Removal of Lead, Copper, Zinc and Cadmium from Water Using Phosphate Rock

Removal of Pb(2+), Cu(2+), ZD(2+) and Cd(2+) from aqueous solutions by sorption on a natural phosphate rock (FAP) was investigated. The effects of the contact time and initial metal concentration were examined in the batch method. The percentage sorption of heavy metals from solution ranges generally between 50% and 99%. The amount of sorbed metal ions follows the order Cu>Pb>Cd>Zn. Heavy metal immobilization was attributed to both surface complexation of metal ions on the surface of FAP grains and partial dissolution and precipitation of a heavy metal-containing phosphate. The very low desorption ratio of heavy metals further supports the effectiveness of FAP as an alternative and low-cost material to remove toxic Pb(2+), Cu(2+), ZD(2+) and Cd(2+) from polluted waters.