Efficiency Evaluation of Wastewater Treatment Plants in Kėdainiai and Rokiškis Towns

Tyrimo objektas – Kėdainių ir Rokiškio miesto nuotekų valyklos. Tyrimo tikslas – nustatyti, įvertinti ir palyginti Kėdainių ir Rokiškio miestų nuotekų valyklų veikimo efektyvumą prieš ir po rekonstrukcijos. Darbo uždaviniai: 1. Surinkus esamus tyrimų duomenis nustatyti, įvertinti ir palyginti Kėdainių ir Rokiškio miestų nuotekų valyklų efektyvumą prieš ir po rekonstrukcijos; 2. Atlikti surinktų duomenų statistinę analizę; 3. Nustatyti priklausomybes tarp teršiančių medžiagų koncentracijų atitekančiose ir ištekančiose nuotekose; 4. Nustatyti teršiančių medžiagų koncentracijų po nuotekų valymo priklausomybes nuo temperatūros; 5. Nustatyti Pb ir Nb koncentracijų priklausomybes ištekančiose nuotekose nuo BDS7/Pb ir BDS7/Nb santykio atitekančiose nuotekose. Tyrimo metodai: Kėdainių ir Rokiškio miestų nuotekų valyklos efektyvumui nustatyti buvo atliekama nuotekų užterštumo analizė atsižvelgiant į biocheminio (BDS7) ir cheminio deguonies (ChDS), skendinčių medžiagų (SM), bendro azoto (Nb) ir bendro fosforo (Pb) koncentracijas prieš užterštų nuotekų valymą ir po valymo. UAB „Kėdainių vandenys“ ir UAB „Rokiškio vandenys” laboratorijose surinkti 2008–2011 metų tyrimų duomenys apdoroti naudojant Microsoft Excel 2007 ir STATISTICA programas. Tyrimo rezultatai: Pirmajame skyriuje aprašomas nuotekų tvarkymas Lietuvoje, nuotekų tvarkymo būdai ir jų efektyvumas, pagrindinės nuotekų užterštumo charakteristikos, reikalavimai išleidžiamoms nuotekoms ir nuotekų valymo metu susidariusio dumblo panaudojimo būdai. Antrajame skyriuje nurodomas darbo tikslas ir uždaviniai. Trečiajame skyriuje aprašomi tyrimo objektai, pateikiama teršalų nustatymo nuotekose ir surinktų nuotekų valyklose duomenų apdorojimo metodika. Ketvirtajame darbo skyriuje yra pateikiami tyrimo rezultatai. Pateikiamos pagrindinės aprašomosios statistikos, analizuojamas nuotekų valyklų efektyvumas bei teršalų koncentracijų prieš nuotekų valymą ir po valymo priklausomybės. Taip pat įvertinama teršiančių medžiagų koncentracijų priklausomybė nuo temperatūros, Pb ir Nb priklausomybė ištekančiose nuotekose nuo BDS7/Pb ir BDS7/Nb santykio. Analizuojant 2008–2011 metų Rokiškio ir Kėdainių miestų nuotekų valyklų charakteristikas nustatyta, kad didžiausias valymo efektyvumas buvo pagal BDS7 ir ChDS ir siekė 88,1–99,6 %. Abiejose miesto nuotekų valyklose nuotekos po rekonstrukcijos valomos efektyviai, išskyrus Nb Kėdainių miesto nuotekų valykloje, kur metinė DLK (15 mg/l) buvo viršyta 1–2 mg/l.Object of the research: wastewater treatment plants in Kėdainiai and Rokiškis towns. Aim of the research work: to determine, evaluate and compare the efficiency of the wastewater treatment plants in Kėdainiai and Rokiškis towns before and after their reconstruction. Objectives: 1. Following the research data, to determine, evaluate and compare the efficiency of the wastewater treatment plants in Kėdainiai and Rokiškis towns before and after their reconstruction; (Why do you repeat the aim??) 2. To carry out the statistical analysis of the obtained research data; 3. To determine the proportion of pollutant concentrations in the incoming wastewater and in the effluent; 4. To determine how the pollutant concentrations that are found after the wastewater treatment are affected by temperature; 5. To determine how the Pt and Nt concentrations in the effluent depend on the proportion of BOD7/Pt and BOD7/Nt in the incoming wastewater. The research methods: to determine the efficiency of the wastewater treatment plants in Kėdainiai and Rokiškis towns, the analysis of the wastewater contaminants was performed considering the following data: concentrations of biochemical (BOD7) and chemical oxygen (COD), suspended solids (SS), total nitrogen (Nt) and total phosphorus (Pt) that were fixed before and after the contaminated wastewater treatment. The data of the research, which was carried out and stored in the laboratories of UAB Kėdainių vandenys and UAB Rokiškio vandenys in 2008–2011, were processed using the Microsoft Excel 2007 and STATISTICA programmes. The research results: The first unit introduces the wastewater management in Lithuania, its methods and effectiveness, the main characteristics of wastewater pollution likewise requirements for the effluent and utilization of the sludge resulting from the wastewater treatment. The second unit specifies the aim and the objectives of the research work.. The third unit describes the research objects and provides the data processing techniques that determined the wastewater pollutants. The fourth unit of the research work introduces the research results. It also provides the main descriptive statistics, the analysis of effectiveness of the wastewater treatment plants, and describes the proportions of pollutant concentrations before and after the wastewater treatment. The unit also deals with the dependence of the pollutant concentrations on the temperature and determines the Pt and Nt dependence on the ratio of BOD7/Pt and BOD7/Nt in the effluent. When analysing the characteristics of the wastewater treatment plants in Rokiškis and Kėdainiai towns in 2008-2011, it has been found out that the greatest wastewater treatment efficiency according to BDS7 and COD amounted to 88.1–99.6 per cent. After the reconstruction, both urban wastewater treatment plants have been effectively operating, except for one parameter in the wastewater treatment plant of the Kėdainiai town (the annual MPL of Pt (15 mg/l) has been exceeded by 1–2 mg/l).Žemės ūkio akademijaVytauto Didžiojo universiteta

