The Application Study Of Catalystic Hydrogenation Bromate Over Noblemetal Loaded On SBA-15

Bromate is a potential human carcinogen with high solubility and stability,which is hard to removed from water by conventional water treatment processes.As a typical DBPs,bomate become the research target of many scholor,there are many technique could separation bromate from water effectively at present,however,bromate couldn't be degraded thoroughly by those technique,and,the regenerative solution and concentrate water produced when purifying bromate are still need treated.Catalytic hydrogenation is an efficient process does not need any chemical agent and will not cause secondary pollution,which attracts much attention for the mild reaction conditions and thorough degradation.However,there is relatively few report researching the removal of bromate by Catalytic hydrogenation,the impact of experimental factors and characteristic of bromate reduction when use different catalyst are still ambiguous.In this paper,we chosed Pd and Pt as catalytic active component,meso-porous silicon SBA-15 with good hydrothermal stability and large specific surface area as catalyst support,synthesised a series of Pd-based and Pt-based catalyst.Through reducing property comparison experiment select out the catalyst with best catalytic activity to research the infulence of reaction condition and co-existing ion for bromate reduction as well as the reusability of catalyst.Furthermore,we tried to modify SBA-15 with the aim that improving the catalytic activity of catalysts.Characterization result indicate that,the study successfully synthesised regular shaped SBA-15 with uniform size,large specific surface area and highly ordered straight channel.Pd and Pt are effectively loaded onto SBA-15 carriers by Ion Exchange.Analysis reduction data of bromate reduction,we found that the catalyst performance of Pt/SBA-15 and Pd/SBA-15 is better than the purchased Pd/C,and,Pt/SBA-15 possesses higher catalytic activity than Pd/SBA-15 when loading rate is the same.4%Pt/SBA-15 has the best catalyst performance,the removal rate of which reaches 64.44% just for 5min.The higher the air flow rate,the higher temperature,the more the catalyst dosage and the lower pH,lead to the qicker reduction rate.Among the four coexisting study object,PO43-and SO42-suppression the reduction,while NO3-and Fcontribute a promotion.Reusability research experimental results indicate,accumulated digestion concentration of Pt in the effluent for first four runs is 0.078mg/L,and the 5minremoval-rate is reduce to the fourth run's 86.78% from the first run's 86.78%.Generally speaking,Pt/SBA-15 has good stability.After modification,the catalytic property of catalysts is generally promoted,aminofunctionalization increased catalysts' point of zero charge dramatically,which improved the adsorptive property of catalysts.Also,the reduction rate promoted to a certain extent.When use 2%Pd/SBA-15 as catalyst,the bromate removal rate for 5 min is 27.99%,and when use 2%Pd/SBA-15-2 the same index increased to 62% derectly.Although,modification makes more improvement on Pd-based catalysts,over all,Ptbased catalysts still possess higher catalytic activity.