ABSTRACT
This study investigates the performance of laboratory pond system containing immobilized cells of Saccharomyces cerevisiae in the treatment of raw tannery wastewater as compared to a pond system without cells. The performance of the pond system was evaluated by the measurements of BOD, COD, sulphate, TS, chloride, pH, chromium and cadmium. Also, the hydraulic characteristics of the pond configuration such as the average retention time and flow rate were estimated. The results obtained indicated that the system containing the immobilized cells yielded better results in the reduction of some of the parameters when operated under the same hydraulic and organic loadings. For example, the overall BOD, COD and chloride removal were 73.5%, 62.96% and 69.56% respectively. Also, chromium and cadmium respectively attained a reduction of an average of 96.21% and 53.77%. Using statistical tools in further analyzing the results showed that the immobilized cells of s. cerevisiae are solely responsible for the reduction of the parameters.