the amount of oxidant injected in each port is effective to reduce the content of {HEAD ~ organic matter} in {TAIL ~ the stream} by a predetermined amount in the primary stream, and 
in
the amount of oxidant injected in each port is effective to reduce the content of { HEAD ~ organic matter } in { TAIL ~ the stream } by a predetermined amount in the primary stream , and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH