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%.