Effect of Solid Content on Start-up of Mesophilic Middle Solid Anaerobic Digestion for Water-sorted Organic Fraction of Municipal Solid Waste
FANG Wei SUN Yong-ming YUAN Zhen-hong
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences Guangzhou Institute of Energy Conversion, Key Laboratory of Renewable Energy and Gas Hydrate ,CAS Guangzhou Institute of Energy Conversion, Key Laboratory of Renewable Energy and Gas Hydrate ,CAS
Abstract：Using water sorted organic fraction of municipal solid waste (WS-OFMSW) as materials, pilot scale (35 L) mesophilic [(30±2)℃] middle solid batch anaerobic digestions were carried out to investigate the effects of reactor total solids (TSr 16.0%, 13.5% and 11.0%) on start-up stability and performance of anaerobic digestion. The experimental results showed that all of three TSr could start up without inhibitions of VFAs and ammonia. The "inhibited steady state" was not found. The anaerobic digestion systems had the ability of self-saving. During the period of start-up, the pH value increased gradually and then kept in neutral. The free VFAs and free ammonia concentrations were lower than 50 and 6 mg/L respectively which were lower than inhibition levels of methane production. The low TSr was favorable for rapid start-up and shortening the period of anaerobic digestion. The peaks of methane productions were found at 32, 25 and 12 d for TSr at 16.0%, 13.5% and 11.0% respectively. The lag time of start-up was10.8, 5.6 and 1.9 d.