Optimization of Cr(III) removal from wastewater using Thespesia populnea particles by response surface methodology

In this study response surface methodology involving central composite design was employed to investigate the effects of different operating conditions (pH, biomass dose, biomass particle size and agitation time) on the removal of Cr(III) from wastewater using Thespesia populnea. The significance of the independent variables and their interactions were tested by the analysis of variance (ANOVA) and F-test statistics. Optimization of the variables for maximum Cr(III) reduction was performed using the quadratic model. The model predicted maximum reduction capacity of 86 % at the best identified conditions of pH = 2.81, biomass dose concentration of 0.91 g L-1, particle size of 0.250 mm, agitation time of 52 min. The analysis of variance revealed that the quadratic polynomial proposed model demonstrated good agreement with experimental values. The results of this study indicate that Thespesia populnea seeds are a viable biosorbent for wastewater treatment.