Green city solutions - a new concept for greener cities and reduction of air pollution

Particulate matter (PM), also known as particle pollution, is a complex mixture of extremely small particles that get into the air. Once inhaled, these particles can affect humans, especially their heart and lungs, and cause serious diseases. PM10 and PM2.5 mean particles which are smaller than 10 or 2.5 µm, respectively. They can be detected using an electron microscope. These particles come in many sizes and shapes and are made from various chemicals. Some are emitted directly from a source, such as buildings, cars, roads, fields, industries, smokestacks or fires. Tests with different plants were carried out at the University of Applied Sciences Dresden to reduce particle air pollution. Growth chambers with a volume of 50 m³ containing no or different plants are used. To measure the PM adsorption of plants, controlled air ventilation was installed. Results show a significantly reduced PM content in the air after passing a canopy of plants. Depending on the experimental design, the investigated plants and the air movement, a reduction of 25 up to 30% of PM was observed. The results are used to design a vertical hydroponic plant system for urban areas, called “The City Tree”.