Study on winter air pollution control in Lanzhou, China

Air pollution control is one of the most important issues in the cities of the developing countries. Based on an analysis of the local economic and te chnological development the paper puts forward 9 air pollution control sche mes. They are 4 briquette schemes, 2 coal gas schemes, 1 centralized heatin g system and 2 comprehensive schemes. A comprehensive diffusion model combi ned with a 3-D advection-diffusion equation and the Gaussian puff model is developed and verified. According to the calculation of potential reduction of pollutant discharge and the corresponding air quality improvement made by each air pollution control scheme, the paper then works out a feasible a nd comprehensive air pollution control scheme, which is characterized by lo w investment and better environmental benefits. When the scheme is efficien tly carried out, 19.3% SO2 and 24.4% soot discharge is to be reduced annual ly in the city. There is a clear descent of air pollution concentration. Th e daily mean concentration of SO2 and TSP declines 24.6-75.4% and 10.4-45.4 %, respectively. SO2 concentation of the whole city does not exceed the sec ond grade of the Ambient Air Quality Standard of China except at a few grid points.