Aukšto dažnio stačiakampių impulsų elektroporacijos sistemos kūrimas ir tyrimas

The dissertation provides the research and development of the high-frequency square wave pulse electroporation system and proposes a topolgy of planar electroporation electrodes for real-time electroporation applications. An analysis and applied research of the electrical pulse forming circuits, the electric field generation technologies and the compensation circuits for high-frequency transient as well as the electric field distribution of planar electroporation electrodes are carried out. The introductory chapter deals with the problem of the thesis, research goals and newness, describes the research methodology and defended statements. The first chapter presents the most relevant scientific literature related to the main subjects of this dissertation. The electroporation phenomena and the dependence of the cell response on electrical pulses duration and frequency are presented. The review of submicrosecond and nanosecond electric pulse generators and high-frequency transient process compensation circuits are also presented. This Chapter concludes in formulating tasks the dissertation. The second chapter presents simulation models of the high-voltage, high-frequency submicrosecond pulsed electric field (nsPEF) generator and planar electrodes for real-time electroporation. The SPICE model of pulse forming circuit is developed and the effects of the parasitic circuit elements and transient processes to the generated electric pulse are investigated. The chapter includes the potential applications and needs of the planar electrodes for electroporation. The topology of planar electrodes and its influence on electric field homogeneity are analysed using finite element method (FEM) in COMSOL Multiphysics environment. The third chapter presents the research and development of novel high-frequency square-wave electroporation system. The developed system can produce single and bursts deliver adjustable square-wave electric pulses with load independent pulse fall time. The pulse amplitude, repetition frequency and pulse duration can be adjusted accordingly up to 3 kV, from 1 Hz to 3.5 MHz and from 100 ns to 1 ms. In this chapter, the system simulation and the experimental results are compared. The prototype system is successfully tested for the inactivation of the human pathogen Candida albicans. The main results of the thesis were published in 6 scientific articles: three – in scientific journals included in Clarivate Analytics Web of Science database with impact factor, two – in international conference publications which are referred by Clarivate Analytics Web of Science database Proceedings, one article is printed in peer-reviewed scientific journal listed in Index Copernicus database. The research results were presented in 10 scientific conferences.Doctoral dissertatio

Development of planar electrodes for real-time electroporation / Planariųjų elektrodų modelis realiojo laiko elektroporacijos tyrimams

