Sustainable catalysts for Electro-Fenton oxidation of ametryn: comparative analysis of iron scrap and biojarosite

This study investigates the role of iron scrap and biojarosite as homogenous catalysts in the Electro-Fenton (EF) oxidation process for the degradation of the herbicide ametryn in water. The process parameters were optimized and the results were statistically validated using the Box-Behnken design (BBD) of the response surface methodology. EF experiments were conducted in a lab-scale acrylic reactor using carbon-felt electrodes. Iron scrap and biojarosite were introduced separately as catalysts at various concentrations, and the degradation of ametryn was measured at different time interval. The results showed that both iron scrap and biojarosite were effective catalysts for ametryn removal, with maximum degradation efficiencies of 76.52% and 75.70%, respectively. The process followed pseudo-first-order kinetics, with rate constants of 0.0072 min^-1 for iron scrap and 0.0079 min^-1 for biojarosite. The BBD optimization revealed that pH, catalyst dosage, and initial ametryn concentration had significant effects on the EF oxidation process. The quadratic regression models developed for both catalysts were found to be highly significant, with low probabilities of error and high correlation coefficients.