| 英文摘要 |
The total amount of kitchen waste in Taiwan is 2,000 tons/day. Usually, kitchen waste was utilized as pig fed, or by composted. However, anaerobic digestion converting waste into biomass energy is an important trend, and will reduce green house gases (GHG). In another way, there are several sewage plants with abundant capacity in anaerobic digesters, it is a possible strategy to treat kitchen waste by co-digestion with sewage sludge.
This project is to study the biogas produced potential of kitchen waste, include what means “pig fed kitchen waste” and “composted kitchen waste”. BMP and BHP test were taken to calculate methane and hydrogen production under different mixing ratio. The potentially inhibition by oil ＆ grease was also observed.
Meanwhile, a pilot plat of two phase anaerobic digester with capacity of 15m3 was tested over more than half year. The substrate was also“pig fed kitchen waste” and “composted kitchen waste”, and mixed with 3 times of sewage sludge to study the biogas production and waste reduction. During the test period, the hydraulic retention time (HRT) was 15~20 days, experimental data was collected after 2~3 HRT days. The behaviors of microorganism was observed by electron microscopy, and by DNA extraction technology to identify the activities of it.
Digestate, which is the effluent of anaerobic digestion, has nutrients contents are of high value as soil amendment and organic fertilizer to grow plants and crops. The composition of digestate was also analyzed and to detect the content of heavy metals.
One of the important conclusion is that, co-digestion of kitchen waste and sewage sludge will improve the performance of anaerobic digestion, and produce more biogas energy, most of the operation parameters were investigated. However due to the agriculture regulation for the sludge application in land and soil was not yet cleared, more effort to resolve the problem is important in the future.
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