Education

Glossary of Terms - L

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

laminar flow - The movement of fluid in a particular direction in a smooth, continuous, non-turbulent parallel layers, which do not mix with each other.

Langelier's Saturation Index - A calculated number used to predict whether or not water will precipitate, be in equilibrium with, or dissolve calcium carbonate (CaCO₃). It is sometimes erroneously assumed that any water which tends to dissolve calcium carbonate (CaCO₃) is automatically corrosive.

LAS - Linear Alkyl Sulfonate

lead (Pb) - A heavy metal that is hazardous to health if breathed or swallowed. Its use in gasoline, paints, and plumbing compounds has been sharply restricted or eliminated by federal laws and regulations.

leakage - The presence in the effluent of the type of ions, present in the feedwater to be treated, which the ion exchange process was supposed to remove. Sometimes caused by caused by incomplete regeneration, excessive flow rates, low temperatures, the concentration or characteristics of the influent ions, or other factors. (See hardness leakage.)

lime (CaO) - A calcined chemical material, calcium oxide (CaO).

lime scale - Hard water scale formed in pipes and vessels (generally more severe on the hot water side) containing a high percentage of calcium carbonate (CaCO₃) or magnesium carbonate (MgCO₃).

limestone - A sedimentary rock composed mostly of calcium carbonate (CaCO₃), and usually some magnesium carbonate (MgCO₃).

linear alkyl sulfonate (LAS) - A term applied to a family of straight chain chemical compounds, widely used as detergents; sometimes called "soft" detergents because they are more readily degraded to simpler substances by biological action than the previously used alkyl benzene sulfonate. (See detergent, alkyl benzene sulfonate.)

liter - The basic international metric unit of volume measure; 3.785 liters equal 1 U.S. gallon; 1 liter of water weighs 1000 grams at 4° Celsius at standard atmospheric pressure.