Physico – chemical study of the adsorption properties of natural minerals for sorption treatment of wastewater from Pb+2, Ni+2, Zn+2 ions

Abstract

One of the urgent challenges is to clean up industrial wastewater from toxic and heavy metal ions in a more efficient and environmentally friendly way. Bentonite montmorillonite, bentonite red, zeolite and diatomite of the Almaty region were selected as the materials of the study. In this study was investigated the adsorption properties of natural minerals by physico-chemical methods for the sorption treatment of wastewater from Pb+2, Ni+2, Zn+2 ions. X – ray phase analysis determines the chemical composition of the materials studied. The main component of diatomite is SiO2, in zeolite – Laumontite composition Ca4Al8Si16O48·14H2O (51.3 %). The base of bentonites is bedellite – montmorillonite, which has an amorphous structure. The method of atomic absorption spectrometry was used to investigate the sorption of heavy metal ions (Pb+2, Ni+2, Zn+2) by the natural adsorbents under investigation. Bentonites, Mukra and Medium Tentec have the best sorption properties. Here, the content of lead, nickel and zinc ions is reduced by an average of 82–85 %. In the case of diatomite, the ion content of the same metals is reduced by approximately 74–76 %, and for zeolite by 64 %. Generally speaking, the adsorption properties of these minerals are expected to be achieved by the high porosity in the case of diatomite and zeolite or the penetration of ions into the interpackage space between the bentonite layers. Mixing adsorbents, increasing their mass percentages and increasing the mass of the mixture leads to increased efficiency of the degree of cleaning from these ions. In conclusion of the study, natural minerals of the Almaty region have sorption properties that can be used for practical purposes, in particular for wastewater treatment