화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.42, No.1, 72-79, 2003
Adsorption of silver onto activated carbon from acidic media: Nitrate and sulfate media
Adsorption of silver from acidic silver nitrate and sulfate media onto a peat-based activated carbon was studied. The effects of pH, temperature, and zinc nitrate and zinc sulfate addition on the adsorption kinetics and capacities were investigated. An XRD study showed that Ag(I) was reduced to Ag(0) on the carbon surface during the adsorption process. Low pH, high zinc salt concentration, and temperature are detrimental to the adsorption of silver. Second-order reactions were involved in the process of silver adsorption with respect to Ag(l). Hydroquinone-like surface oxygen functional groups were probably involved in the reduction reaction of Ag(I) --> Ag(0). The addition of butanol to the solution appreciably reduced the adsorption rate and capacity of silver on the activated carbon. This indicates that graphene layer surfaces might also be involved in the Ag(I) --> Ag(0) reaction because of the enrichment of pi-electrons on the basal planes.