Pilipenko Dmitriy
Faculty of computer information technologies and automation
Cathedra electronic technique
Speciality: Electronic systems
Theme of master`swork: Grounding and researching structure of the electronic system checking
cut-in oxygen airtank of cleansing buildings
Scientific adviser: Korenev Valentin
Abstract
«Grounding and researching structure of the electronic system checking cut-in oxygen aerotank of cleansing buildings»
I General characteristics
Relevance of research topics. The situation with the natural reserves of water in Ukraine is very complicated.
Donetsk region is located in the penultimate place among the regions of Ukraine on
water resources.
Maintenance of obsolete equipment and energy in the water supply sector can disrupt the existing system of water
supply.
Protecting water resources from pollution is largely determined by the efficiency of bioremediation. In the current method of wastewater treatment active silt is the most universal and widely used in the processing of waste water containing organic
and contaminants of different origin.
The useing of technical oxygen, highly symbiotic sludge cultures, stimulants biochemical oxidation, improved designs
airtank, airation equipment and systems for offices active sludge resulted in several times to improve the performance of biological
treatment. Significant reserves hidden in the field of intensification of mass
transfer. However, further increase the efficiency of biological wastewater treatment and intensification possible on the basis
on mathematical description processes of biooxidation and developing ways to optimize and
control processes. Solution to this problem is to describe biological systems, taking
the interaction of biochemical, microbiological, biophysical and technical
factors. Removal of organic contaminants in the biological treatment is an integral component of the substrate resulting from the removal of certain types of bacteria that make up biocenose. Each component is consumed by micro-organisms of several species with different velocities of oxidation. Describes the totality of these processes includes a large number of equations.
The basis of the analysis should serve an integral approach, abandoning the separate description of each element
the system and based on a study of the statistical regularities behavior
complex biochemical systems. An example of approach to biology can be a mathematical theory of population Volterra. It reflects the general pattern of relationships between populations and habitats.
Relationship of academic programs, plans, themes. These studies relate to the plan of «Dongorvodokanala» for reconstruction and development of Donetsk treatment facilities and introduction of advanced monitoring systems.
The degree of scientific development problems.
Researching in technology in wastewater treatment since the inception of the first urban sewage and wastewater treatment plants in England. The most significant development in wastewater treatment plants is the use of pneumatic aeration in the presence of different kinds
microorganisms for biological purification of waste water.
There are significant achievements in exploring dynamics of microbial populations. The calculation of basic technological parameters of wastewater treatment systems are guided by empirical considerations. This leads to an overstatement of the amount
construction biological treatment facilities or to amount insufficient to achieve the desired degree of purification.
In order to improve the performance of biological treatment, it is proposed to use the mathematical apparatus to determine the best methods for biological treatment of wastewater.
Object of the researching. The object of the researching is the phase of biological wastewater treatment in airtank for urban wastewater treatment plants.
Item of the researching. The item of the researching is the distribution of dissolved oxygen in the airtank.
The target and tasks
of the researching. The target of the researching is
grounding and researching structure of the electronic system checking cut-in oxygen
airtank of cleansing buildings for äëÿ optimization of energy costs.
The method of mathematical modeling provides a mathematical model to describe the dynamics of microbial growth and substrate consumption.
Mathematical model allows to calculate the optimal measurement of dissolved oxygen in
airtank.
The main tasks of the researching are:
—researching of the available methods for measuring concentration of dissolved oxygen;
—researching of the regularities of mass transfer section of the corridor
airtank;
—researching the laws of mass transfer along the length of the corridor
airtank;
—building a mathematical model of the spatial distribution of dissolved oxygen in
airtank;
—researching structure of the electronic system checking cut-in oxygen
airtank.
Theoretical sources and methodological basis of research. The theoretical basis for research is the useing of several models of gas exchange:
-Model of stationary diffusion.
As a basis for analysis of the transport model of cotton with a homogeneous spherical structure surrounded by a diffusion layer. In this model
we can formulate the problem fixed diffusion and inconsistent diffusion of one or multiple reagents.
