Cloth media filters help boost capacity and cut backwash volume

Problem: The Portland (Indiana) Wastewater Treatment Plant had been using six granular media filter units with a design average flow of 2.35 mgd for tertiary treatment since the 1980s. The filters required daily maintenance due to valve issues, broken underdrains and loss of media. They also required excessive backwashing (about 10,000 gallons per cycle). Engineers recommended replacement with more efficient cloth media filters. With a fast-track design-build process to ensure state revolving loan funding, the project had to be completed in just over 12 months.

Solution: Aqua-Aerobic Systems installed two 10-disk AquaDisk Cloth Media Filters. Each disk is fitted with OptiFiber media to maximize solids removal with less backwash. Each unit is designed to handle a peak flow of 4.7 mgd; combined capacity is 9.4 mgd.

Result: The filters perform efficiently and cost-effectively. Either one can handle the capacity of the six old filters, providing flexibility for routine maintenance and growth. Backwash volume was reduced 97 percent to about 300 gallons. The outside-in filtering makes the disks easier to clean, and energy consumption has dropped because less water is being pumped back through the system. 815/654-2501; www.aqua-aerobic.com.

Advanced SBR system provides safe, treated effluent for irrigation

Problem: The 1980s-era extended aeration wastewater treatment facilities for the Good Samaritan Community in Kissimmee, Florida, needed frequent repairs, consumed significant energy and had reached end of life. The budget was tight, and space was limited.

Solution: AWT Technologies custom-engineered an advanced sequencing batch reactor (SBR) incorporating a bioselector zone and biological nutrient removal. The system requires minimal land, equipment and instrumentation and is fully automated with a SCADA system for remote monitoring. A highly efficient fine-bubble membrane aeration system minimizes air requirements, blower size and energy usage.

Result: The new system achieves high levels of BOD, TSS, nitrogen and phosphorus removal without chemicals, producing effluent suitable for landscape irrigation in the community. Power use is 50 percent less than with the old system, and routine maintenance has been reduced significantly. 403/453-2298; www.awt-technologies.com.

Bioaugmentation helps boost denitrification and bring slaughterhouse effluent into compliance

Problem: A slaughterhouse in South Korea needed to improve its wastewater treatment and increase capacity to accommodate growth in production. Expansion would be costly and take several months; the company needed a cheaper, faster solution.

Solution: Smart Bio Korea implemented a plan dosing BiOWiSH Aqua FOG from BiOWiSH Technologies, along with aerated reactor mixed liquor suspended solids into upstream chambers to boost denitrification.  

Result: Within three weeks the plant had achieved a stable effluent total nitrogen value of less than 20 mg/L. BOD, COD, TSS and total phosphorus, all of which had been above permit limits, were reduced by more than 75 percent and were in compliance. Plant operators say the bioaugmentation program greatly improved plant stability. 312/572-6700; www.biowishtechnologies.com.

Treatment system helps catering company meet discharge requirements

Problem: A large West Coast in-flight catering and commissary terminal needed a more advanced wastewater treatment system to replace a system using dissolved air flotation followed by activated sludge treatment. The company needed an expanded process that allowed reuse of water within the facility.

Solution: Clean Water Technology replaced the DAF with a GEM System for TSS and FOG removal. The company then installed a compact membrane bioreactor system for BOD removal. A skid-mounted reverse osmosis unit was installed for total dissolved solids reduction.

Result: The system doubled capacity, allowing the facility to upgrade from primary to tertiary treatment within the same footprint. Water reuse saved $300,000 a year in cooling-water costs. BOD was reduced from 1,500 to 3,000 mg/L to less than 1 mg/L, TSS from 1,000 to 2,500 mg/L to no measurable amount, and TDS from 1,000 mg/L to less than 82 mg/L. 310/380-4648; www.cleanwatertech.com.

