Biochar Amendment in the Green Roof Substrate Improve Air Quality

Abstract

In this paper, biochar was added to the green roof in order to study the effect of biochar amendment on improving the air quality. Simulation experiments showed that biochar treatments can reduce the concentration of CO2 by 7.3-28.8%, CO by 10.6-20.7%, SO2 by 9.8-21.6%, and NO2 by 2.1-11.5% in the micro-environment. Outdoor monitoring experiments showed that biochar can reduce 24.0-46.6% of PM2.5, 3.7-23.3% of PM1.0, and 17.3-38.4% of PM10. In addition, the high temperature is the main factor affecting the adsorption of small particles. Structural equation analysis showed that biochar mainly absorbed the particulate matters and harmful gases by reducing the surface temperature, increasing the humidity and promoting the plants growth.