Surface Modification Of Carbon Nanotubes Material To Remove Heavy Metals

With the continuous development of the socio-economic situation of water pollution increased year by year, water purification technology has been one of the hotspots. Carbon nanotubes (CNT) as a new type of carbon material, have unique physical and chemical properties, but also have a larger surface area, are an ideal adsorbent material. Be modified and used for the adsorption of heavy metal ions in water is of great significance for reducing the pollution of heavy metal ions in water.This thesis uses the mixed acid (3:1volume ratio of concentrated sulfuric acid and concentrated nitric acid) on the multi-walled carbon nanotube (MWCNTs) subjected to a surface-modified, relatively good adsorbent of adsorption was prepared. The adsorption characteristics of processed MWCNTs and unprocessed MWCNTs on adsorping the heavy metal ions of Cu2+, Zn2+, Hg2+, Cr6+are researched, and analyze the influence of adsorption such as the adsorption time, solution concentration, solution pH and adsorbent amountfactors. For analyzing infrared spectroscopy characterization of MWCNTs, and comparing the size of the adsorption capacity of the processed MWCNTs and unprocessed MWCNTs affected by the same kind of affecting adsorption factors, to determine the adsorption capacity of processed MWCNTs is better than unprocessed MWCNTs. The research results show that the processed MWCNTs and unprocessed MWCNTs on the adsorption rate of Cu2+, Zn2+, Hg2+, Cr6+plasma increases with increasing adsorption time and after reaching the adsorption equilibrium time, the adsorption rate is no longer rising, and in the adsorption process the adsorption rate of processed MWCNTs is always higher than unprocessed MWCNTs;Also the adsorption rate and adsorption capacity of the two adsorbents(processed and unprocessed) increase with the solution concentration,and the adsorption capacity of the processed MWCNTs is higher than unprocessed MWCNTs; The amount of the adsorbent dosage has a great influence on the adsorption rate of the MWCNTs, but the greater the amount of the adsorbent may not be able to improve its adsorption rate; When the MWCNTs adsorp the heavy metal ions of Cu2+, Zn2+Hg2+, Cr6+, its the best pH range of adsorption is different; when pH of Cu2+, Zn2+, Hg2+Cr6+ion solution is6,4,2.5, and3, the adsorption rates of processed MWCNTs and unprocessed MWCNTs are14%and26%,63%and89%,59%and73%,37%and46%respectively.The results of the infrared spectroscopy characterization of the processed MWCNTs and unprocessed MWCNTs show that the surface of the processed MWCNTs hasalready a certain amount of-COOH and-OH,and there is an increase of functional group of-OH after modification of its surface. The final conclusion is that the adsorption capacity ofthe processed MWCNTs is better than unprocessed MWCNTs.