| Summary: | 碩士 === 國立臺灣大學 === 環境工程學研究所 === 88 === Abstract
This research made use of the anaerobic biofilter, which was packed with the filter medium of the waste from agriculture and stockbreeding. The filter medium was composed of chaff and composts from the dung of pig, chook and cattle, and the waste water containing denitrifying bacteria was blended into it. So the microorganism could grow on the surface of filter media to reduce NO by microbial denitrification. The gas inlet flowrate, inlet concentration of NO, differential type of compost, stage number of the media, and differential temperature that would influence the NO elimination rate of the biofilter were discussed in this study.
The media in use had low adsorption quantity in the gas ,either the media was xerantic or wet. The dry chaff and compost only adsorbed 0.12~0.3 mg per 1g media at eguilibrium, and the breakthrough time was between 2 to 5 hours. The two type of wet media adsorbed 0.48~0.6 mg per 1g media at eguilibrium, and the breakthrough time was between 7.5 to 8.5 hours. Beyond that, the media operated for a long time and the leakage water from the media couldn''t sense any nitrate and nitrite, we could understand that the most NO in the inlet gas was removed by the microoganism in the biofilter.
The results indicated that changing inlet flowrate and temperature of media had obvious influence of the NO removal, and changing inlet concentration of NO, stage number of medium and type of compost had low impact. Bigger the inflow flowrate, smaller the NO elimination rate. After the flowrate raising from 10cm/cm2/min to 30cm/cm2/min, the total elimination rate would decrease from 100% to 60%.
Raising the temperature about 1℃, the removal rate of the biofilter would increase 0.67% to 1.02%. In the first order biological reaction, although the biological reaction constant K20 which was 3.33×10-3 in the second column of the biofilter was bigger than K20 which was 3.00×10-3 in the first column, the temperature coefficient θ which was.1.0333 in the first column was bigger obviously than θ which was 1.0191 in the second column. It meant that raising the temperature increase more removal rate in the first column. The verdict indicated the media mixing with mature compost bought from outside (the first column) has better elimination rate than the media mixing with raw media made by ourself (the second column) in the higher temperature.
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