Research On Bio-Hydrogen Production From Household Organic Solid Wastes

Solid wastes like household solid wastes (HSW) have been the main part of municipal wastes. Typical landfill treatment brings healthy problems or the secondary pollution due to its fermentation, corruption or decay. Burning method is also considered as a high cost, ineffective way to dispose of this kind of high moisture but low heat wastes. However, HSW can be anaerobic digested to produce energy sources like hydrogen or methane since they contain a great deal of biodegradable simple organisms. HSW can be resourced again in this way.In order to fetch energy sources such as hydrogen or methane from HSW, Continuous Stirred-Tank Reactor (CSTR) was used to do the anaerobic fermentation in this research. Some conditions were changed to improve reactor efficiency, including some basic exploration on technological innovation.The results of star-up period of the reactor showed that energy gases were produced form both HSW and sucrose was degraded by anaerobic bacteria in the sludge. Gas production rose while capacity load became higher. Hydrogen percentage in gases from HSW was higher than that from sucrose, but gas production results were reverse.Gas productive rate results of acidogenesis phase reactor at different hydraulic residence time (HRT) showed both gas productive rate and specific hydrogen productive rate was the highest with HRT=2d. But methane production decreased since volatile fatty acid (VFA) accumulated because of short HRT. Long HRT (such as HRT=8d) also decreased gas productive rate because of low capacity load. The suitable HRT was 4, and both specific hydrogen productive rate and COD removal rate appeared high performance.Results of pretreatments with different temperatures or pH value adjustments showed the concentrations of S-COD and VFA were improved in this way, which would benefit the anaerobic digestion in reactor. It was also showed that both temperature and pH value were the key factors during hydrolytic acidification process. High temperature leaded to high efficiency, but pH value was set about 5.5. Composition of HSW showed no effect on hydrolytic acidification. Results of reactor operation showed mean gas production, hydrogen production and specific gas productive rates were improved significantly, and the reactor reached better appearance.