Treatment plant achieves bonus from aeration system upgrade

Problem: The City of Newark, Ohio, sought relief from excessive electric bills through significant updates at its Licking River Wastewater Treatment Plant. Funding included a gridSMART grant from AEP Ohio that could be used to cover energy-saving expenditures if the city could show a seven-year return on investment.

Solution: The original intention was to replace two aging blowers with new, high-efficiency units. However, studies demonstrated more could be saved in the long run with FlexAir MiniPanel bubble diffusers from Environmental Dynamics International in the three aeration basins, waste activated sludge tanks and a post-aeration tank in combination with the new blowers.

Result: Savings from the blower replacement were projected at $168,000 per year. The facility also saw more operating cost savings, and the boost in efficiency enabled the plant to treat all its effluent in two of three basins. This freed up the third basin to treat trucked-in industrial waste and septage, generating revenue. 877/334-2478; www.wastewater.com.

System removes ammonia in cold temperatures in same lagoon footprint

Problem: A residential development on the south side of Cape Girardeau, Missouri, needed a cost-effective way to meet new ammonia effluent requirements of 1.4 mg/L in summer and 2.8 mg/L in winter in a non-aerated, three-cell lagoon system.

Solution: Development leaders selected the NitrOx System from Triplepoint Water Technologies to ensure year-round lagoon ammonia removal. The system required no new land and guaranteed controlled results, even in winter. Two 10- by 10-foot tanks were installed sidestream between the secondary and polishing cell, allowing the lagoon system to provide BOD treatment to 20 to 30 mg/L, at which point bacteria begins to nitrify. Influent water from the aerated cell is pumped into the first tank of the reactor. Sensors and a digital controller optimize temperature during the coldest winter months, and an insulated cover retains heat. High-surface-area media are mixed and aerated via a full-floor grid to foster growth of nitrifying bacteria. After eight total hours of retention time, effluent is released to the polishing cell.

Result: Ammonia limits were met, avoiding a mechanical plant upgrade and preserving the easy operation and low maintenance of the lagoon. The system saved more than $100,000 in capital costs. 800/654-9307; www.tpenv.com.

Cloth media filter helps development meet reuse requirements

Problem: A coastal development in eastern North Carolina had aging traveling bridge sand filters that required extensive and sometimes costly maintenance. The plant was also upgrading from chlorination to UV disinfection, requiring consistent low levels of TSS.

Solution: The operating company, regulators and engineers agreed that the Fluidyne Fixed Plate (FFP) cloth media filter system would provide reuse-quality treatment along with key mechanical and operational advantages. The systems use open-close pneumatic valves and gravity head to control filtering and backwashing. No pumps are needed to create backwash flow. Media panels can remain in place at all times instead of being rotated past a stationary spray or suction manifold. This eliminates moving parts and wear, and allows the filter elements to be square or rectangular instead of circular, easing manufacture, installation, removal and maintenance, while maximizing treatment area. Media elements can be independently isolated and removed from the flow stream without discontinuing or diverting flow.

Result: The system now produces reuse-quality effluent in a tertiary treatment system that is easy to use and maintain and inexpensive to operate. 319/266-9967; www.fluidynecorp.com.

Backup aeration system provides storm coverage

Problem: The LeSourdsville Wastewater Treatment Plant in Butler County, Ohio, must meet dissolved oxygen limits at the outfall on the Miami River. During normal operation, oxygen is added in a cascade basin. However, during storms the river can rise to levels that flood the cascade basin, rendering it useless.

Solution: The plant installed a modular drop-in system incorporating a pump and AirJection technology from Mazzei Injector Company, consisting of a venturi injector and an MTM nozzle manifold. The system eliminated the need for blowers and diffusers and the space and maintenance they require. The aeration system was designed to raise dissolved oxygen at the outfall from 3.5 to 5.6 mg/L under storm flows up to 26 mgd.

Result: The quiet, efficient, reliable aeration system allows the plant to meet outfall dissolved oxygen requirements. After one storm that flooded the cascade, the system maintained dissolved oxygen at 5.6 mg/L at flows up to 31 mgd, 20 percent higher than the system’s peak design flow. 661/363-6500; www.mazzei.net.

