Search results
Results from the WOW.Com Content Network
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 ...
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.
The District of Columbia Water and Sewer Authority (DC Water) provides drinking water, sewage collection, and sewage treatment for Washington, D.C. The utility also provides wholesale wastewater treatment services to several adjoining municipalities in Maryland and Virginia, and maintains more than 9,000 public fire hydrants in Washington, D.C.
Sewage treatment often involves two main stages, called primary and secondary treatment, while advanced treatment also incorporates a tertiary treatment stage with polishing processes and nutrient removal. Secondary treatment can reduce organic matter (measured as biological oxygen demand) from sewage, using aerobic or anaerobic biological ...
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.
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 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.