Method of purifying waste water

US4396463A · kind A · utility

Assignee

• Centre De Recherches Metallurgiques-Centrum Voor Research in De Metallurgie · BE

Inventors

• Christian Josis · Gembloux, BE
• Andre Hans · Waremme, BE
• Theophile Martens · Ertvelde, BE

Key dates

• Filing date: Mar 10, 1981
• Grant date: Aug 2, 1983
• Expiry date: Mar 10, 2001

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C02F1/048
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A method of purifying waste water, for example waste water from a coking plant, comprises supplying waste water to be purified to the upper part of a stripping column comprising a plurality of substantially horizontal plates disposed above one another, supplying vapor to the lower part of the column, and supplying a strong base to the column laterally at one or more levels, wherein the water to be stripped is passed downwardly from the top of the column across a number of successive plates sufficient to permit the pH of the water to decrease to a value below 7, and wherein the base is supplied at a level or levels lower than that at which the pH has decreased to the above value.