Fenton and Sono-Fenton degradation of selective herbicides in water using bioleached Fe-Cu bimetallic nanoparticles (BFe-CuNPs)

Abstract

Bimetallic nanoparticles offer an innovative solution for treating water and wastewater systems using a heterogeneous Fenton-like process. This study investigates the synthesis of iron-copper bimetallic nanoparticles using bioleached iron and copper as precursors and evaluates their performance in the degradation of selective herbicides ametryn and dicamba by Fenton’s oxidation and Sono-Fenton’s oxidation. Bioleaching experiments were conducted separately for iron and copper leaching from laterite ore and chalcocite ore, respectively, using isolated Acidithiobacillus ferrooxidans bacterial strain. Acidothiobacillus ferrooxidans, a chemolithoautotrophic bacterium oxidizes ferrous iron and reduced sulfur compounds, generating sulfuric acid playing a crucial role in the solubilization of iron from laterite ore and copper from chalcocite. In the case of laterite ore, the bacterium’s iron oxidation activity helps release iron from the mineral matrix, making it more accessible for extraction. Similarly, with chalcocite, A. ferrooxidans facilitates the dissolution of copper from chalcocite (Cu<inf>2</inf>S) through its sulfur-oxidizing capabilities. The synthesized bimetallic nanoparticles were characterized using various techniques, including SEM, XRD, EDS, FTIR, and BET analysis. Fenton’s oxidation and Sono-Fenton’s oxidation of mixture ametryn and dicamba in a solution catalyzed by the bioleached Fe-Cu bimetallic nanoparticles were found to be effective, with ametryn degradation reaching 96.4% and 94.2%, and dicamba degradation reaching 98.1% and 99.3%, respectively, at a catalyst loading of 0.5 g/L. The removal efficiency increased with increasing catalyst loading up to 0.5 g/L and increasing H<inf>2</inf>O<inf>2</inf> dosage up to 500 mg/L. Sono-Fenton’s oxidation led to higher COD reduction of 78.41% compared to conventional Fenton oxidation 70.42% with a reaction rate of 0.039/Min and 0.0053/Min respectively. The study demonstrates the potential of bioleached iron-copper bimetallic nanoparticles as a sustainable replacement for commercial catalysts in the oxidative degradation of herbicides. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.