Tallinn University of Technology

Laboratory of Environmental Technology

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The Laboratory of Environmental Technology of the Department of Materials and Environmental Technology was formed in the Tallinn University of Technology on the base of the former Chair of Environmental Protection and Chemical Technology of the Department of Chemical Engineering during the 2016-17 structural reform. As a legitimate continuation of the named Chair, the Laboratory deals primarily with water, air and soil treatment, with the main stress on the implementation of the Advanced Oxidation Processes (AOPs), offering students various research topics on Bachelor's, Master's and Doctoral studies level. Possessing up-to-date analytical equipment, the Laboratory is always open for co-operation with other facilities and enterprises. Additionally, the staff of the Laboratory takes active part in teaching activities.

professor Sergei Preis
Phone 620 3365


Research activity

The main research area of the Laboratory of Environmental Technology is the treatment of air, water and soil mostly with so-called Advanced Oxidation Processes (AOPs). This concept is applied to a range of different oxidative technologies, the common feature of which is the formation and employment of a powerful oxidant, hydroxyl radical (HO•).

In the Fenton process, hydroxyl radicals are obtained by the degradation of hydrogen peroxide with ferrous ions in acidic media. Additionally, there are numerous Fenton-like processes, using elementary iron or iron oxide particles, other metals, neutral media, or different radical sources, e.g. persulphates. The Fenton process and its modifications may be used for water and soil treatment.

Photocatalysis is defined as acceleration of a photochemical reaction by a catalyst. While various metal oxides may be employed as photocatalysts, titanium dioxide and titania-based materials should be specifically noted due to optimal combination of high performance and high chemical stability. Irradiated photocatalyst surface produces oxidants, including hydroxyl radicals. Photocatalysis may be used to treat water and air. From oxygen-free solutions, green fuel, hydrogen and low molecular weight hydrocarbons may be produced; additionally, artificial photosynthesis forming organic compounds from carbon dioxide is also possible.

Ozonation exhibits its performance based on ozone oxidation potential. In water treatment, however, hydroxyl radicals are formed as a rule upon ozone decomposition playing a far more important role. Ozonation has been successfully employed in water treatment business.

Application of gas-phase pulsed corona discharge (PCD) plasma to water and air treatment presents another AOP developed at the Laboratory. The essence of the process consists of the contact with highly ionized plasma, to which water is brought in the form of shower – jets, droplets and films passing through the PCD zone. Utilizing the energy of short-living reactive oxygen species (ROS), radicals, ions and atomic oxygen in surface reactions with aqueous pollutants makes the approach beneficial in oxidation energy efficiency surpassing commercial ozonation by the factor of minimum two.

In addition, various combinations of the abovementioned processes are studied in the Laboratory of Environmental Technology, as well as their combinations with biological treatment providing efficient and cost-effective treatment.

The pollutants being the objects of degradation are both so-called priority pollutants (oil, fuel compounds and additives) and priority micropollutants (mostly pharmaceuticals); in the gaseous phase, the degradation of volatile organic compounds (VOCs) is being studied.


Equipment and Services

The Laboratory of Environmental Technology possesses all the up-to-date equipment necessary for the analyses  of water, air and soil: high-performance liquid chromatograph with diode array detector and mass-spectrometer (HPLC-PDA-MS), liquid chromatorgaph with UV-VIS detector (HPLC-UV-VIS), gas chromatograph with flame ionisation detector (GC-FID), gas chromatograph with mass-spectrometer (GC-MS), ionic chromatograph (IC), luminometer, Fourier transformance infrared spectrometers (FTIR), electrochemical and infrared gas analyser, total organic carbon (TOC) analyser, spectrophotometers, not to mention more ordinary equipment like automatic pipettes, balances, pH-meters, dissolved oxygen meters, etc.

In the Laboratory, large amounts of analyses are done which are used in the environmental technology: chemical oxygen demand (COD), biochemical oxygen demand (BOD), total organic carbon (TOC), total nitrogen (TN) and its various constituents, dissolved ions, hardness, individual pollutants and their groups, differnt volatile organic compounds, and others.

During the course of their studies and research work, students can get acquainted to all of the mentioned equipment and perform respective analyses, thus obtaining practical knowledge of modern equipment.

Theses defended

2022, Priit Tikker. Optimization of Aqueous Media Treatment with Pulsed Corona Discharge: Hydrodynamics and Kinetics Conformed with the Discharge Parameters and Energy Efficiency. Supervisor: Sergei Preis.

2022, Liina Onga. Combination of advanced oxidation methods for the energy-efficient abatement of aqueous and gaseous hazardous pollutants. Supervisor: Sergei Preis.

