Search results
Results from the WOW.Com Content Network
Secondary treatment (mostly biological wastewater treatment) is the removal of biodegradable organic matter (in solution or suspension) from sewage or similar kinds of wastewater. [ 1 ] : 11 The aim is to achieve a certain degree of effluent quality in a sewage treatment plant suitable for the intended disposal or reuse option.
In 1968—1969 a study conducted by Metcalf and Eddy, under the auspices of the State Water Control Board, determined that water quality deterioration in the reservoir was caused by substandard wastewater discharges from 11 secondary wastewater treatment plants and non-point sources of pollution. Following the commissioning of UOSA, the water ...
Vermifilters are most commonly used for sewage treatment and for agro-industrial wastewater treatment. [1] Vermifilters can be used for primary, secondary and tertiary treatment of sewage, including blackwater and greywater in on-site systems and municipal wastewater in large centralised systems.
The basic national standard for U.S. municipal treatment plants is the Secondary Treatment Regulation. [2] Most plants in the U.S. must meet this secondary treatment standard. The permit authority (state agency or EPA) can compel a POTW to meet a higher standard, if there are applicable water quality standards for the receiving water body.
The term sewage treatment plant (STP) (or sewage treatment works) is nowadays often replaced with the term wastewater treatment plant (WWTP). [7] [8] Strictly speaking, the latter is a broader term that can also refer to industrial wastewater treatment. The terms water recycling center or water reclamation plants are also in use as synonyms.
The RBC process allows the wastewater to come in contact with a biological film in order to remove pollutants in the wastewater before discharge of the treated wastewater to the environment, usually a body of water (river, lake or ocean). A rotating biological contactor is a type of secondary (biological) treatment process.
In the treatment of sewage, systems composed of anaerobic ponds followed by facultative ponds usually have overall BOD removal efficiencies between 75 and 85%. Higher efficiencies are difficult to achieve because the effluent contains high concentrations of particulate organic matter, in the form of algae, naturally produced during treatment.
The aeration stage and the disinfecting stage are the primary differences from a traditional septic system; in fact, an aerobic treatment system can be used as a secondary treatment for septic tank effluent. [1] These stages increase the initial cost of the aerobic system, and also the maintenance requirements over the passive septic system.