Stress in wastewater treatment refers to the conditioning of microorganisms to produce the most efficient BOD removal possible. Suspension velocity is the aggregation of particulate material in a two-step sequential process. Settling can be accelerated by use of air in a grit chamber and increased by the reduction of air in a clarifier. Sample of sludge solution from the aeration basin. Volume decrease of sludge is what is looked at.
Temperature is a measure of average random energy.
Toxicity testing involves the study of chemical agents that cause diminished health and death in organisms. The only valid tests to prove toxicity are conducted on living specimens. In testing water quality, fat head minnows and clams are most widely used to determine toxicity levels of various components. Toxins are any of a variety of unstable, poisonous compounds produced by some microorganisms that cause certain diseases or physical reactions. Valves are mechanical devices that allow or impede the movement of a liquid or a gas.