次氯酸钠预处理污泥对厌氧消化的影响

Effects of sodium hypochlorite pretreatment on anaerobic digestion of sludge

采用次氯酸钠对污泥进行预处理,考察了预处理对污泥厌氧消化的影响。以原污泥作为对比,研究了经过次氯酸钠预处理后,厌氧消化过程中污泥性质及甲烷产气量等的变化。经次氯酸钠预处理的污泥,在厌氧消化过程中平均日产气速率为34mL,比未经过预处理的污泥产气速率提高了9.80%;经预处理后污泥厌氧消化总产气量为1 055mL,比未预处理的多产气122mL。预处理污泥出现产气量峰值的时间比原泥提前4d,表明次氯酸钠预处理可以加速厌氧消化速度,缩短污泥停留时间。厌氧消化时SCOD是表示污泥水解增溶程度的参数。实验结果显示,次氯酸钠预处理促进了污泥的水解,厌氧消化过程中,预处理污泥的SCOD浓度高于原泥,最大值为487mg/L,比原泥中SCOD浓度的峰值大11.62%。

Pretreatment of excess activated sludge using sodium hypochlorite（NaClO）was conducted to investigate its effect on anaerobic digestion.The characteristics of sludge and methane production before and after pretreatment was analyzed.It showed that average daily rate in anaerobic digestion of excess sludge was 34 mL,which was 9.80% higher than that of without pretreatment.The gas production rate was 1 025 mL in anaerobic digestion after the pretreatment,which was 122 mL more than the other.The time for maximum gas production rate was 4dearlier than that for the original sludge.This indicates that to pretreat the excess sludge using NaClO can accelerate anaerobic digestion and shorten sludge retention time.SCOD is a parametric representing the degree of hydrolysis and solubilization of sludge in anaerobic digestion.The concentration of SCOD at a maximum of 487mg/L after treatment was higher than that of sludge without pretreatment,and were about 11.62% higher than that of the untreated.