Browsing by Author "Chung, Ying-Chien"

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Analysis of microbial diversity and optimal conditions for enhanced biogas production from swine waste anaerobic digestion
(2013-09-01)
Chung, Ying-Chien
;
Chang, Yu-Cheng
;
Chen, Yu-Pei
;
Lin, Wei-Chih
;
Lin, Hsiao-Hsien
Swine wastewater pretreated by solid-liquid separation was optimized for biogas production and water purification. Dynamic diversity of the bacterial community in the anaerobic plug flow reactor was investigated under various temperatures and hydraulic retention times (HRT). Results of batch experiments indicated that under optimal operating conditions, biogas production, methane production rate, and chemical oxygen demand (COD) removal efficiencies increased up to 26%, 52%, and 44%, respectively. In the continuous experiments, optimal operating conditions for the plug flow operator were found to be HRT of 8 d and temperature of 35 degrees C, under which relatively high CH4 concentration (67%), CH4 production rate (4.6 l/d), and total COD removal (79%) were achieved. A minimum of 12 bands was observed in the denaturing gradient gel electrophoresis profile. Phylogenetic analysis revealed the predominance of phyla Firmicutes, Proteobacteria, and Euryarchaeota in the anaerobic plug-flow reactor. However, the occurrence and prevalence of specific bacterial species varied with HRT and temperature. This study establishes the optimal operating parameters for the anaerobic plug-flow digestion of swine wastewater, which can be employed in a full-scale reactor to maximize biogas production and to purify water quality. (C) 2013 AIP Publishing LLC.
Biofiltration of trimethylamine, dimethylamine, and methylamine by immobilized Paracoccus sp CP2 and Arthrobacter sp CP1
(2008-05-01)
Ho, Kuo-Ling
;
Chung, Ying-Chien
;
Lin, Yueh-Hsien
;
Tseng, Ching-Ping
;
生物科技學系
A biofilter using granular activated carbon with immobilized Paracoccus sp. CP2 was applied to the elimination of 10-250 ppm of trimethylamine (TMA), dimethylamine (DMA), and methylamine (MA). The results indicated that the system effectively treated MA (>93%), DMA (>90%), and TMA (>85%) under high loading conditions, and the maximum degradation rates were 1.4, 1.2, and 0.9 g-N kg(-1) GAC d(-1). Among the three different amines treated, TMA was the most difficult to degrade and resulted in ammonia accumulation. Further study on TMA removal showed that the optimal pH was near neutral (6.0-8.0). The supply of high glucose (>0.1%) inhibited TMA removal, maybe due to substrate competition. However, complete TMA degradation was achieved under the co-immobilization of Paracoccus sp. CP2 and Arthrobacter sp. CP1 (similar to 96%). Metabolite analysis results demonstrated that the metabolite NH(4)(+) concentrations decreased by a relatively small 27% while the metabolite NO(2)(-) apparently increased by heterotrophic nitrification of Arthrobacter sp. CP1 in the co-immobilization biofilter. (C) 2008 Elsevier Ltd. All rights reserved.
Continuous deodorization and bacterial community analysis of a biofilter treating nitrogen-containing gases from swine waste storage pits
(2008-05-01)
Ho, Kuo-Ling
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Chung, Ying-Chien
;
Tseng, Ching-Ping
;
生物科技學系
;
Department of Biological Science and Technology
A biofilter inoculated with Arthrobacter sp. was applied to the simultaneous elimination of trimethylamine (TMA) and ammonia (NH3) from the exhaust air of swine waste storage pits. The results showed that the biofilter achieved average removal efficiencies of 96.8 +/- 2.5% and 97.2 +/- 2.3% for TMA and NH3, respectively. A near-neutral pH (7.3-7.4) was maintained due to the accumulation of acid metabolites and the adsorption of alkaline NH3. Low moisture demand, low pressure drop and high biofilm stability in the system were other advantages. After long-term operation, the bacterial community structure showed that at least twenty-five bands were explicitly detected by a denaturing gradient gel electrophoresis (DGGE) method. However, the inoculated Arthrobacter sp. still maintained a dominant population (> 50%). Paracoccus denitrificans' presence in the biofilter could play an important role in oxidizing NH3 and reducing nitrite by heterotrophic nitrification and anaerobic denitrification. (c) 2007 Published by Elsevier Ltd.
Elimination of high concentration hydrogen sulfide and biogas purification by chemical-biological process
(2013-08-01)
Ho, Kuo-Ling
;
Lin, Wei-Chih
;
Chung, Ying-Chien
;
Chen, Yu-Pei
;
Tseng, Ching-Ping
A chemical-biological process was performed to remove a high concentration of H2S in biogas. The high iron concentration tolerance (20 g L-1) of Acidithiobacillus ferrooxidans CP9 provided sufficient ferric iron level for stable and efficient H2S elimination. A laboratory-scale apparatus was setup for a 45 d operation to analyze the optimal conditions. The results reveal that the H2S removal efficiency reached 98% for 1500 ppm H2S. The optimal ferric iron concentration was kept between 9 and 11 g L-1 with a cell density of 10(8) CFU g(-1) granular activated carbon and a loading of 15 g S m(-3) h(-1). In pilot-scale studies for biogas purification, the average inlet H2S concentration was 1645 ppm with a removal efficiency of up to 97% for a 311 d operation and an inlet loading 40.8 g S m(-3) h(-1). When 0.1% glucose was added, the cell density increased twofold under the loading of 65.1 g S m(-3) h(-1) with an H2S removal efficiency still above 96%. The analysis results of the distribution of microorganisms in the biological reactor by DGGE show that microorganism populations of 96.7% and 62.7% were identical to the original strain at day 200 and day 311, respectively. These results clearly demonstrate that ferric iron reduction by H2S and ferrous iron oxidation by A. ferrooxidans CP9 are feasible processes for the removal of H2S from biogas. (C) 2013 Elsevier Ltd. All rights reserved.
