Glossary of Water and Wastewater Terms

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 Symbols and Numbers

5 random terms from our glossary

Nitrification Stage (NYE-truh-fuh-KAY-shun)

A stage of decomposition that occurs in biological treatment processes when aerobic bacteria, using dissolved oxygen, change nitrogen compounds (ammonia and organic nitrogen) into oxidized nitrogen (usually nitrate). The second-stage BOD is sometimes referred to as the nitrification stage (first-stage BOD is called the carbonaceous stage).

Bedding

The prepared base or bottom of a trench or excavation on which a pipe or other underground structure is supported. Also see MANHOLE BEDDING and SELECT BEDDING.

Oxidation State/Oxidation Number

In a chemical formula, a number accompanied by a polarity indication (+ or –) that together indicate the charge of an ion as well as the extent to which the ion has been oxidized or reduced in a REDOX REACTION.

Due to the loss of electrons, the charge of an ion that has been oxidized would go from negative toward or to neutral, from neutral to positive, or from positive to more positive. As an example, an oxidation number of 2+ would indicate that an ion has lost two electrons and that its charge has become positive (that it now has an excess of two protons).

Due to the gain of electrons, the charge of the ion that has been reduced would go from positive toward or to neutral, from neutral to negative, or from negative to more negative. As an example, an oxidation number of 2– would indicate that an ion has gained two electrons and that its charge has become negative (that it now has an excess of two electrons). As an ion gains electrons, its oxidation state (or the extent to which it is oxidized) lowers; that is, its oxidation state is reduced. Also see REDOX REACTION.

Polarization

The concentration of ions in the thin, boundary layer adjacent to a membrane or pipe wall.

Particulate (par-TICK-yoo-let)

A very small solid suspended in water that can vary widely in size, shape, density, and electrical charge. Colloidal and dispersed particulates are artificially gathered together by the processes of coagulation and flocculation.