Bulgarian scientists invented a filter which purifies air from mechanical, chemical and biological pollutants.
The hydro-cyclone system has been developed entirely by Bulgarian scientists and is a completed technology for destruction of viruses and bacteria, including COVID-19, PhD student Viktor Stoyanov told the Bulgarian National Radio.
The effectiveness of the technology is protected by a number of patents. It was not designed specifically for COVID-19 and is used for many purposes. The first prototype was made back in 2006 in a bioengineering laboratory, the Bulgarian scientist adds.