Following more than a decade of successful application worldwide, the AquaNereda® Aerobic Granular Sludge Technology is now available in the United States and Canada. This advanced biological treatment technology utilizes unique features of aerobic granular biomass including superior settling properties when compared to conventional activated sludge. Additional advantages translate into a flexible, compact and energy efficient process.

The Development of Nereda®

A public-private research partnership in the Netherlands between the world-renowned Delft University of Technology, research institutes, water authorities and Royal HaskoningDHV led to the invention of the first technology applying aerobic granular sludge for the treatment of wastewater.

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Aqua-Aerobic Systems Inc. is the exclusive U.S. and Canada provider of Nereda® technology developed by Royal HaskoningDHV. This revolutionary new approach to water purification relies on a bacteria culture that grows into compact granules, known as Aerobic Granular Sludge or AGS for short.

The Benefits of AquaNereda® Technology

  • Up to 75% Less Footprint
  • Energy Savings Up to 50%
  • Virtually No Chemicals Required for Nutrient Removal
  • SVI Values of 30-50 mL/g and MLSS of 8,000 mg/l
  • No Secondary Clarifiers, Selector Zones or Return Sludge Pumping

Improved Simplicity – Superior Performance

As the industry continues to develop new technologies that define our approach to wastewater treatment processes, one constant is always at the forefront of competitive thinking – We are constantly in pursuit of smaller, more streamlined, pollutant and nutrient removal systems that boast improved performance – at a lower cost and with reduced energy usage as well.

It’s a challenging set of demands. But that’s why ACG Envirocan is so excited to be the exclusive representative for AquaNereda Aerobic Granular Sludge Technology in Eastern Canada.

The AquaNereda three-phase batch process is intended to be executed in a single tank. The treatment solution is comprised of durable granules – a biomass that provides both nitrification and denitrification while at the same time biologically removing phosphorus to impressive minimums without the use of chemicals in the process.

The AquaNereda process requires only diffused aeration to meet process oxygen demands and mixing requirements. No mechanical mixing or sludge recirculating pumps reduces overall power requirements significantly.

The microbiology isn’t so different from what we see in conventional activated sludge systems. But by delivering the biomass in the form of granules instead of osculated sludge, settling velocities are much faster, eliminating the need for secondary clarifiers. AquaNereda granules are made up of layered microbial communities. Within each granule, you have a combination of aerobic, anoxic and anaerobic zones. In effect, each granule acts as a miniature, self-contained BNR treatment plant.

The AquaNereda® Process

Nereda Cycle and granule

  1. The higher the wastewater-to-carbon carbon source, the better food-to-mass ratio the granules provide. Anaerobic conditions drive the release of phosphorus and the purified water is displaced from the top. Granules remain settled at the tank bottom as no air is inducted at this stage.
  2. In the react phase, the wastewater influent flow is turned off and air is introduced to the tank through fine-bubble diffusers and is controlled by the amount of dissolved oxygen and / or ammonia concentration in the tank. At the same time, granules act as a catalyst for nitrification and denitrification.
  3. Finally, in the settle phase, the granules become separated from the treated water. The systems’s inherent rapid settling allows the react phase more time to enhance purification, leveraging small reactor volumes while achieving ultralow enhanced biological nutrient removal. Only a small amount of the aerobic sludge is rendered non-recyclable and is removed from the tank. Then the process begins anew.

The AquaNereda® Difference

The granules in Aerobic Granular Sludge are a living biomass that react carrier-free. What makes AquaNereda AGS unique is specifically the biology selected to create Extracellular Polymeric Substances – the agent responsible for the creation of extremely robust granules that can handle a multitude of adverse conditions in the system. There has never been a case of de-granulation in an AquaNereda operation.

No Chemicals Required

Typically, 10 mg/L for BOD and TSS can be achieved with measurements as low as 3 mg/L in total nitrogen and less than 1 mg/L for total phosphorus – with absolutely no chemical addition whatsoever. If chemical addition is required or opted for, phosphorus down to approximately 0.5 mg/L, is achievable and with tertiary filtration, even lower phosphorus can be met.

Minimal Filtration Requirements

The need for filters is based on the effluent requirements. Only if the target effluent TSS is less than 10 mg/L would a filter be required.

Better for the Environment

AquaNereda Aerobic Granular Sludge boasts a 75% smaller footprint compared to a five-stage bio-logical nutrient removal process. It roughly doubles the mixed liquor suspended solids, to about 8,000 mg/L. Due to the batch nature of the process, you save on the associated cost of final clarifiers. The energy savings are also significant – AquaNereda systems regularly perform thirty to fifty percent more efficiently than conventional systems.

Ideally Suited to Retrofits

AquaNereda is the perfect solution in retrofit applications. The solution can be applied to almost any existing basin’s geometry. Because the AquaNereda process can take place in a single tank, plants that have secondary clarifiers enjoy an opportunity to have their aeration tanks retrofitted with AquaNereda® Aerobic Granular Technology, leaving their clarifiers available to be converted into equalization basins or sludge basins. As a part of the process, flow is significantly improved, and nutrient removal can be made easier through the same system, generating added energy savings as a bi-product. All without the addition of chemicals to the core process.

The Future of Water Purification Technology

The AquaNereda® Aerobic Granular Sludge Technology represents the next evolution in activated sludge water treatment solutions, delivering enhanced results without the use of chemicals. The system’s dramatically reduced footprint and comparatively minimal energy requirements make the AquaNereda process the attractive and competitive alternative that high-performance plants are looking for today.

Nereda® is a registered trademark of Royal HaskoningDHV.