-Model of unsteady diffusion.
The physical model of the unsteady transport diffusion are widely used in the analysis of mass transfer at the boundaries of bubbles and drops. In the analysis of mass transfer is assumed that at time t = 0 surface of the contact comes into contact with a liquid.
-Kinetic model biooxidation.
Description of the kinetics of biological oxidation is based on an analysis of experimental dependences and the theoretical framework, derived from physical models
transport of oxygen to the cotton active sludge.
Scientific novelty of the results of research. Scientific novelty lies in bringing together disparate models into a single mathematical model describing the spatial distribution of dissolved oxygen in airtank.
The theoretical and practical significance of the research. The results can be applied to wastewater treatment plants to optimize energy consumption, monitoring and managing performance of compressor stations, increasing the economic efficiency of the treatment facilities.
Publications.
1. Modeling dynamic processes of biological sewage treatment at wastewater treatment
plants. Pilipenko D. Korenev V. //²íôîðìàòèêà òà êîìï'þòåðí³ òåõíîëî㳿 — 2008 / Ìàòåð³àëè 4 íàóêîâî—òåõí³÷íî¿
êîíôåðåíö³¿ ñòóäåíò³â àñï³ðàíò³â òà ìîëîäèõ ó÷åíèõ —
25—27 ëèñòîïàäà 2008,ÄîíÍÒÓ, Äîíåöüê — 2008 — 530ñ.; ñ ³ë.
2. Automatic control of compressor station sewage plants. Lupinos Î., Pilipenko D., Fedyun R.
Fulltext publication presented in this site at section "Library".
II Main content
Modern sewage treatment plants implemented stage biological treatment for the release of clarified water from the mineral and organic pollutants that are suspended, colloidal and dissolved state. The technological scheme of wastewater treatment plants is shown in Figure 1.
Figure 1. The technological scheme of the wastewater treatment facilities. Flash—animation, 16 frames, 5,84kb, infinite repeat
The main difficulty is in the work of treatment facilities needed in a constantly changing environment of their operation. The work must be based on a model of the biological treatment plant and maintain a continuous calculation of complex technological parameters and to predict the behavior of the system.
Process biological treatment of pollutants is carried out in airtank. It happens contact with sewage
organisms in active sludge with presence of dissolved oxygen and separation of the active sludge from the treated water in the ponds. Active mud
— artificially grown biocenose inhabited by bacteria, protozoa and multicellular animals. Oxygenation occurs through barboratsii effluent oxygen air supplied through a network of perforated pipes at the bottom
aeropack.
The most important factors influencing the development and vitality of the active sludge, as well as the quality of biological treatment are: temperature, availability of nutrients, dissolved oxygen in the sludge mixture, pH, presence of toxins.
Bioremediation is the most power consuming stage spend 85% of the electricity of all wastewater treatment plants for waste water aeration. The role of active sludge is in the biological oxidation of organic matter in waste water to simple compounds and sorption. In its simplest form, this process can be described as the scheme looks like this:
The decisive factor in the treatment plants is control of the concentration dissolved oxygen in airtank. The normalized value of the oxygen concentration is 2mg / l in any point airtank. For objective analysis of the oxygenation is necessary to take design of airation systems and processes of mass transfer in cross—section airtank and its length. Oxygenation occurs during the air bubbles rise to the surface. Task is to create models airtank and establish the laws of distribution oxygen in the spatial coordinates. Researching model is necessary to determine effective locations for sensors of dissolved oxygen. Airtank is a reactor for carrying out the biochemical process oxidation of impurities. For the calculation of the reactor it is necessary to have data on the kinetics elementary act of bio oxidation and know the nature of fluid motion in a reactor. To simulate the majority designs suitable flow reactor of ideal displacement. There is no mixing (diffusion) along the stream and the liquid passes through the apparatus compact mass. Length of stay in the reactor is equal for all its components. In the reactor of the liquid changes the length of reactor. The material balance for the reacting substance is necessary for a basic content ΔV (Figure 2).
