Used to remove chlorine from solution or as a titrant for determination of dissolved oxygen by the Winkler method.
All of the solids in the water, including dissolved, suspended, and settleable components.
A relative measure of the ability of a chemical to be toxic. Usually refers to the ability of a substance to kill or cause an adverse effect. High toxicity means that small amounts are capable of causing death or ill health.
A particular class of poisons, to which the body may respond by the production of antitoxins.
Presence of suspended or colloidal matter or planktonic organisms that reduces light penetration of water.