Magnetic Fe-modified biochar realizes highly efficient removal of refractory organic pollutants

Abstract

Material modification of biochar is considered a promising strategy to enhance the removal efficiency of refractory organic pollutants from wastewater. In this study, the performance of magnetic Fe-modified biochar produced via pyrolysis in removing organic dyes has been thoroughly investigated. Fe-modified biochar was more effective in degrading organic dyes relative to the pure biochar, and the pseudo-first-order reaction rate constants reached 18.2 × 10−3 min−1 for methylene blue (MB) degradation and 23.3 × 10−3 min−1 for rhodamine B (RhB) degradation, approximately 3 times higher than that of the pure biochar application. The improvement in organic dye removal efficiency following Fe-modified biochar application was attributed to the Fe-modification effect, which increased the number of active sites on the biochar surface and promoted electron transfer, generating more free radicals. In addition, the magnetic Fe-modified biochar exhibited stability and reusability in organic dye removal, regardless of whether MB or RhB was degraded. These findings suggest that Fe-modified biochar offers a facile approach to remediate refractory organic dye-contaminated wastewater.