Pumping and aeration are typically the largest energy users at a wastewater treatment plant, and aeration blowers are essentially low pressure, high volume air compressors, according to a 2010 US EPA report. Ultra Controlo distributes and services Elmo Rietschle side channel blowers and Thomas linear pumps, which their makers list for water tank and sewage aeration, and supplies the ULTRAOX VSA oxygen plant, whose datasheet lists wastewater treatment plants.
The US EPA (2010), the US Department of Energy (2016), the Water Research Foundation (2022) and a 2016 US patent describe these uses at wastewater plants and in sewers.
Blowers feed air through the piping to diffusers; the intake typically has filters that protect the blowers and diffusers from airborne particulates (US EPA).
Pumps provide hydraulic head, convey flows, solids and effluent, and move wastewater through the collection system; pumping is in many cases second only to aeration in energy (US EPA).
Designing and operating aeration to match the actual oxygen demand as closely as possible saves energy; fine-pore diffusers have the highest transfer efficiency (US EPA).
A high oxygen transfer rate and a higher biological oxidation rate that can allow significantly smaller bioreactors; attractive for certain industrial wastewaters with high soluble BOD (Water Research Foundation).
Dissolving oxygen into the wastewater prevents the anaerobic conditions in which sewer bacteria form the sulphur compounds that cause odours and corrosion (US patent 9,340,438).
The US Department of Energy lists vacuum filters and conveying as example uses of compressed air in wastewater treatment.
Sources: US EPA, Evaluation of Energy Conservation Measures for Wastewater Treatment Facilities, EPA 832-R-10-005 (2010); US DOE and Compressed Air Challenge, Improving Compressed Air System Performance (2016), Table 1.2; Water Research Foundation, WRF 4973 fact sheet (2022); US Patent 9,340,438 B2 (2016), background.
The Water Research Foundation (2022) and a 2021 training presentation hosted by Oak Ridge National Laboratory describe high-purity oxygen (HPO) activated sludge.
Attractive for certain industrial wastewaters with high soluble BOD or volatile organics that need containment, where a small footprint is needed and nutrient removal is not required.
Source: WRF 4973 fact sheet (2022).
CO2 builds up in the closed headspace and depresses the pH, which slows nitrifier growth; very few HPO plants remove nutrients, and oxygen generation needs specially skilled operators.
Source: WRF 4973 fact sheet (2022).
Trucked-in liquid oxygen, or on-site generation by PSA, VPSA or a cryogenic system; oxygen is added at 2 to 3 times the rate of conventional processes.
Source: L. W. Moore, ORNL training series (2021).
ULTRAOX VSA delivers 75% to 95% oxygen at 50 kPa; its datasheet lists wastewater treatment plants and H2S reduction. Sources: WRF (2022); Oak Ridge National Laboratory (2021); ULTRAOX VSA datasheet.
The 2010 EPA report takes these ranges from WEF (2009) and from WEF and ASCE (2010).
| Type | Typical flow and pressure | Notes from the EPA report |
|---|---|---|
| Positive displacement | 5 to 50,000 scfm, 1 to 14 psig | Fixed volume of air per shaft revolution; low capital cost; hard to run at variable flow without a VFD, can be noisy, needs more maintenance, typically least energy efficient |
| Centrifugal, multi-stage | 500 to 30,000 scfm, 4 to 14 psig | Can be more energy efficient than positive displacement; efficiency decreases with turndown |
| Centrifugal, single-stage, integrally geared | 500 to 70,000 scfm, 4 to 24 psig | Can keep good efficiency at turndown; higher capital cost |
| Centrifugal, single-stage, gearless (high-speed turbo) | 400 to 10,000 scfm, 4 to 35 psig | Small footprint; efficient for lower air flows; described in 2010 as a new technology with limited experience |
Equipment that the Ultra Controlo Industrial 2026 catalogue, the partner makers and the ULTRAOX VSA datasheet tie to aeration and to wastewater treatment.
Output up to 3,000 m³/h; Elmo Rietschle lists aeration and ventilation of water tanks and process aeration among their uses.
Elmo RietschleCompact linear diaphragm pumps that run without oil lubrication; Thomas lists sewage aeration and greywater treatment among their uses.
Thomas75% to 95% oxygen at 50 kPa, on a skid or in a container; the datasheet lists wastewater treatment plants and hydrogen sulphide (H2S) reduction processes.
ULTRAOX VSASources: Ultra Controlo Industrial 2026 catalogue, pp. 11 and 15; Elmo Rietschle, side channel blowers (elmorietschle.com); Thomas, linear pumps (thomaspumps.com); ULTRAOX VSA datasheet, pp. 2 and 3.
Ultra Controlo is a Portuguese manufacturer of compressed air, vacuum and technical gas systems, with 40 years of experience. We design, assemble and test our own compressors, dryers and carbon towers in Portugal, and supply and service five partner brands.
ULTRASCREW compressors, ULTRASEC and ULTRADRY dryers and ULTRAK activated carbon towers.
Gardner Denver, Elmo Rietschle, Thomas, Speck Pumpen (Circutec) and Speck Triplex.
Preventive and corrective maintenance, original spare parts and emergency support, by our own team.
Source: Ultra Controlo Industrial 2026 catalogue, pp. 3, 10, 16, 17 and 22.
A 2010 US EPA report, citing WEF, puts aeration at 25 to as much as 60 percent of total treatment plant energy use, and says pumping is in many cases second only to aeration.
The 2010 US EPA report describes positive displacement blowers as typically least energy efficient and hard to run at variable flow without a VFD, and says centrifugal blowers can be more energy efficient.
The Water Research Foundation (2022) explains that CO2 accumulates in the closed headspace and depresses the pH to 6.0 to 6.5, which reduces nitrifier growth rates.
The US Department of Energy sourcebook (2016) lists sparging, aerating or oxygenating a liquid with compressed air among potentially inappropriate uses of compressed air, and names low-pressure blowers and mixers as alternatives.
The ULTRAOX VSA datasheet lists wastewater treatment plants and hydrogen sulphide (H2S) reduction processes among its applications. The plant delivers 75% to 95% oxygen at 50 kPa, with a booster for higher pressures on demand.
The flow, the aeration basins and diffusers, the blowers you run today, or the oxygen you buy. We reply with the equipment that fits.
