While industry standard, aeration control systems are conceptually simple, they are not easy to operate or tune. Standard control systems use the PID algorithm to adjust for errors. This control algorithm is initialized for each control loop at system commissioning. For tight control, retuning is often required as process conditions change. The control algorithms featured in Symphony are relational so operators understand how the system accounts for errors. The system also supports user preferences so now the system performs within the limits set by the operator. Symphony controls are also self-tuning, so high precision and accuracy are provided over the life of the system.

Symphony is an umbrella program. For technologies other than aeration, Symphony partners with the best appropriate technology for each plant. For controls, EDI enjoys and exclusive, strategic partnership with BioChem Technology, Inc. (BCT). BCT is the industry's leading biological process and aeration controls supplier. BCT brings extensive experience and has demonstrated operations in plants including some of the largest (1BGD) in the world.


Physical equipment upgrades (aeration, blowers, mixers, instruments, actuators, valves, and parts & service) can be provided as part of your Symphony upgrade, or you can source them directly.

The Maestro Operations Control module is a stand-alone control panel that interfaces with your existing SCADA system or it can be setup to function directly with the instruments and blower MCP (master control panel). Two control systems are currently available:

- BIOS (Bioprocess Intelligent Optimization System) - proprietary, ammonia-based, feed-forward system adjusts process setpoints in real-time to deliver the intended level of treatment at the lowest possible energy requirement. Existing customers report process improvements up to 25% or a 3mg/L improvement of effluent TIN.
- PAL (Predictive Aeration Logic) - patented, aeration control system provides unparalleled automation precision, accuracy, and operating efficiency for the highest level of operational control and energy use. Existing customers have reduced energy use up to 50% or $30,000 per year for a 1 MGD plant.

The Maestro Management Control module supplements the Operations Control Module. In addition to expanded control functionality, the Management modules includes a Management service package (renewable 5 yr contract). The program includes annual plant visits, onsite staff training, and one-on-one meetings with Management to review business objectives. Recommendations for new operating objectives that arise from these meetings will be provided in a service call report. This collaboration helps ensures that Symphony is meeting the full needs of the plant for the term of the installation.

Yes; the BIOS control system guarantees that the process setpoints will represent the best operating condition to yield the desired level of treatment performance. The full terms of the guarantee are detailed in the proposal.

Yes; the PAL control system guarantees that the aeration system will operate within a 0.5mg/L control band, 95% of the time, and one control valve will be maintained in a mostly open position 100% of the time. The full terms of the guarantee are detailed in the proposal.

For highest operating efficiency, PAL interacts with the blower control panel with a total airflow signal. This eliminates the pressure PID blower control loop and reduces the operating discharge pressure at the blower by as much as 1 psig. This increases savings and the operating capacity of the blower. PAL supports all blower technologies and suppliers and we have operating systems with Turblex, ABS, HST, Aerzen, Neuros, Atlas-Copco, and many others.

Optimized performance will not be delivered without proper process setpoints and tight operations to these setpoints; BIOS evaluates and varies setpoints to provide desired performance and lowest energy use, and PAL operates the aeration components to these setpoints. Your Symphony Advisor will work with you to demonstrate how these critical functions work together to deliver desired performance.

IDEAL is an Intermittently Discharged Extended Aeration Lagoon that delivers advanced treatment and nutrient removal in an earthen basin. IDEAL is able to accomplish this performance by combining long sludge age with a batch process and incorporating attached growth media.

Effective Utility Management programs and improved rate-payer value require a focus beyond effluent compliance. The Management Program of Symphony including the Service Module is an important tool to support these broader business outcomes.

The patented IDEAL is a hybrid extended aeration/batch process that accepts constant influent but has a batch release of effluent. IDEAL uses a prolonged SRT and low F:M ratio that is not normally cost effective in conventional SBR, and the simple, balanced solids management protocols provided with the IDEAL Process minimizes solids management. IDEAL also incorporates the patented BioReef BioCurtain as a biologically active hydraulic buffer that addresses short-circulating potential, provides contact stabilization during settling and decant cycles, and increases biomass in the reactor.

