The application of the powdered biomass of Zygophyllum coccineum plants for the removal of Pb and Cu ions from water has been investigated. Energy-dispersive X-ray analysis and Fourier-transform infrared characterization revealed the presence of functional groups related to various components of the biomass. Surface area analyses and scanning electron microscopy demonstrated the nonporous and low surface area nature of the powdered biomass. The contact times required for Pb and Cu ion removal to reach equilibrium were 60 and 45 min, respectively. The optimum pH for the highest percentage of removal was 4. In 50 mL Cu ion solution (50 ppm), 0.2 g of powdered biomass was sufficient for Cu ion removal, while at similar concentrations, Pb ion removal increased significantly with the increase in the biomass. The best particle size for the removal of both ions was 0.212-0.50 mm. Pb ion removal was found to correlate with the Langmuir model, while Cu correlated with the Freundlich model. Langmuir isothermal model revealed adsorption capacities of 25.5 and 14.8 mg g-1 for Pb and Cu ions, respectively. This study shows that Z. coccineum biomass is efficient in removing Pb and Cu from water.
Keywords: Z. coccineum biomass; copper; isothermal study; lead; water treatment.