{HEAD ~ A flow} of {TAIL ~ contaminated liquid phase water} migrates toward the freeze front and a concentration of impurities is established in front of the advancing freeze front 
of
{ HEAD ~ A flow } of { TAIL ~ contaminated liquid phase water } migrates toward the freeze front and a concentration of impurities is established in front of the advancing freeze front
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH