Field Testing of a Small-Scale Continuous-Flow Wastewater Electrodisinfection Unit Using Direct Current

AbstractThis paper describes field testing of a small-scale, continuous-flow electrodisinfection reactor assembled with four IrO2-coated titanium plates and operated in bipolar mode using direct current, installed at the Marrero wastewater treatment plant in Marrero, Louisiana. The objective of this testing was to demonstrate the technical feasibility of replacing the current wastewater-effluent hypochlorination process with this new disinfection technology. Bacterial inactivation and chlorine production were the main parameters recorded. The experiments reported in this study demonstrate that the electrodisinfection process can meet and exceed 5-log coliform removal in a short contact time, thereby proving to be efficient enough to be considered as an alternative to chlorination in wastewater treatment facilities. Optimum operational conditions for fluid retention time, and volumetric current density and rate, were stablished from the experimental results. The following design recommendations summarize these findings: retention time of 5±0.3 min, minimum volumetric current density of 1,000 A/m3, and minimum volumetric current rate of 80 A·h/m3. Implementation of these operational conditions in the field yielded excellent disinfection efficiencies and low chlorine residual production.