Statics simulation of the sulphate iron-containing wastewater neutralization process

Abstract

At the present stage of technical progress, all industries face an extremely complex problem of creating reliable barriers that prevent the penetration of industrial emissions into the environment. Currently, the issues of stabilizing the quality of wastewater treatment have become especially important in connection with the task of developing wastewater-free industrial complexes. Among the complex scientific and technical problems associated with this task, the problem of stable and reliable maintenance of water quality parameters at the outlet of technological systems is crucial, as leakage of pollutants immediately affects the state of basic production, disrupting its technology and infecting ecosystems.
 The focus of industry on a sharp reduction in emissions and on the creation of industrial cycles with circulating water supply requires intensive efforts to improve the wastewater treatment technology, the introduction of high-performance processes and devices, as well as the synthesis of control systems for typical wastewater treatment processes. 
 For the performance of automated control systems for typical cleaning processes, it is necessary to develop a software package on the basis of appropriate mathematical models of typical processes. To obtain them, methods of mathematical and simulation modeling and variance analysis were used.
 In order to assess the quality of modeling, the presented mathematical model describing the statics of the neutralization process for ferrous sulfate water was tested for compliance. To do this, two experiments were performed (the first at an initial concentration of sulfuric acid of 800 [mg/l] and ferrous sulfate of 4000 [mg/l] and the second at an initial concentration of sulfuric acid of 800 [mg/l] and ferrous sulfate of 2000 [mg/l]). First of all, a precondition for the reproducibility of experimental results was verified using the Cochrane test. The mathematical model was verified for adequacy on the basis of Fisher's criterion for the significance level q = 0.05 with degrees of freedom j1 = 16 and j2 = 17.
 For the first experiment, Grozr = 0.50557 and Gmab = 0.73; i.e., Grozr < Gmab and dispersions are homogeneous. Frozr = 1.0225 and Fmab = 2.4 and thus Frozr < Fmab, and there is no reason to say that the model is inadequate.
 For the second experiment, Grozr = 0.50308 and Gmab = 0.73; i.e., Grozr < Gmab and dispersions are also homogeneous. Frozr = 1.0005 and Fmab = 2.4 and thus Frozr < Fmab, which also indicates that the model is adequate.
 The issue related to the performance of technological systems for wastewater treatment in non-stationary modes is directly dictated by the specific operating conditions of treatment facilities, which are expressed by the instability of parameters at their inlet. The inability to apply the necessary technological action to the flow in time is a serious obstacle to the implementation of the cleaning depth, which is guaranteed by the physicochemical basis of the methods incorporated in technological systems and requiring cleaning standards. The operator cannot handle this complex task manually. On the basis of the proposed mathematical model, a structural-parametric diagram of the automated process control system has been developed, which makes it possible to proceed to the elaboration of algorithms and software for the control system necessary for automated control of the wastewater treatment process.