BIOSORPTION DYNAMICS OF CADMIUM(II) IN A PACKEDBED COLUMN USING IMMOBILIZED Spirogyra subsalsa sp: A GREEN APPROACH TO WASTEWATER TREATMENT

This research aims to study the biosorption of cadmium(II) by green algae S. subsalsa biomass immobilized in sodium silicate (IMSB) using the continuous packed-bed column method. The effects of various parameters, such as flow rate, influent pH, and influent metal concentration, were investigated. In general, there is no difference between pure S. subsalsa biomass (PSB) and IMSB in terms of functional groups, as shown by the IR spectra. The biosorption process is a rapid process, wherein more than 50% of the final uptake value occurs at a rate of 0.5 mL/minute. The biosorption capacities of biomass for cations increase rapidly between pH 2.0–3.0, and then the maximum sorption was seen at pH 4.0. The biosorption capacity increased with initial concentration in the range 50–200 mg/L. A comparison of the biosorption of cadmium(II) by IMSB showed an increase in uptake of over 8.84%. The immobilized biomass could be regenerated using nitrate acid and proportional with the amount of nitrate acid concentration, with up to cadmium(II) recovery more than 80% by HNO3 0.5 M. This study suggests that such an immobilized biosorbent system has the potential to be used in the industrial removal and recovery of cadmium(II) from aqueous solution.