牛粪单级干发酵产气中试研究

在中温37℃条件下,以牛粪为研究对象,采用连续式单级干发酵技术对其进行180d产气中试试验研究,结果表明：（1）根据产气速率、TS、pH值及氨氮浓度变化在时间上可划分为启动阶段、稳定阶段、抑制阶段和恢复阶段,各阶段产气速率、pH值及氨氮浓度存在明显差异;（2）在启动阶段系统pH降至5.5左右,酸化现象明显,采用NaOH溶液调节每日回流渗滤液的方法解决酸化问题;（3）在稳定阶段系统平均产气速率为55.37L·d-1,牛粪产气潜能（以VS计）为79.9L·kg-1,HRT为40～20d,系统未出现酸化现象;（4）中试运行至第90d后出现严重的氨氮抑制现象,此时氨氮浓度达2500mg·L-1以上,产气速率下降至23.1L·d-1,只有高峰期的40.2%,采用稀释回流液的方法,30d后氨氮浓度降低至1689mg·L-1,产气速率为45.5L·d-1。

A Pilot-Scale Single Phase Dry Fermented Reactor for Treatment of Cattle Manure

Under mesophilic condition（37 ℃）, a bench-scale experiment based on dry fermentation process of live manure was conducted in a fed-batch single phase reactor. The result showed：（1）According to gas production rate,TS,pH value and ammonia concentration change, there were mainly four stages concerned：start-up stage,stabilization stage,inhibition stage and recovery stage.（2）At the start-up stage, the pH value reached minimum of about 5.5 and acidification occurred,which was resolved by NaOH solution adjusted daily leachate;（3）At the stabilization stage gas production rate reached 55.37 L·d-1,the potential gas production of cow manure was 79.9 L·kg-1·VS-1 when the hydraulic retention time（HRT） was 40～20 d, there was no acidification occurred at this stage;（4）There was a ammonia inhibition at 90th day, the gas production rate fell to 23.1 L·d-1, which was 40.2% of maximum when ammonia concentration was higher 2 500 mg·L-1. Ammonia concentration fell to 1 689 mg·L-1 by adding pure water dilution for 30 days,the gas production rate was 45.5 L·d-1.