جذب فلزات سنگين به وسيله باطله هاي معدني

چكيده انگليسي :

Adsorption of Heavy Metals by Mine Tailings Akram Noori Kamari akram nouri 1738d@yahoo com Date of submission 17 2 2009 Department of Natural Resources Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Norolah Mirghafari Address mail mnorolah@cc iut ac irAbstractPopulation growth industrial development and increasing of water consumption especially in the countrieswith 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 theliving tissues as well as their carcinogenic effects it is necessary to respect the environmental standards fordischarge of industrial wastewater containing heavy metals The general methods for removal of heavymetals from aqueous solutions include chemical precipitation reverse osmosis adsorption and ionexchange However because of some restrictions such as high cost and low efficiency adsorption of heavymetals by cheap absorbents atracted more attention in recent decades In this research mine tailings fromIrankouh lead and zinc mine situated in Isfahan was utilized as sorbent of heavy metals Some of tailingcharacteristics such as cation exchange capacity CEC chemical composition constitutive phases andspecific surface area was determined by ammonium acetate XRD XRF and N2 BET respectively Theadsorption experiments were performed by bath and column methods using synthetic solutions andindustrial 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 andregeneration of sorbent was carried out by column method The mine tailing was treated by acid base anddistiled water to modify the adsorptive properties The appropriate equilibrium time was 30 and 60 minutesfor 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 maximumadsorption of cadmium and lead at pH 5 was 62 and 76 and for zinc copper and nickel at pH 6 was53 56 and 32 respectively The adsorption amount was increased with decrease in particle size Thesorption isotherms of zinc nickel and copper were describeb using Freundlich linear model and cadmiumwith Longmuier linear model Lead adsorption was described well with both models The modificationtreatments affected the adsorption of cadmium zinc and copper significantly p 0 05 The modificationtreatments increased the sorption capacity in the following order base distiled water acid More than90 of the initional Solution cadmium and lead sorbed on base treated sorbent Regeneration of saturatedtailings by acid and distiled water washing showed that these materials have the ability to be reused withoutdecreasing adsorption capacity In the related tests of industrial wastewater adsorption percentage was highin low concentrations of heavy metals Key Words adsorption heavy metal mine tailing synthetic solutions wastewater

نوري كمري ، اكرم

جذب فلزات سنگين به وسيله باطله هاي معدني

جذب سطحي , محلول هاي آزمايشگاهي , پساب هاي صنعتي