System analysis methods and resource-saving electromembrane technologies in creating a low-flow water system using of Tatarstan Republic energy facilities

Abstract

THE PURPOSE. theoretical substantiation of resource-saving technologies and development of "terminal" electromembrane installations when creating a low-flow water use system for energy facilities of the Republic of Tatarstan.METHODS. In the work, the methods of system analysis were used and a mathematical model was developed to describe it. The description and technical characteristics of the developed devices and installations for testing the proposed technologies are presented.RESULTS. At Kazan CHPP-3, a technology was developed and a pilot electromembrane plant was installed for the disposal of blowdown water from the thermal desalination complex. As a result of the operation of the electromembrane unit, a transparent alkaline solution is formed with a pH of 13.86 and a concentration of OH ions of 2.7% (up to 4%). The content of salt components in the concentrate is 2% by weight. The resulting concentrated alkaline solution can be used in the cycle of the station for the regeneration of anion exchange filters of the 1st stage. The softened saline solution is fed to the heating network. The electromembrane plant processes 0.5 tons per hour of alkaline wastewater with a ratio of concentrated alkaline solution to softened brine of 1:9. The specific power consumption is 6 kWh per 1 ton of blowdown water. The operation of the plant is characterized by the complete absence of waste and bezreagnosti. At the ion-exchange water treatment plant of the Nizhnekamsk CHPP-1, a method was proposed, a technology was developed, and an experimental pilot plant was installed for processing alkaline spent regeneration solutions of anion-exchange filters. The electromembrane plant processes 1.5 tons per hour of alkaline waste. The capacity of the plant is 0.1 tons of 4% alkaline solution. Specific power consumption - 4 kWh per 1 ton of alkaline waste solutions. During the operation of the installation, there is a complete absence of waste with a reagent-free wastewater disposal process.CONCLUSION. The return of regenerated alkali solutions and softened water to the production cycle makes it possible to obtain a significant improvement in indicators that characterize environmental friendliness and resource saving without the use of chemical reagents.