2021, Maarja Kask. Combination of advanced oxidation methods for the energy-efficient abatement of aqueous and gaseous hazardous pollutants. Supervisors: Juri Bolobajev, Marina Kritševskaja.

2020, Balpreet Kaur. Development of photo-induced persulfate-based processes for efficient application in water treatment. Supervisor: Niina Dulova.

2018, Eneliis Kattel. Application of Activated Persulfate Processes for the Treatment of Water and High-Strength Wastewater. Supervisors: Niina Dulova, Marina Trapido.

2017, Natalja Pronina. Degradation of Persistent Micropollutants in Suspended-Bed Reactor by Photocatalytic Oxidation and Combination of Biological Treatment with Photocatalysis. Supervisor: Marina Kritševskaja.

2017, Liina Kanarbik. Ecotoxicological Evaluation of Shale Fuel Oils, Metal-Based Nanoparticles and Glyphosate Formulations. Supervisors: Marina Trapido, Irina Blinova.

2016, Juri Bolobajev. Effects of organic reducing agents on the Fenton-like degradation of contaminants in water with a ferric sludge reuse. Supervisors: Anna Goi, Marina Trapido.

2015, Irina Epold. Degradation of pharmaceuticals by advanced oxidation technologies in aqueous matrices. Supervisors: Marina Trapido, Niina Dulova.

2014, Marika Viisimaa. Peroxygen Compounds and New Integrated Processes for Chlorinated Hydrocarbons Degradation in Contaminated Soil. Supervisor: Anna Goi.

2014, Olga Budarnaja. Visible-light-sensitive Photocatalysts for Oxidation of Organic Pollutants and Hydrogen Generation. Supervisor: Deniss Klauson.

2012, Aleksandr Dulov. Advanced oxidation processes for the treatment of water and wastewater contaminated with refractory organic compounds. Supervisor: Marina Trapido.

2012, Svetlana Jõks. Gas-Phase Photocatalytic Oxidation of Organic Air Pollutants. Supervisor: Marina Kritševskaja.

2010, Deniss Klauson. Aqueous photocatalytic oxidation of non-biodegradable pollutants. Supervisor: Sergei Preis.

2009, Elina Portjanskaja. Photocatalytic oxidation of natural polymers in aqueous solution. Supervisor: Sergei Preis.

2008, Niina Kulik. The Application of Fenton-Based Processes for Wastewater and Soil Treatment. Supervisor: Marina Trapido.

2005, Anna Goi. Advanced oxidation processes for water purification and soil remediation. Supervisors: Rein Munter, Marina Trapido.

2003, Marina Kritševskaja. Photocatalytic Oxidation of Organic Pollutants in Aqueous and Gaseous Phases. Supervisor: Sergei Preis.

2022, Helina Prükk. Degradation of 1-ethyl-3-methylimidazolium chloride in aqueous solution by advanced oxidation processes. Supervisors: Niina Dulova; Dmitri Nikitin.

2022, Roman Fadejev. Degradation of metformin by advanced oxidation processes. Supervisors: Niina Dulova; Dmitri Nikitin.

2022, Arina Borissenko. Oxidation of toluene by pulsed corona discharge in air-water mixtures followed by photocatalytic exhaust air purification. Supervisors: Juri Bolobajev, Maarja Kask.

2021, Kätlin Eeron. Degradation of tramadol by advanced oxidation processes. Supervisor: Niina Dulova.

2021, Jaana Ehiloo. Removal of iron, manganese, ammonium, and radionuclides from drinking water using HMO-technology - a pilot study. Supervisors: Juri Bolobajev, Siiri Salupere.

2021, Heleene Hollas. Study on hydrogen peroxide activation methods for the development of disinfectants. Supervisors: Juri Bolobajev, Siimu Rom.

2021, Marten Jaanimets. Development of liquid density measurement standard by hydrostatic weighing method at National Metrology Institute of Estonia AS Metrosert. Supervisors: Marina Kritševskaja, Kristjan Tammik.

2021, Glory Adedotun Oladele. Photochemical oxidation of vancomycin in aqueous solution. Supervisor: Niina Dulova.

2021, Sofia Pereskoka. Application of ferrocene aerogel and iron-doped organic aerogel in Fenton-like and photolytic processes for oxidation of N-nitrosodiethylamine and trimethoprim in water - a comparative study. Supervisors: Maarja Kask, Juri Bolobajev.

2021, Kristel Sepp. Analysis of treatment alternatives for hazardous liquid wastes in Estonia. Supervisor: Marina Kritševskaja.

