Reconstruction of wastewater treatment plants in Kolomyia with analysis of calculation methods and technological schemes of biological wastewater treatment for nitrogen and phosphorus removal.
Students Name: Bekesha Taras Andriiovych
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: 2020-2021 н.р.
Language of Defence: англійська
Abstract: Bekesha T.A, Popadiuk I.Yu. (supervisor) "Reconstruction of wastewater treatment plants in Kolomyia with analysis of calculation methods and technological schemes of biological wastewater treatment for nitrogen and phosphorus removal". Extended annotation The project of reconstruction of wastewater treatment plants in Kolomyia, Ivano-Frankivsk region is due to unsatisfactory work of biological wastewater treatment structures. The existing complex of treatment plants for complete biological treatment of domestic wastewater built in 1985 has a design capacity of Q = 15000 m3/day. At present, the average flow of incoming wastewater is 19000 m3/day, and the concentration of suspended solids is - 67 mg/l and 45 mg/l by BOD5. These structures are currently morally and physically obsolete. The requirements for the quality of wastewater treatment (MAC) have also changed, which in accordance with European standards regulate not only the residual content in the treated water of the organic component of pollutants, but also the residual content of nitrogen and phosphorus compounds [1,2]. The composition and quality of inlet wastewater significantly affects the operation of treatment plants. Namely, low concentration of organic pollutants, variable ratio of organic component of pollution and concentration of nitrogen compounds, and significant fluctuations in the concentration of pollutants during the day negatively affect the living conditions of activated sludge and its sedimentation properties. There was a need to analyze the equipment of biological treatment structures - nitrite – denitrifier structures, settling tanks etc. To solve this problem, theoretical studies of technological schemes of biological wastewater treatment for nitrogen and phosphorus removal and methods of calculation of these structures were carried out [3,4,5,6]. In recent years, new technological schemes for biological treatment of urban wastewater have been developed. Which can solve such a problem as the removal of nutrients from urban wastewater. In the practice of wastewater treatment, there are two main nutrients: nitrogen (N) and phosphorus (P), which tend to accumulate in the biomass of activated sludge - up to 6-8% nitrogen and 2% phosphorus in the dry mass of sludge [4]. In modern practice, various methods and schemes of biological removal of nitrogen and phosphorus are used. [5]. Nitrogen and phosphorus removal technology includes three main elements: the zone of anaerobic treatment of a mixture of sludge and wastewater; anoxide zone for denitrification; oxide (aerobic) zone for nitrification. In the anaerobic zone as a result of the activity of facultative and anaerobic microorganisms of activated sludge enzymatic hydrolysis of organic pollutants contained in wastewater with the formation of volatile fatty acids, which are consumed in the same zone, accumulate phosphorus bacteria Acinetobacter. In the anoxide zone there is a process of denitrification, with the reduction of nitrates to nitrogen gas. The next aerobic zone is a nitrifier and at the same time a structure in which phosphates accumulate with Acinetobacter microorganisms present in the biocenosis of activated sludge. The more volatile fatty acids were removed in the anaerobic zone, the more phosphates will be removed by Acinetobacter bacteria in the aerobic zone [4]. All technological schemes of wastewater treatment from nutrients can be divided into two groups. The first group includes schemes with oxide channels - carousel-type (circular) aeration tanks, Biodenipho-process, UNITANK-process, cyclic schemes. The second group consists of schemes that can be implemented in conventional corridor aeration tanks. These schemes are interesting of actions on replacement of a part of existing water treatment technologies, modern technologies for the purpose of qualitative change of indicators of clearing without considerable capital expenses. Schemes for the total number of zones with mixing and aeration can be divided into two-, three-, four- and five-stage. Analysis of existing technological schemes of nitri-denitrification, namely: A/O, A2/O, VIP, UST-process (Cape Town University), Bardenpho (5-stage), Ludzak-Ettinger, etc., and Ukrainian experience in this field showed that for conditions of Kolomyia WWTP, the most appropriate is the introduction of a modified Ludzak-Ettinger-process, which is implemented in bioremediation facilities by alternating anoxide and aerobic zones and using in aeration zones a combination of suspended and immobilized on inert media cultures of microorganisms. For this, the project envisages the conversion of single-corridor aeration tanks, which are located in two units of tanks, into bioreactor nitrite denitrifiers by creating zones with different oxygen conditions in their volume. In this case, wastewater after the primary settling tanks and circulating activated sludge will enter the first anoxide zone of the bioreactor, equipped with stirrers. The second zone of the bioreactor will perform the function of aerobic. The reconstruction Kolomyia WWTP and implementation of modern high-efficiency energy-saving technological will ensure reliable operation of treatment facilities and obtain high quality indicators of wastewater treatment according to the established MAC, namely: suspended solids - 15.0 mg/l; BOD5 - 15.0 mg/l; COD - 80.0 mg/l; ammonium nitrogen - 3.0 mg/l; nitrites - 0.4 mg/l; nitrates - 10.0 mg/l, phosphates - 3.5 mg/l. Object of research: biological structures of wastewater treatment plants Subject of research: study of the experience of aeration tanks, in which technological schemes of biological removal of nitrogen and phosphorus compounds from wastewater are implemented. The purpose of the study: analysis of the influence of organic substances on the process of nitrite–denitrifier; consideration of technological schemes of biological wastewater treatment for nitrogen and phosphorus removal and methods of calculation of these structures; introduction of nitrite-denitrification biotechnology during reconstruction of Kolomyia treatment plants Research results: The project provides for measures to intensify and optimize the operation of the treatment plant. Key words: aeration tank, bioreactors, nitrification, denitrification, aerobic zone, anaerobic zone. Перелік використаних літературних джерел. 1. https://zakon.rada.gov.ua/laws/show/z0403-02 2. Zbirnyk normatyvno-pravovykh aktiv Yevropeiskoho Soiuzu u sferi okhorony navkolyshnoho seredovyshcha. – Lviv: Ekopravo, 2004. – 192 s. 3. Dolina, L. F. Ochistka stochnyih vod ot biogennyih elementov: [monografiya] / L. F. Dolina. – Dnepropetrovsk: Kontinent. 2011. – 198 s. 4. Zhmur. N. S. Tehnologicheskie i biohimicheskie protsessyi ochistki stochnyih vod na sooruzheniyah s aerotenkami / N. S. Zhmur. – M.: AKVAROS, 2003. – 512 s. 5. Vasilenko A.A. i dr. Rekonstruktsiya i intensifikatsiya sooruzheniy vodosnabzheniya i vodootvedeniya: Uchebnoe posobie / A.A. Vasilenko, P.A. Grabovskiy, G.M. Larkina , A.V. Polischuk , V.I. Progulnyiy. – Kiev – Odessa: KNUSA, OGASA, 2014. – 307s. 6. D.A. Danilovich, A.N. Epov, M.A. Kanunnikova. «Primenenie osnovnyih tehnologiy na sooruzheniyah ochistki stochnyih vod: analiz dannyih v tselyah tehnologicheskogo normirovaniya» NDT vyipusk 34, 2015. 7. ДБН В.2.5.-75: 2013 «Каналізація. Зовнішні мережі та споруди. Основні положення проектування». п.п. 10.3.2.9., Додаток Г,п. 59, 107, 110, 112, 184). 8. ATV–DVWKA 131E, 2000 9. Danilovich D.A., Epov A.N. Sravnitelnyiy analiz metodik rascheta sooruzheniy biologicheskoy ochistki stochnyih vod s udaleniem azota. Vodoochistka. Vodopodgotovka. Vodosnabzhenie. 2017. # 4. S. 28–40.