redox polymers for cyanide ion decomposition

• DOI: 10.25669/0cpo-by14
• Publication Date: 1997-01-01
• Authors: Zhang, Yu
• Keywords: Redox; Decomposition; Polymers; Cyanide; 500; Ion; 540

Insoluble, macroporous styrene-divinylbenzene copolymers bearing redox N-alkyl-N-chlorosulfonamide functional groups were used for removal of cyanide from aqueous solutions. These resins contain active chlorine and show oxidative properties. The use of these resins for oxidation of cyanide to less or nontoxic compounds was investigated in aqueous media containing different concentrations of cyanide and different pH values. Examples of the use of these resins as a polymer-supported reagent for oxidation of cyanide under static and dynamic conditions were given. Active chlorine readily oxidizes cyanide to cyanate. The decomposition of cyanate was also studied. The two decomposition methods investigated were oxidation with redox resin and hydrolysis using a cation exchange resin (H{dollar}\sp+{dollar} form). The data show that the cyanate is easily hydrolyzed, but is difficult to oxidize. During the oxidation process the {dollar}-{dollar}SO{dollar}\sb2{dollar}NClR groups are transformed to {dollar}-{dollar}SO{dollar}\sb2{dollar}NHR groups. They can be reactivated by the use of hypochlorite solutions.