Joe Tardio, Product Manager - AquaNereda, Aqua Aerobic Systems Inc.
The AquaNereda® technology provides advanced secondary wastewater treatment using the unique features of aerobic granular biomass composed of granular sludge. The technology has been used successfully for more than 15 years in full-scale wastewater treatment facilities, with over 80 plants currently in operation or under design and construction.
The technology consists of a three-phase process completed in a single tank. Durable granules often greater than 2 millimeters in diameter and composed entirely of biomass can be thought of as "mini" wastewater treatment plants (WWTPs), as they are very efficient at simultaneously performing nitrification and denitrification, while also biologically reducing phosphorus to low levels without chemical addition or mechanical mixing and with closely controlled air introduction. One of the main characteristics of aerobic granular sludge is its outstanding settling properties. Based on the density of the granules, granular biomass settles significantly faster than flocculent sludge. These excellent settling properties lead to lower volumes required for treatment. The ability to achieve biological nutrient removal in a single tank concept, with no sludge recirculation, efficient use of oxygen and fast settling, makes the AquaNereda technology ideal for advanced secondary treatment in a small footprint with the lowest lifecycle costs.
The technology was first applied in industrial settings. In the lab as well as in the field, it has been demonstrated that granules are less sensitive to toxic feed conditions, sudden load fluctuations, less favorable process conditions or sudden salinity changes when compared to conventional activated sludge. The biofilm-like structure of the granule, with its chemically stable extracellular polymeric substance (EPS)-biopolymer backbone, is the reason for this superior observed robustness.
Another important aspect is the ability for the system to adjust and optimize cycle structure as well as aeration set-points based on flow and analytical measurements. This allows for consistent operation even with hydraulic variation and variations in the organic load. Finally, the AquaNereda system can operate with both concentrated and diluted influent wastewater. These advantages make the technology particularly suitable for industrial applications.
There are many distinct advantages AquaNereda offers compared to conventional biological treatment, including up to 50-percent energy savings by eliminating the need for sludge recirculation pumps, mechanical mixing and optimized aeration utilization; up to a 75-percent smaller footprint due to the elimination of primary and secondary clarifiers, sludge pumping systems, and separate aerobic, anoxic and anaerobic selector basins; excellent effluent quality without chemical addition; robustness and resilience to toxic shocks and influent load fluctuations; and easy operation with automated adjustable cycle structure.
Nereda technology has seen 15 years of use across a wide variety of industries. In North America, a major success was the startup of the Wolf Creek WWTP in Foley, Alabama. The three-reactor plant treats domestic wastewater and has a design capacity of 3.5 million gallons a day (MGD) on average with a 6-MGD peak. Due to the rapid startup and granulation process, the full plant flow was transitioned to AquaNereda ahead of schedule. Within 30 days, the plant was meeting stringent effluent requirements.
Despite the obvious impacts the industry has felt in terms of travel limitations in 2020, Aqua-Aerobic's business remains strong. We are currently executing five new AquaNereda projects, which are all expected to start up within the next six to 12 months. Overall, we have seen rapid adoption of the technology in the North American market, which we expect to continue as the installation base grows.
Aqua-Aerobic Systems Inc. is the exclusive U.S. and Canada provider of Nereda technology developed by Royal HaskoningDHV.
For more information, visit www.aqua-aerobic.com or call (815) 654-2501.
