Application of experimental design methodology to optimize dye removal by Mucuna sloanei induced coagulation of dye-based wastewater
Patrick Chukwudi Nnaji, Chika Anadebe, Okechukwu Dominic Onukwuli
Abstract
ABSTRACT A Box–Behnken design implementing response surface methodology was employed to investigate the sludge generation and removal of pollutants from dye-based wastewater using Mucuna sloanei seed powder (MSSP) in their natural form as biomass in the coagulation process. With color/total suspended solids (CTSS) removal, chemical oxygen demand (COD) removal and sludge volume index as the three responses, the three quadratic models of three variables including MSSP dosage, solution pH and stirring time were developed. At the optimal conditions, the response recorded for CTSS removal was 87.7% with 1.8 g/L dosage at solution pH 2 and 15 mins stirring time. While COD removal was 91.69% with 1.8 g/L dosage at solution pH 6 and stirring time of 30 mins, and maximum sludge of 104.3 mL/g was generated with 1.4 g/L dosage at pH 2 and stirring time of 30mins. The use of MSSP thus exhibited great potential for dye-based wastewater treatment and thus, contributes to the green environment.