DOMESTIC WASTEWATER TREATMENT PROCESS’ AUTOMATION SCHEME
[1. Информационные системы и технологии]
Автор: Abramova Alla, PhD, associated professor, National Technical University of Ukraine "Ihor Sikorsky Kyiv Polytechnic Institute", Kyiv; Skladannyy Denys, PhD, associated professor
National Technical University of Ukraine "Ihor Sikorsky Kyiv Polytechnic Institute", Kyiv
The technological scheme of the domestic wastewater treatment process, proposed in , provides for the high efficiency wastewater treatment from nitrogen and phosphorus compounds, suspended substances and organic compounds, and is also aimed at minimizing the waste generated amount by the modern technologies introduction.
The deep biological wastewater treatment device is used for treatment and averaging economic and domestic wastewater from cottages, individual residential buildings, restaurants, bars, as well as low-rise buildings located in areas where connection to the city sewage system is unprofitable or absence. The device is also used for industrial wastewater treatment, which are similar in composition with full-fledged additional purification on filters with previously cleaned wastewater loading and disinfection effluents to the standards for discharge into a normal reservoir [2, 3]. The device works as follows:
- the wastewater is divided into fractions in the receiving chamber.
- initial wastewater saturation by oxygen; at the airlift pumps, that is, under the air bubbles effect, effluents are pumped, while the biomass is not damaged;
- entering the aeration tank, the biomass becomes a balanced activated sludge, on the flakes of which the main cleaning takes place;
- spent sludge moves into the chamber, where activated sludge is stabilized;
- treatment effluents are freed from suspended particles in the secondary sedimentation tank;
- after the process, the treated effluents are discharged into a reservoir or onto the nature topography;
- the sludge becomes ecologically safe and can be used as biofuel or high-quality fertilizer in agriculture.
The provided technological solutions reliably ensure the absence of a negative impact for the sewage treatment facilities on the environment, which, if necessary, allows to reduce the sanitary protection zone to 50 m.
Based on the process’ material balance calculation [4, 5], the material flows of the scheme are calculated. Based on these calculations results, an automation scheme  is proposed, presented in figure 1.
The proposed scheme provides for the installation both local control devices and treatment process control using an industrial microcontroller. The scheme allows the use the inexpensive domestic controllers.
The liquid control levels at various treatment stages is carried out with the help of conductometric sensors, which are set by the user on the marks: "Level 1", "Level 2", "Level 3", given by the technological process conditions. LED indicators on the instrument panel are used for the fluid level visual control.
The wastewater treatment degree after passing through this sewage treatment plant with an installed automation system meets all standards and allows the purified wastewater discharge onto the terrain or nature reservoirs in the absence of a full-fledged centralized sewage system.
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