2021, Julia Vinogradova. Modern technologies for air disinfection. Supervisor: Marina Kritševskaja.

2021, Anne Mari Kääp. Degradation of oxalate in water by pulsed corona discharge and hydrogen peroxide combination. Supervisors: Priit Tikker, Niina Dulova.

2021, Eteri Libe. Nanomaterials application in environmental technology and related environmental problems. Supervisor: Marina Trapido.

2021, Kaja Markin. Non-traditional applications of ozone. Supervisor: Marina Trapido.

2020, Chika Constance Ogumka. Oxidation of Acid Orange 7 and Indigotetrasulfonate Textile dyes with Pulsed Corona Doscharge: Impact of Treatment Conditions. Supervisors: Sergei Preis, Liina Onga.

2020, Dmitri Nikitin. Oxidation of bisphenol A by pulsed corona discharge: impacts of plasma-liquid contact surface and a surfactant radical scavenger. Supervisors: Sergei Preis, Priit Tikker.

2020, Daniil Gornov. Degradation of herbicide alachlor using pulsed corona discharge. Supervisors: Sergei Preis; Juri Bolobajev.

2020, Aleksandra Kuznetsova. Heavy metal removal technologies from water and wastewater. Supervisor: Eneliis Kattel-Salusoo.

2020, Mirjam Lätt. Degradation of oxalic acid in water by pulsed corona discharge in combination with persulfate. Supervisors: Niina Dulova, Priit Tikker.

2020, Ave Jalakas. Degradation of antibiotics in aqueous solution by ozone-based processes. Supervisor: Niina Dulova.

2020, Kaie Eha. Photochemical oxidation of losartan in aqueous solution. Supervisors: Niina Dulova, Balpreet Kaur.

2020, Dmitri Ivanov. Gas-phase photocatalytic activity of spray-pyrolysis-synthesized TiO2 thin films modified by increased amount of acetylacetone in precursor solution. Supervisors: Marina Kritševskaja, Jekaterina Spiridonova.

2020, Anna Setskaja. Mass transfer of ozone and its decay in semi-continuous reactor: a case study. Supervisor: Juri Bolobajev.

2020, Marko Jaaksaar. Application of ozonation, photolysis and O3/H2O2 combination for the oxidation of N-nitrosodimethylamine and N-nitrosodiethylamine - a comparative study. Supervisors: Juri Bolobajev, Maarja Kask.

2020, Lisett Kiudorv. Determination of nitrosodimethylamine and nitrosodiethylamine in water samples using solid phase extraction combined with gas chromatography-mass spectrometry. Supervisor: Juri Bolobajev.

2019, Kristen Altof. Comparison of Biogas Upgrading Methods Based on the Operating Parameters of Refining Technologies. Supervisor: Marina Kritševskaja.

2019, Jevgenia Eichmann. Photocatalytic oxidation of toluene and acetaldehyde on TiO2 thin films synthesized by spray-pyrolysis. Supervisor: Marina Kritševskaja.

2019, Jüri Kristjan Käen. Degradation of micropollutant dibutyl phthalate in water by combination of ozone and ultraviolet irradiation. Supervisor: Juri Bolobajev.

2019, Natalja Matskevitš. Characterization of gas-phase photocatalytic activity of spray pyrolysis-synthesized TiO2 thin films coatings by oxidation of acetone and heptane. Supervisor: Marina Kritševskaja.

2019, Irina Petrotšenko. Effect of ozone on photocatalytic degradation of acetone vapour on P25 TiO2 coating. Supervisors: Marina Kritševskaja, Maarja Kask.

2019, Svetlana Puustusmaa. Photochemical oxidation of endocrine disrupting compound in artificial and natural water matrix. Supervisors: Niina Dulova, Balpreet Kaur.

2019, Tatjana Rein. Technologies for dairy wastewater treatment. Supervisor: Marina Trapido.

Research projects

ERA-MIN3 Joint Call 2021 project (01.02.2022−31.01.2025)

Co-operation partners: Bowmen Consulting, s. r. o., United Energy, a. s., Sokolovská uhelná, právní nástupce, a.s., AV EKO Color, s. r. o., and University of Chemistry and Technology Prague (Czech Republic); ETI Aluminyum, Arslan Aluminyum, Yeditepe University and Istanbul Technical University (Turkey); KTH Royal Institute of Technology (Sweden); Public University of Navarra (Spain).

ABtomat project aims at the aluminum products development derived from aluminum-containing industrial wastes - mining and manufacturing tails. Often not designed for pure metal extraction, the recovery methods are able to produce useful and doable aluminum-containing compositions, such as coagulants, alumo-silicate and zeolite catalyst supports and adsorbents, testing of which lays on the Laboratory of Environmental Technology of Tallinn University of Technology. Testing is planned in water/wastewater treatment applications, as well as in photocatalytic systems for air cleaning.

