Water treatment plant successfully makes switch from gas to liquid chlorine
Problem: An Indiana water treatment plant in Indiana facing regulatory and safety challenges with chlorine gas disinfection needed an alternative. A switch to sodium hypochlorite required a new approach to dosing.
Solution: The plant team chose eight Blue-White FLEXFLO M3 and M4 peristaltic metering pumps, seven to feed sodium hypochlorite and one for dosing a polymer to improve filtration performance. Over time, a total of 11 peristaltic pumps were deployed.
Result: Plant operators praised the smooth, accurate dosing, intuitive interfaces and low maintenance. The switch enhanced safety and reliability while reducing downtime. 714-893-8529; www.blue-white.com
Screens increase safety, decrease costs and minimize risk
Problem: The Minnesota city of Crookston, Minnesota (population 8,000), operates a pond treatment system supported by pump stations that remove influent solids. At one station an outdated climbing screen failed, causing frequent pump plugging and requiring service calls and manual debris removal. Snowmelt brought sand and rocks into the sewers; these along with wipes and other debris overwhelmed the pump station’s grinders and damaged equipment. Pumps required frequent maintenance, and grinders wore out quickly.
Solution: The city selected the Duperon FlexRake IQ screen. With sequence technology, enhanced scraper geometry and a FlexLink system, the screen efficiently removes debris without shutdown, automatically adjusting raking speed based on flow and debris conditions, extending the service life and optimizing performance.
Result: The pump station saw fewer service calls and lower equipment wear and required no manual channel entry. The system keeps sand and grit from reaching the pumps. After three years, the screen continued to perform reliably. 800-383-8479; www.duperon.com
Scalable dewatering solution for growing biosolids volumes
Problem: The Wilmington (Ohio) Wastewater Treatment Plant faced increasing waste activated sludge volume. The existing system struggled to maintain efficiency and could not meet current or future capacity requirements.
Solution: Esmil supplied an MDQ-404(3) CLD multi-disk screw press. Designed for scalability, the unit included three active dewatering drums and was preconfigured to add a fourth to allow capacity expansion. The Esmil field engineering team installed the unit with a smooth plug-and-play launch.
Result: Performance improved immediately with cake dryness about 25%, reducing hauling costs significantly. The unit provided a self-cleaning, low-maintenance design, compact footprint and energy efficiency. Full automation reduced operators’ workload and ensured stable, continuous performance. 646-286-5512; www.esmil.us
Investments in dewatering plant pay off quickly
Problem: A wastewater treatment service provider owned by 14 municipalities in Finland needed effective biosolids dewatering to enable cost-effective transport, recycle, landfilling or incineration.
Solution: The company, processing wastewater from industries and some 300,000 residents, replaced two older decanter centrifuges with two new decanter centrifuges from Flottweg.
Result: The plant reduced solids management costs by about 25%, recouping the equipment investment in one year. 859-448-2300; www.flottweg.com
Chopper pumps and mixers fuel advances in biogas
Problem: The Middleton digester in Dane County, Wisconsin, makes biogas from farm manure and substrate for export to the natural gas grid. The digester mixers regularly broke down, and the site’s chopper pumps had to be stripped apart several times weekly.
Solution: The facility switched to Flygt BIS-1 submersible mixers and Flygt 3153 chopper pumps (a Xylem brand). The BIS-1 mast assembly can alter mixer height and perform full swings left to right. The chopper pumps produce uniform material, making processing easier and more efficient with less maintenance.
Result: “The site gets waste stream from different facilities, and the chopper pumps can chew up just about anything,” says Joel Klose, owner of American Bioenergy Services, which maintains the facility. “After installation, we had no more issues. There were no clogs, and the materials produced were uniform.” The mixers also helped increase biogas yield by 15-20%. 914-323-5700; www.xylem.com/en-us/brands/flygt
Rapid response and field training support for wastewater treatment
Problem: Hamlett Environmental approached SEEPEX about a critical issue at a Michigan wastewater treatment facility experiencing a mechanical failure involving a seized plug-in shaft within the output shaft of a gearbox. The company shipped the pump to SEEPEX for repair.
Solution: The plug-in shaft could not be removed, but SEEPEX sourced a replacement gearbox and the components needed to restore the pump’s functionality and promptly returned it, minimizing downtime. The company then was invited on site to service two other pumps, a visit that provided hands-on training for facility technicians.
Result: To further empower the maintenance team, SEEPEX provided a comprehensive care package that included fully assembled rotating units and essential wear parts, enabling the facility to stock critical components and make future repairs quickly. 937-864-7150; www.seepex.com
Achieving grit removal efficiently and cost-effectively
Problem: The nearly 100-year-old village of LeRoy (New York) Wastewater Treatment Plant needed modernization. The staff partnered with lead designer CPL and subcontractor JM Davidson to devise a cost-effective rehabilitation. The plan included new headworks equipment.
Solution: The plant staff and consultants agreed on a complete PISTA Grit Removal System from Smith & Loveless able to meet flows up to 7 mgd. The flat-floor PISTA VIO Grit Chamber provided flexibility to arrange the inlet and outlet flumes in a compact 90-degree orientation. The system includes grit handling and dewatering with a top-mounted PISTA Turbo Grit Pump to convey the grit slurry to a PISTA Grit Screw Conveyor with a cyclonic PISTA Grit Concentrator.
Result: After more than a year of operation, the plant achieves 95% removal of grit down to 100-micron particles across all flows and through the entire system. 913-888-5201; www.smithandloveless.com
Aerators save city from lagoon dredging costs
Problem: The wastewater treatment lagoon in Teutopolis, Illinois, had accumulated nearly two feet of biosolids over time. With water depths averaging 3-4 feet, oxygen levels were low, and new state ammonia and nitrogen limits were difficult to meet. Earlier attempts to improve performance mixed the upper layers, leaving biosolids, carbon food and nutrients undisturbed below.
Solution: The city installed three 50TRN45.5 submersible aerators from Tsurumi Pump instead of dredging. The TRN design pulls water from below, creating a powerful bottom-up mixing of the settled sludge, improving oxygen transfer, reducing solids buildup and promoting consistent biological activity throughout the lagoon. The aerators were selected for their durability, ease of maintenance and cost.
Result: Within months, ammonia and nitrogen levels dropped, oxygen levels improved and effluent BOD5 stayed well below permit limits. This enabled the city to avoid dredging, extend lagoon life and maintain a residual DO in the effluent receiving stream. 888-878-7864; www.tsurumipump.com
