Preparation and properties of modified spherically granulated chitosan for sorption of 137Cs from solutions

A composite sorbent based on spherically granulated chitosan modified with a mixed ferrocyanide K2Cu3[Fe(CN6)]2 (SGC-FC) was prepared. The sorbent is highly effective toward 137Cs. The physicochemical parameters of 137Cs+ sorption by this sorbent were determined: total and equilibrium static exchange capacity, dynamic exchange capacity, sorption equilibrium constants, etc. The influence of the chemical composition of the solution on the 137Cs+ sorption by SGC-FC was examined in detail. Based on the calculated value of the dimensionless Biot number Bi, a conclusion was made that the kinetics of 137Cs+ sorption on SGC-FC is mainly determined by external diffusion of 137Cs+ ions to reaction centers of the sorbent. The possibility of using the sorbent in monitoring of sea areas was considered.