Eco-friendly and effectively glyphosate removal using novel banana peel-derived biopolymer-supported CoFe2O4 activated peroxydisulfate: kinetic and mechanism insights
摘要
In this work, an eco-friendly and novel heterogeneous catalyst deriving biopolymer extracted from banana peel for supporting CoFe2O4 (CoFe2O4@BP-BiP) was successfully developed to activate peroxydisulfate (PDS) for mineralization removal of glyphosate (GP) herbicide from wastewater. GP mineralization performance, evaluating via COD removal efficiency, in CoFe2O4@BP-BiP/PDS system was compared with that in CoFe2O4/PDS system under various operational conditions. The chemical-physical properties were systematically analyzed to explore the mineralization mechanisms of GP. Quenching and competitive anion tests were conducted to study mineralization mechanisms of GP by CoFe2O4@BP-BiP activing PDS during catalytic process. The results illustrate that composition of BP-BiP and CoFe2O4 remarkably reduced the agglomeration of nanoparticles and enriching oxygen-containing functional groups (OCFGs), which accelerated electron transfer cycles of Co3+/Co2+ and Fe3+/Fe2+ redox couples to continuously regenerate Fe2+ and Co2+. This led to the effective decomposition of PDS, generating more reactive oxygen species (ROS) for promoted mineralization of GP. CoFe2O4@BP-BiP system exhibited higher GP mineralization performance and rate, approximately twofold greater than the CoFe2O4/PDS system. Mechanistic studies showed that GP mineralization occurred via both non-free radical and free radical pathways, involving ROS such as singlet oxygen (1O₂) and radicals (*SO4−, *OH, *O2−). Additionally, CoFe2O4@BP-BiP demonstrated excellent stability and reusability across five consecutive runs with minimal Co and Fe leaching. These findings suggest that CoFe2O4@BP-BiP is an effective and sustainable catalyst for activating PDS in the removal of glyphosate from wastewater.