Abstract
Organic pollutant degradation by biochar could be promoted by Fe because of the Fenton-like reaction. However, studies have also confirmed that reactive oxygen species (ROS) play only a limited role in organic pollutant degradation by biochar. Herein, we quantitatively identified 2,4-dichlorophenol (2,4-DCP) adsorption and degradation in Fe-biochar systems and obtained degradation (k1) and adsorption rate constants (k2) by two-compartment first-order kinetics modeling. The k1 was approximately 710 times lower than the corresponding k2 and the positive correlation between k1 and k2 illustrated that adsorption and degradation were kinetically associated. ROS quenching only slightly inhibited 2,4-DCP degradation. Chemicals with similar structures to ROS quenchers (without quenching ability) also inhibited 2,4-DCP degradation, probably because of the competition of the active degradation sites on biochars. Electrochemical analysis and pH-impact experiments further elucidated that 2,4-DCP underwent oxidation-dominated degradation in the adsorbed phase via direct electron transfer. Fe(III) obviously increased 2,4-DCP adsorption through cation bridging and enhanced electron density by Fe-O conjugations on the biochar surface, which facilitated subsequent degradation. This study emphasized the importance of degradation on the biochar solid phase and that a breakthrough of the mass transfer bottleneck of adsorption will greatly promote degradation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.