The removal efficiency of heavy metals from spent printing developer

Abstract

This study was concerned with the possibility of removal of heavy metal ions, Cr(total), Zn(II) and Cu(II) from spent printing developer by adsorption using low-cost materials: natural zeolite (NZ, clinoptilolite), activated carbon (AC, Norit Row 0.8 Supra) and their mixture (NZ + AC). Concentrations of Cr(total), Zn(II) and Cu(II) were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), using a PerkinElmer Elan 5000 mass spectrometer. The adsorption of Cr(total), Zn(II) and Cu(II) onto clinoptilolite and activated carbon was studied in laboratory batch mode. Adsorption data have been interpreted in terms of the Freundlich, Langmuir and Dubinin-Kaganer-Radushkevich (DKR) equations. The results provided strong support for the heavy metals adsorption onto these adsorbents, and all the data fitted well to the Freundlich isotherm (R 2>0.97). The lowest correlation coefficient for all target ions was obtained using their mixture (NZ + AC). The adsorption capacities of NZ and (NZ + AC) mixture decreased in the order: Cu(II)>Zn(II)>Cr(total), while that of AC followed the order: Zn(II)>Cu(II)>Cr(total).