Efficient Removal of Cr (VI) with Biochar and Optimized Parameters by Response Surface Methodology

A highly efficient reduction process of Cr (VI) with biochar was conducted in this paper. The results showed that nearly 100% Cr (VI) was reduced at selected reaction conditions: Dosage of biochar at m (C)/m(Cr) = 3.0, reaction temperature of 90 degrees C, reaction time of60 min, and concentration of H2SO4 of 20 g/L. The reduction kinetics analysis demonstrated that the reduction of Cr (VI) fitted well with the pseudo-first-order model and the apparent activation energy was calculated to be 40.24 kJ/mol. Response surface methodology confirmed that all of the experimental parameters had a positive effect on the reduction of Cr (VI). The influence of each parameter on the reduction process followed the order: Dosage of biochar>concentration of H2SO4>reaction temperature >reaction time. This paper provides a versatile strategy for the treatment of wastewater containing Cr (VI) and shows a bright tomorrow for wastewater treatment.

Automated summary

This study conducted a highly efficient reduction of Cr (VI) using biochar, with nearly 100% of Cr (VI) being reduced under selected reaction conditions. The reduction process was well described by a pseudo-first order model, with an apparent activation energy calculated at 40.24 kJ/mol. Response surface methodology confirmed that all experimental parameters had a positive effect on the reduction of Cr (VI), with the order of influence being dosage of biochar > concentration of H2SO4 > reaction temperature > reaction time.