Population growth, industrial development and increasing of water consumption especially in the countries with in arid and semi arid climate, have resulted in a sever limitation of water resources for different uses. A major compounds present in the industrial wastewater are heavy metals. Due to their accumulation in the living tissues as well as their carcinogenic effects, it is necessary to respect the environmental standards for discharge of industrial wastewater containing heavy metals. The general methods for removal of heavy metals from aqueous solutions include chemical precipitation, reverse osmosis, adsorption and ion exchange. However, because of some restrictions such as high cost and low efficiency, adsorption of heavy metals by cheap absorbents atracted more attention in recent decades. In this research, mine tailings from Irankouh lead and zinc mine situated in Isfahan , was utilized as sorbent of heavy metals. Some of tailing characteristics such as cation exchange capacity (CEC), chemical composition, constitutive phases and specific surface area was determined by ammonium acetate, XRD, XRF and N 2 -BET, respectively. The adsorption experiments were performed by bath and column methods using synthetic solutions and industrial effluents containing cadmium, lead, zinc, copper and nickel. The effects of equilibrium time, solution pH, initial ion concentrations, sorbent particle size and ratio were studied by bath method, and regeneration of sorbent was carried out by column method. The mine tailing was treated by acid, base and distiled water to modify the adsorptive properties. The appropriate equilibrium time was 30 and 60 minutes for cadmium and zinc, respectively. Adsorption percentage was increased with increase of pH significantly (p 0.05), due to decreasing with H + ion the competition and increasing of adsorption sites. The maximum adsorption of cadmium and lead at pH=5 was 62% and 76%, and for zinc, copper and nickel at pH=6 was 53%, 56% and 32%, respectively. The adsorption amount was increased with decrease in particle size. The sorption isotherms of zinc, nickel and copper were describeb using Freundlich linear model and cadmium with Longmuier linear model. Lead adsorption was described well with both models. The modification treatments affected the adsorption of cadmium, zinc and copper, significantly (p 0.05). The modification treatments increased the sorption capacity in the following order: base distiled water acid. More than 90% of the initional. Solution cadmium and lead sorbed on base treated sorbent.
