pH Dependent Hexavalent Chromium Adsorption Experiments by Biochar Derived by Rice Husk

Rice husks (RHs) is a low-cost biowaste that has been widely studied for a few decades.In environmental remediation field, rice husks can be used to removal heavy metals as an adsorbent.And plenty of modification have been implemented on rice husks.In this study, the adsorption capacity of RHs and modified RHs was investigated by conducting Chromium (VI) adsorption experiments at different pH conditions.The results show that the carbonization of RHs helps little with the adsorption capacity to Chromium (VI).However, the chemical modification by sodium hydroxide plays a significant role in the heavy metal removal tests, which increase the removal rate from 30% to 84% at pH 3, comparing to raw RHs.Also, lower pH was confirmed as the most appropriate condition for Chromium(VI) removal.