Please Select an Alphabetical Section:

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

Section O:

organic matter--plant and animal residues, or substances made by living organisms. All are based upon carbon compounds.

osmosis--the movement of water molecules through a thin membrane. The osmosis process occurs in our bodies and is also one method of desalinizing saline water.

outfall--the place where a sewer, drain, or stream discharges; the outlet or structure through which reclaimed water or treated effluent is finally discharged to a receiving water body.

oxygen demand--the need for molecular oxygen to meet the needs of biological and chemical processes in water. Even though very little oxygen will dissolve in water, it is extremely important in biological and chemical processes.