Low-energy biological treatment on slowly rotating discs — simple, reliable and ideal for decentralised sewage treatment.
An RBC grows a biofilm on large discs that rotate slowly through the wastewater and the air, treating sewage with very little energy and almost no operator effort. It’s a proven, dependable choice for small communities, resorts and decentralised STPs where simplicity and low running cost matter most.
A Rotating Biological Contactor consists of closely spaced discs mounted on a shaft. As the shaft turns, the discs move alternately through the wastewater and the air.
A biofilm of bacteria grows on the disc surfaces; rotation alternately feeds it with wastewater and with oxygen from the air, so it breaks down the organic pollutants continuously.
Because the discs turn slowly and no air is blown into the tank, an RBC uses far less energy than aeration-based systems — while remaining stable and easy to run.
Wastewater is pre-treated, then treated by biofilm on slowly rotating discs, before final clarification.
Coarse screening removes rag and grit ahead of the discs.
A primary stage removes settleable solids.
Biofilm on the rotating discs breaks down organic load as it alternates through water and air.
Sloughed biofilm settles out in a final clarifier, leaving clear treated water.
Slow rotation replaces energy-hungry aeration blowers.
Few controls and stable biology — easy to run.
Robust mechanics need little attention.
Staged discs support nitrification and nutrient reduction.
A small footprint suited to decentralised sites.
Attached biofilm rides out flow and load swings.
Much lower energy and simpler operation, without blowers or sludge recycling.
Similar attached-growth robustness with even lower energy, at smaller scale.
More controlled contact and better nutrient removal in a compact unit.
For small communities, resorts and developments off the main sewer, an RBC delivers dependable sewage treatment on minimal power and attention — a practical fit where energy is costly and skilled operators are scarce.
Since 1998, CWG Watch Water Technology has delivered advanced water & wastewater solutions across Pakistan — wastewater plants, RO, demineralization, softening, filtration, specialty chemicals and complete plant engineering. With decades of experience, international technology partnerships and a proven portfolio, we design customised water and wastewater treatment solutions built specifically for Pakistan’s industrial requirements.
Tell us your flow and site, and CWG will assess whether an RBC is the most economical, low-effort route to compliant treatment.
