Efficacy of physically pretreated Mangifera indica biomass for Cu2+ and Zn2+ sequestration

To develop a strategy for the eradication of Cu2+ and Zn2+ from contaminated waters, the waste biomass of Mangifera indica was pretreated physically (autoclaved, boiled and heated) for assessing the uptake capacity of native and pretreated biomass for Cu2+ and Zn2+ biosorption on batch scale, concentrating on pH, pretreatment, biosorbent dose, metal concentration, contact time and temperature as operational parameters. To measure the goodness-of-fit error functions as sum of square error (SSE), chi-square (χ2) and residual root mean square error (RMSE) were used. Best results were obtained at pH 5 (80.65 mg/g) and 6 (94.25 mg/g) for Cu2+ and Zn2+, respectively, with autoclaved leaves. Sorption capacity of biomasses was found to be decreased with increase in biosorbent dose and temperature while it increased with increase in metal ion concentration and with time. Freundlich isotherm was found favorable to describe sorption mechanism, whereas pseudo-second-order kinetic model was best employed to describe sorption rate.