Thomas H Wentzler

US Patent:

50394282, Aug 13, 1991

Filed:

Mar 5, 1990

Appl. No.:

7/488643

Inventors:

Thomas H. Wentzler - The Woodlands TX
Surendra K. Mishra - The Woodlands TX
Roger N. Kust - Spring TX
E. Stuart Savage - Wexford PA

Assignee:

Tetra Technologies, Inc. - Houston TX

International Classification:

C02F 152

US Classification:

210711

Abstract:

An improved process for removing dissolved metals from waste water using a recycle high density sludge is described. Specifically, the process comprises the steps of: (1) treating waste water containing dissolved metals with a recycle stream containing alkaline surface active recycle particles to precipitate the dissolved metals on the surface of the recycle particles; (2) treating a portion of the treated waste water containing metal precipitate solids with an alkaline reagent to form alkaline surface active recycle particles; (3) recycling the alkaline treated stream containing the alkaline surface active particles; and (4) separating the portion of the stream from step (1) not treated with alkaline reagent into a water component which is free of dissolved metals and solids and a sludge component which contains solids. The improved process is further enhanced by using a solids classification step to preferentially separate finer metal precipitate particles, which are treated with an alkaline reagent and recycled, from larger metal precipitate particles, which are discarded.