Fatkulina G. The ecological safety enhancement of technogenic regions through the use of water treatment technologies in systems with and without phase transition

The thesis deals with the water treatment processes in reverse osmosis units with aftertreatment in the mixed bed filters (without phase transition) and concentrates freezing-out (with phase transition) processes aimed at reducing the discharge of saline effluent that will significantly improve the ecological condition of the environment. Home and foreign industry experience in the field of ecological safety of water treatment technologies has been analyzed and taken into account. New technologies using reverse osmosis, ion exchange treatment of permeate and freezing-out of сoncentrate are suggested. The characteristics of applying reverse osmosis technology for devices with fiber membranes (costs of energy, the degree of desalination and concentration of salts) allowing to identify limits of its use are detected. The main indicators of desalinated water quality, types of ion exchange resins, its absorption capacity and selection of reagents used for regeneration of ion exchangers are identified. The parameters of processes aimed at the reducing saline wastewater discharges after the water treatment equipment through freezing-out are studied. The features of scale formation in the recirculation loops are outlined. Parameters of make-up and reverse (recirculation) water treatment using different technological methods and reagents are investigated. Mathematical models determining the ion product of main scale formation materials - calcium carbonate and calcium sulfate - are found.