Sludge biochar accelerates transformative phenolic compounds removal from wastewater via the coupling mechanism

Abstract

In this work, we investigated the mechanism of the oxidation of phenolic compounds (PCs) by graphitic sludge biochar (SDBCs) via a catalytic coupling regime in the presence of potassium persulfate (PDS). In-situ synchrotron attenuated total reflection Fourier transform infrared spectroscopy (in-situ ATR-FITR) combined with Raman spectroscopy directly monitored the formation of SDBC-PDS* complexes, which drove the electron-transfer pathway as evidenced by electrochemical tests and galvanic cell experiments. The coupling of pollutants into oligomers effectively reduced total organic carbon in water with a low PDS usage (PDS consumption to phenol degradation ratio of 2.2). Furthermore, our research showed that the biochar-based nonradical system effectively treats various PCs, with oxidation rates related to their half-wave potential and Hammett constant. Overall, this work explored sludge biochar engineering, PCs transformation and interfacial coupling mechanism, providing a novel approach for the efficient and cost-effective treatment of phenolic wastewater with low chemical input. © 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies. © 2024 Elsevier B.V.