低温短时热水解对剩余污泥厌氧消化的影响及相关性分析

Effect of short time low temperature thermal pretreatment on sludge anaerobic digestion and correlation analysis

摘要:

研究了70℃-120℃，20min热水解预处理对剩余污泥有机物溶出、重金属释放及厌氧消化的影响。实验结果表明，COD、碳水化合物、蛋白质、DNA及氨氮（NH4-N）等指标的溶出在110 ℃以下都随着温度增加且在90到100 ℃之间有显著跳跃性增长，在120 ℃反而有所下降。污泥中微生物细胞在100℃ 时破裂。通过研究VS去除率和沼气产率来表征低温热水解对厌氧消化的影响，这两项指标均在110 ℃取得最大值。在上述研究基础上进行了相关性分析及回归分析，结果表明，所有的有机物溶出指标及厌氧消化性能均与预处理温度有显著的相关性，而单位降解VS产气与碳水化合物及蛋白质的溶出率呈很好的多元线性关系。

Abstract:

The effect of thermal pretreatment with temperature between 70 and 120℃ and last for 20min on sludge organic matter solubilization, heavy metal release and anaerobic digestion was investigated. Flocs as well as cells were broken down and organic matter was released to liquid phase. Solubilisation of properties such as COD, carbohydrate, protein, DNA and ammonia all increased with temperature below 110 ◦C and experienced a significant jump at 100◦C .However, solubilisation of major organic compounds decreased at 120◦C. Cells of microorganism were broken down at 100◦C. The concentrations of heavy metals in the soluble phase increase with temperature. But no remarkable increase was observed for heavy metal release. VS removal and biogas production were investigated to evaluate the effect of thermal pretreatment on efficiency of anaerobic digestion. Both the two characteristics reached peak at 110◦C. Correlation matrices of biogas production per VS eliminated and VS removal rate with SCOD, soluble protein and soluble carbohydrates were explored to determine the influence of these selected variables on anaerobic digestion. Then the influence of soluble protein and soluble carbohydrates on biogas production per VS is illustrated by the stepwise linear regression equations.