Dewatering improves solids handling

Problem: The 8 mgd Bluebonnet Water Supply Corp. Water Treatment Plant in Temple, Texas, generated up to 106 million gallons per year of spent backwash water and clarifier sludge, stored in three concrete lagoons. Solids never dried sufficiently to permit effective removal. Paying a hauler to remove the sludge was a major expense.

Solution: The facility added three modified sludge collection basins with vacuum transport units, two lift stations, the Poly-Mate polymer system and Sludge-Mate dewatering containers from Flo Trend Systems. Material now settles in the basins to a depth of no more than 1 foot before the sludge is transferred. When the sludge collection system activates, 19,600 pounds of solids flow by gravity to the first lift station, where the material is dewatered to 15 percent solids cake. Filtrate drains to the second lift station and is returned to the headworks.

Result: Chief of Operations Damon Boniface and staff stay ahead of sludge production and control disposal costs. 713/699-0152; www.flotrend.com.

Modularity brings high-quality sewage treatment to RV park

Problem: Bay Meadows, a year-round RV park on Lake Ontario, relied on subsurface treatment. However, stricter regulations and lack of space for subsurface treatment expansion called for a more sophisticated treatment solution. The park lies next to Pleasant Bay, a lagoon separated from Lake Ontario by a narrow strip of land. That barrier keeps the waters from mixing with Lake Ontario, and without that dilution Pleasant Bay cannot assimilate the park’s discharge.

Solution: Gunnell Engineering recommended a self-contained membrane bioreactor (MBR) system from Newterra, able to meet permit limits of 5.0 mg/L TSS and CBOD. Within 20 weeks, the company engineered, built, installed and commissioned a modular, self-contained system that treats 22,000 gpd.

Result: Minimal site work was required for the factory-built system. It arrived pre-plumbed, pre-wired and fully tested. It was installed and has worked without incident. 800/420-4056; www.newterra.com.

Replacement of aerobic digestion system stops air and nutrient pollution

Problem: The aerobic digestion system in Fort Pierce, Florida, received regular complaints of odors and had high energy costs, greenhouse gas emissions and nutrient pollution. The city sought a solution to protect its coastal environment and robust tourism industry.

Solution: In 2014, NuTerra installed a CleanB system and centrifuge from BCR Environmental Corporation that wastes directly from the clarifier. Eliminating wasting to a DAF unit for thickening and holding sludge in an aerobic holding tank before dewatering and landfilling reduces energy usage, greenhouse gas emissions and nutrient pollution and eliminates odors.

Result: The system saved $242,000 in annual biosolids treatment and disposition, and $54,000 in annual energy costs ($37.02 per dry ton). It eliminated a 75 hp aerobic digestion blower, reduced polymer usage by 40 percent and reduced nutrients and biosolids returned via filtrate by 70 percent. Improved nutrient capture in biosolids (182 percent increase in nitrogen and 476 percent increase in phosphorus) created a more valuable soil amendment. Drier cake (21 percent wet weight reduction) resulted in 52 fewer truckloads hauled annually. 904/819-9170; www.nuterra.green.

Filtration system helps municipality save potable water

Problem: A 100 mgd wastewater treatment in the Midwest has a large demand (nearly 3 mgd) for service water with low suspended solids for equipment cleaning, cooling of biogas-fueled engine/generator sets, and other purposes.  

Solution: An automatic self-cleaning screen filtration system provided by Orival Water Filters now supplies reuse water for in-plant needs, saving enough potable water to supply over 7,000 homes. Operating at up to 2,000 gpm, the system controls initiate a cleaning cycle when a 7 psi loss across the filtration system is reached. A manually set timer in the control panel can also initiate the cleaning cycle. The screens are cleaned by drawing water back through the screen at high velocity.

