Wastewater treatment Process

Two big problems faced by our world today are water scarcity and water pollution.

Out of total amount of water on earth only 0.01% is available as fresh water and human demand for water is far much greater than this! Additionally, this 0.01% available fresh water is getting polluted at a very high rate.

Nature amazingly can cope with water pollution but only when it is in small amounts.

Thus to solve the problems of water scarcity and water pollution, solution such as wastewater treatment has been brought up and needs to be used extensively.

What is wastewater treatment?

Wastewater treatment is a process wherein wastewater (used water) is treated using a number of treatment procedures. This treated water can be either returned to water cycle to minimize environmental issues or reused.

Wastewater treatment Process Steps

At Perfect Pollucon Services, treatment of wastewater is carried in four stages to remove pollutants from it. These stages are;

  • Preliminary treatment
  • Primary treatment
  • Secondary treatment
  • Tertiary treatment

The general procedure of treatment of wastewater remains same for sewage of municipal or industrial origin. Depending upon the grade of water quality slight modifications are made in the procedure.

The following flowchart represents the general process of treatment of wastewater.

Wastewater treatment Process

Wastewater treatment plant

Wastewater treated in wastewater treatment plants almost follow the same process for treatment of wastewater but, depending upon the wastewater, treatment plants can be classified into two.

  • Sewage treatment plant (stp)
  • Effluent treatment plant (ETP)

Sewage treatment plant (STP)

A sewage treatment plant is preferred for wastewater of domestic or municipal origin.

The solid by-product from the STP is used as compost or manure and the treated water is usually put used for flushing or gardening purposes. Thus in this way STP is helping to solve the problem of water scarcity, water pollution and waste management.

Effluent treatment plant (ETP)

An effluent treatment plant is preferred for wastewater of industrial origin. For small scale industries a common wastewater treatment plant is usually set up to treat industrial effluent to minimize pollution load on water bodies. These common waste water treatment plants are known as CETP (common effluent treatment plant).

To further decrease the pollution load on water bodies, technology such as ZLD (zero liquid discharge) has been introduced.

Zero liquid discharge (ZLD)

ZLD is a process where no effluent or no discharge is left over. This means that technologies are used to purify and recycle all wastewater coming in the plant for treatment. The following figure developed at perfect pollucon services shows the process of zero liquid discharge.

Wastewater treatment
Figure: process of zero liquid discharge
Note: – reject means remaining untreated wastewater


Wastewater treatment was initially started to treat wastewater for release into the water bodies, to reduce pollution levels. The wastewater released is treated under standard levels prescribed by central pollution control boards.

Now a days, to reduce water pollution and water scarcity problem, waste water treatment in industries have started incorporating zero liquid discharge (ZLD). The government of India has also made it mandatory to have waste water treatment plant (STP) in high rise residential and commercial buildings. We perfect pollucon services offer services in designing, commissioning & upgradation of effluent/sewage treatment plants for residential and commercial buildings.

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