Treating Wastewater: How Things Usually Happen Down There?

Sanitary water is one of the most basic human needs. However, there is only a limited amount of drinking water available for us. Thus, we need to treat and recycle water.

Wastewater collection

The first step in the treatment is the collection of wastewater. Residential and commercial pipelines drain wastewater into a collection area designated by the municipal corporation. The water is then directed to treatment plants using underground drainage systems.

Odor Control

the first step in the treatment plant is removing the obnoxious smell generated as a result of waste particles in the water. Chemicals are used to neutralize the odor causing agents and remove the smell.


By 22Kartika (Own work) [CC BY-SA 3.0 or GFDL], via Wikimedia Commons

Screening involves removing the large items present in waste water as a result of bad hygiene practices. Diapers, Tissues, Sanitary Napkins, Broken bottles etc., are collected and directed to landfills for dumping solid wastes. Grit washed down along sewer lines is removed by specially designed equipment.

Primary Treatment

By Kristian Bjornard from Baltimore, Maryland (IMGP1119) [CC BY-SA 2.0], via Wikimedia Commons

Primary treatment involves removing macrobiotic solids from the water. Large scrapers are used to collect sludge, the solid matter which settles at the bottom of the tank, and pump it out.

Secondary Treatment

The remaining water then undergoes the activated sludge process to further decontaminate it. This includes pumping seed sludge and air into the water to fuel microorganism growth which consume the organic waste. JNE Environmental develops world class water treatment systems.

Bio-solid Handling

By Steven Olswang (Own work) [CC BY-SA 4.0], via Wikimedia Commons

To remove the remaining solid, the water is passed into digesters heated at room temperature and treated for a month. Anaerobic digestion produces nutrient rich bio-solid which are drained.

Tertiary Treatment

By Qualit-E at English Wikipedia (Transferred from en.wikipedia to Commons.) [Public domain], via Wikimedia Commons

Tertiary treatment removes 99% of the remaining contamination in the water and makes it close to drinking quality. However, this stage is expensive and not all treatment facilities can afford it.


Removal of solid waste does that guarantee germ-free quality. To disinfect water, a solution of chlorine and sodium hypochlorite is used. This treatment lasts for at least 20-25 minutes and the result is potable water.

Sludge Treatment

By Moreau1Own work, Public Domain, Link

The sludge collected during primary and secondary phase of treatment is then allowed to settle and water is collected from it. This water is sent to aeration tanks for further treatment.


Leave a Reply