Formalization of the Task of Creating a Mathematical Model of Combined Wastewater Treatment Processes

Abstract

This paper focuses on the formation approach to formalize the mathematical modeling of wastewater treatment processes for further forming decision support systems for wastewater treatment facilities management on such a theoretical basis. To create an experimental model of formalization of modeling problems, research was conducted on activated sludge from municipal sewage treatment facilities by introducing an oxidant (H2O2) during standard operation of wastewater treatment facilities and introducing a toxicant (sulfur compounds). It was determined that under conditionally standard conditions, the influence of the oxidant is negative: exceeding technological standards of the concentration of dissolved oxygen in water solutions (3.0–13,7 mg/l), low water column transparency (1.4–1.6 cm), higher concentrations of ammonia nitrogen and phosphorus. With the appearance of a toxicant in the form of reduced sulfur compounds (sulfide ions and hydrogen sulfide 1.4–2.8 mg/l), on the contrary, the positive effect of H2O2 on biological water treatment processes was determined: the concentration of dissolved oxygen increases to 3.4 mg/l and the swelling of activated sludge stops. In this case, using a simplified scheme of expert evaluation as a global quality criterion of the biological stage management process of water treatment for rapid assessment of the vitality of activated sludge is justified. As parameters available for direct automatic measurement, it was proposed to use ORP and pH approximated by the regression equation. Also, a conditional scheme of the decision support system for water treatment management was proposed, which will provide two-level hierarchical control: situational and operational in real-time with a preventive response to emergencies; tactical with daily, at least daily, forecasting of the treatment plants.