Various factors affecting heavy metal ion sorption from aqueous media by sorbent containing cellulose

Abstract

The specific adsorption of heavy metal ions on hydrophilic monodentate biosorbent sites was studied. The solvation and coordination mechanism of cation distribution in heterophase system was suggested. Bivalent metal cation desorption mechanism affected by monovalent metal salts (NaCl) was represented in the form of cation-cation resolvation on monodentate sorbent sites, involving ion pairs of hydrated cations and counter ions (anions). The metal ion degree of extraction was found to decrease by 20%, when the solution/sorbent module increased from 75 to 1000. Heavy metal ion sorption by polysaccharide sorbent was identified as exothermic process. The estimated values of ΔH and ΔS enabled to consider sorption of metal cations on polysaccharide sorbent as specific reversible adsorption.