Installations are typically designed to operate as a balance biological system. Excess sludge is wasted during each decant cycle through the decanters. The self-regulated SRT equilibrium is well above the critical growth rate of nitrifiers. Waste pumps may be used when manual wasting is desired or when other solids treatment operations exist.

Waste solids discharged from the IDEAL reactor are highly stabilized and exert minimal oxygen demand and nutrient rebound potential. Waste solids are stored and undergo additional aerobic digestion in the downstream partial mix lagoon. This aspect of the IDEAL Process is no different than a traditional aerated lagoon system, except that the solids that leave the IDEAL are more stabilized.

IDEAL is designed to accommodate hourly peak flows during each and every cycle. The configuration of the primary reactor is sized to handle most storm and surge flows without any change in the process. the IDEAL solution includes a Storm Cycle for peaks that exceed the design capacity for the plant. If the water in the IDEAL reactor reaches a critical level, an alarm is triggered, the blowers shut off, and the sludge is allowed to settle. This allows storm water to pass through the settled sludge blanket and first BioCurtain for contact treatment, and then over the sludge blanket and second BioCurtain to eliminate washout of the reactor. The Storm Cycle ends once the water level drops and aeration will reset accordingly.

A number of control configurations are available depending on the needs of the client.

The standard options include:

  • Analog controls with visual and audible alarms; includes Storm Cycle
  • Digital controls with visual and audible alarms; includes Storm Cycle
  • Digital controls with visual and audible alarms; includes Storm Cycle and DO Control for energy efficiency and maximum nitrate and total nitrogen removal
    - The digital control packages are available with online monitoring or online monitoring and control

The IDEAL has demonstrated the ability to remove ammonia to less than 0.05 mg/L even when the water in the IDEAL was less than 3 degrees Celsius! The IDEAL may be thermally insulated to minimize reactor cooling if extremely low temperatures are anticipated.

EDI experience shows negligible ammonia rebound in the IDEAL Process because of the highly stabilized sludge, long aerobic digestion times, and ample dissolved oxygen (DO) in the PM lagoon. Peer-reviewed literature confirms no rebound occurs in partial mix lagoons provided DO remains above 2mg/L.

IDEAL does not require regular operator input for process performance. IDEAL relies on similar hardware and operational requirements as a typical CM/PM lagoon system. Regular equipment checks and monitoring are recommended as with any process.

Coarse Bubble: Otherwise known as large bubble diffusers, coarse bubble diffusers get their name from the type of bubble they produce. Coarse bubble diffused systems are composed of dozens to hundreds of coarse bubble diffusers, each attached to a PVC or stainless steel air supply line fixed to the bottom of the lagoon. The most common coarse bubble aerator for lagoons is what is known as a static tube. When large bubbles are released at the bottom of the tube, they create an effect whereby water is pulled from below the static tube and pushed towards the surface.

Fine Bubble: Fine Bubble diffuser systems disperse the diffused gas volume to transfer an equivalent amount of oxygen as a coarse bubble system. The diameter of gas bubble has a dramtic impact on surface area. Comparing 1 cubic foot of air used in fine, medium, and coarse bubble systems demonstrates why fine pore diffusers optimize the use of air and reduce energy consumption.

PU: Polyurethan offers UV protection and long-term stability in DWP. Does not contain extractable oil content. The smooth surface characteristics inhibit fouling and prevent build-up of bio-solids. Will also withstand harsh wastewater environments.

EPDM: The face of the EPDM diffuser disc is coated with a molecular thin layer of PTFE compound. This thin layer of coating is an interesting composition of approximately 97% polyurethane with about 3% PTFE dispersed into the layer on the outside of the EPDM membrane. The body of the diffuser membrane is 100% EPDM. 

