Metal ion adsorption by Phomopsis sp biomaterial in laboratory experiments and real wastewater treatments

An insoluble material of polysaccharidic nature has been obtained by thermal alkali treatment of the filamentous fungus Phomopsis sp. FT-IR spectrum of the resulting material as well as its nitrogen content suggest that chitosan and glucans are the main components of the biomaterial. Information on Lewis base sites has also been obtained and used as a guideline in the evaluation of the complexing ability against a number of metal ions in aqueous media at pH in the range 4-6. Results indicate that after 24 h contact time, up to 870 mu mol/g of lead, 390 mu mol/g of copper, 230 mu mol/g of cadmium, 150 mu mol/g of zinc and 110 mu mol/g of nickel ions are adsorbed into the material. After approximately 10 min, about 70% of the overall adsorption process has already been completed. Adsorbed metal ions can be recovered by washing with dilute acid. Experiments have been extended to a real wastewater effluent confirming the potential of this biomaterial as a depolluting agent. (c) 2005 Elsevier Ltd. All rights reserved.