Research On Advanced Treatment Of Heavymetal Wastewater By Amino Methylene Phosphoric Acid Resin

The amount of Non-ferrous metal mining heavy metal wastewater is large,and the content is high. In order to achieve the reuse of effluent water quality requirements and the "Surface Water Quality Standards"(GB3838-2002) Class Ⅲ water standards. This paper makes an advanced treatment for the wastewater that has been met the standard of sewage discharge using amino methylene phosphoric acid resin D402.And studied the adsorption and regeneration performance of D402 resin to Pb(II)、Cd(II)systematic.(1) Static experiments show that, with the increasing of p H, the adsorption capacity of D402 resin for Pb(II), Cd(II) increase first, and then have a slight decrease. Adsorption capacity arrives the maximum when the p H is 6.0, is 365.6mg/g and 239.1mg/g respectively. As the temperature increasing, the adsorption capacity for Pb(II) and Cd(II) is increasing.When the temperature is 313 K, the adsorption capacities for Pb(II) and Cd(II) are 370.5mg/g, 248.3mg/grespectively.The adsorption processes for Pb(II) and Cd(II) according to the Freundlich equation, and the correlation coefficients are greater than 0.99. Ca(II) and Mg(II) of high concentration have effection on the adsorption of Pb(II) and Cd(II).(2) Dynamic experiments shows that, D402 resin material adsorbs single-containing Pb(Ⅱ)(1.09mg/L) or Cd(Ⅱ)(0.098mg/L) simulated water samples, the adsorption capacity are 7000mg/L and 735mg/L. When the solution is mixed by Pb(II) and Cd(II),and the concentration is 5times of standard of sewage discharge,the adsorption capacity are 5800mg/L and 715mg/L. The main factors affecting the adsorption capacity during the removal processes are p H, overcurrent speed, raw water concentration,other ion interference(salinity, hardness ions mainly) and so on.With the increasing of p H, the adsorption capacity of D402 resin for Pb(II), Cd(II) increases first, and then have a slight decrease. Adsorption capacity arrives the maximum when the p H is 6.0, is 5800mg/L and 710mg/L respectively. At a lower flow rate, D402 resin fails slowly and the adsorption capacity is high. The higher the concentration of Pb(II) and Cd(II), the earlier the breakthrough time,and the lower the adsorption capacity.(3) Regeneration Experimental of D402 resin studies have shown that, best regeneration agent is a 6% HCl, regeneration mode is acid-base regeneration, the amount of regeneration agent is 5 times of the resin volume, regeneration time is 5h, the best temperature is 25 ℃.(4)While using D402 adsorption process, it needs 5.757 million yuan to treat the project with 200m3/h of heavy metal wastewater from nonferrous metal mines. It includes the operating costs for power, medicament, labor and depreciation cost totally about 0.792 yuan per cubic metre. The recovery period of investment cost for the project is about 5 years, that has high economic benefit, social benefit and environmental benefit.