|  | C |
SECTION C — CHEMISTRY AND METALLURGY

CHEMISTRY

|  | C02 |
TREATMENT OF WATER, WASTE WATER AND SEWAGE (distilling, filtering, separating Fulltext... Hierarchy... Expanded...B01)

|  | C02B |
TREATMENT OF WATER, e.g. PURIFICATION (adding materials to water to prevent corrosion of metals Fulltext... Hierarchy... Expanded...C23F)

|  | C02C |
TREATMENT OF SEWAGE AND WASTE WATER (Fulltext... Hierarchy... Expanded...C02B takes precedence)

|  | C02D |
WATER IMPREGNATED WITH CARBON DIOXIDE OR OTHER GASES