Removal of phosphate and suspended solids by electrocoagulation coupled with woven fabric membrane at pilot plant

Abstract

The objective of this study was to develop a rapid, economical, and eco-friendly process for the efficient removal of phosphate and suspended solids (SS) from the wastewater in the continuous mode at pilot plant scale. In this method, electrocoagulator (EC) was coupled with woven fabric membrane and the effluent was removed directly from the reactor through the membrane thus omitting the settling stage. The experiment was carried out for four months by maintaining an optimal current density of 0.8 mA/cm2 in the EC reactor. No chemical injection was made at any stage of the investigations and the membrane was operated at very high flux rates ranging from 25 to 75 LMH. The phosphate and SS removal efficiencies of the developed hybrid method were around 98 and 99%, respectively, while the removal efficiencies of these contaminants were between 78 and 61%, respectively, by providing only EC treatment. The final effluent phosphate and SS contents were less than 0.20 and 0.35 mg/L, respectively, in the treated wastewater. The removal rates were identical at all flux rates and the maximum increase in transmembrane pressure was 10 kPa at 75 LMH. SEM images showed that woven fabric membrane had excellent regeneration ability. It had high robustness, generated good quality effluent, and only needed physical cleaning.