Pollution control is the process of reducing or eliminating the release of pollutants into the environment . It is regulated by various environmental agencies which establish pollutant discharge limits for air, water, and land. Air pollution control strategies can be divided into two categories, the control of particulate emissions and the control of gaseous emissions. There are many kinds of equipment which can be used to reduce particulate emissions. Physical separation of the particulates from the air using settling chambers, cyclone collectors, impingers, wet scrubbers , electrostatic precipitators, and filtration devices, are all processes that are typically employed.