MODELLING AND OPTIMIZATION OF CADMIUM REMOVAL FROM WASTEWATER ONTO SUGARCANE BAGASSE ACTIVATED CARBON

Abstract

The presence of sugarcane bagasse as an agricultural waste in the environment is a cause for concern as it defaces the environment. It is bulky and difficult to manage. This prompt the need to research into the reuse of sugarcane bagasse in a more rewarding way, thereby saving the environment from its litters. In this study, Sugarcane bagasse was collected from Gaskiya Road in Zaria and converted to activated carbon using thermal and chemical methods. The Sugarcane bagasse was divided into three portions and carbonized at temperatures of 300, 325 and 350oC and then chemically modified with 1M H3PO4 acid at ratio of 1:2. Batch adsorption experiments were carried out using three input variables: adsorbent dosages of 0.2 - 1.0 g; initial cadmium concentrations of 5 - 25 mg/l and carbonization temperatures of 300 - 350 oC with the corresponding output variables of removal efficiency (X1) and adsorption capacity (X2). The experimental data were modeled, optimized and validated using Response Surface Methodology (RSM). The optimum operating conditions for adsorption of cadmium onto sugarcane bagasse activated carbon were: carbonization temperature of 300 oC, initial cadmium concentration of 25 mg/l and adsorbent dosage of 1.0 g with the corresponding optimized removal efficiency and adsorption capacity of 100% and 2.5mg/g, respectively. The optimized removal efficiency and adsorption capacity were validated and the errors of 0.000 and 0.009%, respectively were recorded. It was concluded that sugarcane bagasse was effective in the removal of cadmium from wastewater and hence its reuse as an adsorbent in wastewater treatment is a viable waste management option. Also the model developed had proven to be valid in predicting the output variables.