In wastewater treatment, aeration is often the single largest energy consumer, sometimes accounting for more than half of the total plant energy usage. At the heart of many aeration systems lies the Roots blower, a robust and reliable machine designed to deliver consistent airflow under varying process conditions.

Selecting the correct Roots blower is not simply a matter of choosing a capacity or matching a pressure rating. It requires a deeper understanding of process requirements, system dynamics, and the interaction between mechanical and biological performance.

Roots blowers are classified as positive displacement machines. Unlike centrifugal blowers, which depend on dynamic energy transfer, Roots blowers move a fixed volume of air per revolution. This makes them particularly suitable for applications requiring stable and predictable airflow.


In wastewater treatment plants, Roots blowers are commonly used in:

  • Equalization tanks (Mixing),
  • Aeration and Nitrification Tank, 
  • Airlift RAS System,
  • Scouring & Backwashing systems of MBR,
  • Sludge Holding

Their primary role is to supply oxygen to microorganisms that break down organic pollutants. The effectiveness of this process depends not only on the amount of air delivered but also on how efficiently it is distributed within the system.

CFD Roots Blower In wastewater treatment, aeration is often the single largest energy consumer, sometimes accounting for more than half of the total plant energy usage. At the heart of many aeration systems lies the Roots blower, a robust and reliable machine designed to deliver consistent airflow under varying process conditions

Basic Working Principle of Roots Blower

A Roots blower operates using two counter-rotating lobes inside a casing. As the lobes rotate:

  1. Air is drawn into the inlet at low pressure
  2. Air is trapped in pockets between the lobes and casing
  3. The trapped air is carried to the outlet
  4. Air is discharged against system pressure

It is important to note that compression does not occur internally in the same way as in a screw compressor. Instead, pressure builds up when the transported air meets resistance at the discharge side.

This characteristic leads to several important implications:

  • Flow rate is relatively constant
  • Pressure is system-dependent
  • Efficiency is influenced by downstream system.

Selecting a Roots blower for wastewater treatment is not just about matching specifications. It is about understanding how airflow, pressure, and system dynamics interact.

A well-selected blower ensures:
  • Stable operation
  • Energy efficiency
  • Long-term reliability
Engineering decisions are often influenced by the need for quick solutions. However, wastewater treatment systems are inherently complex.

A blower is only one part of a larger ecosystem and true optimization requires understanding:
  • Process requirements
  • Mechanical performance
  • System interaction

More importantly, it supports the overall performance of the treatment process.

In many cases, the best solution is not replacing equipment, but improving system balance.

---



PT HINEKO CITRA MADANI
Water & Wastewater Technology

We provide engineering solutions for efficient and reliable wastewater treatment systems.
For consultation and system evaluation: