Dechlorination of disinfection by-product monochloroacetic acid in drinking water by nanoscale palladized iron bimetallic particle

Nanoscale palladized iron(Pd/Fe)bimetallic particles were prepared by reductive deposition method.The particles were characterized by X-ray diffraction(XRD),X-ray fluorescence(XRF),scanning electron microscope(SEM),transmission electron microscope(TEM),and Brunauer-Emmett-Teller-nitrogen(BET-N_2)method.Data obtained from those methods indicated that nanoscale Pd/Fe bimetallic particles containedα-Fe^0.Detected Pd to Fe ratio by weight(Pd/Fe ratio)was close to theoretical value. Spherical granules with diame...

Catalytic dechlorination of chlorinated methanes by nanoscale Pd/Fe bimetallic particles

This paper examined the potential of using laboratory-synthesized nanoscale Pd/Fe bimetallic particles to dechlorinate chlorinated methanes, including dichloromethane (DCM), trichloromethane (CF) and tetrachloromethane (CT). Nanoscale Pd/Fe bimetallic particles were characterized in terms of surface area, morphology, size and structure. The parameters affecting the dechlorination efficiency were studied through batch experiments. Effects of Pd content, Pd/Fe addition, and the initial pH value of reaction system on the dechlorination efficiency of chlorinated methanes were determined systematically. Results show that nanoscale Pd/Fe bimetallic particles play a prominent role in the dechlorination of chlorinated methanes. The change of pH value and ferrous ion concentration during dechlorination reaction were also investigated in this study. It is found that the dechlorination efficiency of chlorinated methanes is in the order of CT>CF>DCM.

Rapid degradation of hexachlorobenzene by micron Ag/Fe bimetal particles

The feasibility of the rapid degradation of hexachlorobenzene （HCB） by micron-size silver （Ag）/iron （Fe） particles was investigated.Ag/Fe particles with different ratios （0,0.05%,0.09%,0.20%,and 0.45%） were prepared by electroless silver plating on 300 mesh Fe powder,and were used to degrade HCB at different pH values and temperatures.The dechlorination ability of Fe greatly increased with small Ag addition,whereas too much added Ag would cover the Fe surface and reduce the effective reaction surface,thereby decreasing the extent of dechlorination.The optimal Ag/Fe ratio was 0.09%.Tafel polarization curves showed that HCB was rapidly degraded at neutral or acidic pH,whereas low pH levels severely intensified H2 production,which consumed the reducing electrons needed for the HCB degradation.HCB degradation was more sensitive to temperature than pH.The rate constant of HCB dechlorination was 0.452 min-1 at 85℃,50 times higher than that at 31℃.HCB was degraded in a successive dechlorination pathway,yielding the main products 1,2,4,5-tetrachlorobenzene and 1,2,4-trichlorobenzene within 2 hr.

Roles of metal element substitutions from the bimetallic solid state electrolytes in lithium batteries

All-solid-state lithium batteries(ASSLBs),receiving extensive attentions and studies,exhibit better safety,environmental friendliness,stability,wider electrochemical stability window and higher energy density than traditionally liquid lithium batteries.In a variety of inorganic materials,with highly replaceable,the non-lithium metal elements emerge in endlessly and affect performances in diversiform ways.Due to facile preparation,convertible structures and excellent properties,the lithium-containing bimetallic granular materials are often applied as important components of electrolytes in lithium batteries.In this review,in terms of the properties of substituted elements,changing crystal structures,increasing vacancies or defects and improving the interfacial conductions,the roles of metal element substitutions of inorganic particles on the improvement of solid-state electrolytes are expounded.And the applications of substituted strategies in ASSLBs as the host of inorganic particles electrolytes and as fillers or modifications for composite electrolytes are also investigated and discussed.It also summarizes the current concerns and obstacles that need to be broken through,as well as provides a basis guide for the selection and optimization of inorganic particles.