| Based on the investigation and analysis of odor from municipal pumping stations, we sleeted hydrogen sulfide, ammonia and trimethylamine as the target pollutants. Biofiltration technique for treating these pollutants was investigated. The research aimed at understanding parameters affecting bioreactor performance and biodegradation mechanism of pollutats. On the aspect of microbiology, denaturing gradient gel electrophoresis (DGGE) of specifically amplified 16S rDNA gene fragments has been used to monitor and evaluate microbial community dynamics in the biofilters during the experiment. By the traditional isolation methods, two strains of trimethylamine-degrading bacteria were isolated.The results of biological removal of hydrogen sulfide by peat biofilter showed that when the gas retention time was above 25 sec, the HiS removal efficiency was higher than 99%, and the reactor was robust enough to recover reasonably quickly in a shock loading scenario. However, the pressure drop during the experiment was high, and it could be due to its physical characteristics. Higher pressure drop causes higher operational costs.The laboratory scale biofilter packed with compost was continuously supplied with hydrogen sulfide and ammonia gas mixtures. The elimination of hydrogen sulfide and ammonia simultaneously occurred in the biofilter. The hydrogen sulfide removal efficiency reached was very high above 99%, and ammonia removal efficiency was about 80%. According to analysis of products in the packing, ammonia in the biofilter was mainly removed by adsorption/absorption onto the carrier material and reaction with sulfuric acid.Biological removal of ammonia was investigated using two types of packing materials, compost and sludge in laboratory-scale biofilters (8 L reactor volume). The aim of this study is to investigate the potential of unit systems packed with these supports in terms of ammonia emissions treatment. Experimental tests and measurements included analysis of removal efficiency, metabolic products, and results of long-termoperation.Removal efficiencies of the compost and sludge biofilters were in the range of 97 ~ 99% and 95 ~ 99%, respectively when the inlet concentration of ammonia was below 110 mg m-3, However, removal efficiency and elimination capacity of both biofilters significantly decreased as the inlet concentration increased to above 110 mg m-3, the possible reason was osmotic pressure due to high salt concentrations which inhibit the activity of nitrifying bacteria. The profile of DGGE showed that the same carrier at different time had the different bands' patterns. The structural diversity of the microbial community was examined by the Shannon index of general diversity H. DGGE banding patterns and sequencing showed that Nitrosospira and Nitrosomonas were present in both biofilters. Nitrosospira multiformis and Nitrosomonas eutropha were primary ammonia-oxidizing bacteria in the compost and sludge biofilter, respectively.A systematic study on the transient behavior of odor treatment using biofilters was described. The biofilters were exposed to variations in contaminant loading and periods of non-use. Two bench-scale biofilters with different filter media were used. Biofilters responded effectively to NHa concentration variations and shock loading by rapidly recovering to the original removal rates within 6-12 hr. The results indicated re-acclimation times ranged from several hours to longer than a day. Longer idle phase produced longer re-acclimation periods than periods of no contaminant loading. When the media was dried during the biofiltration process, elimination capacity dropped accordingly for both biofilters. After 24 hours of drying, the biofilter experiment could be restarted and run for a few days for recovering. Two strains of trimethylamine-degrading bacteria were isolated from paddy soil and activated sludge of municipal wastewater treatment plant. The strains grew both aerobically as well as anaerobically under nitrate reducing conditions on trimethylamine. The isolates aerobical...
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