Surface Modification And Dispersion Of Pd/Fe Nanoparticles For Catalytic Dechlorination Of2,4-dichlorophenal

The chlorophenols organic compounds are widely used in pesticides herbicides, fungicides, disinfectants for medical use in the production and application process, they can find their way into the environment and pollute the environment. The chlorophenols organic pollutants are carcinogenic, teratogenic and mutagenic to organisms. They are difficult to be degraded in the environment, causing great harm to the environment. In recent years, there has been a growing interest in the use of zero-valent iron for the treatment of chlorinated organic compounds in water and groundwater. Compared to other dechlorination methods, Pd/Fe nanoparticles have higher specific surface area, a higher surface reactivity, and a higher efficiency of dechlorination.Our research used the liquid phase method to prepare Pd/Fe bimetallic nanoparticles, and the ethanol solution of palladium acetate was used as palladium solution. Pd/Fe bimetallic nanoparticles were extensively characterized in terms of XRD, BET-N2, SEM, TEM and XPF to identify the specific surface area, morphology, particles shape, size, crystal structure, Pd content. The results suggest that, modified Pd/Fe bimetallic nanoparticles had smaller aggregation tendency, more uniform particle size distribution, higher purity and lower degree of oxidation than pristine one. The specific surface area of pristine Pd/Fe, PEG modified Pd/Fe, Starch modified Pd/Fe and guar gum modified Pd/Fe nanoparticles are26.8m2/g,44.6m2/g,32.1m2/g and30.8m2/g, respectively.2,4-dichlorophenol was dechlorination by pristine and modified Pd/Fe nanoparticles. The effect of Pd content of pristine Pd/Fe and additive amount of dispersant of modified Pd/Fe nanoparticles on dechlorination efficiency were analyzed. The results suggested that the most optimal Pd contene of pristine Pd/Fe was0.10wt%, and the most suitable concentration of PEG, Starch and Guar gum were1.0wt%,0.1wt%and0.05wt%, respectively. And the modified Pd/Fe bimetallic nanoparticles had higher dechlorination efficiency than the pristine Pd/Fe nanoparticles.Effects of initial pH value, Pd/Fe nanoparticles addition on dechlorintion efficiency of2,4-dichlorophenol were investigated. The results suggest that the most suitable initial pH value is7.0. Dechlorination efficiency of2,4-dichlorophenol increased with the increase of Pd/Fe nanoparticles addition. When the nanoparticles addition reached lOg/L, dechlorination efficiency of reaction system were reached100%, Although dechlorination rate can be increased with the increase of nanoparticles addition, the follow-up processing would became more difficult.