SYNTHESIS OF LOCAL CONTROL SYSTEMS OF REAGENTS CONSUMPTION IN REDUCTION OF TOXIC IMPURITIES AT WASTEWATER IN A PERIODICAL ACTION REACTOR

Abstract

The article presents a solution to the problem of regulation of reagent consumption during the reduction of toxic impurities during wastewater treatment in periodical action reactors. The disadvantage of the existing dosing systems is that during the reduction reaction, the active reaction of the wastewater medium increases, which significantly reduces the reduction efficiency and requires the continuous maintenance of the pH value within the specified limits and the dosing of an excess amount of the reducing agent. Considering the interdependence of the processes of reduction and acidification for the control system, the most effective is the method of complex stepwise regulation of pH and Eh parameters, which consists in the stepwise, sequential dosing of reagents at each of the stages according to the measured values of the redox potential Eh and the active reaction of the pH medium with subsequent stabilization of the redox potential of water. The method of determining the parameters of the regulator in the feedback control system with step-by-step periodic adjustment of the parameters for the neutralization of hexavalent chromium in periodical action reactor has been developed. The technique allows determination of such values of the regulator parameters that allow the object to be transferred from one state to another in a given period of time with a given amount of reagent.