What is the full form of STP

STP: Sewage Treatment Plant

STP stands for Sewage Treatment Plant. It is a facility that receives the waste from domestic, commercial and industrial sources and filters it to remove the harmful substances that deteriorate water quality and affect public health and safety when discharged into rivers, canals, and other water bodies.

How Sewage Treatment Plant Works?

A typical STP is basically made up of a one-piece vessel that performs three different functions. It acts as a primary settlement tank, biozone chamber, and a humus chamber.

The primary settlement tank: It functions just like a septic tank as it separates the solids and liquids by allowing the liquid to move into a chamber, called the biozone chamber. The wastewater and sewage are fed into the main settlement tank where solids and liquids are separated, and the liquid is passed into the biozone chamber. In this chamber, a pump is used to aerate the waste and uses good bacteria to digest or break down the organic matter in order to purify it.

The biozone chamber: It contains the good bacteria that can breaks down the waste. It has perfect conditions for this bacteria to populate and do this job. The bacteria digest organic matter present in the liquors, which purify the water to a high level before draining.

The humus chamber: It receives the treated sewage from the biozone chamber. It allows the remaining solids if any to settle out before discharge. This chamber remains still and has sloped walls to let the solids to slide down to the bottom to dissipate. The waste, when released from the final chamber (humus chamber) is around 95% clean and is ready to be discharged into local ponds, canals and land drainage systems.