A competitive adsorption of Cu2+, Ni2+, and Cd2+ ions from a synthetic wastewater onto nanomaterial was studied.(Fe3O4) nanoparticles obtained from US Research Nanomaterials, Inc., Houston, TX 77084, (USA), was used as nanosorbent. Experimental parameters included pH, initial metal concentrations, and temperature were studied for nanosorbent. The uptake capacity 11.5, 6.07 and 11.1 mg/g for Cu2+, Ni2+and Cd2+, respectively, onto nanosorbent . The optimum pH values was 6 and the contact time was 50 min. for Cu2+, Ni2+and Cd2+, respectively. The equilibrium isotherm for nanosorbent single system component is of a favorable type and Freundlich isotherm model gives the best fit model for representing the experimental data for this system. Binary and ternary component systems were conducted in order to find the adsorption isotherm constants for each component system using nanosorbent. A set of adsorption models were tested to choose the best fit model for the experimental data, Combination of Langmuir- Freundlich model seems to give the best fitting. In single, binary and ternary component systems, Cu2+ always adsorbed more favorable onto nanosorbent than Cd2+and Ni2+. The adsorption capacity parameters were: Cu2+> Cd2+> Ni2+. Thermodynamic study was carried out for these three pollutants onto nanosorbent. The results of adsorption show that the adsorption nature for heavy metals is an endothermic and physical nature process.
