| Suspended growth reactor | (Environmental Engineering) A reactor in which the microorganisms are suspended in the wastewater. Examples of suspended growth reactors are activated sludge reactors and anaerobic digesters. See attached growth reactor. |
| Total dissolved solids | (Environmental Engineering) (TDS) is the amount of dissolved matter in the water. |
| Total solids | (Environmental Engineering) (TS) is the amount of organic and inorganic matter which is contained in a water. |
| Total suspended solids | (Environmental Engineering) (TSS) is the amount of suspended (filterable) matter in a water. |
| Ultimate biochemical oxygen demand (BODu) | (Environmental Engineering) The total amount of oxygen required to oxidize any organic matter present in a water, i.e. after an extended period, such as 20 or 30 days. |
| Volatile solids | (Environmental Engineering) (VS) is the amount of matter which volatilizes (or burns) when a water sample is heated to 550EC.Volatile suspended solids |
| Wastewater | (Environmental Engineering) Consumed or used water from a municipality or industry that contains dissolved and/or suspended matter. |
| Wetland | (Environmental Engineering) Semi-aquatic land, that is land that is either inundated or saturated by water for varying periods of time during each year, and that supports aquatic vegetation which is specifically adapted for saturated soil conditions. |
| AAC - Autoclaved Aerated Concrete | (Concrete Engineering) Exceptionally lightweight precast concrete with high thermal qualities and fire resistence. Suitable for cutting with ordinary hand tools. Mix design is composed of portland cement, sand or siliceous material, lime, gypsum, finely powdered aluminum, and water. Initial mix is a combination of portland cement, sand, lime and gypsum to produce a slurry. Finely powdered aluminum mixed into a paste is added prior to placement into large, rail-like forms. The finely powdered aluminum reacts with the alkaline components of the cement and lime to produce hydrogen gas, which increases the volume approximately five times producing a uniformly, dispersed cellular structure. Units are cut to required shape. Units are placed in an autoclave, an enclosed pressurized chamber, and steam cured at 3500 F. Approximately 80% of the ultimate volume consists of air voids. |
| Absolute Volume | (Concrete Engineering) The volume of an ingredient in its solid state, without voids between individual pieces or particles, in the case of fluids, the cubic content occupied. In concrete, the actual volume occupied by the different ingredients determined by dividing the weight of each ingredient pounds, by ifs specific gravity, times the weight of one cubic foot of water in pounds. Example: Absolute Volume of one sack of cement equals: 94 ๗ (3.15X62.4) = 0.478 cubic feet |