Lagoon Fine-bubble Aeration and Process Upgrades


Your challenge:

Improve lagoon BOD/TSS removal

Reduce BOD/TSS: Improve Biological Oxygen Demand and suspended solids removal performance to meet lower limits without constructing additional lagoons.

Increase capacity: Upgrade the lagoon to increase the design capacity of the system and accommodate new industrial contributions or community growth.

Reduce energy consumption: The old aeration is using a lot of power to little effect. Upgrade existing aeration coarse bubble aeration or surface aerators with fine bubble aeration to reduce energy requirements.

Stop odors and sludge build-up: Reducing nuisance odors can result in a reduction in complaints and uhappier neighbors, while reducing sludge accumulation can save money by lengthening the sludge removal interval.

Save space, time, and money: Doing more treatment in a smaller footprint, maintaining operational simplicity, with less expensive solutions keeps everybody happy.


Our technology:

optAER® Fine-Bubble Lagoon Aeration

The Nexom optAER system is an efficient pond-based wastewater treatment solution used in a broad spectrum of applications. In comparison to conventional mechanical treatment facilities, optAER process-enhanced lagoons maintain the simplicity of a lagoon system at a fraction of the cost to construct and operate.

Of course, aside from financial benefits, the documented performance of optAER systems make it a reliable solution for achieving high effluent quality and meeting increasingly stringent wastewater effluent regulations, especially when paired with Nexom’s other lagoon-based process upgrades (including SAGR™ post-lagoon nitrification and MITA® Cloth Disk Filter-based Phosphorus Removal System).

The sludge digestion capability of the optAER process results in minimal long-term solids accumulation, extending the design life of the lagoons and allowing longer operation prior to de-sludging.




Key advantages:
  • Effectively improves lagoon cBOD and TSS treatment
  • Stops nuisance odors
  • Reduces sludge by promoting internal digestion
  • Facultative lagoons/waste stabilization ponds
  • Old or underperforming aerated lagoons
  • cBOD removal
  • TSS removal
  • Algae control/pH stabilization
  • Water Reuse
  • Sludge reduction

How it works

Optimizing dissolved oxygen and retention times for maximum impact

The focal point of the optAER® system is the fine-bubble aeration distributed through our diffusers placed at or near the lagoon bottom.

optAER fine-bubble aeration diffusers provides excellent operational flexibility. The diffusers are available in a range of sizes and configurations, nad each can operate over a wide airflow range. The airflow can be adjusted to accommodate variable load conditions and provide cost effective future upgrades to increase capacity. In addition, the diffusers are available with a wide range of membrane materials, suitable for most wastewater applications.

The fine bubbles produced by the diffusers both rise more slowly (compared to traditional “coarse bubbles”) and result in high total surface area per volume of air introduced into the system, increasing the overall oxygen transfer efficiency of the system. The bubbles also mix the water, ensuring aerobic conditions throughout the water body.

The diffusers can be combined with self-tensioning floating laterals providing cost effective installation and low maintenance, or with submerged laterals for lagoons and storage ponds with varying water levels. For high diffuser density applications, Nexom’s patented Float-Sink retrievable lateral system enables easy access to the aeration laterals and diffusers for routine maintenance and inspection. Installation and maintenance for floating, submerged, and float-sink lateral aeration systems can occur without de-watering the lagoon or taking cells out of service.

cBOD Reduction

cBOD is reduced to carbon dioxide, water, and inert ash by natural bacteria, which receive their oxygen supply from air provided through the optAER aeration diffusers. Where additional treatment is required, baffles can be used to partition cells into multiple treatment zones to improve efficiency and reduce short circuiting. For more intensive treatment requirements, optAER complete mix aeration is implemented, increasing the reaction kinetics in the basin.

Suspended Solids Removal

Through the rise of bubbles and subsequent mixing, convection cells are created between diffusers. Not only does the water rise with bubbles, the solids settle out through the downward motion of the water between diffusers where the circulation loop is completed. The mixing rate is reduced in the secondary cells to minimize turbulence and facilitate additional suspended solids removal. Where required, covered cells are used to control algae to meet stringent suspended solid limits. In addition, MITA Cloth Disk Filter can be used for additional suspended solids removal.

Controlling Odors

Sizing the aeration system to meet the oxygen requirements of the biological processes in the aerated ponds eliminates nuisance odors from the system. Anoxic ponds used for denitrification are sized such that oxygen requirements are met by the nitrates in the wastewater, further keeping odors at bay. Where anaerobic ponds are required in the treatment process, odors can be controlled by the use of floating covers.

Sludge Reduction

The optAER system provides a combination of aerobic and anaerobic sludge digestion within the sludge layer at the bottom of the pond. Oxygen provided by the optAER diffuser allows for aerobic digestion at the sludge-water interface. Further, long-term sludge digestion occurs under anaerobic conditions within the settled sludge layer. The environmental impact and cost of sludge removal and disposal can be minimized with the optAER system due to minimal organic bottom sludge accumulation. The low sludge production also retains the pond retention time required for long-term cBOD removal.

What it Delivers

Reducing BOD/TSS to <20mg/L with minimal O&M

Improve the performance of your wastewater treatment lagoon with the addition of optAER® technologies. It’s amazing what such a simple-to-operate system can produce when equipped with Nexom’s fine-bubble aeration system and optional flow optimization baffles or lagoon cover. Add on:

…and you have a wastewater treatment plant producing effluent that can exceed the effluent quality of more complicated wastewater treatment plants, with a fraction of the operational complexity or ongoing maintenance requirements.

Want to know what optAER® could do for your lagoons?

Submit your RFP today and our on-staff professional engineers can help you size and design an optAER fine-bubble aeration and treatment upgrade to meet your wastewater treatment requirements.


Will optAER aeration improve our ammonia levels?

Very likely. The availability of dissolved oxygen is often a limiting factor for nitrification (ammonia removal), and the increased mixing that aeration can provide also helps ensure ammonia-rich wastewater comes in contact with nitrifying bacteria. But if you live somewhere that gets cold in the winter, remember that cold water can be a far more significant limiting factor than even dissolved oxygen, and if it’s ammonia removal you’re looking for, post-lagoon technologies such as the SAGR® or BioPorts™ MBBR are the answer.

Is dewatering required for maintenance?

No, with most optAER configurations dewatering is not required for aeration system maintenance, including inspecting diffusers and changing diffuser membranes. Nexom’s optAER diffusers can be accessed from the water’s surface, allowing individual diffusers or entire laterals to be inspected in a full lagoon.

What special equipment is required for maintenance?

For most optAER systems, the most specialized equipment required for maintenance is a light, stable boat from which an operator can work. No barge or heavy lifting equipment is required.

Have a question that wasn’t answered here?

Contact one of our product specialists (or your local Nexom rep) and we’d be happy to answer it.