1. Introduction
Whey is the aqueous fraction of milk generated as a by-product of cheese manufacturing. Approximately 9 kilograms of whey are produced in the manufacture of 1 kilogram cheese. Worldwide production of whey is of the order of 130 million tonnes per year, with cheese production increasing at a year rate of about 3%. This could have a negative effect for environment if the whey is not treated before discharge to the environment, exhibiting a COD value 60,000 – 80,000 ppm [1].