Continuous Manifold Electrocoagulation System for Enhanced Phosphate Removal in Decentralized Wastewater Treatment Units
Decentralized wastewater treatment systems (DWTS) are often insufficient in removing phosphorus from domestic wastewater, making these units primary contributors to eutrophication. The objective of this thesis was to develop a continuous electrocoagulation system based on a manifold design aimed at removing phosphorus from septic tank effluent. Using a current density of 2.0 mA/cm2, a hydraulic retention time (HRT) of 10 minutes and influent concentrations of 20 mg/L, the removal rates of orthophosphate, polyphosphate and total phosphate were found to be 99.9%, 86.0% and 88.1%, respectively. At these operating conditions, average effluent Al3+ concentration was found to be 1.0 mg/L with total suspended solids concentration of 51 mg/L. HRTs beyond 10 minutes had no effect on orthophosphate removal and minimal effect on polyphosphate removal. The reactor was successful in mitigating the risk of eutrophication and shows viability in being an option for DWTS owners looking for an enhanced phosphorus removal system.