Effect of probe-ultrasonication treatments on carbendazim fungicide degradation and toxicity assessment

Sonochemistry is an innovative and sustainable method among the emerging non-thermal technologies for agrochemical removal, food processing, and preservation. The study aimed to investigate the effects of probe-type ultrasound (PU) on the residual degradation mechanisms of carbendazim (CBZ) fungicides, potential reduction pathways, and toxicity assessment. The results showed that CBZ fungicide residues were significantly reduced ( p < 0.05 ) by up to 79.20 % as the PU power level increased. The GC–MS analysis identified six degradation products of CBZ fungicides, including 3–2-Hydroxyphenyl-1,2,4-triazol-5-amine, 2-aminobenzimidazole, hexahydropyridine, 3-methoxy-benzaldehyde oxime,1,4-dimethylpyrazole, and 1-alanine-ethylamide. In addition, the toxicity of CBZ was evaluated against Aspergillus Niger (AN) using colony counts as an indicator of fungal growth, inhibition ratio, and survival rate. The results revealed that the lower power level showed a strong inhibition ratio of up to 73.30 % compared to the highest power level, which was 28.50 %. Increasing the power level significantly increased the AN’s survival rate from 25.50 % to 75.60 %. The current study’s results suggest that sonication has significant potential to degrade agrochemicals by generating hydroxyl radicals. The current study provides new insights into the sonication-assisted degradation of CZB by describing its degradation mechanism and toxicity assessment. Unlike literature-reported studies, our results proposed a detailed degradation pathway, degradation byproducts, and a toxicity assessment of degradation intermediates, providing both the degradation behavior and the effectiveness of sonication treatment in reducing agrochemical residues.