Glossary - Index [ 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 ] acid: a substance
with a quantity of positively charged hydrogen ions. acid rain:
rain with a pH of less than 5.6; results from atmospheric
moisture mixing with sulfur and nitrogen oxides emitted from
burning fossil fuels; may cause damage to buildings, car
finishes, crops, forests, and aquatic life. aeration: exposing
to circulating air; addition of oxygen to wastewater or water,
as in first step of both activated sludge wastewater treatment
process and drinking water treatment. agriculture: farming,
science of cultivating the soil, producing crops, and raising
livestock. aquifer: porous, water-bearing layer of sand, grave),
and rock below the Earth’s surface; reservoir for groundwater.
aquatic: living or growing in or on water. aquitard: a low-
permeability layer of rock or clay that can store water but
transmits it very slowly from aquif