Записки Горного института (Jul 2024)
Analysis of the geochemical barriers effectiveness as the basis for the use of nature-like water purification technologies
Abstract
Nature-like technologies are being introduced into many human activities including mining wastewater treatment. This work is based on long-term studies of the Sibay copper-zinc-pyrite deposit development. It is dedicated to assessment of geochemical barriers effectiveness in Cu, Zn, Cd removal from water of the Karagayly River (receiving quarry and dump drainage water). The research is based on the elements’ content and forms in water and bottom sediments, pH values etc. Four types of hydrogeochemical environment (formed due to changes in the water use over the past 20 years) were distinguished using discriminant analysis. The mechanisms of barriers formation and destruction were described. Statistical modeling of the metals’ precipitation was performed by multivariate regression analysis. Cu is adsorbed by recently formed Fe hydroxides, and, to a lesser extent, precipitates with sulfates as water pH increases. Antagonism to Mn hydroxides has been demonstrated, due to different physicochemical conditions for their precipitation. Zn enters solid phase mainly with sulfates, this element also forms its own mineral phases. The second mechanism is adsorption by recently formed Mn hydroxides, which corresponds to the idea of similar conditions for the precipitation of metal hydroxides. Cd behavior reflects conditions intermediate between these of Cu and Zn. Contribution of both mechanisms (related to Fe hydroxides and aqueous sulfates) is equal. Antagonism to Mn is absent. According to the assessment results using of nature-like technologies in situ in watercourses, canals and other water drainage systems is promising. Developed statistical models can be used for needs of experimental studies and artificial geochemical barriers engineering.
