eTutorPhysics

neutralization	chemical addition of either acid or base to a solution such that the pH is adjusted to 7.

nitrification	the conversion of nitrogenous matter or free nitrogen into nitrates and ammonia by bacteria.

nonsettleable matter	the suspended matter which neither settles nor floats to the surface of water in a period of one hour.

nonsettleable solids	wastewater matter that will stay in suspension for an extended period of time. Such period may be arbitrarily taken for testing purposes as one hour.

normal	a solution concentration of one gram equivalent per liter of solution.

normality	a measure of solution concentration expressed in equivalent weights of solute per liter of solution.

NTU	see nephelometric turbidity unit.

nutrients	materials which are considered essential to the support of biological life.

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