INTRODUCTION
Whey, the greenish translucent liquid obtained from milk after precipitation of casein, has been viewed as one of the major disposal problems of the dairy industry, because of the high volumes produced and having a high biochemical oxygen demand (Marwaha and Kennedy, 1988; Mawson, 1994). As a general rule, about nine litres of whey is obtained for every kilogram of cheese produced. Thus, the volume of whey to be processed, originating from just one typical large scale cheese making operation can exceed 1 x 106 litres/day (Jelen, 2003). A dairy farm processing 100 t of milk per day produces approximately the same amount of organic products in its effluent, as would a town with 55000 residents (Sienkiewicz and Riedel, 1990).