Water management design of a self-service car wash for 5 posts in Lviv, Lviv Region
Students Name: Kosarev Dmytro Volodymyrovych
Qualification Level: magister
Speciality: Hydrotechnical Construction, Water Engineering and Water Technologies
Institute: Institute of Civil Engineering and Building Systems
Mode of Study: full
Academic Year: 2023-2024 н.р.
Language of Defence: ukrainian
Abstract: In the master’s qualification work, a complex of water management structures has been developed. During the development, construction, and operation of the complex of water management structures, the focus is on improving technologies and methods to achieve maximum efficiency and economy. The main task is to use advanced methods of hydraulic calculation to optimize the elements of the complex. Regardless of the water pressure in the system and the number of operating bays, the distribution of detergent expenses is evenly distributed across all bays. Regulation of these expenses is carried out through remote internet access, minimizing unauthorized access to technological equipment. Dosing valves and devices are made of stainless steel, which increases their effective usage life and operational reliability. The system guarantees rational use of detergents and the possibility of effective control. The water preparation and accumulation system consists of two inlet mechanical water filters, pumps to equalize the inlet pressure, a two-column softener, and a reverse osmosis system integrated into the electronic control system. The equipment set includes two accumulation tanks (1000 liters each), preventing a shortage of demineralized water. The minimum pressure in the water supply system is 3 bar, and the water temperature for the production process should be within 5-40 °C. Local sewage treatment facilities consist of a system of concrete septic tanks, including a water receiving tray (sand trap), a sedimentation tank for suspended substances, an oil product separator, and a sampling tank. The connection of the septic tanks is made using PVC pipes for external drainage. Land area - 1,608.00 m? Landscaping area - 667.50 m? Area for collecting rainwater (streets, driveways, roofs) - 1,003.20 m? The properties of water incoming for domestic and industrial needs from an alternative source were subjected to chemical analysis using water from well No. 1, with a sampling depth of 9.30 meters. Chemical composition of the water: Total hardness - 15.00 mg-equiv/l Hydrogen ion concentration pH - 6.7 Mineralization - 1245.5 mg/l Water softening is performed using a factory-made filter. The choice falls on the Ecosoft FK1035CABCEMIXC filter, which has a productivity of 1.5 m? of purified water per hour. The system operates automatically, and its maintenance is limited to timely addition of tablet salt to a 1000 mm diameter tank (1.0 m). Water after use (car washing) enters the drainage tray and undergoes the first stage of purification (sand trap) - suspended substances - 200 mg/l, oil products - 55 ml/l, BOD - 80 mg/l, pH - 6.5...8.5. Then, the wastewater enters the suspended substance sedimentation tank (second stage of purification). After that, the wastewater enters the oil product separator, then into the circulating water tank where a pump is installed for reusing the treated water. Upon entering the water supply system, the reused purified water enters the reverse osmosis filter. The aim of the scientific research part of the work is to study the impact of the coagulation process and filtration through sand-gravel loading on the quality of car wash wastewater. Object of study - wastewater of the car wash at the car service station. Subject of study - the process of coagulation and filtration through sand-gravel loading of car wash wastewater. To achieve the goal of the work, the following research tasks are set: Characterize the methods of wastewater treatment of the car wash. Characterize the physicochemical indicators of the quality of car wash wastewater. Determine the optimal dose of coagulant for cleaning car wash wastewater. Determine the effect of cleaning car wash wastewater (according to the main quality indicators) by coagulation and filtration through sand-gravel loading. Conclusions The process of purifying car wash wastewater by a combined method of coagulation and filtration through sand-gravel loading has been studied. As a result of the treatment mentioned above, the following quality indicators of wastewater decreased by 100%: concentration of suspended substances, BODtotal, COD, sulfates, as well as oil and oil products. The turbidity of wastewater decreased by 98%, mineralization - by 48%, electrical conductivity - by 42%, and pH - by 3.7%. The salt content of the wastewater did not change during treatment. The obtained results are important for further design of the wastewater treatment process of real car washes. Keywords: wastewater, sewage treatment facilities, sewage pumping station, car wash, water preparation facilities, reconstruction.