恒电流模式下污泥电渗透的脱水性能及能耗分析

Performance and energy consumption of electro-osmotic sludge-dewatering in constant current mode

对传统机械脱水后的污泥采用电渗透技术进行二次脱水,在恒电流模式下研究了电流密度、机械压力、污泥厚度、初始含水率对脱水效率及能耗的影响.结果表明:在恒电流模式下,增加电流密度和初始含水率及降低污泥厚度对污泥电渗透脱水速率有促进作用.脱水后的最终含水率随着机械压力和初始含水率的增加及污泥厚度的降低而降低.电渗透脱水的最佳工艺参数为:电流密度为178.3 A·m^(-2),机械压力为31.4k Pa,污泥厚度为0.8 cm,初始含水率为81.5%,脱水后污泥的含水率可降至51. 3%.恒电流模式下污泥电渗透脱水单位能耗为0. 135～0. 269kW·h·kg^(-1),初始含水率对能耗影响最大,初始含水率每增加2%,单位能耗平均降低0.05 kW·h·kg^(-1).

Electro-osmotic technique was used for sludge dewatering after traditional mechanical dewatering,and the effects of electric current density,mechanical pressure,sludge thickness and initial moisture content on dewatering efficiency and energy consumption were investigated in constant current mode. The results show that the electro-dewatering rate increased with the increase of electric current density and initial moisture content,and with the decrease of sludge thickness. The final moisture content of dewatered sludge decreased with the increase of mechanical pressure and initial moisture content,and with the decrease of sludge thickness. The moisture content of sludge was reduced to 51. 3% after electro-dewatering under the optimal conditions： current density 178.3 A·m-2,mechanical pressure 31.4 k Pa,sludge thickness 0.8 cm,and initial moisture content 81.5%. In constant current mode,the unit energy consumption of electro-dewatering was 0.135 ～ 0.269 kW·h·kg-1,on which the initial moisture content of sludge had the greatest impact. When the initial moisture content increased by 2%,the unit energy consumption decreased by an average of 0.05 kW·h·kg-1.