Calculated dependence of determination of actual dose of microsand and influence of its value on efficiency of coagulation process in Actiflo clarifier

Operational test of the preliminary water cleaning systems is the first and most critical stage when putting into pilot operation a water treatment plant at a thermal power plant (TPP). We have sufficient experience of equipment setting up and operating when most traditional devices of preliminary water purification are used. Also, the main stages and features of the work carried out are known, and a sufficient amount of methodological literature has been published, compared to employment of modern and promising devices. These devices include Actiflo clarifiers. The main feature of the Actiflo technology is introduction of microsand into the stream of treated water. It forms the so-called “centers” of coagulation and is used to make wastewater sludge heavier. The development of a methodology to assess the impact of the actual dose of microsand on the water clarification process will contribute to the solution of the priority task of adapting the promising Actiflo technology for water treatment systems of TPPs. In laboratory studies, the method of pilot coagulation has been used. It allows us to assess the efficiency of coagulation process using generally accepted methods of quantitative analysis of indicators of natural water quality. In subsequent industrial tests, along with the quantitative analysis of water, the actual value of the microsand dose has been assessed using measurements of the proportions of separate fractions in the formed sand-sludge pulp. The results of laboratory and industrial studies of “cold” coagulation process of the Kama River water using Actiflo clarifiers have been obtained. The dependence of efficiency effect of water clarification on the dose of coagulant and the dose of microsand has been determined. To check and maintain the operating mode of the clarifier, a method to assess the actual values of the microsand dose has been developed and proposed. The research results are applicable for low-turbidity colored surface water sources. The results of operating tests of Actiflo clarifiers can be used as practical examples for coagulating water in devices similar in design, for example, VTI-M clarifiers. The proposed method to assess the actual dose of microsand can be used as a technological parameter during the development of the parameter tables when Actiflo clarifiers are used.