Adsorptive Removal of Bisphenol A From Aqueous Solutions by Activated Carbon Derived From Walnut Shells: Optimization by Response Surface Methodology

Presence of bisphenol A in water resources is harmful for health of human beings. Therefore, it should be addressed to eliminate and prevent its contamination. The aim of this study was to evaluate the activated carbon adsorbent efficiency of walnut shells in removing bisphenol A from aqueous solutions.
In this study, adsorbent preparation using walnut shells was performed according to standard methods. The independent variables are pH, initial concentration of bisphenol A and adsorbent dose. The surface response method was used to design the experiment and determine the optimum adsorption conditions.
The results showed that output of removal rate of the contaminating increased at a dose of 1.5 g, pH = 3, and initial concentration of bisphenol A was 40 mg/L. Also, the analysis of variance of data revealed that the model obtained from the response surface method was statistically significant.
Based on the results using walnut shell as an inexpensive and available adsorbent, it is possible to remove up to 97% of the bisphenol A from the aqueous solution by creating optimal conditions.