Ecological environment is the key condition to support human life and maintain sustainable development. Environment protection is not only the important issues of common concern to the whole world, but also an important share responsibility for human. Since the 18th century Industrial revolution, serious air pollution events have occurred in many countries around the world. In order to learn the lessons of the air pollution, and summary the experiences on the treatment of air pollution, the major air pollution events occurred and the treatment measures of air pollution in some countries around the world were introduced in the paper. The efforts for control the China's air pollution was also described. The developments and requirements on air pollution control were discussed.

This paper discusses electrostatic precipitation for fine particle emission control. According to the so-called electrostatic precipitator (ESP) index, a novel ESP sizing method is presented for both mechanical and electrical specifications. By using threephase rectifier transformer power sources, ESPs give very high collection for fine particle emission control. The ratio of PM_2.5 over PM₁₀ is between 6% and 20%. When PM₁₀ emission is around 5-15 mg/m³, PM_2.5 is below 2.5 mg/m³. By upgrading ESP and flue gas desulfurization (FGD), particle emissions can be reduced to below 5 mg/m³, and PM_2.5 below 2.5 mg/m³.

This paper discusses PM₁₀ and PM_2.5 emission reduction by upgrading four-filed electrostatic precipitators (ESPs) with a 660 MW coal-fired power generator. By using a traditional single-phase high-voltage rectifier transformer (T/R), the PM, PM₁₀ and PM_2.5 emissions are around 75, 63 and 23 mg/m³, respectively. After upgrading the T/R by using a three-phase T/R, the PM, PM₁₀ and PM_2.5 emissions drop below about 18, 15 and 2.5 mg/m³, respectively. Their reduction efficiencies are around 76%, 76% and 89%, respectively.

This paper discusses how to upgrade electrostatic precipitators (ESPs) with four 330 MW coal-fired generators. For the two four-field ESPs, the upgrading includes replacement of high-voltage electrodes and the high-voltage power sources. For the two five-field ESPs, only the power sources are retrofitted. The ESP outlet PM₁₀ and PM_2.5 emissions are less than 15 and 2 mg/m³, respectively. The flue gas desulfurization (FGD) can be effective for PM₁₀ emission reduction, but not for PM_2.5. This paper also presents the rapping and gas temperature effects on particle emission. When reducing the gas temperature from 150-160℃ to about 110℃, PM_2.5 emission from the ESP or FGD is always less than 2 mg/m³.