水热预处理对污泥理化性质的影响

剩余污泥进行水热预处理时，研究了水热温度、时间和污泥固液比对污泥理化性质的影响?。结果表明：随着水热温度的升高，COD_Cr溶出率和污泥减量化程度逐渐提高，200 ℃时，COD_Cr溶出率最大，较原泥提高了96.5%，污泥减量化最大为80.1%，氨氮呈不规则性变化；水热时间对污泥减量化和氨氮溶出影响较小，当水热时间为1 h时，污泥中COD_Cr溶出率最大，较原泥提高了96.5%；固液比为10%，水热预处理后污泥中氨氮溶出最小，为1.093 mg/g。通过考察3个因素对污泥理化性质的影响，得出最佳水热预处理条件为污泥固液比为10%时，在200 ℃下，水热1 h后，污泥预处理效果最好，COD_Cr溶出率可达到最大值。

Effect of Hydrothermal Pretreatment on Physicochemical Properties of Sludge

The effect of hydrothermal reaction temperature, time and solid-liquid ratio on the physicochemical properties of excessive sludge was investigated during the hydrothermal pretreatment of excessive sludge. The results showed that the dissolution rate of CODCr and the reduction of sludge increased with the increasing of hydrothermal reaction temperature. At 200 ℃, the dissolution rate of CODCr was the highest, 96.5% higher than that of the raw sludge. The maximum reduction of sludge was 80.1% and the ammonia nitrogen changed irregularly. The hydrothermal time had little effect on the reduction of sludge and the dissolution of ammonia nitrogen. When the hydrothermal time was 1 hour, the dissolution rate of CODCr reached the highest, 96.5% higher than that of the raw sludge. When the solid-liquid ratio was 10%, the dissolution of ammonia nitrogen reached the least of 1.093mg/g after hydrothermal pretreatment. By comprehensively investigating the effect of the three factors on the physicochemical properties of excessive sludge, the optimal hydrothermal conditions were identified at solid-liquid ratio of 10% at 200 ℃ after 1hour of hydrothermal treatment. Under these conditions, the best sludge pretreatment effect could be obtained, and the maximum CODCr dissolution ratio thus reached.