Adsorption of soluble Pb(II) by a photocrosslinked polysaccharide hybrid: A swelling-adsorption correlation study

A biosorbent for adsorption of soluble, inorganic Pb(II) was prepared through a photocrosslinking of a mixture of xanthan gum and guar gum at various mass ratios. The polysaccharide mixes were irradiated using UV A in presence of benzophenone. Chemical crosslinks were formed which led to a controlled swelling of the polysaccharide mix (swelling ratio < 20%), referred as crosslinked hybrid in the text. The hybrids were characterized for microstructure, rheology, surface area and surface charge behavior. Interesting changes in crystallographic pattern, both in the pre and the post adsorption stages, was investigated using x-ray diffraction technique. Adsorption efficiency was estimated in respect of blend composition, adsorbate-adsorbent concentration and pH under competitive and non-competitive conditions. A correlation between the swelling of the crosslinked hybrid and the metal adsorption was drawn at various pH to elucidate an interaction between the two phenomena.