Microbial populations analysis and field application of biofilter for the removal of volatile-sulfur compounds from swine wastewater treatment system
(2008-04-01)
Ho, Kuo-Ling
;
Chung, Ying-Chien
;
Lin, Yueh-Hsien
;
Tseng, Ching-Ping
;
生物科技學系
A biofilter packed with granular activated carbon (GAC) was applied to eliminate volatile-sulfur compounds (VSC) emitted from solid-liquid separation tank in swine wastewater treatment system. Hydrogen sulfide, methanethiol, dimethyl disulfide, and dimethyl sulfide were effectively reduced to 96-100% at gas residence times of 13-30 s. Elemental sulfur and sulfate are their primary oxidation metabolites. Regarding odor, an average of 86% reduction was achieved at short residence time (13 s). In addition, bioaerosol emissions could also be effectively reduced by 90% with the biofilter. Advantages of the system include low moisture demand, low pressure drop, and high biofilm stability. Further characterization of bacterial populations of the activated carbon samples using the fluorescent in situ hybridization (FISH) technique revealed that Pseudomonas sp. remained the predominant community (56-70%) after long-term evaluation of 415 days. (c) 2007 Published by Elsevier B.V.
SYSTEM AND PROCESS FOR TREATING WASTE GAS EMPLOYING BIO-TREATMENT TECHNOLOGY
(2008-09-18)
Tseng, Ching-Ping
;
Chung, Ying-Chien
A waste gas treatment process using biological treatment technology including filtering waste gas to be treated, and introducing the filtered waste gas into a biological treatment system periodically and switchably from two ends of the system.
Treatment of high H2S concentrations by chemical absorption and biological oxidation process
(2006-11-01)
Chung, Ying-Chien
;
Ho, Kuo-Ling
;
Tseng, Ching-Ping
;
生物科技學系
;
Department of Biological Science and Technology
The feasibility of a chemical absorption and a biological oxidation process to remove high H2S concentrations (500-1500 ppm) was evaluated. The experiment included the effects of gas retention time (GRT) and H2S concentration on H2S removal efficiency, Fe3+ oxidation rate, and Fe2+ production rate in the chemical absorption reactor. The effects of carbon source and liquid flow rate on pH value, Fe2+ oxidation rate, Fe3+ production rate, total iron concentration, and growth of Thiobacillus ferrooxidans CP9 in the biological oxidation reactor were also examined. The optimal operating conditions for the individual process and design guidelines for the serial processes were established. The results of this study indicated that a long GRT could elevate H2S removal efficiency under all operating conditions. However, a high H2S concentration (e.g., 1,500 ppm) resulted in a significant difference. H2S removal efficiency stayed above 99.5% for the first 10 h of reaction, but it then decreased because of the decreasing ferric iron concentration in the liquid. The presence of 0.1% glucose favored T. ferrooxidans CP9 growth as well as the Fe2+ oxidation rate and prevented the occurrence of jarosite precipitates in the biological oxidation process. In addition, the presence of glucose brought about different Fe2+ oxidation patterns (linear or curved type) and recovery percentages of total iron (95 and 74%). The results suggest that the liquid flow rate in the biological oxidation reactor was controlled at 3 mL/min, the volume ratio of biological reactor to chemical reactor was 13.5:1 when 150 g-S/m(3)/h of inlet H2S loading was introduced to the system.
Two-stage biofilter for effective NH3 removal from waste gases containing high concentrations of H2S
(2007-03-01)
Chung, Ying-Chien
;
Ho, Kuo-Ling
;
Tseng, Ching-Ping
;
生物科技學系
;
Department of Biological Science and Technology
A high H2S concentration inhibits nitrification when H2S and NH3 are simultaneously treated'in a single biofilter. To improve NH3 removal from waste gases containing concentrated H2S, a two-stage biofilter was designed to solve the problem. In this study, the first biofilter, inoculated with Thiobacillus thioparus, was intended mainly to remove H2S and to reduce the effect of H2S concentration on nitrification in the second biofilter, and the second biofilter, inoculated with Nitrosomonas europaea, was to remove NH3. Extensive studies, which took into account the characteristics of gas removal, the engineering properties of the two biofilters, and biological parameters, were conducted in a 210-day operation. The results showed that an average 98% removal efficiency for H2S and a 100% removal efficiency for NH3 (empty bed retention time = 23-180 sec) were achieved after 70 days. The maximum degradation rate for NH3 was measured as 2.35 g N day(-1) kg of dry granular activated carbon'. Inhibition of nitrification was not found in the biofilter. This two-stage biofilter also exhibited good adaptability to shock loading and shutdown periods. Analysis of metabolic product and observation of the bacterial community revealed no obvious acidification or alkalinity phenomena. In addition, a lower moisture content (similar to 40%) for microbial survival and low pressure drop (average 24.39 mm H2O m(-1)) for system operation demonstrated that the two-stage biofilter was energy saving and economic. Thus, the two-stage biofilter is a feasible system to enhance NH3 removal in the concentrated coexistence of H2S.