| Yield stress: | (english) A material loaded beyond its yield stress, no longer exhibits linear elastic behavior. Metals, particularly mild steel, generally have a very well defined yield stress compared to other materials. Yield stress is sometimes called yield strength. |
| Baghouse filter | (Environmental Engineering) A fabric filter device used to remove particulate air pollutants. |
| Clarifier (sedimentation basin) | (Environmental Engineering) A tank in which quiescent settling occurs, allowing solid particles suspended in the water to agglomerate and settle to the bottom of the tank. The solids resulting from the settling being removed as a sludge. |
| Coagulation | (Environmental Engineering) Particle destabilization to enhance agglomeration. |
| Colloids | (Environmental Engineering) Small particles which have a negligible settling velocity. These particles have a very small mass so gravitational force is low compared to surface frictional forces. Typical colloidal sizes range from 10-3 mm to 1 mm. |
| Compression settling | (Environmental Engineering) Settling which occurs in the lower reaches of clarifiers where particle concentrations are highest. Particles can settle only by compressing the mass of particles below. |
| Discrete settling | (Environmental Engineering) Settling in which individual particles settle independently, neither agglomerating or interfering with the settling of the other particles present. This occurs in waters with a low concentration of particles. |
| Electrostatic precipitator | (Environmental Engineering) A device which uses an electric field to trap particulate pollutants. |
| Flocculant settling | (Environmental Engineering) Settling in which particle concentrations are sufficiently high that particle agglomeration occurs. This results in a reduction in the number of particles and an increase in average particle mass. As agglomeration occurs higher settling velocities result. |
| Fluidization | (Environmental Engineering) The suspension of particles by sufficient upward velocity of the fluid. During fluidization the gravity force is overcome by a combination of buoyancy and fluid friction. |