Characterization of greywater in an Indian middle-class household and investigation of physicochemical treatment using electrocoagulation

Wastewater produced from all the domestic uses of water sans toilet flushing is known as greywater. It is often the major component in the domestic wastewater but has fewer pollutant load. Recycling and reuse of treated greywater for non-potable purposes may significantly reduce the stress on the fresh water requirement. This article presents the result of a study undertaken for characterization as well as laboratory-based investigation for treatment of greywater generated from an Indian single household. The greywater constituted at least 80% of the total wastewater with maximum contribution (44%) from the kitchen. The treatment studies, undertaken in an electrochemical reactor where the voltage and current were varied for sacrificial aluminum anodes, revealed that about 70% of the total COD and more than 99.9% pathogens could be removed with an energy consumption of 0.3 kW h/m(3) of wastewater. COD removal reached a maximum of 70%, irrespective of the applied voltage and current density, at an aluminum release from the anode at a rate of 15 mg/L as aluminum. The electrochemical reactor aluminum electrodes, operated with maximum potential difference of 12 V, showed potential for scale-up for real-life use in households for removal of pathogens, turbidity and COD contents of greywater. (C) 2014 Elsevier B.V. All rights reserved.