CONTINUOUS SOME METALS REMOVAL FROM AQUEOUS SOLUTIONS BY BIOMASS IN PACKED-BED COLUMN

Abstract

The aim of our study was to evaluate the potential of a white rot fungi (Phanerochaete chrysosporium) immobilized on sepiolite, in a continuous flow removal of trace heavy metals. The present work proposes the use of a white rot fungi (Phanerochaete chrysosporium) immobilized on sepiolite as a new sorbent in trace metal determination. The procedure is based on the biosorption of Cr(III), Ni(II) and Cd(II) ions on a column of sepiolite loaded with dried, dead fungi components prior to their determination by atomic absorption spectrophotometry. The effects of pH, amount of solid phase, eluent type and volume of the sample solution, flow rate of solution on the retention of the metal ions have been studied. The optimum pH value of quantitative sorption for Cr(III), Ni(II) and Cd(II) was found to be 5. These metal ions can be desorbed with 1 M HCl (recovery 95-100 %). The effects of some interfering ions were also studied. The optimum experimental parameters were determined to be pH 5, concentration of 10 mg/L, contact time of 30 min and 0.2 g of adsorbent for a quantitative adsorption of the metals. The optimum flow rate was found as 2.5 mL/min for all metal ions. Each column can be used up to 20 successive analyses without considerable change in recoveries of metal ions. This procedure was applied to Cr(III), Ni(II) and Cd(II) determination in aqueous solutions, including tap water system. These metal ions can be desorbed with 1 M HCl (recovery 95-100 %). The results indicate advantages of high metal biosorption capacity and satisfactory recovery of Cr(III), Ni(II) and Cd(II). The proposed method is very good as regards simplicity, sensitivity, selectivity, precision, accuracy and column stability.