Result: Each filter takes less than 15 seconds to clean without interrupting the filtration process. Less than 1 percent of the flow is sent to a drain. 201/568-3311; www.orival.com.

Product helps city decrease pond sludge

Problem: Sludge in a pond in an Illinois city was taking up valuable treatment capacity and causing odors. Sludge had accumulated until part of the sludge blanket was exposed to the surface, allowing odors to escape. State regulators were also demanding improvements because BOD5 test results were too high.

Solution: The city de-sludged its lagoons with BIO ENERGIZER from Probiotic Solutions, a product designed to improve odor control, increase digester capacity, enhance sludge destruction and improve settleability and decants.

Result: After 14 months of treatment, 70 percent of the sludge blanket was removed. Before treatment, sludge depth averaged 41 inches. After treatment, the average depth dropped to 12 inches. The results satisfied the Illinois EPA. 800/961-1220; www.probiotic.com.

Filter nozzle replacement increases filtration capacity

Problem: The Quail Creek Water Treatment Plant in Hurricane, Utah, had 12 twin-cell gravity filters in need of new media. Four of the filters also needed new filter nozzles. There was also an interest in increasing filtration capacity to support population growth, but without having to source complete new filter underdrains.

Solution: Orthos Liquid Systems provided a custom filter nozzle configuration that incorporated into the existing filter underdrains to accommodate higher filtration rates and ensure good performance on air scour and backwash cycles. Based on trials, the plant decided to replace all the nozzles in the 12 filters.

Result: The contractor removed the media and installed the new filter nozzles a couple weeks ahead of schedule. The project has prolonged the filtration cycle, reduced backwash and air scour cycle times, and increased the filtration rate by 20 percent. 843/987-7200; www.orthosnozzles.com.

Grease-busting system prevents grease buildup, solves odor issue

Problem: The Mill Creek pumping station operated by the Jeffersonville (Indiana) Wastewater Department created an odor problem. The 30-foot cube-shaped tank accumulated rags and grease up to 2.5 feet thick, interfering with pump floats. Vacuuming was subcontracted at a considerable cost.

Solution: The department purchased a Pulsed Hydraulics grease-busting system. Upon startup, the odor was gone. “We run it 24/7, pulsing between once every 30 seconds to once a minute,” says Josh Boggs, the department’s odor control specialist. “We’ve had the compressor serviced once, but the only other maintenance item has been the regular three-month air filter inspection and cleaning, and I think we’ve replaced the filter once.”

Result: “The system solved the grease blanket buildup, which was the No. 1 priority, and knocked out the odor problems as well,” says Boggs. 800/641-1726; www.phiwater.com.

Cheese manufacturer uses biological treatment to reduce odor, BOD

Problem: A Midwest cheese manufacturer with a 3-million-gallon lined lagoon discharged whey onto a meadow. Typically the lagoon established an active green algae population during summer. During winter, the anaerobic whey wastewater was discharged directly into the emptied lagoon system, which retained all whey discharge until February/March. The collection tank in the factory had fluctuating BOD loadings from 3,860 to 10,600. The pH range in the collection tank was from 9.8 to 11.6. At this pH range, no microbiology was present. The periodic discharge from the tank into the lagoon was up to 6,200 gpd. In winter, the lagoon was ice-covered. In spring, aeration started up, dark green algae grew and severe odor occurred. Company owners sought to eliminate odor and reduce BOD.

Solution: The company installed the TVT-BIO 32 System from TVT US Corporation in the primary treatment lagoon in February 2014. In April bioaugmentation was added after the lagoon temperature increased to 56 degrees F.

Result: After 10 months, results indicated increased microbial diversity. Dominant blue-greens (cyanobacteria) were replaced by aerobic microlife forms (bacteria, protists, microcrustaceans). Odor was nearly eliminated. BOD loading was reduced by 73 percent while sludge was reduced within the lagoon system by 50 percent. The pH was reduced to 7.7. There was also significant biological nutrient removal. 585/264-1058; www.tvt-bio.com.

