We are talking on how to make cities of the future “smart” and green with Tatiana Krupnova, Associate Professor of the SUSU Department of Ecology and Chemical Engineering, Senior Research Fellow of the Laboratory for Studying Environmental Problems in Post-industrial Agglomerations.
– At the beginning of the 20th century, only 13% of the population lived in cities, and a century later already more than half of the population. Is urbanization inevitable?
– Yes, by 2050 two thirds of the world’s population will live in big cities. The point is, first of all, that cities are economically profitable. By 2025, 440 cities with a population of 600 million people, that’s 7% of the world’s population, will be accounted for half of the world’s GDP. At the same time, the history of human development has shown that cities are extremely adaptive. Cities are resilient entities that can survive wars and disasters. Cities can transform in such a way so as to allure people with prospects and glaze. And also, cities represent a harsh reality, a life of stretching oneself beyond limit. The time in cities flies at an unprecedented speed, thereby forcing to live to the limit of capabilities, provoking stress and mental illnesses. In cities, environmental problems are acutely manifested, especially the problem of air pollution in large cities.
– In this regard, does Russia differ from other countries?
– Most large cities in our country are industrial cities, they are unique urban ecosystems. The massive clustering of industrial enterprises in a small area and the lack of planning often makes them centres of environmental problems. Unfortunately, very few interdisciplinary scientific research studies in the field of sustainable urban development are conducted in Russia.
– So, this means that the only salvation is the American dream, a cottage in the suburbs?
– Why so? There are certain advantages in the density of a city centre. Paradoxical as it may sound, there is an opinion that comparing to scattered suburbs, cities are winning. Cities emit less pollutants and consume less energy than scattered settlements. Density reduces the negative impact on nature. Densification is an effective way to achieve environmental sustainability. There are also studies that have shown that people who live closer to the city centre tend to be happier, healthier, and less obese.
– In your opinion, how will the city of the future look like?
– This summer, my colleagues and I attended the 7th International Regional Economics Conference “Cities of New Age: GLASS”, organized by the Institute of Economics of the Ural Branch of the Russian Academy of Sciences in Yekaterinburg. Over three days, more than one and a half hundred regional scientists from Russia, America, and China have been discussing concepts that would help shape the image of the city of the future.
The GLASS concept was proposed: the city should become Green, Livable, Amiable, Smart, Sustainable. A set of these 5 named parameters (GLASS) allows to take a comprehensive look at the urban system: fragile, but, at the same time, strong. This approach to urban development simply captivated me.
– Many people heard about smart cities. These have become part of the everyday life of our planet’s population in the early 2020s with the development of the IoT (Internet of Things) technologies. How can smart sensors transform the city of the future?
– Yes, modern digital environment suggests such a solution as smart cities. Millions of built-in sensors will allow artificial intelligence to coordinate transport, minimize crime and reduce environmental pollution. And to improve the ecological state of cities, so-called nature-like technologies are widely used.
– It seems like one only needs to plant as many green plants as possible. Or is an accurate calculation also needed here?
– It may seem that one just needs to plant more trees and the air will become cleaner, but things are not that simple. First, it is not always possible to plant a large number of trees in dense urban areas, and seedlings take root very poorly in open areas, along busy highways, where they are exposed to high concentrations of car exhaust gases. The plants themselves help in monitoring atmospheric pollution. Plants that are especially susceptible to negative environmental factors are called bioindicators or biomonitors. At the same time, of course, they also serve as phytoremediators: they reduce the level of air pollution. It is important to create programs allowing to use them most effectively.
– Can ordinary city trees serve as bioindicators?
– Yes. The leaves of city trees absorb fine dust best. On the websites of meteorological centres, you can sometimes find the PM10 and PM2.5 indicators: dust particles no larger than 10 and 2.5 micrometers, respectively.
The research studies of our laboratory have shown that birch leaves collected near the metallurgical enterprises of the city contain extremely high concentrations of zinc, and zinc is deposited not from the soil, but from the air as part of the very PM10 and PM2.5 dust particles that we imperceptibly inhale.
That’s why it’s so important to take the fallen leaves out of the city, and not leave them on the lawns.
However, trees do not always absorb dust from the air equally well. We investigated the ability of urban greenery to reduce lead concentrations in the same PM10 and PM2.5. An analysis of satellite images did not reveal a connection between the level of landscaping and lead contamination. But ground-based studies have led to the conclusion that the more birch trees are planted in an urban environment, the less lead-containing dust appears in the air.
In our study, the needles of evergreen pine needles absorbed such dust the least. We solved the riddle using an electron microscope: the stomata of the needles were clogged with anti-icing agents accumulated on the roads during the winter, and therefore the needles did not absorb fine dust with lead from the air.
– Could you please tell us about other “smart” innovations for monitoring and cleaning the air that your research team has developed?
– For example, this is the “Smart Tree”: a device for air purification, which is a body with moss panels containing a filter substrate, an irrigation system, a ventilation system, and phytolamps. Moss cleans the air from polluting gases and sensors monitor the state of the environment.
Another invention is a sensor for low concentrations of formaldehyde. It is known that city trees emit isoprene, which then, as a result of a chain of chemical reactions, turns into dangerous formaldehyde. Our device (which is a substitution for equipment from Finland and America) allows to continuously monitor the content of this dangerous pollutant in the air and detect the danger earlier, before it exceeds the official MPC figures.
There is also one more interesting case. We managed to synthesize a paint that uses nature-like fine dust absorption technology. In nature, dust is absorbed by stomata located on the leaves of trees. Our silicate paint, after drying, forms a porous coating, which, like the stomata of tree leaves, absorbs PM10 and PM2.5 particles from the air. Thus the facades covered with this paint will purify the air. The composition of the paint is currently at the stage of patenting, we have filed the application to Rospatent.