Influence of Filter Cloth on the Cathode on the Electroosmotic Dewatering of Activated Sludge

The mechanical dewatering of activated sludge is troublesome due to its high compressibility of solids. The dewatering can be enhanced dramatically by the use of electroosmosis, in which an electric field is applied to the sludge cake. In this study, the influence of filter cloth on the cathode on the dewatering of activated sludge was investigated. It was found that thicker filter cloth led to lower water removal from the sludge cake, so a stainless steel cathode net with small pore size instead of filter cloth was applied, which improves the dewatering efficiency and reduces the electric power consumption. Moreover, water absorbent materials were helpful to remove the water from the sludge cake. For the electroosmotic dewatering at 7 kPa and 24 V.cm(-1), the water content in the sludge cake decreased to 60% (by mass) with the average 0.075 kW.h.kg(-1) of water removed by using the cathode net.