Section 13. MISCELLANEOUS WASTES
THE DYNAMICS OF AUTOMATED EQUALIZATION
BASIN-REACTOR SYSTEMS
Boris Khudenko, Assistant Professor
Department of Civil Engineering
Wayne State University
Detroit, Michigan 48202
An important feature of wastewater treatment processes is the significant variabdity of
input parameters. In continuous flow technological units (reactors, separators, etc.) this
may result in a substantial decrease in the efficiency of treatment processes from that
required and attainable by virtue of the physical principles that are employed in the process.
Under such conditions, adequate control of the efficiency of the treatment processes
can be achieved by the employment of equalization basins, automatic control systems, or
a combination of the two. The selection of control means and the determination of their
parameters depends on (a) the variabdity of input parameters, (b) the dynamic properties
of equalization basin, reactor, and automatic control system, and (c) the required characteristics of output parameters. For purposes of optimal design, these three concepts
must be quantitatively defined. On the basis of this information, the propagation of various
disturbance signals through equalization basins and reactors can be analyzed. Such analysis
establishes the basis for optimal design (synthesis) of treatment systems.
The problem of the opitmal design of dynamic systems can be formulated as follows:
for given variations of input parameters and required stabdity of output parameters, the
process must be designed in such a way that the required stability of output parameters
is satisfied and expenses are minimized. Various optimization problems can be considered.
In general, monetary expenses must be minimized. In practice, this is usually reduced to
the following most important cases: (a) determination of the optimal distribution of the
dynamic load between reactor and equalization basin, (b) distribution of the total volume
of tanks between reactor and equalization basin, (c) minimization of consumption of reagents in the equalization tank-reactor system.
Based on literature review and the author's experience, this paper presents methods of
analysis for input and output parameters, methods of analysis of dynamic response of major
elements of treatment systems, and illustrates the application of these principles to design
problems. Only linear processes are discussed herein; in particular, reagent treatment of
monocomponent wastewater when chemical processes are instantaneous or can be described
by linear or linearizable kinetic equations. However, the principles discussed can also be
applied to the analysis and design of more complex systems.
MAJOR RELATIONSHIPS IN THE DYNAMIC ANALYSIS OF
TREATMENT SYSTEMS
Variations of Input Parameters
The fluctuations of input parameters are attributable to a wride variety of sources. However, these fluctuations can be classified into the following five types of variations:
1. shock changes (eat., from the discharge of a batch of wastewater);
2. sudden changes (cat., due to prolonged changes in the processes generating wastewater):
3. cyclic oscillation* (e.g.. caused by the periodicity of technological processes);
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