210 / | HD | LIQUID PURIFICATION OR SEPARATION |
600 | DF | PROCESSES {14} |
660 | DF | .~ Ion exchange or selective sorption {8} |
690 | DF | .~.~ Sorbing organic constituent {1} |
691 | DF | .~.~.~ From aqueous material {2} |
692 | DF | .~.~.~.~ Utilizing synthetic resin {1} |
693 | .~.~.~.~.~ Oil removed |