An investigation into biological treatment of fruit cannery wastes

Abstract

Includes bibliographical references.The production of canned fruits and vegetables in the Republic of South Africa is an important factor in the country's export trade. South Africa exported goods valued at R2 016m in 1972, of which R69m was accounted for by canned fruits and vegetables. (Bulletin of Statistics 1974 and Stats 1974). The major fruit and vegetable growing areas are in the Western Cape and the canneries are situated in those towns in close proximity to both the farms and railheads. The wastewaters generated by the numerous canneries vary greatly in composition - being dependent upon the particular fruit or vegetable being processed. The wastes generally have high BOD or COD concentrations (mainly due to sugars and starches) and low concentrations of the nutrients, nitrogen and phosphorus. In many towns the seasonal 'pollution' load from the canneries can exceed by several times the municipal load. Usually the municipal waste water treatment facilities are inadequate to handle the seasonal peak loads. This, in conjunction with the nutrient deficient nature of the cannery wastes, results in poor treatment efficiencies being recorded at the purification works