Development of advanced ion exchange materials and methods for the removal of toxic metals from metallurgical waste effluents
Metallurgical industries produce large volumes of harmful and toxic metal-bearing process and waste solutions. Waste effluents are usually purified by conventional hydroxide precipitation processes, which often do not result in satisfactory decontamination yields. Increasingly stringent regulations against metal releases require more effective purification methods. In this project a wide variety of ion exchange and adsorbent materials has been evaluated for their prospective use in purification of metal-bearing waste effluents and in the recovery of metals. These include organic ion exchange resins, especially chelating exchangers, inorganic ion exchangers, specialty adsorbent materials such as processed seaweed residue and activated carbons. The research covered the synthesis, physical characterization, fundamental ion exchange properties, mathematical modelling of ion exchange equilibrium and kinetics as well as the testing of performance with real waste solutions and development of new ion exchange technology for large-scale exploitation. Most important outcomes of the project are: - Preparation of new more effective ion exchange resins - Development of drying and granulations technology for seaweed residues - Evaluation of ion exchange and sorbent materials for their use in metals removal processes - Deeper knowledge of ion properties of ion exchange materials and sorbents - Physical characterisation of activated carbons and seaweed materials - Modelling of ion exchange equilibrium and column performances - Testing of ion exchange and sorbent materials for actual metal-bearing waste and process solutions - A pH parametric pumping technology to separate metals from mixtures was developed.