Removal of Pb(II) from aqueous solutions by using dioctyl sodium sulphosuccinate-EDTA modified Amberlite XAD-7HP resin

417-425The removal of Pb(II) from aqueous solutions by using modified Amberlite XAD-7HP resin has been studied. The resins have been prepared by complete mixing of Amberlite XAD-7HP resin with anionic surfactant-dioctyl sodium sulphosuccinate (DOSSS) and EDTA-disodium salt (Chelating agent) in an aqueous solution. SEM studies revealed the morphological observations of the unloaded adsorbent and thereby changes in the adsorbed polymeric resins. FTIR studies showed that the impregnation of the extractant on the Amberlite XAD-7HP resin is achieved partly through hydrophobic interaction between the alkyl group of the extractant and aliphatic chain (methyl) of the support and also through polar or electrostatic forces. The equilibrium adsorption level was determined as a function of contact time, pH and adsorbent doses. Adsorption isotherms of Pb(II) on adsorbent were determined and correlated with common isotherm equations such as Langmuir and Freundlich models. The adsorption kinetics of Pb(II) on modified XAD-7HP resin could be best described by the pseudo-second-order model. The lead(II) ions could be successfully recovered  from the modified XAD-7HP resin by treatment with 7% NaCl. The modified XAD-7HP resins thus regenerated could be used again to remove the heavy metal ions. The adsorbent was also tested for the removal of Pb(II) from lead battery wastewater

Removal of Ni(II) from water and wastewater using modified Duolite XAD-761 resin

245-253Complete mixing of cross-linked phenol-formaldehyde polymeric resin (Duolite XAD-761) with anionic surfactant -sodium dioctyl sulphosuccinate (SDOSS) and EDTA-disodium salt (Chelating agent) in an aqueous solution led to the formation of a modified resin. FT-IR studies showed that the immobilization of the extractants results from hydrophobic interaction between the alkyl group of the extractants and phenyl group of the support, and also from other mechanisms like polar or electrostatic forces. The modified resin was used in batch adsorption experiments for the removal of Ni(II) were carried out as a function of agitation time, pH, adsorbent dosage and adsorption capacity. Adsorption data could be interpretated by Langmuir and Freundlich equations. The results showed that the adsorption kinetics of Ni(II) on modified XAD-761 resin could be best described by the pseudo-second-order model. SEM studies revealed the morphological observations of the pure resin, modified resin and Ni(II) adsorbed modified resin.The adsorbent was also tested for the removal of Ni(II) from synthetic wastewater