Unveiling Synergistic Effects for the Optimizing Photoelectro-Fenton Process for Enhanced Terbutryn Herbicide Degradation

Abstract

Escalating herbicide pollution in natural water bodies necessitates further exploration of effective remediation strategies. This study investigated the electro-degradation of Terbutryn (TBT) at concentrations comparable to those encountered in agricultural practices. Anodic oxidation (AO), electro-Fenton (EF), and photoelectron-Fenton (PEF) were employed for TBT abatement. AO achieved moderate removal (68%), EF significantly improved efficiency (99%), and PEF surpassed both, reaching near complete removal (99.4%) by combining EF with UV light-induced •OH generation. Statistical analysis confirmed that optimizing treatment conditions was crucial. All three factors (current density, Fe2+ concentration, and initial TBT concentration) independently affected the PEF process ability to remove TBT pollutants. However, the interplay between these factors was even more important. Sufficient Fe2+ was critical for high TBT concentrations, and a balance between current density, Fe2+, and initial TBT concentration was necessary. Excessive levels of any could hinder COD removal. High-performance liquid chromatography (HPLC) was employed to monitor the degradation profile of by-products, including desthiomethyl Terbutryn, 2-hydroxy Terbutryn, and cyanuric acid. The analysis of these degradation products facilitated the proposal of a degradation pathway for Terbutryn. PEF stands out as a viable approach for TBT removal, especially in high-TBT wastewater.