EnvirEx® Disc AErAtors improvE pErformAncE AnD rEDucE

Envirex® Disc Aerators Improve Performance
and Reduce Maintenance in Tomball, TX
Tomball, Texas
When its wastewater treatment plant’s brush aerators reached their end of service life, The
City of Tomball replaced them with Evoqua’s Envirex® Disc Aerators, maintaining compliance
and improving reliability.
The City of Tomball, Texas is in the heart of Houston’s oil country. The city is proud
of its German heritage, its bluegrass music festival, and its namesake civic leader and
congressman, Thomas Ball.
Quality of life in Tomball depends in no small part on the quality of its water, and on
the performance of the city’s two wastewater treatment plants, which serve a growing
population of more than 10,000 residents. In late 2013, operators of the 1.5 MGD
South Plant found themselves facing increasing maintenance issues with three brush
aerators operating in the plant’s two-channel oxidation ditch. The aerator failures were
threatening to compromise effluent quality and environmental compliance.
“Trying” situation
In January 2014, these breakdowns were at a critical point, and the city concluded that
the aerators were reaching their end-of-life. “It was pretty trying,” says Glen Williams,
plant supervisor. “We had to rent floating aerators while we were repairing the brush
units in order to maintain compliance.”
When the municipality secured funding to replace the aerators, plant management
contacted Evoqua. Upon evaluation of the facility, Evoqua determined that existing tank
widths were ideal for Envirex Disc Aerators. Envirex Disc Aerators use nodules and
dimples molded into disc surfaces to transfer energy and oxygen into wastewater.
Disc aerators: more efficient, more reliable than brush aerators
More efficient and more reliable than brush aerators, disc aerators are recommended as
replacements for brush aerators. The replacements is a simple retrofit for contractors
using the existing tanks. The discs allow for improved mixing efficiency, lower energy
use, simpler operation, and less maintenance. In addition, access platforms to drives
and outboard bearings make disc aerators easier to maintain. Since the HIPS plastic
discs do not deteriorate or corrode like carbon steel brush aerators, the disc system has
a significantly longer operating life.
Key advantages of disc aerators include:
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Longer operating life due to non-metallic construction
Improved mixing efficiency, lower energy, simpler operation,
and less maintenance
No additional baffles or mixers required
Significantly reduced misting
Easier on drive systems
www.evoqua.com
Tomball had limited experience with disc aerators, and asked Evoqua to provide parallel
proposals for brush and disc solutions so they could evaluate them side by side. Evoqua
supplies both aerator types as retrofit solutions that require relatively minor engineering.
After investigating the choices and evaluating nearby disc aerator installations, Tomball
chose to replace the first of its three aging brush rotors with an Envirex disc unit. Evoqua
installed the unit in 2014.
Reduced noise, fewer dead zones, better compliance
After start-up, plant operators noted reduced noise, fewer mixing “dead zones”
and fewer odors due to the disc aerator’s superior mixing and oxygenation. Energy
consumption was also reduced. And, most important, according to supervisor Glen
Williams, “We haven’t had any compliance challenges since.”
A clean sweep
After the evaluation, Tomball decided to replace its remaining two brush aerators with Envirex
Disc Aerators as well. “All of our brush units were at end of life,” says Glen Williams. “We
were satisfied with the performance of the Evoqua disc unit, and decided to move ahead.”
The two additional units were ordered in the fall of 2014 and are now in place. Since the
disc aerators have been installed, the focus of the plant’s maintenance staff has shifted
from emergency maintenance of the old system to preventive maintenance of the new
system … a much less stressful, less costly way to operate.
Industry
Municipal Wastewater
Business challenge
Replace existing brush aerator system that had reached the end of its operating
life while maintaining effluent quality and compliance.
Keys to success
Envirex® Disc Aerators from Evoqua replace brush aerators with little or
no structural modifications while improving mixing efficiency and reducing
maintenance and energy costs.
Results
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Maintenance challenges eliminated.
Effluent quality and compliance goals met consistently.
Solutions/Services
Envirex® Disc Aerators
For more information, visit http://www.evoqua.com/disc-aerators
Customer’s primary business
The City of Tomball’s Waste Water Treatment Plant system operates two
treatment plants and 11 lift stations to provide wastewater services for the city’s
10,000 residents.
2607 N Grandview Blvd, Suite 130, Waukesha, WI 53188
+1 (800) 524-6324 (toll-free) +1 (262) 547-0141 (toll) www.evoqua.com/retrofit
Envirex is a trademark of Evoqua Water Technologies, its subsidiaries or affiliates,in some countries.
All information presented herein is believed reliable and in accordance with accepted engineering practices. Evoqua makes no
warranties as to the completeness of this information. Users are responsible for evaluating individual product suitability for
specific applications. Evoqua assumes no liability whatsoever for any special, indirect or consequential damages arising from the
sale, resale or misuse of its products.
© 2015 Evoqua Water Technologies LLC Subject to change without notice MU-DISCAERATOR-TWWTP-CS-1115