Sono-assisted electrocoagulation and cross-flow membrane processes for brewery wastewater treatment

Abstract

The combinations of treatment processes are one of the hot topics in environmental engineering. Especially, the highly-polluted wastewater can be treated effectively using combined processes. The objective of the present study was to investigate the treatment performance of brewery wastewater using electrocoagulation (EC), ultrasonication (US), and sono-electrocoagulation (SEC) processes. A cross-flow membrane system was integrated to succeed continuous treatment. The effect of electrode combination (Fe and Al), current density (50–100A/m2), pH (5.0–9.0), and operating time (0–60min) on the treatment of wastewater were investigated to obtain maximum treatment efficiency. The maximum removal efficiencies of color and chemical oxygen demand (COD) were obtained as 99.2 and 60.5%, respectively, at the electrode combination of Al/Al, current density of 100A/m2, pH 7.0, and reaction time of 60min. In order to improve treatment quality, a cross-flow membrane process was integrated to the sono-electrocoagulation process. Nanofiltration (NF) and reverse osmosis (RO) membranes were tested. The combined sono-assisted electrocoagulation and membrane system supplied 100% color and 90.8% COD removal efficiency when supported with RO membrane. The results indicated that the proposed integrated process supplied higher pollutant removal compared to the alone electrocoagulation and sonication process. Operating cost of the combined process was calculated as 1.83 $/m3. Moreover, the genotoxic effect of brewery wastewater was also assessed by comet assay before and after treatment. This process can be used to treat a different kind of wastewater as an efficient technique.