Decontamination and optimization study of hexavalent chromium on modified chicken feather using response surface methodology

Present research highlighted the efficacy of alkali-treated (1% NaOH) chicken feather toward removal of Cr(VI) from aqueous solution through batch study. Box-Behnken design (BBD) by response surface methodology was used to optimize the adsorption process. Kinetics and sorption isotherms have been determined considering the effect of initial metal concentration, adsorbent dose, contract time, and temperature. Batch sorbent data were fitted to various sorption models, and results indicate that Cr(VI) sorption process using alkali-treated chicken feathers followed the pseudo-second-order rate model, while sorption isotherms were described properly by both Langmuir (R-2: 0.997) and Freundlich isotherms (R-2: 0.979). Based on BBD design, the quadratic models were developed co-relating the adsorption variables to removal efficiency. Analysis of variance (ANOVA) was incorporated to judge the adequacy of model (F:3484.72). Model predicted optimized conditions are initial concentration 5.64mg/L, adsorption dose 0.15g, contract time 29.60min, pH 1.06 gave 88.9% removal efficiency. Sorption isotherms show that the experimental maximum sorption capacity of Cr(VI) was found to be 90.91mg/g at 40 degrees C and pH 2. Therefore, present results demonstrate that alkali-treated chicken features should be regarded as a low-cost alternative for the removal of Cr(VI) from aqueous solution.