New device for air disinfection with a shielded UV radiation and ozone

A. Martinovs¹*, L. Mezule², R. Revalds¹, V. Pizica¹, V. Denisova², A. Skudra³, G. Kolcs¹, E. Zaicevs¹ and T. Juhna²

¹Rezekne Academy of Technologies, Faculty of Engineering, Atbrivosanas aleja 115, LV-4601 Rezekne, Latvia
²Riga Technical University, Water Research and Environmental Biotechnology laboratory, P.V. Valdena 1-303, LV-1048 Riga, Latvia
³University of Latvia, Institute of Atomic Physics and Spectroscopy, Jelgavas iela 3, LV-1004 Riga, Latvia
*Correspondence: andris.martinovs@rta.lv

Abstract:

Indoor air disinfection has become particularly relevant recently because of the Covid-19 pandemics. A shielded device for air and surface disinfection with UV radiation and ozone has been developed. It contains 28 low intensity (11 W) UV lamps (254 nm) in a specially designed three-dimensional grid to provide a large flow cross-sectional area and long path for the air particles to be irradiated. The device can be used in medical institutions, veterinary clinics, manufacturing plants, public premises, poultry, and livestock farms. It does not generate air-ions and ozone concentrations do not exceed the allowed 8-hour average values. The large number of UV lamps and powerful fans ensure air disinfection in large rooms in a relatively short time (400 m3 h-1). Simultaneously, the floor surface under the appliance is disinfected. Disinfection efficiency tests demonstrated 99.9999% reduction for Escherichia coli, Staphylococcus aureus and Pseudomonas phage Φ6 aerosols within a single transfer through the system (10 seconds of treatment). The housing of the device protects from direct UV radiation; therefore, people can be in the room during the operation of the device.

Key words:

air ions, disinfection, ozone, prototype, UV radiation

Changes in air ions concentration depending on indoor plants activity

N. Siņicina* and A. Martinovs

Rezekne Academy of Technologies, Faculty of Engineering, Atbrīvošanas aleja 115,
Rēzekne, LV-4601, Latvia
*Correspondence: natalija.sinicina@rezekne.lv
Abstract. Lack of negative ions in the air can cause deterioration

Abstract:

Lack of negative ions in the air can cause deterioration of the health which is described in many scientific articles. At the same time, an air saturated with negative ions can improve the state of health and provide a comfortable indoor environment. In addition, there are considerable evidences that drowsiness, apathy, headache etc. get even worse indoors, and these health problems may be effectively eliminated with a help of moderate concentrations of negative ions. Literature sources and earlier researches state that plants may be able to produce a variety of air ions, including negative light ions. The most plants emit different types of volatile organic compounds, and the indoor plants can improve the air quality: they effectively remove organic pollution and reduce the number of microorganisms in the air by releasing phytoncides. In this article, the regularity of influence of plants on the number of ions in the room is being proved, basing on a series of experiments performed with the following plants: Spathiphyllum, Pinus mugo, Aloe arborescens, Chlorophytum comosum, Cactaceae opuntia.

Key words: