Which of the following is NOT an air pollution control method?

The identification of ignition as a method that does not control air pollution is based on an understanding of air pollution control principles. Ignition typically refers to the process of starting a combustion reaction, which is primarily concerned with burning fuel and generating energy. While ignition can play a role in emissions (such as producing pollutants from burning fuels), it does not serve as a control method to reduce or manage air pollution.

In contrast, methods like catalytic combustion involve using catalysts to facilitate combustion reactions at lower temperatures, thereby lowering the formation of harmful emissions. Filtration refers to the removal of particulate matter from gases by passing them through a physical barrier, effectively controlling the release of pollutants into the air. Distillation, while primarily a separation process, can also be involved in treating gaseous emissions from various processes to separate and remove volatile organic compounds and other harmful substances.

Thus, ignition does not fit within the framework of air pollution control methods, while the other options are all recognized techniques that actively work to reduce air pollutants.