Packaged wastewater treatment plant handles increased flow

Problem: The 30-year-old packaged wastewater treatment plant in Dillard, Georgia, needed an upgrade to handle growth and address new effluent regulations. The mountainous site offered minimal space for expansion and called for a special design. The terrain also posed challenges for equipment delivery. Off-loading of trucks, laydown space and the sequence of system installation required precise planning and staging.

Solution: Engineers at RWL Water designed a 200,000 gpd extended aeration packaged plant to treat the city’s domestic wastewater. The plant uses a triple-wide tank system to fit the site. The existing plant was converted to a sludge-holding chamber. New mechanical equipment was assembled inside this tank to complete the conversion. The extended aeration system comprises three trains in a parallel, attached configuration.

Result: RWL Water created a cost-effective design that works within the space limitations and uses the existing plant as a component. 800/879-3677; www.rwlwater.com.

Reflective UV system offers nearly maintenance-free operation

Problem: Decentralized treatment systems are increasingly replacing septic systems on Cape Cod, and UV disinfection was needed for a compact 24,000 gpd Aquapoint Bioclere system.

Solution: King’s Landing in Brewster, Massachusetts, installed two UV Pure Technologies Hallett 30 systems to provide final disinfection. Cross-fire technology reflects UV energy to provide a high UV dose, even at UV transmittance as low as 65 percent, enabling the system to reduce total coliform to less than 200 MPN/100 mL. The systems are connected to the plant’s PLC controls, enabling remote monitoring, alarm notifications and data collection.

Result: The systems are nearly maintenance-free. Two high-output UV Pure lamps are mounted in air rather than in a quartz sleeve. This design prevents overheating of the lamps and makes lamp changes fast and simple, since the unit does not need to be drained. Each system has an automatic, mechanical wiper that prevents fouling of the quartz sleeve and ensures maximum light intensity, reducing manual cleaning and nuisance alarms due to fouling. 888/407-9997; www.uvpure.com.

Blowers help wastewater treatment facility save costs

Problem: In 2013, the City of Danbury, Connecticut, upgraded its water pollution control plant to meet a nitrogen limit. The plant treats 9 mgd of wastewater and 12 million gallons per year of septage for a population of 64,000.

Solution: As part of the upgrade, the Spencer Turbine Company provided its AyrJet Series high-speed, high-efficiency turbo blowers with magnetic bearing technology. As the blower shaft is levitated and centered at both ends in a permanent magnetic field, there is no contact and the motor can operate at a very high speed without oil or grease. Continuous monitoring and adjustment of the magnetic fields to maintain the shaft’s centered position ensures protection from catastrophic failure.

Result: The high-speed magnetic bearing technology reduces energy cost by 10 to 40 percent. The upgraded plant meets the nitrogen limit in the general permit, while saving up to $200 per day in energy costs. 800/232-4321; www.spencerturbine.com.

Emergency lagoon treatment reduces ammonia, BOD and hydrogen sulfide

Problem: A U.S. poultry processing plant was in danger of violating its discharge permit as its 3.5-million-gallon aerated lagoon could not maintain sufficient dissolved oxygen and could not meet ammonia and BOD discharge limits. These conditions were caused by high seasonal temperatures and elevated BOD loading. The oxygen-depleted lagoon also generated hydrogen sulfide odors. The plant faced fines, a temporary shutdown and lost revenue.

Solution: USP Technologies provided a turnkey, rapid-response solution that included 50 percent hydrogen peroxide, a bulk storage system, a feed skid and field support within 72 hours from the initial phone call. After one day of dosing hydrogen peroxide, lagoon DO levels increased and H2S  odors were eliminated.

Result: By week’s end, DO levels were in the 2 to 3 mg/L target range and ammonia and BOD levels were trending downward. The plant was out of danger of discharge violation. 877/346-4262; www.usptechnologies.com.