Immobilisation of humic substances

Attempts were made to immobilise humic substances (HS) by grafting them onto different carriers (styrene-divinylbenzene copolymers, cellulose and silica) as well as by their crosslinking with formaldehyde. Reaction with Merrifield resin was used for the immobilisation of HS, coupling by means of water-soluble carbodiimides to carriers containing amino-groups. Crosslinking of HS with formaldehyde (also in presence of other substances able to enter polycondensation reactions with formaldehyde) was shown to be an efficient method for their insolubilisation. Properties of the obtained immobilised HS were studied, including their potential use as sorbents for several metal ions and organic substances. The adsorption efficiency was found to depend both on the sorbate used, type of humic substance immobilised and character of the polymeric matrix. Immobilised HS can be regarded as a prospective sorbents for the removal of different organic molecules and metals ions from the aquatic environment. (C) 2002 Elsevier Science B.V. All rights reserved.