Process investigation of ion sorption of complex compounds made by chromium, zinc, nickel and cobalt contained in wastewater bentonite clay

Abstract

This article outlines the outcomes of laboratory investigations focusing on the sorption behavior of Cr (III, VI), Zn, Ni, and Co on bentonite. The study encompasses a broad spectrum of solution pH levels and sortable component concentrations, aiming to unveil the states of micro-components in aqueous solutions. The research also addresses the identification of optimal chemical concentration conditions and the establishment of a sorption mechanism for these components on clay adsorbents based on bentonite. In aqueous solutions, the ions of these metals undergo hydrolysis, resulting in the formation of complex compounds. The study discerns that the sorption process on bentonite clays predominantly initiates at pH levels around 4-5 and concludes at pH exceeding 7.5-10. These findings shed light on the critical pH ranges where sorption reactions are most significant and highlight the cessation of sorption at elevated pH levels. The research contributes to a comprehensive understanding of the sorption dynamics between bentonite and metal ions, emphasizing the pH-dependent nature of these interactions. By identifying the optimal conditions for sorption and elucidating the underlying mechanisms, this study offers valuable insights into leveraging bentonite clay as an effective adsorbent for the removal of Cr (III, VI), Zn, Ni, and Co from aqueous solutions.