Physical and chemical characteristics of waste activated sludge treated with electric field

This study investigates the physical and chemical characteristics of sludge treated with controlled levels of electric field. The results indicated that the potential gradient and contact time strongly influenced the physical and chemical characteristics of sludge. Based on the settling velocity measurements, a potential gradient of 6 V/cm with a treatment time of 10 min is recommended as an optimal condition for improving sludge settling. For sludge disintegration, applying a higher potential gradient and a longer treatment time to the sludge are more efficient than applying lower levels. The results of the experiments presented here show that an electric field not only disintegrates sludge and destroys microbial cells but also removes and solubilizes organic substances. Possible mechanisms of electric field treatment are also discussed.

► We investigate the physical and chemical characteristics of sludge treated with controlled levels of electric field.
► Electric field pretreatment could release organic substances by destroying sludge structure and degrading the pollutants.
► Higher supplied power could lead to increased organic matter decomposition and solubilization.
► A potential gradient of 6 V/cm with a treatment time of 10 min is an optimal condition for improving sludge settling.