原料比例和pH值对厨余垃圾和废纸联合厌氧消化的影响

Influences of Feedstock Proportion and pH Value on Anaerobic Co-digestion of Kitchen Waste and Waste Paper

以厨余垃圾和废纸为原料,考察了不同原料比例和酸化阶段pH对消化稳定性及产甲烷性能的影响.结果表明,原料比例为厨余垃圾/废纸100:0的厌氧消化由于挥发性脂肪酸抑制不能形成稳定的产甲烷过程.原料比例83:17时,酸化阶段pH为6.5,7.2和7.9的3组厌氧消化甲烷产率(以挥发性固体计)分别为313,346和360mL/g,COD去除率为86.3%,93.2%和95.2%,甲烷含量稳定在70%～80%.原料比例62:38、pH为6.5,7.2和7.9的3组厌氧消化甲烷产率分别为97,247和279mL/g,COD去除率为32.6%,80.5%和86.8%,甲烷含量稳定在60%～80%.

Using kitchen waste and waste paper as anaerobic co-digestion material, the influences of feedstock proportion （ratio of kitchen waste to waste paper at 100：0, 83：17 and 62：38, calculated by volatile solid） and pH value adjustment （6.5, 7.2 and 7.9） in the acidification stage on anaerobic digestion stability and performance was investigated. Experimental results showed that the proportion of 100：0 can not realize stable methane production due to the inhibition of volatile fatty acids. For the proportion of 83：17, methane yields were 313, 346 and 360 mL/g VS for three digestions with adjusting pH value at 6.5, 7.2 and 7.9 in the acidification stage. Methane contents of three digestions were 70%～80%. COD reductions were 86.3%, 93.2% and 95.2%. For the proportion of 62：38, methane yields were 97, 247 and 279 mL/g VS respectively, methane contents were 70%～80% for pH adjustment at 7.2 and 7.9 （60%～70% for pH adjustment at 6.5）, COD reductions were 32.6%, 80.5% and 86.8%. Compared with pure kitchen waste, the anaerobic co-digestion of kitchen waste and waste paper could avoid the inhibition of volatile fatty acids and improve good performance of digestions.