| Abstract [eng] |
Indoor air quality is an influential factor in human health. To achieve a standard of comfort, it is necessary to have an interaction of variables, such as the optimization of relative humidity, temperature, and measurements of indoor air quality. Another important factor is the need for air renewal in the environment. Low rates of air exchange in indoor environments cause a considerable increase in chemical and biological pollutants in the air. Chemical products comprising volatile organic compounds, particulate matter, and others are released into the air from everyday products, various constructions, and processing tools. The largest is fresh construction materials. In general, it is common to spend more time working, living, or in leisure activities indoors. Nowadays, this topic is gaining more and more attention in debates and research, such as the concern to reduce its risks, as it is a matter of public health. For these reasons, it is crucial to decide on air abatement technology to clean the air effectively and efficiently. In this master thesis, a prototype is analyzed to decompose the VOC concentration, where terpene is applied to the airflow to create an atmosphere with VOCs so that its decomposition can be investigated. This device is divided into stages: non-thermal plasma, UVC photolysis, bipolar ionization, electrostatic precipitator, and an ozone destructor. In this prototype, advanced oxidation processes are utilized to remove aerosol particles in the complex air cleaner device. The study aims to investigate the efficiency of the complex air cleaner prototype by observing how aerosol particles as a by-product of the VOCs oxidation/decomposition process are generated at different air cleaning device stages. The objectives are: An overview of scientific literature on VOCs as an indoor pollution source, as well as aerosol particles generation as a by-product of the VOCs oxidation/decomposition process and its removal technologies; To create a research plan and prepare a methodology for generated aerosol particle sampling in the complex air cleaner prototype; To evaluate the influence of individual complex air cleaner module parameters (bipolar ionization power and the number of UV lamps) on the generation of aerosol particles; To determine the dependence of the generated aerosol particle removal efficiency (efficiency of electrostatic precipitator) on the process parameters. Experiments utilized ELPI+ Dekati as an analytical instrument to measure real-time particle number concentration of the aerosol formation at each sampling point. As a result of it, the particle size distribution and total suspended particles were plotted and analyzed. The initial concentrations had smaller diameters and higher concentrations, however, when observing the data at different sampling points (after the reaction chamber where the particles passed through UVC photolysis and bipolar ionizer), it had a slighter decrease in concentration, and the influence of a number of the UVC lamps and bipolar ionizer did not appear to affect the relationship of increase in gas-to-particle conversion rate. At the last sampling measurement point, a significant decrease in concentration occurred leading to an increase in particle size. Overall, the complex air cleaner prototype had a removal efficiency of approximately 99,7%. |
