Anaerobic Treatment of Cane Sugar Effluent from Muhoroni Sugar Factory using Batch Reactors

Abstract

Cane sugar mill effluent is characterized by high COD, BOD and Suspended Solids (SS) contents and its treatment by aerobic biological methods is usually difficult. Due to the high content of lignin-cellulose in the SS of the wastewater, its pH falls rapidly during treatment to low levels, which is adverse to microorganisms. The aim of this study was to determine the anaerobic biodegradability of sugar mill effluent. Batch reactor experiments were carried out under three environmental conditions: Case I with both pH correction and seeding; Case II with seeding and no pH correction; and Case III without both pH correction and seeding. After 30 days retention period the COD, BOD and SS percentage reductions for the three cases were as follows: 81.5%, 14% and 63% respectively for Case I; 78%, 39%, and 67% respectively for Case II. Retention periods less than 10 days resulted in very little improvement in effluent quality. Biodegradability, as measured by the BOD/COD ratio, rose steadily during the reactor operation for cases I and II but relatively constant for case III. It was therefore concluded that anaerobic treatment, particularly with pH control and seeding shows potential in first stage management of sugar mill wastewater.

Keywords: cane sugar mill effluent, anaerobic treatment, batch reactor, waste stabilization ponds

Journal of Civil Engineering Research and Practice Vol. 5 (1) 2008: pp. 63-78