The invention allows for {HEAD ~ the repeated treatment} of a gas stream to reduce {TAIL ~ the level} of mercury and other pollutants through reduction steps, allowing targeted treatment of specific compounds 
to reduce
The invention allows for { HEAD ~ the repeated treatment } of a gas stream to reduce { TAIL ~ the level } of mercury and other pollutants through reduction steps , allowing targeted treatment of specific compounds
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH