Electrocoagulation of potable water

Abstract

Coagulation caused by electrolytically produced ions (electrocoagulation) followed by filtration has been studied as a possible alternative to the conventional coagulation process. Electrochemical processes have been used in water and wastewater treatment since 1887. Electrocoagulation is looked upon as an interesting process in use at small water treatment plants. There are several important design aspects of this process which deserve further study. This study presents results showing the correlation between the current density and the aluminium dosing and provides results showing the necessary overpotential. The process has proved efficient with regard to removal of aquatic humus. A comparison of this method with conventional coagulation shows that the aquatic humus is removed equally well with both methods. Conventionally coagulated water (using alum) contains higher concentrations of sulphate and thus has a higher specific conductivity than the electrochemically treated water. The electrochemically treated water contains higher residual aluminium concentrations than the conventionally treated water due to the higher pH values.