Performance Study on the Treatment of the vent gas of the Fermentation process of Compost by Biotrickling Filters
Kitchen waste compositing plants emit odorous gas streams with sulfur-, nitrogen-, and oxygen-containing compounds and other hydrocarbons. A pilot-scale biotrickling filter with a space of 0.3 m square and 1.0 m height packed with fern chips was used for removing the odorous components from the kitchen waste compositing gas. An average weight ratio of ¡§kitchen waste: bulking material: seeding compost¡¨ of 90:4.5:5.5 was used to prepare the compositing material for producing the odorous gas for test. The kitchen waste was composed of residual material from food preparation and meal wastes. The bulking material was either wood trimmings or dried leaves and the seeding material was a blend of manure and bird feather compost. Experiments indicate that the composting material could develop to 32-55 oC during a composting period of 6 weeks and the vented gas contained ammonia, amines, mercaptans, and hydrogen sulfide to maximum values of 700, 1,000, 53, and 1.0 ppm, respectively. A maximum odor concentration of 23,000 was obtained and the odor intensity was closely related to mercaptans in the vented gas.
Results indicate that by using the bio-treated effluent of the school-owned domestic wastewater treatment plant as a supplemental water and nutrition sources for the biotrickling filter, 0.5-5 and 1-15 ppm of ammonia and amines, respectively, in the introduced odorous gas could completely be removed at conditions of empty-bed-retention-times (EBRT) of 15 s and liquid/gas flow ratio (L/G) of 0.003 m3/m3. Particularly, with an EBRT of 7 s at a fixed L/G of 0.002, 99.7% of odor intensity (dilution to the threshold ratio, DT) in the influent gas with a DT of 5,500 could be removed.
Instead of effluent wastewater, by supplementing tap water with 25 mg/L of milk powder to the biotrickling filter, results indicate that with an EBRT of 7 s at a fixed L/G of 0.002, 99.7% of odor intensity in the influent gas with a DT of 13,000 could be removed. Milk powder supplementation gave better performance than the effluent wastewater one.
Advisor:Ming-Shean Chou; Shui-Jen Chen; none
School:National Sun Yat-Sen University
School Location:China - Taiwan
Source Type:Master's Thesis
Keywords:biotrickling filter compositing odor control
Date of Publication:06/28/2006