生物炭介导的鸡粪厌氧消化产甲烷工艺参数优化

Optimizing Process Parameters for Methane Production during Biochar-mediated Anaerobic Digestion of Poultry Manure

为探究生物炭介导的鸡粪厌氧消化产甲烷最优工艺参数,在前期试验的基础上,以鸡粪添加量、生物炭添加量和碳氮比为参数,在(35±1)℃条件下进行了生物炭介导的鸡粪序批式三因素二次旋转组合厌氧消化试验。以单位挥发性固体(VS)累积产甲烷量为评价指标,通过响应面法获得单位VS累积产甲烷量随三因素变化的二次回归模型。结果表明:回归模型拟合性较好,能较好描述单位VS累积产甲烷量随鸡粪添加量、生物炭添加量和碳氮比变化的规律。通过对模型工艺参数寻优,得到最优工艺参数为鸡粪添加量14.35 g、生物炭添加量4.97%、碳氮比22.02,此条件下单位VS产甲烷量为283 m L/g,为生物炭介导的鸡粪厌氧消化工程应用提供了参考依据。

The quadratic orthogonal rotation regression combination design was employed in this study to determine effects of poultry manure amount, biochar dosage and C / N ratio on biochar-mediated mesophilic anaerobic digestion of poultry manure. These three factors were then subjected to response surface methodology to obtain optimum parameters for methane production. The results showed that specific cumulative methane production（ SCMP） could be obviously increased by adding appropriate amount of biochar during anaerobic digestion of poultry manure. SCMP was increased as biochar dosage increased from 2. 5% to 5. 0%,but was significantly decreased with the further increase of biochar dosage up to 7. 5%（ P〈0. 05）. Lower poultry manure amount could result in higher SCMP. The effect of C / N ratio on SCMP showed the same trend with biochar dosage,namely an initial increase up to certain level and followed by decreasing change. The highest SCMP（ 288 m L / g） was observed with biochar dosage of 5. 0%,poultry manure amount of 17. 83 g and C / N ratio of 25. The developed mathematical regression model here showed a good fit with the experimental data. Moreover,the model predicted that the maximum SCMP could be obtained with biochar dosage of 4. 97%,poultry manure amount of 14. 35 g and C / N ratio of 22. 02.