Ozone and oxygen reduce odor at collection system and lift station

Problem

A Pacific Northwest regional wastewater authority received multiple odor complaints especially during summer. Hydrogen sulfide levels ranged from 75 to 250 ppm.

Solution

After a demonstration from Anue Water Technologies, the authority chose a Phantom oxygen/ozone injection system with two HydroSpear conditioning heads in the wet well at the lift station. Pre-demonstration data had shown odors caused by aqueous and vapor-phase sulfides and elevated mercaptan levels.

Result:

Soon after the demonstration began, odors at the lift station vanished and complaints ceased. Hydrogen sulfide levels dropped immediately to single-digits and remained at less than 10 ppm. The decreased odor also reduced blower runtime, saving $2,000 to $3,000 per month. 760-727-2683; www.anuewater.com

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Facility finds success in phosphorus removal process

Problem

The Drake Water Reclamation Facility in Fort Collins, Colorado, needed phosphorus removal to meet new regulations from the state Department of Public Health & Environment.

Solution

The facility chose MagPrex from Centrisys/CNP for the lowest life cycle cost after Carollo engineers evaluated all available phosphorus removal technologies.

Result:

Since 2020, the facility has achieved effluent phosphorus below 0.5 mg/L. The reactor reliably removes more than 90% of orthophosphate from the phosphorus recycle loop going back to the front of the plant, enabling the facility to consistently meet the lower phosphorus limits. Carollo, Fort Collins and Hydro Construction completed the project in 18 months. 262-747-2384; www.centrisys-cnp.com

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Plant saves taxpayer money with peroxyacetic acid

Problem

In 2015, the New Jersey Department of Environmental Protection restricted the release of chlorine residuals to limit disinfection byproducts. The 3.1 mgd Berkeley Heights Wastewater Treatment Plant needed to replace their disinfection method, find an alternative to sodium hypochlorite/sodium bisulfate and meet the DEP’s permit levels.

Solution

The plant chose peroxyacetic acid treatment and used SaniDate 15.0 (BioSafe Systems) for disinfection. Dosing 1.5 mg/L after the sand filters proved effective. Average fecal coliforms were reduced from 229 to 41, and average E. coli from 150 to 18, well under the limits. The PAA dosing system was implemented quickly, and PAA doesn’t risk creating DBPs. It showed stronger oxidizing potential than chlorine, used shorter contact time, and certified degradation of problem chemicals. The facility reduced operating costs by 12% and avoided a million-dollar UV installation with a $50,000 annual maintenance cost.

Result:

Berkeley Heights has been successfully using SaniDate 15.0 for disinfection since 2017. 888-273-3088 www.biosafesystems.com

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Package treatment plant enables expansion and reduces maintenance at RV park

Problem

The Yogi Bear’s Jellystone Park full-service campground in Waller, Texas, had expanded its sewage treatment system many times, and it was again at capacity, restricting park expansion and requiring costly maintenance. An engineer was asked to design a new system with 30,000 gpd capacity to meet state permit requirements.

Solution

The campground team chose a package treatment Plant (Delta Treatment Systems) using an extended aeration and oxidation process. It yields clear and odor-free effluent that meets permit requirements. The custom plant was installed on an engineered, reinforced concrete structural slab. It has dual aeration basins, sludge holding tanks, blowers and pumps, and a 10-foot-diameter mechanical clarifier with skimmers and a clarifier bridge. A separate pump tank was incorporated into the design. 

Result:

The plant was built at the factory and shipped to the site as a self-contained unit and required little assembly. It continues to perform as expected. 800-219-9183; www.deltatreatment.com

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Self-cleaning filters utilized in treatment and reuse of stormwater

Problem

The City of Los Angeles needed on-site treatment and beneficial reuse of retained stormwater to irrigate of Temescal Canyon Park. The project included a 120-foot stormwater line with a 500 gpm pump inside an existing buried reservoir to the treatment building.

Solution

Forsta Filters worked with a local contractor to provide a 200-micron self-cleaning filter. The B6-180 model self-cleaning filter handles the maximum flow for the Temescal pump station system. The filter protects drip tubing and irrigation spray nozzles from debris buildup. Clogged nozzles can lead to damage to turf and landscape, which requires time-consuming and costly replacement.

