OWP will be closed from 4:00 pm on Friday, December 20, 2024, until 8:00 am on Thursday, January 2, 2025, for Winter Break.
(All times are PST.)

If exams are submitted:	Course certificates will be mailed:
By December 13th	By December 20th
After December 20th	Early January

Please note: Postmark dates will not be honored.

Water and Wastewater Terms Beginning H

A B C D E F G H I J K L M N O P Q R S T U V W Y Z

hydroxide precipitation

A method of removing common metals from wastestreams by the precipitation process. The pH of the metal waste is increased to an optimum level for metal hydroxide precipitation. The metal precipitates are settled out of the wastestream in clarifiers and are removed from the bottom of the clarifiers as metal sludges.