treated for one day at $120^{\circ}C$. Although one day treatment duration at $120^{\circ}C$ showed the highest SCOD, soluble carbohydrates, and VFAs concentration, its hydrolysis rate was only about 12%. The results reveal that the thermal pretreatment conditions tried in this study are not enough to solubilize the organic matter contained in dairy manure and sawdust mixtures. In order to maximize hydrolysis performance, the further research needs to determine the factors influences on organic material solubilization in addition to thermal pretreatment temperature and duration.
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Kim, Eunjong,Lee, Dong-Hyun,Won, Seunggun,Ahn, Heekwon Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.5
Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg $O_2/g$ VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS's optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust's coarse particle size and bulking effect.
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Hyeonsoo Jo,Seunghun Lee,Eunjong Kim,Heekwon Ahn 한국토양비료학회 2017 한국토양비료학회지 Vol.50 No.4
This experiment was conducted to evaluate the effect of leachate replacement frequency on solid state anaerobic digestion (SSAD) of dairy manure using 22 L volume lab-scale digesters at mesophilic temperature(37°C) in batch mode. Three different leachate replacement strategies (no replacement, once every three days, and once every nine days) were applied and three digesters per each treatment were operated for 45 days. Results showed that leachate replacement test unit every nine days resulted in 1.6 times more methane production (53.8 N·mL g<SUP>-1</SUP>·VS) from SSAD compared to test unit every three days (34.0 N·mL g<SUP>-1</SUP><SUP></SUP>·VS). No leachate replacement strategy applied group showed slightly higher methane production (56.3 N·mL g<SUP>-1</SUP>·VS) than every nine days replaced one. When added the methane production potential of replaced leachate itself to the methane produced from digester, leachate replacement every nine days resulted in quite similar methane production (56.5 N·mL g<SUP>-1</SUP>·VS) to no leachate replacement group. Even though methane production potential of replaced leachate itself added to the methane produced from digester, every three days replacement showed only 34 N·mL methane production per gram of volatile solids. These results suggest that farmers do not need to replace leachate during SSAD of dairy manure and sawdust mixture in order to maximize methane production. If there are any concerns with accumulation of inhibiting substances in the digester, the 9-day cycle leachate replacement is appropriate.
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Ammonia and Hydrogen Sulfide Removal from Swine House Exhaust Air Using a Dip Injection Wet Scrubber
Myeongcheol Shin,Seunghun Lee,Jisoo Wi,Heekwon Ahn 한국토양비료학회 2017 한국토양비료학회지 Vol.50 No.6
This study was conducted to evaluate the odor reduction efficacy of the dip injection wet scrubber (DIWS) using tap water as washing fluid. The NH₃ and H₂S removal efficiency of 7 day batch operated DIWS was evaluated twice over a total of 14 days of experiment. The NH3 removal efficiency ranged from 26 to 37%. The H₂S removal efficiency was between 22 and 30%. The pH of the washing fluid maintained below 8 and the NH₄<SUP>+</SUP> concentration tended to keep constant around 350 ppm after 5 days of washing-fluid replacement. Therefore, the 5-day washing fluid replacement interval is more preferable than the 7-day interval. The NH₄ <SUP>+</SUP> concentration and the electrical conductivity (EC) showed a high correlation. The EC measurement can be used as an alternative to conventional NH₄ <SUP>+</SUP> concentration measurement method for real time monitoring of washing fluid condition.
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Ammonia and Hydrogen Sulfide Removal from Swine House Exhaust Air Using a Dip Injection Wet Scrubber
Shin, Myeongcheol,Lee, Seunghun,Wi, Jisoo,Ahn, Heekwon 한국토양비료학회 2017 한국토양비료학회지 Vol.50 No.6
This study was conducted to evaluate the odor reduction efficacy of the dip injection wet scrubber (DIWS) using tap water as washing fluid. The $NH_3$ and $H_2S$ removal efficiency of 7 day batch operated DIWS was evaluated twice over a total of 14 days of experiment. The $NH_3$ removal efficiency ranged from 26 to 37%. The $H_2S$ removal efficiency was between 22 and 30%. The pH of the washing fluid maintained below 8 and the $NH_4{^+}$ concentration tended to keep constant around 350 ppm after 5 days of washing-fluid replacement. Therefore, the 5-day washing fluid replacement interval is more preferable than the 7-day interval. The $NH_4{^+}$ concentration and the electrical conductivity (EC) showed a high correlation. The EC measurement can be used as an alternative to conventional $NH_4{^+}$ concentration measurement method for real time monitoring of washing fluid condition.
