title: Cu2+, Cd2+ and Pb2+ adsorption from aqueous solutions by pyrite and synthetic iron sulphide.
abstract: In this study, removal of Cu(2+), Cd(2+) and Pb(2+) from aqueous solutions by adsorption onto pyrite and synthetic iron sulphide (SIS) was investigated as a function of pH, contact time, adsorbent dosage, initial metal concentration and temperature. It has been determined that the adsorption of metal ions onto both adsorbents is pH dependent and the adsorption capacities increase with the increasing temperature. The mechanisms governing the metal removal processes were determined as chemical precipitation at low pH (<3) due to H(2)S generation and adsorption at high pH (in the range of 3-6). The metal adsorption yields also increased with the increasing adsorbent dosage and contact time and reached to equilibrium for both adsorbents. The Cu(2+), Cd(2+) and Pb(2+) adsorption capacities of both adsorbents decrease in the order of Pb(2+)>Cu(2+)>Cd(2+). Except for cadmium, little fraction of copper and lead in the solid adsorption residues was desorbed in acidic media.
authors.affiliation: Department of Environmental Engineering, Firat University, 23279 Elaziğ, Turkey.
authors.forename: Arzu
authors.initials: A
authors.lastname: Ozverdi
authors.forename: Mehmet
authors.initials: M
authors.lastname: Erdem
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007501:Iron / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D019216:Metals, Heavy / Q000737:chemistry; D008956:Models, Chemical; D013053:Spectrophotometry; D013440:Sulfides / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods; D014873:Water Pollutants; D018508:Water Purification / Q000379:methods*
chemical_list: D007477:Ions; D019216:Metals, Heavy; D013440:Sulfides; D014873:Water Pollutants; D002104:Cadmium; C011342:pyrite; D007854:Lead; D003300:Copper; D007501:Iron