EDI diffusers are exceptional within the market and offer a variety of benefits including:

- Various sizes: 7-inch, 9-inch, and 12-inch disc diffusers available
- Larger range of air capacity compared to competitors
- Several different mounting options such as: 3/4" threaded, KlicLocTM Saddle Mount, Universal Diffuser Mount, Glue on Saddle
- Strength has been proven to be 2 times that of competitor's
- Material benefits: Fiberglass filled polypropylene, strength high, chemical resistant, UV resistant
- Temperature resistance:High temp capability over 230oF, high cold weather strength (not brittle)
- Piping: KlickLocTM saddles fit 3-inch and 4-inch pipe sizes. Threaded pipe and UDM fit any size or type of pipe.
- Pipe supports: SuperStrutTM offers a non-metallic construction that is polypropylene fiberglass filled with maximum strength of up to 640 lbs. SuperStrutTM also offers easy height adjustment, snaplok install, 1 bolt mounting, stress relief design, mounting options on slope or flat floor, height extension standard, high temperature, and stability at low temperature.
- Materials: Advanced membrane technology with multiple membrane polymers (EPDM, Polyurethane, PTFE Coated EPDM, Silicone, Specialty Polymers, and EDI controlled membrane manufacturing)
- Perforation: Controlled in-house perforation for optimum performance (0.5 mm, 0.75 mm, 1.0 mm, 1.25 mm, 1.5 mm, 2.0 mm, plus special perforations available.
- Oxygen Transfer: Highest oxygen transfer for Disc Diffusers with NanoPoreTM and MicroPoreTM applications and full floor cover densities

EDI's Aeration Works division offers installation, evaluation, maintenance, service, consulting, and warranties. Aeration Works will be with your plant from the beginning of its life, throughout the years it is in production.

Yes, there are four (4) warranty options available for the end user when Aeration Works is involved in the installation of an EDI system:

1) Aeration Works Inspection for General Performance: This inspection by qualified Aeration works personnel is performed to make sure all aspects of the installation were done in accordance with factory-standard procedures. Once confirmed, Aeration Works warrants the start-up performance of the system.

2) Aeration Works Supervised Installation: When an installation is accomplished under the direct supervision of an Aeration Works supervisor, the system is certified that it will perform to the factory specifications.

3) Contractor Installed; Aeration Works Tested: After a contractor installed system is considered to be ready for startup, Aeration Works can be contacted to do a complete and thorough inspection. Any items determined to not be correctly installed are then brought to the attention of the system operators.

4) Aeration Works System Installations: When AW is contracted to install a new system, extended warranties (for both product defects as well as system performance) are available.

Three extended maintenance programs that help your plant run longer and better, from replacement, to preventative maintenance and diffuser cleaning.

1) Preventative Maintenance: This program allows facility operators to outsource the regularly scheduled aeration system maintenance. Our team will take care of basic system maintenance by cleaning diffuser membranes and making any required system repairs. 

2) The Infinity Program: Never worry about your system's efficiency levels again. Under this program, AW preserves the physical condition of the membranes through preventative maintenance procedures and will replace or adjust the equipment to ensure the system operates within a pre-determined performance envelope.

3) Membrane Replacement: Don't let old, fouled membranes keep your system's efficiency down. AW's Membrane Replacement Program keeps your diffusers operating at their optimum performance levels by ensuring the membranes are replaced when necessary. You can arrange regular change-outs or contact our team on an as-needed basis.

The DBBR, or Decanted Bio-Balanced Reactor, integrates a number of technologies and process advancements to deliver advanced treatment performance. Combining extended aeration design with a batch process allows the DBBR to take advantage of unique characteristics possessed by each. The DBBR also balances the hydraulic and shock loading resistance of suspended growth bacteria with the low-temperature treatment benefits of attached growth biomass to form a system uniquely suited to lagoon application. The balance between aerobic and anoxic cycles provides excellent BOD, ammonia, and total nitrogen removal, as well as superb sludge settling characteristics, more stable pH levels, and low energy consumption.

