Dicamba Degradation Using a Low-Cost Chlorine/Ferrous-Based AOP: ANN-PSO Model Development, Intermediate Identification, and Toxicity Assessment Using Microalgae

초록

Inthis study, the degradation of Dicamba methyl ester(DME) wasinvestigated using a low-cost chlorine/ferrous process. The degradationyield was determined by examining the influence of several factors,such as NaClO concentration, dicamba concentration, FeSO4 catalyst mass, and initial solution pH, over a 15 min period. Todetermine the optimal conditions for DME degradation, an artificialneural network (ANN) model with 4-5-1 architecture was developed.The particle swarm optimization (PSO) algorithm was then utilizedin conjunction with the ANN model to identify the optimal factor levelspredicted yield of 88%. The following optimal conditions were identified:[NaClO] = 422.3 & mu;M, [Dicamba] = 4.4 mg/L, [FeSO4]= 9.5 mg/L, and a pH of 2.56. GC/MS analysis was conducted to identifythe byproducts that were generated during DME degradation. Benzene,1,2,4-trichloro-3-methoxy DME-BP (m/z 210) was the only identified byproduct that contained chlorine inits structure. A proposed reaction pathway for the DME degradationwas suggested based on the obtained mass spectra. In the final stageof the study, total organic carbon (TOC) removal was analyzed usinga Fenton-like process under optimized conditions for a duration of195 min. To confirm the effectiveness of DME and its byproduct degradation,toxicity assessments were performed using the Chlorellavulgaris microalgae as a model organism. The resultsindicated a low toxicity of 20% when the DME mineralization reached62.52%. These findings provide strong evidence that support the effectivenessof the proposed low-cost system for DME removal.

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