The role of nonradicals in simultaneous degradation and detoxification of Malachite Green via biochar decorated with δ-MnO2

The advanced oxidation process (AOPs) has aroused great interest in the fields of sewage treatment for its effective removal performance of varied pollutants which are hard to biodegrade. In this study, delta-MnO2 was used to activate PDS, and biochar (BC) was introduced as a capable carrier and electron-transfer provider in PBC@delta- MnO2/PDS system. Malachite Green (MG) was selected as a pollutant probe to assess the efficiency of this system, experiments and multiple detection methods were conducted to evaluate the feasibility of MG removal and explore the relevant mechanism of this system. The results showed that wastewater containing MG could still be toxic if it was not thoroughly treated, whereas PBC@delta-MnO2/PDS could significantly reduce the toxicity by over 80%, and the major active species in PBC@delta-MnO2/PDS system was confirmed to be1O2 rather than free radicals, which contributed more than the other factors such as physical adsorption, electrostatic interaction and chemical bonding in the process of MG removal. Furthermore, this work comparatively expounded the MG detoxification performance led by1O2 through T.E.S.T software, and provided novel ideas for the application of PBC@MnO2/PDS system.(c) 2022 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).