Fixed bed column study for Pb (II) adsorption using calcium-alginate treated shea butter husk (TSBH)

Abstract

The continuous adsorption of Pb (II) in a fixed column was studied in this work. Shea butter husk was treated in a polymeric mixture of calcium alginate to produce beads of approximately 1.56 mm 0.14 spherical shapes. Optimum parameters evaluated revealed an effective column performance at flow rate of 0.5 ml/min, bed heights of 12 cm and at initial concentrations of 50 mg/L. The percentage removal (%R) of the Pb (II) ions at 0.5 ml/min was 77.31 % with an adsorption capacity of 1.888 mg/wet bead. The Thomas and Yoon Nelson model predicted the breakthrough curve to a large extent with the correlation coefficients ranging between 0.8098-0.9676. Their rate constants (KTh and KYN) were higher at the lower flow rates, higher bed heights, and at lower concentrations. The adsorption capacities of the column at these conditions were 6431.606 and 76, 536.111 mg/g respectively for the Thomas and Yoon Nelson model These results revealed that with the enhancement of the shea butter husks, polluted effluents concentrations can be reduced to their threshold values before discharged into the water bodies via a continuous fixed-bed column.