In this paper the concept of planar electrodes for real-time electroporation on a microscope stage is presented and the structure is analyzed using finite element method (FEM) analysis. A multiparametric investigation of the chip topology is performed in COMSOL Multiphysics environment to define the configuration of electrodes, electric field distribution and other electroporation parameters to ensure a homogeneous cell exposure. Based on the simulation results, an optimal electrode configuration, which is suitable for the investigation of the permeabilization thresholds during electroporation, is proposed. Santrauka Šiame straipsnyje pristatomas planariųjų elektrodų, skirtų realiojo laiko elektroporacijos tyrimams, ant mikroskopo objektinio staliuko baigtinių elementų modelis. Pasiūlytas daugiaparametrio elektrodų lusto topologijos tyrimas atliekamas „COMSOL Multiphysics“ aplinkoje, siekiant nustatyti tinkamą elektrodų konfigūraciją, elektrinio lauko pasiskirstymą ir kitus elektroporacijos parametrus, kuriems esant būtų užtikrintas tolygus ląstelių poveikis. Remiantis modeliavimo rezultatais, siūloma optimali elektrodų konfigūracija, kuri užtikrina pakankamą permeabilizacijos slenkstinę įtampą elektroporacijos tyrimų metu. Reikšminiai žodžiai: elektroporacija, permeabilizacija, elektrinis laukas, planarieji elektrodai, COMSOL modelis, modeliavimas

Validation of a SPICE Model for High Frequency Electroporation Systems

In this paper, we present an analysis and a validation of a simulation program with integrated circuit emphasis (SPICE) model for a pulse forming circuit of a high frequency electroporation system, which can deliver square-wave sub-microsecond (100–900 ns) electric field pulses. The developed SPICE model is suggested for use in evaluation of transient processes that occur due to high frequency operations in prototype systems. A controlled crowbar circuit was implemented to support a variety of biological loads and to ensure a constant electric pulse rise and fall time during electroporation to be independent of the applied buffer bioimpedance. The SPICE model was validated via a comparison of the simulation and experimental results obtained from the already existing prototype system. The SPICE model results were in good agreement with the experimental results, and the model complexity was found to be sufficient for analysis of transient processes. As result, the proposed SPICE model can be useful for evaluation and compensation of transient processes in sub-microsecond pulsed power set-ups during the development of new prototypes.This article belongs to the Section Circuit and Signal Processin

3 H activity comparison between FTMC, VNIIM and LNE-LNHB

Proceedings of the 20th International Conference on Radionuclide Metrology and its Applications (ICRM), 6-11 June 2015, Vienna, Austria. Organizer TU Wien. Editors Franz-Josef Maringer, Dirk Arnold, Uwe Wätjen.International audienceAn activity comparison of tritiated water was organized in 2013 between 3 laboratories: FTMC (Lithuania), LNE-LNHB (France) and VNIIM (Russia). The solution was prepared by LNHB and ampoules were sent to the others laboratories. This solution was standardized in terms of activity per unit mass by participant laboratories using the Triple to Double Coincidence Ratio (TDCR) method in liquid scintillation counting (LSC). The tritiated water solution is traceable to the solution prepared by LNHB for the CCRI(II)-K2.H-3 2009 H-3 international comparison

Concepts and Capabilities of In-House Built Nanosecond Pulsed Electric Field (nsPEF) Generators for Electroporation: State of Art

Electroporation is a pulsed electric field triggered phenomenon of cell permeabilization, which is extensively used in biomedical and biotechnological context. There is a growing scientific demand for high-voltage and/or high-frequency pulse generators for electropermeabilization of cells (electroporators). In the scope of this article we have reviewed the basic topologies of nanosecond pulsed electric field (nsPEF) generators for electroporation and the parametric capabilities of various in-house built devices, which were introduced in the last two decades. Classification of more than 60 various nsPEF generators was performed and pulse forming characteristics (pulse shape, voltage, duration and repetition frequency) were listed and compared. Lastly, the trends in the development of the electroporation technology were discussed.This article belongs to the Special Issue Electroporation Systems and Application

Holistic view of needs and requirements of multi-market flexibility trading

publishedVersionPeer reviewe

Planar inductor for biological experimentation in pulsed magnetic fields

In this paper we present the novel design of the multilayer planar inductor for biological experimentation in pulsed magnetic fields. The presented planar inductor, together with developed high voltage generator, is capable to deliver 1T homogeneous magnetic fields in the volume of 17 µl with pulse repetition frequency up to 10 kHz. The finite element methods were applied to evaluate the magnetic field distribution and heat dissipation of proposed multilayer planar inductor under aluminium dioxide Al2O3 substrate. The computed and experimental results are presented as wel

High-frequency submicrosecond electroporator

In this work, we present a novel electroporator which is capable of generating single and bursts of high power (3 kV, 60 A) square wave pulses of variable duration (100 ns to 1 ms) with predefined repetition frequency (1 Hz to 3.5 MHz). The proposed synchronized crowbar implementation ensures a constant pulse rise and fall times, which are independent from the load, thus highly relevant in electroporation. The electroporator was successfully tested for the inactivation of the human pathogen Candida albicans. The device is compatible with standard commercial electroporation cuvettes