电化学处理改善剩余污泥脱水性能

Investigation on the improvement of sludge dewaterability after electrolysis pretreatment

以毛细吸水时间(CST)作为衡量污泥脱水性能的指标,采用铱/二氧化钌电极板为阳极、钛/二氧化钌网状极板为阴极,对剩余污泥进行电化学处理,考察了电压、处理时间等因素对剩余污泥脱水性能的影响.结果表明,电压对污泥脱水性能影响较大,当电压为30V、极板间距为4cm、搅拌速率为100r.min-1、处理30min条件下污泥调理效果最佳,此时剩余污泥的CST下降了35.5%.电镜结果显示,此时的污泥表面结构被破坏,菌胶团内的自由水被大量释放出来,污泥脱水性能得到改善;当电压增加到50V时,污泥絮体结构破碎严重,导致污泥颗粒变小,比表面积增大,污泥脱水性能变差.

Sludge dewaterability could be improved by the pre-treatment of electrolysis process.With Ir/RuO2 and Ti/RuO2 mesh used as the anode and cathode in the electrolysis facilities,respectively,Capillary Suction Time（CST） was measured as a metric of the sludge dewaterability.The factors which affect the sludge dewaterability and the optimal parameters were determined.It was found that CST value of sludge decreased the most significantly by 35.5% when the operation conditions were as follows：30 V voltage,electrolysis time of 30 min,electrode distance of 4 cm.and mixing at 100 r.min-1.The corresponding SEM image of sludge showed that the sludge structure was deformed,and the sludge dewaterability was improved due to the release of the cell interstitial water from sludge when treated at the optimal electrolysis condition.However,the dewaterability of sludge deteriorated when pretreated at 50 V,because the sludge structure was destroyed seriously,and the floc size became smaller.