American Journal of Engineering Research (AJER) 2013 www.ajer.us Page 128 American Journal of Engineering Research (AJER) e-ISSN : 2320-0847 p-ISSN : 2320-0936 Volume-02, Issue-05, pp-128-134 www.ajer.us Research Paper Open Access Mathematical Modelling of Cassava Wastewater Treatment Using Anaerobic Baffled Reactor A.O. Ibeje 1 , B.C.Okoro 2 Department of Civil Engineering, Imo State University, Owerri, Nigeria; Department of Civil Engineering, Federal University of Technology, Owerri, Nigeria. Abstract: The performance of an anaerobic baffled reactor (ABR) was evaluated in the treatment of cassava wastewater as a pollutant residue. An ABR divided in four equal volume compartments (total volume 4L) and operated at 35°C was used in cassava wastewater treatment. Feed tank chemical oxygen demand (COD) was varied from 2000 to 7000mg L -1 . The objective of the study was to formulate an improved mathematical model to describe cassava wastewater treatment without taking into account its inhibition characteristic. In the study, Kincannon-Stover model constants max and K s , were found to be 0.8803mg/L. d and 0.2113COD/m 3 . day respectively and Monod Model constants max and K s , were found to be 100mg/L. d and 98mgCOD respectively. The coefficient of determinations (R 2 ) of Kincannon-Stover and Monod Models were evaluated as 0.634 and 0.986. This showed that the Monod model is a more applicable model for describing the kinetics of the organic removal in anaerobic baffled reactor for treating cassava wastewater. Keyword: Mathematical Modeling; Anaerobic Baffled Reactor (ABR); Cassava Wastewater; COD Removal; Treatment I. INTRODUCTION Wastewater treatment in developing countries is a problem to manage. The major components of the effluents from garri processing industries is cyanide and starch, and in most cases, these effluents are channeled into pits where they continue to accumulate and gradually percolate into the surrounding soils thereby posing serious health and environmental hazard. The wastewater from cassava processing or its derivative (garri) ends up with domestic sewage if processed in small quantities while others end up being carried with industrial wastes if processed in large industrial quantities. Lastly, others percolate into the soil depending on the processors. Wastewater from cassava processing, if released directly into the environment before proper treatment, is a source of pollution. In many areas where traditional processing is practiced, wastewater is normally discharged beyond the “factory” wall into roadside ditches or fields and allowed to flow freely, settling in shallow depressions. Eventually this will percolate into the subsoil or flow into streams. Cassava roots contain cyanogenic glucosides (the precursors of HCN) in various concentrations depending on the variety and growing conditions (Bolhuis, 1954). This cyanide is released during peeling, slicing and crushing. The bound cyanide is converted to free cyanide during the milling operation. About 40% to 70% of the total cyanide appears in the water used to wash the starch from the disintegrated tissue (Maduagwu and Umoh, 1988). The press water, although produced in relatively low volumes (250 – 300 litres per tonne of roots), is the main problem because of its high biological oxygen demand (BOD) of 25,000 – 50,000 mg/l with a typical cyanide concentration in excess of 400 mg/l (Gomez et al., 1984). Cyanide, being an acidic component will naturally have an inhibiting action on the biological degradation of cassava wastewater. Cassava wastewaters are often discharged into sewers or allowed to percolate into the soil causing environmental degradation. This effect on the environment is significant as the air we breathe becomes contaminated with the odor emanating from it, an effect yet to be addressed properly in developing countries due to inadequate equipment and lack of research materials. The cassava wastewater may introduce some toxic elements e.g. cyanide in sewage which may inhibit the usual degradation processes. It is therefore very important to establish the pathway of degradation, the level of inhibition and the extent of treatability of cassava wastewater. The objective of this study is to formulate an