Preparation And Application Of Silica Gel Bonded By 1,5-Diphenylcarbazone For Enrichment And Separation Of Heavy Metalions From Water

Two silica gels modified with 1 ,5-diphenylcarbazone were prepared based on chemical binding and physical adsorption approaches. Analytical characteristics of these modified silica gel have been investigated. The stability, lift time and maximum adsorption capacities of the chemically modified silica gel was found to be superior to those of the physically adsorbed one. The 1 ,5-diphenylcarbazone grafted silica gel has quite good application to the selective enrichment and separation of mercury, cadmium, zinc and copper from other metal ions at optimized conditions. The maximum adsorption capacities of mercury, cadmium, zinc and copper are 3. 99, 12. 8, 3. 91 and 3. 93 mu mol/g, respectively, under given pH, and these four metal ions could be enriched simultaneously, then eluted individually by suitable eluting agent. Therefore, one of the four metal ions could be separated from other three ions in this way.