Removal of Waterborne Particles by Electrofiltration

A pilot-scale evaluation to assess the application of direct current to a rapid sand filter (termed "electrofiltration") verified the theoretical effectiveness of electrofiltration in enhancing the performance of conventional filtration within a water treatment facility. The efforts which are described in this paper were based on prior bench-scale assessments of the electrofiltration process. The analysis, combined with the theory used to describe the phenomenon, was used to design and construct the pilot filter using sand from existing filters in the filtration plant. The filter was tested using effluent from a presedimentation basin, at influent turbidities typically around 30 nephlometric turbidity units (NTU). Initial tests verify that electrofiltration can improve the performance of a filter in terms of both particle removal and turbidity reduction. Results from the preliminary analyses and future plans are presented.