Immobilized humic substances as sorbents for trace element removal

Intensive studies have been made in the research of humic substances (HS), particularly owing to the diverse application capacity. While different commercial sorbents are available, there is still need for research to obtain products with a specific selectivity. Due to unique properties of humic substances, they are the main sorbent in soil for organic and inorganic chemicals, whereas HS appear to have the greatest capacity for sorption of trace elements in cationic form and sorption and complexation processes are the main binding mechanisms. A main focus of this work is on the characterization of metal ion sorption onto humic substances immobilized onto differing polymeric matrixes. The potential of immobilized humic substances as sorbents for removal of trace elements, such as Zn, Cu, Ni, Pb, Fe, was studied. Four differing polymeric matrixes were selected for immobilization of humic substances. The results of sorption study demonstrated that humic substances have strong affinity for several chemical elements, e.g., Cu, Zn, Ni, Fe, Pb, forming relatively stable complexes.