PROMISING MULTIFUNCTIONAL ANIONITES FOR THE EXTRACTION OF CHROMIUM (VI) IONS

Abstract

30% of the chromium ore reserves in the world are concentrated in Kazakhstan, during the processing of which large volumes of wastewater containing toxic chromium salts, are formed. Сhromium is one of the priority components both in terms of emission and toxicity (for Cr(VI), the maximum permissible concentration is 0.05 mg/l). The compounds of chromium (III) and especially chromium (VI) have a general toxic, allergenic, carcinogenic, mutagenic effect on the human body, and are among the most dangerous pollutants for the environment. The aim of this work is to develop a technological scheme for the extraction of Cr (VI) ions by multifunctional ion exchangers. Methods. Anionite, based on diglycidyl ether of dioxyphenylpropane, allylglycidyl ether and polyethylenimine – Ionite No. 1 has been synthesized by polycondensation, and epoxyamine has been synthesized from benzylamine and epichlorohydrin, by the condensation of which Ionite No.2 has been obtained with polyethylenimine. The sorption of chromium ions on newly synthesized anionites has been studied, using model solutions with the concentrations of 25, 50, 75 and 100 mg/l Cr (VI). Results and discussion. It has been established that Ionite No.1 exhibits greater affinity for Cr (VI) ions. So, its maximum sorption capacity is 13.5, and that of Ionite No.2 is 11.7 mg/g. Conclusion. We have proposed a basic technological scheme of a desalination plant, consisting of modular units: reagent-mechanical, sorption, membrane, ion exchange and bacterial purification. It has been established that reagentmechanical purification is the initial stage of water treatment, designed to isolate insoluble coarse- and fine-dispersed impurities.