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What Are Sewage Effluents?

An effluent is a flow of water out of something and can be natural or man-made. For example, the Mississippi River effluent empties the water from the river into the Gulf of Mexico. When referring to sewage, effluents are man-made and are the devices used to discharge wastewater. Oftentimes, this waste is dumped into a natural flow of water, such as a river, and can be potentially harmful to the environment.

  1. Where the Waste Comes From

    • Sewage originates from the byproducts of human and industrial consumption. Water that is flushed through a toilet or that goes through any drain in a household eventually becomes sewage as it collects in the sewer system. Wastewater that comes from industrial or commercial buildings is also amassed in the same sewer system. This waste is unavoidable with the modern plumbing system used today. In recent decades, the way that the waste has been handled has been drastically improved.

    Sewage Treatment

    • In 1998, demand for regulation that was supported and influenced by the EPA (Environmental Protection Agency) started to make a difference. The Standard Sewerage Law was enacted in this year, which controlled the quality of water being dumped by sewage effluents. This law increased the required amount of treatment and set the standard on how treatment is done. Today, the EPA is responsible for leading and organizing the program.

    How Water Is Treated

    • The main problem with sewage water is that it contains a high biochemical oxygen demand (BOD). The higher the BOD, the more oxygen microorganisms needed to breakdown any natural matter found in the water. To lower the BOD, there are two steps. The first step is to simply let the sewage sit. This allows any undissolved solid waste to separate from the water. The second step is to then expose the effluent to microorganisms and oxygen. The microorganisms breakdown the harmful substances in the water and turn it into safe gases.

    Other Treatment Methods

    • The two steps outlined previously represent the majority of the action taken to treat water. However, some communities attempt to treat the sewage effluent further in order for water to be recycled even more safely. After the secondary treatment, chlorine can be added to neutralize any harmful bacteria. After this, the chlorine is removed using a chemical that counteracts and dissipates it. Finally, sometimes the water needs what is called advanced treatment, which removes any excess nitrogen or phosphorous that came about from the treatment itself.

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