| 210 / | HD | LIQUID PURIFICATION OR SEPARATION |
| 600 | DF | PROCESSES {14} |
| 702 | DF | .~ Making an insoluble substance or accreting suspended constituents {14} |
| 723 | DF | .~.~ Utilizing precipitant, flocculant, or coagulant, each with accelerator or with each other or plural precipitants, flocculants, or coagulants {3} |
| 724 | | .~.~.~ Regulating pH {1} |
| 725 | DF | .~.~.~.~> Utilizing organic precipitant |