Result:

Forsta engineers conducted comprehensive training at the Temescal Canyon site. The equipment installed has reliably provided filtered water for irrigation. 888-936-7782; www.forstafilters.com

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Blower specified for SBR system

Problem

A plant in the Pacific Northwest had issues with blower reliability on a sequencing batch reactor due to frequent starts and stops. The plant team wanted a high-efficiency blower, but it had to be able to start and stop every 20 to 30 minutes.

Solution

The plant chose the Inovair IM-30 Geared Centrifugal Blower (Stacked). To avoid unnecessary wear, Inovair engineers designed the gearbox with unlimited-life non-contact floating ring oil-film journal bearings and tapered land thrust bearings. These bearings have been used for decades in the turbo-machinery market and operate on the same basic principles as crankshaft bearings in cars.

Result:

After a year and thousands of starts/stops, the blower worked flawlessly. The plant team is experiencing improved reliably and lower operating costs. 855-466-8247; www.inovair.com

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Injector system helps plant make switch to UV disinfection

Problem

The Hagerstown (Maryland) Wastewater Treatment converted to UV from ozone for disinfection. With ozone system, the effluent dissolved oxygen met regulatory standards. With UV, the regulatory agency was concerned about lower DO discharges. (Due to a denitrification step upstream, the effluent naturally has zero DO.)

Solution

Since the compressors and oxygen concentrators in the old system still worked, they were used to feed oxygen to reach their effluent DO goal (as high as 8 mg/l). A pure oxygen injection system was purchased including a booster pump, a 4-inch stainless steel injector from Mazzei Injector, a pipeline flash reactor (PFR), and two oxygen control and instrumentation manifolds. A fraction of the mainline flow is taken off the effluent pipeline, directed through a booster pump and then through an injector to aspirate pure oxygen. The oxygenated sidestream is then mixed back into the 36-inch effluent pipeline through an inline PFR. This eliminates the need for an additional tank/basin and drastically reduces the energy consumption and footprint.

Result:

Since startup of the injection system, mainline flows have varied from 3.5 to 30 mgd with an average plant flow rate of 6.5 mgd. The system has successfully increased the effluent DO levels, exceeding discharge requirements under all conditions with minimum maintenance and low operator involvement. 661-363-6500; www.mazzei.net

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Chloramine management system keeps disinfection consistent

Problem

The Colony on the east shore of Lake Lewisville north of Dallas, Texas, occupies 2,500 acres and has seen its population almost triple in 15 years to 45,000. A persistent area of low disinfectant residual was under the influence of one of four elevated storage tanks, with a 1 million-gallon capacity. Lower turnover periods saw chloramine disinfectant residuals in the tank plunge, requiring flushing and even taking the tank offline. The periodic testing and manual intervention was costly and disruptive.

Solution

The Colony staff chose the Monoclor RCS chloramine management system from PSI Water Technologies, a UGSI Solutions Company. The system automatically generates a constant and reliable chloramine residual in the reservoir by creating a homogeneous mixture, introducing ammonia and chlorine rationally and monitoring the equilibrium with control logic in real time. The system automatically manages the chloramine breakpoint chemistry to ensure that regardless of conditions the tank effluent always has the appropriate disinfectant residual.

Result:

Once the system was installed, the pressure zones had far fewer taste and odor complaints. “The Monoclor RCS system successfully managed our chloramine disinfectant residual through all seasons and played a big part in improving water quality in the downstream pressure zones,” says Jimmy Arthur, water production supervisor. 888-774-4536; www.ugsicorp.com

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Water reclamation facility upgrades nutrient recovery system

Problem

The Tres Rios Water Reclamation Facility in Pima County, Arizona, had battled struvite buildup in pipelines and equipment after anaerobic digestion for many years. A combination of ferric chloride downstream of the digesters and dilution water in the centrate return lines slowed struvite buildup, but performance had to be improved.

Solution

The facility staff aimed to stop struvite scaling issues, eliminate ferric chloride and dilution water addition and reduce phosphorus return loading to the plant. This led to a project to treat digestate and remove phosphorus by sequestering the produced struvite within the biosolids. The NuReSys Struvite Management System from Schwing Bioset was selected to precipitate struvite in the digestate stream for removal with the biosolids.

Result:

The system treats digestate flow following the digesters. The precipitated struvite then becomes entrained in the biosolids and exits the plant with the dewatered cake. The system is exceeding performance metrics and is on pace to save the county hundreds of thousands of dollars annually on maintenance. 715-247-3433; www.schwingbioset.com