Extended aeration plants operate by having a low food (i.e., BOD, ammonia, etc.) to microorganism ratio in the reactor.  Generally referred to as an “F to M ratio”, having a low F/M ratio, which correlates to a long sludge retention time, provides very high treatment capability with high resistance to shock loads. Combining this stability with the batch process gives the DBBR the ability to more fully treat the incoming water while delivering solids retention and reducing the overall reactor footprint.

Suspended biomass is known for providing more robust treatment under varying degrees of influent quality.  It can better adjust to loading and flow variations for consistent treatment. Attached growth biomass has shown a unique ability to nitrify under very cold conditions and, when used in combination with suspended growth, can raise the overall biomass concentration in the reactor to provide high levels of treatment in relatively small basin volumes.

Excess sludge is retained in a partially mixed (PM) pond and stored just as it is in a conventional aerated lagoon system.  Solids undergo aerobic digestion until fully stabilized. The simple sludge management of a conventional aerated lagoon system is retained.  

Installations are typically designed to operate as a balanced biological system.  Excess sludge is wasted during each decant cycle through the decanters and the system is self-regulating. The key is that the self-regulated SRT is well above the critical growth rate of nitrifiers. Waste pumps may be used when manual wasting is desired or when solids treatment operations exist.

The hydraulic nature of the DBBR is designed to accommodate a peak flow or peaking factor that is supplied by the engineer.  The geometry and HRT of the lagoon allows the reactor to handle most storm and surge flows without any change in the process.  The DBBR is designed with a Storm Cycle for severe peaks.  If the water level in the DBBR reaches the Storm Cycle Level then an alarm is triggered, the blowers shut-off, and the decanters open after a set period, which allows the MLSS to settle.  This allows storm water to pass through the sludge blanket for contact treatment and through the DBBR without washout of the reactor.  Once the flood level decreases the normal treatment sequence is initiated with the aeration phase.

A number of control configurations can be applied depending on the needs of the client.  The standard options include:

  • Analog controls with visual and audible alarms; includes Storm Cycle
  • Digital controls with visual and audible alarms; includes Storm Cycle
  • Digital controls with visual and audible alarms; includes Storm cycle and DO control for energy efficiency and maximum total nitrogen and nitrate removal
    - The digital control packages are available with online monitoring or online monitoring and control

The DBBR has demonstrated the ability to removal all trace of ammonia to less than 0.05 mg/L even when the water in the DBBR was less than 3°C! Data for this demonstration was collected twice a week using 24-hour composite samplers and tested at a third-party laboratory. These excellent results are due to the maximization of biomass in the reactor; providing more soldier to fight the fight.

EDI experience shows little to no ammonia rebound occurs in a typical DBBR lagoon-based process because of the long aerobic digestion times involved and the proper DO concentration being maintained in the PM lagoon. Literature confirms little to no rebound occurs in polishing ponds if they maintain a dissolved oxygen concentration of 2 mg/L or greater.

EDI has developed the DBBR process to minimize operator attention for stable process performance. The DBBR incorporates similar hardware and operation requirements of a typical CM/PM lagoon system. By maintaining lagoon infrastructure, aerated lagoon operators can be comfortable with the operation and maintenance.  No moving parts in the reactor or PM lagoon are a key benefit.

All DBBR systems come with onsite operator training during start-up and a refresher with system tune-up at least once a year for up to three years into the life of the system. EDI recognizes each installation is unique and our contract maintenance division, Aeration Works, will be happy to provide a customized maintenance contract that meets the needs of the client.

Core DBBR technology represents no lost investment if effluent criteria become more stringent. Simple, affordable add-ons, such as DO control, can increase total nitrogen removal from the standard 66% up to 80% or more.  Simple coagulant addition to the DBBR can help reduce total phosphorous while improving overall performance of the system.  An easy-to-operate disc filter can always be added to the back of the process to ensure minimal solids pass through, which reduces BOD, TSS, total nitrogen and total phosphorous.