Onanko Y. Optimization of filters parameters with polystyrene foam and zeolite media at purification of natural and wastewater

The analysis of modern sources of domestic and world scientific literature revealed that one of the most common and urgent needs in the treatment of natural and wastewater is the quality of the filter medium and the need for periodic replacement. Given the domestic characteristics of natural resources and economic indicators, the most competitive are two types of raw materials for filter medium: gravel-sand from natural material (rock prepared by grinding) clinoptilolite Sokyrnytsky deposit and artificial material based on foamed granules of polystyrene food brands. The literature analysis of the existing physical and mathematical models of the main stage of filtering revealed that they do not take into account the features of the initial stage of filtering. These models were developed for the use of quartz sand as a filter media having a negative ζ-potential charge. Besides, relevant scientific publications show that the use of modern high-precision measuring instruments has made it possible to directly measure the ζ-potential of polystyrene foam and determine that its charge is positive. This experimentally determined fact, according to Coulomb's law, transfers the parameter of ζ-potential from the category of factors that prevent the retention of colloidal particles (the vast majority of which have a negative charge of ζ-potential) by polystyrene foam media granules in the category of factors contributing to this process. This necessitated the development of a physical and mathematical model of the initial stage of filtration of the aqueous suspension through a filter with a bulk medium, which complements the existing physical and mathematical models of the filtration process. Given the formulation and statement of the problem, it was used the power of modern information technology. For this purpose, the use of the algorithmic means apparatus to parameters of technological modeling is best suited. Based on the developed physical and mathematical model of the filtration process of aqueous suspensions and parameters that are well known from the scientific literature, developed a logical structure of the algorithm for selecting optimal technological and design parameters of the filter with the bulk medium. Based on the developed physical and mathematical model, comparative experiments on the treatment of natural and treated wastewater with the help of the above filter materials were planned and conducted. For this purpose, appropriate research methods and research installations have been developed. Based on the results of these studies, an empirical model of the filtration process of an aqueous suspension through a filter with a bulk medium for surface (natural) water treatment and wastewater treatment was developed. However, the disadvantage of this model was its accuracy for specific objects of study, which is not universality. Therefore, there is a need to develop a universal theoretical model of the above process. For this purpose, modern mathematical means of artificial neural network work optimization were applied. The correctness of the optimization algorithm is verified by comparing it with the results of experimental studies on real water treatment facilities. The disadvantage of this approach was the inability to determine some of the parameters using the optimization algorithm. The combination of the above factors created the need to develop a mixed or semi-empirical model in the form of a technological modeling algorithm of aqueous suspension filtration through the bulk medium. In which technological and design parameters that can be correctly determined using mathematical optimization tools are determined using a developed theoretical model. And all the others are given in the semi-empirical model as constants and are determined using the developed empirical model. As a result of the application of this semi-empirical model the design of the clarifying filter - the phytoplankton retainer for purification of circulating waters of the state enterprise – the spirit factory "Chervonoslobidsky" which is engaged in processing of agricultural products are developed. Due to this, a new design of the clarifying filter - phytoplankton retainer was developed. The practical application of such a filter provided the required level of retention of cells and conglomerates of cyanobacteria from the treated water. The implementation of scientific and technical developments obtained in this study made it possible to increase the economic efficiency of the circulating use of wastewater of the spirit factory "Chervonoslobidsky" by 1.5 - 1.7 times in comparison with the market offers of mechanical filters.