环境工程专业英语uni

3 Biological Wastewater TreatmentApplication of microbial degradation and removal of undesirable co

3Biological Wastewater Treatment Application of microbial degradation and removal of undesirable constituents in industrial and municipal wastes is not anew con__pt. It is commonly used pro__ss for general wastewater treatment activities and has been for __ny years. As the awareness of chemical contamination of the enviro__ent, much research on biological degradation of toxic chemicals has occurred. Among the range of treatment technologies, biological degradation ranks among the most effective. Its __nagement and application is enhan__d by the potential to apply biological treatment in sequen__ with other chemical and ther__l pro__sses. Activated sludge The activated sludge pro__ss is stypical type of suspended growth biological treatment system and probably the most widely used biological pro__ss for the treatment of organic and industrial wastewaters. However, it can only treat aqueous organic wastestreams h__ing less than 1% suspended solid content, and can not tolerate shock loading of con__ntrated organics. Therefore, the wastestream entering this pro__ss will usually h__e passed through apretreatment pro__ss which includes aclarifier (pri__ry clarifier) and an equalization basin. The pri__ry clarifier is used for removal of grit, oily and fatty __terial and gross solid __terial, while the equalization basin is used to dampen wastewater flow variations and to provide more uniform organic loading to the activated sludge system. Activated sludge pro__ss are used to treat municipal and industrial wastes sin__ they are versatile, flexible, and can be used to produ__ an effluent of desired quality by varying pro__ss parameters. The pro__ss was so-named because it produ__s an active __ss of microorgani__s capable of aerobically stabilizing awaste. __ny versions of the