Design Of Modified Fe-Pd Nanoparticles For Dechlorination Of P-chlorophenol

Nanoscale zero valent iron?nZVI?has shown considerable promise in the treatment of chlorinated organic compounds,but rapid aggregation and inactivation hinder its application.The present work adopted two kinds of polymers?poly??-glutamic acid?and poly??-glutamic acid?-Dopamine composite?as the modifiers for the preparation of Fe-Pd nanoparticles.P-Chlorophenol?p-CP?was selected as a model pollutant to evaluate the dechlorination activity of modified Fe-Pd NPs.We examined the dechlorination of p-CP over nanoparticles with different dosage of modifiers and Pd loading and investigated the influence of different factors on their dechlorination performance.The main works are summarized as follows.We synthesized the palladium-doped zero-valent iron nanoparticles involved poly??-glutamic acid??Fe-Pd NPs@PGA?.The dechlorinationr results demonstrated that Fe-Pd NPs@PGA show high activity for p-CP even in the weak alkaline condition.The maximum rate constant reached 0.331 min^-1 with a Fe to p-CP ratio of 100?PGA dose=50 mg,Pd content=0.8 wt%?.Additionally,the dechlorination activity of Fe-Pd NPs@PGA is more than 10 times higher than that of the bare Fe-Pd NPs,demonstrating the crucial role of PGA in this system.Furthermore,in consideration of NZVI inactivation caused by common anions in real groundwater,the influence of anion on the dechlorination was also investigated in detail.The results indicated that Fe-Pd NPs@PGA can maintains its high activity in the presence of Cl^-,H₂PO₄^-and HA.We fabricated poly??-glutamic acid?-dopamine composite?PGA-DA?and adopted it as stabilizer of Fe-Pd nanoparticles and complexing agent of Fe ions to created a continuous and rapid dechlorination system.Fe-Pd NPs@PGA-DA had high dechlorination activity for p-chlorophenol?p-CP?and significantly outperformed PGA modified ones in catalytic activities in weak alkaline condition.Fe-Pd NPs@PGA-DA?10 mg PGA-DA and 0.4 wt%Pd loading?could achieve 100%p-CP removal within60 min.It's worth mentioning that the presence of DA alone could overwhelm dechlorination capacity of Fe-Pd NPs toward p-CP.