Figure 2— Equation of material balance reactor of ideal displacement. Flash-animation, 3 frames, 2,24kb, infinite repeat
Consider a simple reactor, which is located at a distance x from the entrance of reactor. If the concentration of reagent at the inlet and outlet of the elementary
content ΔV equal respectively L(x) and L(x+Δx),
it is clear for the time Δt→0 and Δx→0
mass of the reagent is changed to value 
Now
we get a differential equation of process
,where
—bulk velocity of fluid motion along the axis of the reactor with a
cross—section S; L—concentration of the reagent, making the subject;
ρ(L) — the rate of chemical transformations. Further transformation of the equation will give expression to determine the time (the period of aeration), it is necessary to make the reagent with the concentration
Lo to concentration Le
To research processes of contamination need to know the medium mixing intensity of the reactor. The best indicator would be the local velocity of fluid flow relative to the center of its rotation. On Figure 3 is represented the cross section airtank and flow of liquid.
Figure 3— Flow of liquid in the section airtank. Flash-animation, 5 frames, 7,85kb, infinite repeat
Rotational moment creates an ascending gas stream from the tube. Consumption of liquid able to calculate the expression
,
where Vï —air flow; H—depth.
After diffirentiation get the value of the linear velocity of ascending flow Vmax . As a first approximation, the center of rotation is the intersection of the diagonals airtank (point 0). To determine the velocity of flow in any part of the section at a distance r, you can use the expression
,
where
, H—depth; — width of airtank.
Analysis model of mass transfer processes and allow gas helps to justify points of control parameters and evaluate the quality work of airtanks. It will reduce the amount complex of technical equipment, increase its informativeness. The volume and composition of sewage varies continuously, depending on time of day, the operational control of the work airtank can reduce energy consumption and improve the quality of effluent.
After the phase of establishing points for sensors of dissolved oxygen
we needed electronic information collection and analysis. Electronic system must perform the following
functions:
— electrical support equipment and devices of the system;
— collection of sensor information;
— data transfer to the laboratory and dispatching station;
— storage, archiving of the data;
— maintaining records;
— data analysis and statistics summarizing the work airtank.
Restructuring scheme illustrated on Figure 4.
Figure 4— Block diagram of electronic system
Legend:
D — concentration of dissolved oxygen sensor;
DC — data controller ;
IT — interfaces transfer ;
RG — radio-gateway;
PC — personal computer;
SW — software;
DB — database
SD — supervisor device.
Consider the principle operation of the scheme. DC is constantly monitors readings of sensors, dissolved oxygen concentration (D) and stores the last results in his own memory. In view of considerable length of airtanks, provides the installation of DC for each airtank. By a certain time interval interface transfer (IT) will examine all the DC and receive data from it. Data will be transmitted to the radio gateway (RG ) for wireless transmission in the laboratory complex and the dispatcher in the compressor station. Radio gateway needed to monitor and allocate resources of the radio channel, to conduct indetification and addressing data. Set in a laboratory complex personal computer (PC) is required to operate the software (SW) system and work with the database (DB ). Manager compressor station must know the current concentration of dissolved oxygen in airtank for a controlling influence on compressor units.
III Annotation
Pilipenko D. Grounding and researching structure of the electronic system checking cut-in oxygen airtank of cleansing buildings. — Manuscript.
This work researching the mechanisms of gas exchange in airtank treatment facilities, construction and grounding mathematical models of various processes of mass transfer in order to build a structural scheme of the electronic control system of dissolved oxygen. Creating this system makes it possible to optimize power consumption of compressor stations and improve the quality of biological wastewater treatment.
Keywords: cleansing buildings, airtank, dissolved oxygen, metabolism, mass transfer, active sludge, turbulence, mathematical model.
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Completion of the master's work is scheduled for 31 December 2009.