How does inDENSE® work?

The process starts with the controlled feeding of return activated sludge into hydrocyclones. Inside the cyclones, centrifugal forces separate the sludge into two fractions:

• Underflow (10–20%): a concentrated, heavier sludge fraction with excellent settling properties, which is returned to the biological process.
• Overflow (80–90%): the lighter fraction, discharged as waste sludge.

This continuous selection ensures that only the best-settling sludge—such as phosphate-accumulating organisms—remains active in the process.

Result: stable and efficient treatment

The structurally lower SVI creates a stable and robust treatment process:

• Higher sludge concentrations in the biological process
• Improved biological phosphorus removal
• Increased hydraulic capacity
• Reduced sensitivity to seasonal peaks (such as in spring)
• More efficient use of existing tank volumes

The difference is clearly visible: with inDENSE®, sludge quality is continuously optimized, resulting in better performance and a lower risk of sludge washout.

Plug & Play integration

inDENSE® is designed for easy implementation in existing installations. The compact system can be integrated with minimal modifications, delivering rapid results without long downtime or major investments.

Benefits of inDENSE^®:

• Better sludge settleability – higher hydraulic load system
• Improved biological phosphate removal
• Low investment
• Very compact system, requires little space
• Easy integration in any existing kind of activated sludge system
• Low energy consumption and no chemical consumption

BIOCOS® - Maximum treatment performance with minimal resources

BIOCOS® technology, BIOlogical COmbined System, offers a smart, sustainable and space-saving solution for biological treatment of wastewater and is a lower-cost alternative to conventional activated sludge systems. Combining the power of activated sludge with the efficiency of granular sludge, this hydraulic system is distinguished by unique sludge selection and a cyclic process, fully controlled by air.

Integration with inDENSE® technology creates a compact, fast-settling biomass that provides excellent nitrogen, phosphorus (Bio-P) and carbon removal. The result? A robust system with high effluent quality, minimal maintenance requirements and up to 25% energy savings.

Why choose BIOCOS®?

• Compact and efficient: Small floor area, rectangular tanks, no pumps or mixers.
• Low energy costs: Smart air-controlled system (airlift), with no moving parts underwater.
• High effluent quality: Biological floc filtration via sludge blanket - perfect for water reuse.
• Improved Bio-P removal: By cyclone-controlled sludge selection in combination with inDENSE®.
• Low maintenance and reliable: No mechanical parts in aeration and sedimentation.
• Space-saving design: Ideal for sites with limited infrastructure.
• Proven technology: More than 150 installations worldwide, from 1,000 to 600,000 PE.

All you need is air.
An innovative technology based on simplicity. Developed at the University of Innsbruck and now successfully applied all over the world.