接种比例对餐厨垃圾高固体浓度厌氧发酵的影响

摘要

文章在12%～18%高固体浓度和中温（35±1）℃条件下,开展了不同接种比例对餐厨垃圾厌氧发酵过程影响的研究。考察了沼气产率、发酵液特性和TS、VS去除率等随接种比例变化的关系。结果表明,接种比例不低于50%的沼气日产率、累积沼气产率和平均甲烷含量显著高于接种量低于25%的发酵过程,并且pH值相较于低于25%的发酵体系能够稳定在6.8～7.2之间。提高接种比例能够降低发酵液中TN、TP和CODcr的浓度。餐厨垃圾与接种污泥TS比为1∶1时,甲烷含量和TS、VS去除率达到最大值,分别为64%、43.6%和52.8%。此时,累积沼气产率为228.6 ml/gVS。%Effect of various feed to inoculum ratios on high-solids anaerobic fermentation of food waste was conducted in laboratory scale,which was operated at mesophilic(35℃±1℃) and high-solid(12% to 18% total solids) conditions.The biogas yield,properties of fermentation broth mixture and removal efficiency of TS and VS were investigated.Results showed that inoculation over 50% had a higher biogas production rate,cumulative biogas yield and methane content than those by inoculation ratio less than 25%.Inoculum addition could not only enhance buffer capacity of fermentation system with stable and appropriate pH values,which lied between 6.8 to 7.2,but also reduce the concentration of total nitrogen,phosphorus and CODcr.As the feed to inoculum ratio of 1.0,methane content as well as reduction rate of TS and VS reached the maximums,64%,43.6% and 52.8%,respectively,for which the cumulative biogas yield was 228.6 ml/gVS.