沼渣好氧发酵原料配比优化研究

Optimization of raw material ratio for aerobic fermentation of biogas residue

为研究以沼渣为主要原料的好氧发酵物料配比,用响应曲面法(RSM)中Box-Behnken设计和主成分分析法对发酵产品的含水率、有机质含量、种子发芽指数(GI)、pH值、E4/E6、C/N进行分析,建立响应值模型并拟合.结果表明,9组堆体的50℃以上持续时间达到相关无害化标准;发酵产品的含水率在20%~58%;13组发酵产品的C/N为11.58~16.52,有机质含量为46.34%~59.94%,总养分含量为7.03%~9.26%,E4/E6为1.65~2.83,且11组的GI均大于85%,说明11组处理发酵产品腐熟程度较高,无植物毒性.以沼渣为主要原料的好氧发酵最佳物料质量配比为沼渣:猪粪:秸秆=8:4.5:5.验证试验结果表明,试验结果与预测值的误差为4.77%,说明RSM预测的沼渣好氧发酵原料配比能进行应用.

To optimize the ratio of raw materials for aerobic fermentation, in which the biogas residue is the main ingredient, the Box-Behnken design of Response and PCA are used to analyze the organic matter content, C/N, pH value, moisture content, E4/E6 and seed germination index(GI) of the aerobic fermentation products. The optimal mixture ratio of aerobic fermentation raw materials with biogas residue, pig manure and straw is obtained by RSM. The results show that 9 products last in thermophilic phase for 5~7 days. The moisture content of products range from 20% to 58%, C/N from 11.85 to 16.52, the organic matter contents from 46.34% to 59.94%, the E4/E6 from 1.65 to 2.83, the GI of 11 products are all greater than 85%, suggesting that these products have reached the high maturity level and no phytotoxicity is found in them. Response surface analysis indicates that, with biogas residue as the main raw material, the optimum ratio for aerobic fermentation is identified to be: biogas residue: pig manure: straw = 8:4.5:5. The error between the measured results and the predicted values is 4.77%. As such it may come to the conclusion that RSM can be used to optimize the raw material ratio and the optimum ratio is applicable.