| Yield strain: | (english) A material deformed beyond its yield strain, no longer exhibits linear elastic behavior. See yield stress. |
| Anaerobes | (Environmental Engineering) A group of organisms that do not require molecular oxygen. These organisms, as well as all known life forms, require oxygen. These organisms obtain their oxygen from inorganic ions such as nitrate or sulfate or from protein. |
| Autotrophic | (Environmental Engineering) Organisms which utilize inorganic carbon for synthesis of protoplasm. Ecologists narrow the definition further by requiring that autotrophs obtain their energy from the sun. In microbiologist parlance, this would be a photoautotroph. See photoautotrophic and chemoautotrophic. |
| Autotrophs | (Environmental Engineering) A group of organisms capable of obtaining carbon for synthesis from inorganic carbon sources such as carbon dioxide and its dissolved species (the carbonates). This group includes plants and algae. |
| Baghouse filter | (Environmental Engineering) A fabric filter device used to remove particulate air pollutants. |
| Carbonaceous biochemical oxygen demand (CBOD) | (Environmental Engineering) The amount of oxygen required to oxidize any carbon containing matter present in a water. |
| Chemotroph | (Environmental Engineering) Organisms which obtain energy from the metabolism of chemicals, either organic or inorganic. |
| Decomposers | (Environmental Engineering) Organisms which utilize energy from wastes or dead organisms. Decomposers complete the cycle by returning nutrients to the soil or water and carbon dioxide to the air or water. |
| Disease | (Environmental Engineering) Any impairment of the normal function of an organism. |
| Equivalent | (Environmental Engineering) The mass of the compound which will produce one mole of available reacting substance. Thus, for an acid, this would be the mass of acid which will produce one mole of H+, for a base, one mole of OH-. |