Response Surface Modeling and Optimization of Chromium (VI) Removal from Waste Water using Custard Apple Peel Powder

Abstract

The potential use of custard apple peel powder for the removal of chromium (VI) from waste water has been investigated in batch mode experiments. Influences of parameters like initial chromium (VI) concentration (5 - 30 mg/l), pH (2 - 4), and biomass dosage (8 - 12 g/l) on chromium (VI) adsorption were examined using response surface methodology. The Box-Behnken experimental design in response surface methodology was used for designing the experiments as well as for full response surface estimation and 15 trials per the model were run. The optimum conditions for maximum removal of chromium (VI) from the waste water are as follows: adsorbent dosage (10.3613 g/l), pH (2.78459) and initial chromium (VI) concentration (9.03197 mg/l). The maximum percentage removal of chromium at optimum conditions was 92.82 % (with metal uptake of 2.3045 mg/g). The high correlation coefficient (R2 = 0.997) between the model and the experimental data showed that the model was able to predict efficiently the percentage removal of chromium (VI) from waste water using custard apple peel powder. doi:10.14456/WJST.2014.3

Keywords

• Response surface methodology
• Box-Behnken design (BBD)
• custard apple peel powder
• chromium (VI)
• adsorption