Reduction of chemical oxygen demand in distillery spent wash using electro-caogulation

Abstract

A renewed interest in electro-coagulation has spurred by the search for reliable, cost effective method for the treatment of polluted water. Electro-coagulation presented a robust novel and innovative alternative in which a sacrificial metal anode corroded,due to an applied electric potential, with the simultaneous evolution of hydrogen at the cathode which was removed by floatation.This had the major advantage of providing activecations required for coagulation, without increasing the salinity of water. Electro-coagulation is a complex process with a multitude of mechanisms operating synergistically to remove the pollutants from the water.This research presented an in depth discussion and consideration of factors that are the requirements for the optimum performance of this technology.The objective of the study was to lower chemical oxygen demand of the distillery spent wash from Bwendero dairy farm limited. This was achieved by allowing for the coagulation of the metalions from the corroded aluminum anode and floatation of light materials by the hydrogen gas at an optimum pH, in an electric cell with hydrochloric acid as an electrolyte. The original amount chemical oxygen demand(COD)was70,000mg/Land the results showed the amount of 10,080mg/L at optimum pH of 3, giving a percentage reduction in COD of 85.6%.