Q.Suggest two engineering or technological methods that industries use to reduce particulate emissions from their exhaust stacks before the gases are released into the air.

Two widely used engineering methods for reducing particulate emissions from industrial stacks are electrostatic precipitators and bag (fabric) filters. An electrostatic precipitator gives suspended particles in the exhaust stream an electric charge and then passes the stream between oppositely charged collector plates, which attract and hold the charged particles so that only cleaned gas continues out of the stack. A bag filter instead forces the exhaust gas through a fine woven fabric mesh, physically trapping particles the way a household vacuum-cleaner bag traps dust while letting air pass through. Wet scrubbers, which pass the gas through a spray of water or slurry, are a third commo …

Name the mechanism each method uses (electrical charge vs physical filtration) so the two methods …

Confusing stack-level particulate control (precipitators, filters, scrubbers) with tailpipe gas-phase control (catalytic conver …