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