Removal of Lead Ions and Turbidity from Waste Water by Adsorbent Materials Derived from Cactus Leaves

Abstract

The current work explores simple ways of developing cheap adsorbents materials from Cactus, a plant easily found in dry and semi-arid regions for use in water purification. The adsorption capacity and efficacy of its biomass, charcoal, ash and ash residue in removal of lead ions and turbidity from contaminated water is reported. The biomass was obtained by drying and grinding dry leaves to powder. Ash was obtained by heating the dry leaves in a furnace while the residue was obtained by dissolving and removing the soluble fraction. The charcoal was prepared by heating dry cactus leaves in a furnace in limited air. Batch experiments were carried out to determine the effect of initial concentration, PH, contact time, temperature and adsorbent dose on percentage removal of Pb²⁺ and turbidity. The data for Pb²⁺adsorption on ash residue was found to best fit in the Langmuir isotherm model while biomass, charcoal and ash data best fitted in the Freundlich model. Adsorption capacities for lead ions on ash residue, ash, charcoal and biomass were 1000.0000, 173.6201, 13.3352 and 3.1696mg/g respectively. The findings showed that the adsorbents are effective in removal of turbidity and lead (II) ions from contaminated water.

Keywords: "lead", "Adsorption", "isotherms", "cactus", "green adsorbents"