A Review on The Effectiveness of Electrocoagulation, Advanced Oxidation Process, and Aeration-Enhanced Electrocoagulation for Treating Distillery Spent Wash

Abstract

For every liter of alcohol generated in the distillery sector, around 8-15 liters of byproduct known as spent wash are released as wastewater; exhibiting extremely elevated levels of chemical oxygen demand as well as biological oxygen demand. In the absence of proper treatment, discharging spent wash into water-receiving bodies could result in potential harm to aquatic ecosystems. A comprehensive Systematic literature review is presented on Electrocoagulation, Aerated Electrocoagulation Process and Advanced Oxidation in treating distillery spent wash. The review encompasses several sections viz., treatment options and work done by various researchers using different electrodes, operating parameters, and variables. A cumulative 101 articles were chosen due to their content validity, relevance to the research question, strength of evidence, publication year (2003–2023), and alignment with the research area. The electrocoagulation method is acknowledged as an outstanding technique that gains various advantages viz., high efficiency over a short treatment period and cost-effectiveness in materials and operation conditions. Aerated Electro-Coagulation (AEC) is a hybrid method that merges aeration and electrocoagulation techniques within the scope of physical-chemical treatment processes. This approach eliminates the need for chemical oxidants, as the supplied oxygen is the oxidizing agent. Advanced oxidation processes are distinguished by the production of a significant amount of hydroxyl radicals, which play a pivotal role in the treatment of spent wash.