A green approach to DDT degradation and metabolite monitoring in water comparing the hydrodechlorination efficiency of Pd, Au-on-Pd and Cu-on-Pd nanoparticle catalysis

DDT (1,1,1-trichloro-2,2-bi(p-chlorophenyl)-ethane) and its metabolites (DDD, 1,1-dichloro-2,2-bis-(4'-chlorophenyl)ethane, and DDE, 1,1-dichloro-2,2-bis-(4'-chlorophenyl)ethylene) are persistent organic pollutants that can be catalytically degraded into a less toxic and less persistent compound. In this work, ecofriendly methodologies for catalyst synthesis, catalytic degradation of DDT and reaction monitoring have been proposed. Three types of Pd-based nanoparticles, NPs, (Pd, Au-on-Pd and Cu-on-Pd) were synthesized and used for catalytic hydrodechlorination ofDDT and itsmetabolites. The structural and electronic properties of NPswere investigated using TEMand XAS spectroscopy. Au-on-Pd showed the highest hydrodechlorination efficiency within 1 h of reaction. To obtain the best reaction conditions, the effects of H-2 flowand base addition Au-on-Pd NPs activitywere investigated. To study the effectiveness of the different NPs, a solvent-free analytical method was optimized to detect and measure DDT and its by-products. The SPME-GC-MS method provided low detection limits (0.03 mu g L-1) and high recovery (>= 88.75%) and was a valuable tool for the NP degradation study. In this way, a green method for degradation and monitoring of DDT and its by-products in water was achieved. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study proposed ecofriendly methodologies for the catalytic degradation of DDT and its metabolites, using three types of Pd-based nanoparticles to effectively treat harmful compounds in water. Among them, Au-on-Pd nanoparticles showed the highest degradation efficiency within 1 hour, with the SPME-GC-MS method providing effective monitoring capabilities.