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