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Jo, Hyeonsoo,Lee, Seunghun,Kim, Eunjong,Ahn, Heekwon 한국토양비료학회 2017 한국토양비료학회지 Vol.50 No.4
This experiment was conducted to evaluate the effect of leachate replacement frequency on solid state anaerobic digestion (SSAD) of dairy manure using 22 L volume lab-scale digesters at mesophilic temperature ($37^{\circ}C$) in batch mode. Three different leachate replacement strategies (no replacement, once every three days, and once every nine days) were applied and three digesters per each treatment were operated for 45 days. Results showed that leachate replacement test unit every nine days resulted in 1.6 times more methane production ($53.8N{\cdot}mL\;g^{-1}{\cdot}VS$) from SSAD compared to test unit every three days ($34.0N{\cdot}mL\;g^{-1}{\cdot}VS$). No leachate replacement strategy applied group showed slightly higher methane production ($56.3N{\cdot}mL\;g^{-1}{\cdot}VS$) than every nine days replaced one. When added the methane production potential of replaced leachate itself to the methane produced from digester, leachate replacement every nine days resulted in quite similar methane production ($56.5N{\cdot}mL\;g^{-1}{\cdot}VS$) to no leachate replacement group. Even though methane production potential of replaced leachate itself added to the methane produced from digester, every three days replacement showed only $34N{\cdot}mL$ methane production per gram of volatile solids. These results suggest that farmers do not need to replace leachate during SSAD of dairy manure and sawdust mixture in order to maximize methane production. If there are any concerns with accumulation of inhibiting substances in the digester, the 9-day cycle leachate replacement is appropriate.
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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.
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Lee, Jaehee,Lee, Seunghun,Kim, Eunjong,Jo, Hyunsoo,Ahn, Heekwon 한국토양비료학회 2015 한국토양비료학회지 Vol.48 No.2
The performance of chamber and bag digesters for solid state anaerobic digestion (SS-AD) of separated solid fraction of swine manure was investigated using lab-scale digester (4,460 mL total volume and 1,800 mL of effective volume) operating at $37^{\circ}C$ for 63 days. The performance of two different digester types was evaluated in terms of the kinetic constants of methane production obtained from the Gompertz and Gaussian equations. Methane production potential of chamber and bag digester was 202 and $218N{\cdot}mL$ $CH_4/g$ VS. Time to produce 95% methane production potential (T95) and calculated effective anaerobic digestion time were 55.5 days and 41.8 days for chamber digester and 52.8 days and 43.5 days for bag digester, respectively. Our results reveal that the performance was not significantly different between chamber and bag digester.
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Lee, Seung-Hun,Jo, Hyeon-Soo,Lee, Myung-Gyu,Yabe, Mitsuyasu,Ahn, Heekwon FACULTY OF AGRIC PUBLICATIONS-KYUSHU UNIV 2017 Journal of the Faculty of Agriculture, Kyushu Univ Vol.62 No.1
<P>This study was conducted to determine the optimal substrate/inoculum (S/I) ratio for solid state anaerobic digestion (SS AD) of beef manure and sawdust bedding mixtures. The organic material removal and methane yield performance were evaluated at five different S/I levels (1, 2, 4, 50, and beef manure alone on a VS basis) for 49 days at 37 degrees C. Results showed that biodegradable volatile solids (BVS) reduction of beef manure alone test unit was 76% which was not significantly different from the rest of all inoculated test units. The methane production potential of all five test units showed similar levels (135 to 154 mL/g VS), regardless of S/I ratio. Although it showed similar methane production potential, the beef manure alone and S/I ratio 50 test units showed the highest methane yields of 7.3 and 7.2 based on the volume of methane produced per volume of digester, respectively. In addition, when considering utilization efficiency of the available digester volume, the beef manure alone treatment was 15% higher than that of the S/I ratio 50 treatment. These results reveal that the beef manure and sawdust bedding mixture does not require inoculation to improve SS AD performance.</P>
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