1 August 2017

Wastewater treatment methods


Industry and commerce account for the vast majority of the millions of gallons of wastewater emitted into the municipal sewer system every day.


Laws are in place to protect public health and the environment and the local water authorities are clamping down on businesses to reduce the levels of FOG (fats, oils, and grease) and TSS (total suspended solids) in their municipal waste prior to off-site disposal.

Methods of treating industrial wastewater

There are several ways to treat industrial wastewater before discarding it into the sewage system. Companies are encouraged to undertake a variety of measures in order to reduce the levels of harmful by-products in the wastewater that is hazardous to the health of the population and the environment. 

In order to comply with industrial wastewater regulations, businesses are encouraged to use less water to reduce the amount of wastewater emitted into the sewage system. On top of this, companies are expected to treat water using physical, biological and chemical methods.

Physical methods of wastewater treatment 

Physical treatments are typically preliminary treatment methods which use natural forces such as gravity and electrical attraction to remove contaminants from wastewater. Methods include:

  • Separation – wastewater passes through screens to separate large solid objects from the water.
  • Filtration – organic matter is filtered out as wastewater passes through carbon granules or a sand-like material.
  • Sedimentation – gravity allows dense, heavy particles to sink to the bottom and grease and oil to rise to the top for effective removal. 

Biological methods of wastewater treatment 

Biological treatment methods are most often primary water treatment methods. During the biological treatment of wastewater, a variety of microorganisms such as bacteria are added to the wastewater. There are two methods of biological wastewater treatment:

  • Aerobic – oxidation converts soluble inorganic matter into insoluble matter by a process of aeration to break down organic substances.
  • Anaerobic – anaerobic treatment occurs in a septic tank, free of oxygen. Bacteria ‘digest’ organic matter to break it down. 

Chemical methods of wastewater treatment

Chemical treatments are secondary wastewater treatment methods and are used as a fast and effective way of removing any remaining contaminants from wastewater. The two main chemical treatments include:

  • Coagulation and flocculation – aluminum or iron precipitate particles into larger, denser pieces and gravity allows these heavier particles to sink and be separated as sludge.
  • Disinfection – disinfectants such as sodium or hydrogen chloride (chlorine) are used to ensure than any remaining harmful bacteria is removed from the water.

NCH Asia can help you to reduce downtime, increase efficiency and cut costs.

If you are in need of advice about industrial or commercial wastewater treatment processes, our wastewater specialists are happy to help.


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