Personal Research Funding, Team Grant (01.01.2020-31.03.2021)

Abatement of refractory pollutants at maximum energy efficiency is feasible using cold pulsed corona discharge (PCD) plasma combined with catalytic/photocatalytic processes. The development of utmost efficient technology presents an objective in oxidation of highly potent anthropogenic micro-pollutants, carcinogenic nitroso substances and volatile compounds in water, air and excess sludge, improving disintegration of the latter. The experimental research in PCD combined with Fenton-like oxidation and gas-phase photocatalysis establishing the process parameters determining the treatment efficiency, reaction paths and limitations is undertaken. Quantitative assessment of the top-efficiency process parameters in abatement of various pollutants comprises a prerequisite for the widening of PCD applicability, up-scaling and improved safety. The approach presents a strategic breakthrough in application of energy-saving human-friendly technology in water supply and environment protection. 

EU LIFE programme project (02.10.2017−30.09.2021)

The project partners are Fundación CARTIF - Applied Research Centre (Spain), CIESOL - Research Centre (Spain), DIPALME - Diputaciόn de Almeria (Spain), University of Tartu (Estonia), Viimsi Vesi AS (Estonia).

The ALCHEMIA project addresses one of the current challenges of water for human consumption such as the presence of natural radioactivity. There is a considerable lack of knowledge by the actors involved and it can be stated that, despite the current legislation (Directive 2013/51/Euratom), radioactivity is not systematically monitored at the European level. However, this is an environmental problem that cannot be solved at source, as it is generated by the groundwater dilution of minerals rich in radioactive isotopes, mainly from uranium (U), radium (Ra) and thorium (Th) series. Thus, the main objectives of the project are: (1) to demonstrate the technical and economic feasibility of filtration (HMO) process that will be optimized to remove radioactivity from water and to minimize the waste generation defined as Naturally Occurring Radioactive Materials (NORM) exceeding the exemption level at three pilot plants in Spain and one in Estonia; (2) to replicate the project solutions in facilities of other five European countries (Italy, Poland, Finland, etc); (3) to encourage the implementation of the Directive 2013/51/Euratom.


Interreg Baltic Sea Region Programme 2014-2020 project (01.03.2016−28.02.2019)

Co-operation partners: Luonnonvarakeskus Luke, Suomen ympäristöopisto SYKLI, Länsi-Uudenmaan vesi- ja ympäristö ry (LUVY) and Novago Yrityskehitys Oy (Finland); Latvijas Universitate and Salacgrīvas novads (Latvia); Aleksandro Stulginskio Universitetas and Šilutės rajono savivaldybė (Lithuania); Instytut Technologiczno – Przyrodniczy and Urząd Gminy Sokoły (Poland); Kuusalu Municipality Government and Kuusalu Soojus OÜ (Estonia).

The main challenge of this project is to find the most cost-effective and environmentally friendly wastewater treatment solutions for the scattered dwelling households not connected to urban wastewater plants in order to decrease wastewater emissions into the Baltic Sea to the level set by the forthcoming EU water legislation. The main objective is to support the needs of households to avoid unnecessary investments and operating costs when shifting to improved wastewater treatment and thus encourage them to implement new treatment systems. Wastewater treatment systems will be assessed for technological, economic, environmental and social aspects in order to find out the potentially best-fitting systems for the improved wastewater treatment in the households of scattered dwelling regions. Preparation of the user-friendly information tool is the most important result of the project. It will provide the best-fitting suggestions for wastewater treatment systems meeting the circumstances and the priority criteria set by any individual user primarily in the partner countries.


Institutional Research Funding (01.01.2013−31.12.2018)

Micropollutants in water bodies, streams and groundwater are considered as a very urgent problem in the European Union. It is possible to avoid spreading of micropollutants in the water bodies and streams only through advanced purification of wastewater. Advanced oxidation technologies (AOTs) are the most suitable technologies as their main advantage is a rapid chemical oxidation of contaminants. The current project aims to extend AOTs application to environment protection from priority pollutants and emerging micropollutants. The goal is to elaborate technologies for their removal from water/wastewater and soil. The improvement the efficiency of AOPs will be achieved by introducing novel oxidants, catalysts and renewable energy sources (solar radiation) to power the process. The chemical engineering approach to optimisation of processes is used. The outcome of the research will provide the scientific basis and recommendations for AOPs implementation for micropollutants’ control.