Continuous removal of Pb (II) and Cu (II) ions from synthetic aqueous solutions in a fixed-bed packed column with surfactant-modified activated carbon

This work investigates the incorporation of sodium dodecyl sulfate (SDS) onto activated carbon made from coconut shells to improve the removal of Pb (II) or Cu (II) from synthetic wastewater in a packed column. The activated carbons were characterized using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy-energy dispersive x-ray (SEM-EDX). The column dynamics were studied to calculate its performance. The adsorption data were fitted into the Thomas, Yoon-Nelson, and Adams-Bohart models. The activated carbon has a pore volume of 0.453 cm3/g and a BET-specific surface area of 513 m2/g. The incorporation of SDS surfactant onto the surface of the activated carbon (AC) significantly enhances the removal of Pb (II) and Cu (II) from synthetic wastewater in a packed column. An increase in flow rate or initial metal concentration decreases break-through and exhaustion time, while an increase in bed height increases break-through and exhaustion time. When the bed height increased from 5 to 20 cm, the Yoon-Nelson adsorption constant (KYN) increased from 0.0324 to 0.0372 (1/min) for the Pb (II)-AC-SDS system, while KYN increased from 0.0293 to 0.0353 (1/min) for the Cu (II)-AC-SDS system. The adsorption data only fit well into the Thomas and Yoon-Nelson models.