REMOVAL AND RECOVERY OF HEAVY METAL IONS FROM INDUSTRIAL WASTEWATER USING IMMOBILIZED ALGAE

THE PLATING AND ELECTRONICS INDUSTRIES ARE REQUIRED BY STATEAND FEDERAL REGULATIONS TO REMOVE TOXIC, HEAVY METALS FROM WASTEWATER STREAMS BEFORE DISCHARGE. THE SEMICONDUCTOR AND AND PRINTED CIRCUIT INDUSTRY ALONE REMOVED OVER 7.2 TONS OF HEAVY METALS FROM WASTEWATER IN 1983. MUCH OF THE RECOVERED METALS ARE DISCARDED AS SLUDGES, BECAUSE TECHNIQUES FOR RECOVERING AND SEPARATING THE METAL IONS ARE UNECONOMICAL. BIO-CLEAN HAS DEVELOPED METHODS FOR IMMOBILIZING ALGAE IN SILICA GELS WHICH CAN BE PACKED INTO COLUMNS AND USED MUCH LIKE ION EXCHANGE RESINS IN THE REMOVAL AND RECOVERY OF HEAVY METAL IONS FOR SOLUTIONS. LIKE ION EXCHANGE RESINS, THE IMMOBILIZED ALGAE CAN BE RECYCLED, BUT IN CONTRAST TO CHELATING ION EXCHANGE RESINS, HARD WATER COMPONENTS (CA(II)MG (II) INTERFERE MINIMALLY WITH THE BINDING OF TRANSITION METAL IONS. IN ADDITION, CONDITIONS HAVE BEEN DEVELOPED FOR REMOVING METALIC OXOANIONS (CRO4-2, MOO-2) FORM AQUENOUS REMOVING METALIC OXOANIONS (CRO 4-2, MO O-2) FROM AQUENOUS SOLUTIONS USING IMMOBILIZED ALGAE. FURTHERMORE, THE BINDING CAPACITY OF THE ALGAE FOR CERTAIN METAL IONS MAY EXCEED TEN PERCENT OF THE DRY WEIGHT OF THE ALGAE. IT APPEARS THAT THE COST OF THIS SYSTEM WILL BE BUT A FRACTION OF THE COST ASSOCIATED WITH ION EXCHANGE TECHNOLOGY. IT IS THE PURPOSE OF THIS PROJECT TO DEVELOP AN ECONOMICAL PROCESS USING IMMOBILIZED ALGAE TO PRODUCE AN EFFECTIVE SYSTEM FOR REMOVING HEAVY METAL IONS FROM INDUSTRIAL WASTEWATERS.