Study On Thermophilicanaerobic Digestion Of Organic Waste In Qingdao

As the trial operation work of classification of urban waste in Qingdao is being carried out, kitchen and other organic waste will be separate from garbage. Considered in the point of view of the characteristics food waste, kitchen waste and other organic waste, landfilling and incineration are not best option for treatment and resource recovery. Therefore, the anaerobic digestion technology has become a challenging option for the resource recovery of this kind of organic waste. A food waste treatment plant is under preparation. Anaerobic digestion technology will be used to achieve organic waste stabilization and recovery of biogas. This experiment is the experimental test to study the technical feasibility of anaerobic digestion of food waste and vegetable market waste. The results show as follow.By monitoring the gas production rate, gas production, methane content, pH value, COD, VFA and ammonia and other parameters of food waste anaerobic digestion process, we can conclude that anaerobic digestion and biogas recovery of food waste and vegetable market waste is technically feasible in Qingdao.The maximum organic loading of food waste system can achieve 3.96 kg VS/m~3·d, the largest vegetable market waste anaerobic digestion of organic loading up to 6.23 kg VS/m~3·d.When system stable, in food waste system, 0.15 m3 methane were generated by one kilogram VS per day; In vegetable market waste system, 0.397 m3 methane were generated by one kilogram VS per day.In poorly run food waste anaerobic digestion system, volatile fatty acids inhibit methanogenic bacteria seriously. At the same time, H2S generated, which can reach 490 ppm at most.Under the same organic loading, small feeding amout and high feeding frenquency is effective, which is helpful to the regulation of anaerobic digestion system, and the methane production increased significantly.