The Ultimate Recycling
Nutrients removed from municipal wastewater in Oregon are helping to restore the salmon fishery in British Columbia. Itâs a novel arrangement built around stringent phosphorus and ammonia removal requirements at the Durham Advanced Wastewater Treatment Facility near Portland, innovative technology from Canadian nutrient recovery company Ostara, and the need to counteract overfishing in the coastal waters along Vancouver Island.
Rob Baur, senior operations analyst at Clean Water Services (CWS), the public water resource management utility that operates the Durham facility, explains: âWe remove phosphorus biologically because we have strict effluent limits, including the first total maximum daily load (TMDL) for phosphorus on any river in the country. The Ostara process removes phosphorus and ammonia from our dewatering centrate and converts it into struvite pellets, called prills by the fertilizer industry.â
The British Columbia Ministry of Environment purchases some of the struvite; volunteers bag it and place it in the headwaters of salmon streams where the struvite slowly releases nutrients into the water. The nutrients are critical because overfishing has reduced the population of adult salmon, which normally would swim upstream to spawn and die.
In the natural cycle, their decaying carcasses nourish the larvae and algae required to sustain the new salmon fry. Without the imported nutrients, the fry would struggle to grow strong enough to make it to the ocean and back again. âFor 35 years, Iâve been removing phosphorus and ammonia from wastewater,â says Baur. âItâs hard to believe that now Iâm putting them back into a river.â
LOOKING BACK
When the Durham facility was completed in 1976, it used high lime treatment as best available technology to achieve about two parts per million of phosphorus in the effluent, before release to the Tualatin River. In 1993, after the imposition of the phosphorus TMDL, the facility began using alum to remove the phosphorus with lime addition to adjust alkalinity. Durham later transitioned to biological phosphorus removal, dramatically reducing chemical usage and saving ratepayers money.
Today the plant, in Tigard, Ore., is designed for an average flow of 20 mgd (up to 100 mgd during wet weather) and includes a number of innovations besides the struvite process.
A new influent pump station has achieved the first LEED Silver certification for a pump station in the nation from the U.S. Green Building Council. The station has a peak capacity of 180 mgd and has a self-cleaning wet well. Each pump (ITT Water & Wastewater â Flygt) has a 1-ton flywheel to keep the pumps spinning while the check valves close to prevent water hammer.
In the updated headworks, Vulcan 3/8-inch continuously cleaning bar screens remove debris and trash, and the material is sluiced by water to a washer/compactor. A Smith & Loveless PISTA grit removal system follows. Primary tanks are covered, and primary effluent is pumped to the biological system. A surge basin helps the plant deal with wet-weather flows.
FLEXIBLE SYSTEM
In the face of widely varying seasonal flows and seasonal nutrient removal requirements, the biological system is highly flexible. The first two cells are anaerobic. Cells three and four are anoxic, using mixed liquor recycle to denitrify and recover alkalinity and oxygen. Cells five and six are aerobic. The first six cells represent 50 percent of the basin volume.
The second half of the basin is a serpentine plug-flow system that enables cost-effective nitrification during summer. During high flows, the primary effluent is sent to cell three, while cells one and two are 100 percent return activated sludge (RAS) to reduce the solids load on the clarifier. At extreme flows, contact stabilization is accomplished by sending the primary effluent to cell seven so that 50 percent of the aeration basin is RAS. The required weekly median is 0.2 mg/l for ammonia from May to November. (The phosphorus limit is 0.1 mg/l monthly median.)
After the secondary clarifiers, the treated water passes through three tertiary clarifiers where alum is added. Then a series of three chlorination units disinfect the water before it is filtered in a battery of 13 mixed-media units, followed by dechlorination before discharge. Between 1.5 and 2.0 mgd of purified effluent is recycled for irrigation use on community golf courses, parks, schools and athletic fields.
âItâs unusual to disinfect before filtration, but weâre set up that way to avoid additional pumping costs,â says Nate Cullen, CWS engineering division manager.
Before 1994, biosolids were incinerated, but today the waste activated sludges are thickened in Sharples centrifuges (Alfa Laval) and anaerobically digested, and the digested material is dewatered in Humboldt centrifuges (Andritz). The 23 to 25 percent solids cake is a Class B product.
In winter, the material is trucked to the arid regions of eastern Oregon to support alfalfa crops. In summer, it is spread on farmland in the nearby Willamette Valley. Digester gas generates electricity plus hot water, and both are used within the plant. The plant is in design for a fats, oils and grease (FOG) receiving system and new cogeneration facility
RECOVERING NUTRIENTS
The centrate from the dewatering step is where things get really interesting. About two years ago, the utility contracted for Ostaraâs proprietary fluidized bed reactor system to recover phosphorus and ammonia from the dewatered sludge centrate. When magnesium chloride (purchased by Ostara) is added to the mix, the nutrients form struvite, which precipitates out of the system in pure white prills, 1.0 to 3.5 mm in diameter.
Capturing the centrate phosphorus as struvite results in a 20 percent reduction in the phosphorus load to the plant. Operations analyst Mike Mengelkoch, responsible for operating the complex plant, explains, âRemoving all that recycled phosphorus is like having an additional aeration basin removing phosphorus.â
The prills are stored in a hopper, then bagged in 1-ton sacks. Ostara buys all the product, trucks it away and markets it as Crystal Green slow-release fertilizer. âIt is approved by the Department of Agriculture as a commercial fertilizer, but itâs an order of magnitude lower in heavy metals than mined phosphorus,â says Baur. âIt measures 5-28-0-10. That means 5 percent nitrogen, 28 percent phosphorus as P205 (12.6 percent as P), zero potassium, and 10 percent magnesium.â
The Durham plant is the first in the nation to successfully employ the Ostara technology. The $2.5 million system produces about 300 tons of Crystal Green fertilizer a year. In addition to the amount sent north to enrich the salmon streams, the product is marketed to landscapers, turf farms and container nurseries.
âThe slow release results in deep root development and green, healthy growth,â says Baur. âPeople really like it, especially in sandy soil conditions.â Operation of the Ostara system has been fairly simple since startup in May 2009, and the payback has been encouraging.
CONTROLLING QUALITY
âWe were the first of the lot, so it was new to everybody,â says Baur. âSome bugs popped up, and we had to do some thinking on our feet. We tried two different kinds of knife gates and changed some piping, but once we got to a steady state, things ran smoothly.â The system was installed in an existing building.
Ostara controls the recipe via a Web-based system and is responsible for the quality of the end product. The Durham staff handles startup and shutdown, preventive maintenance, repair and cleaning. âWe havenât had to add any operators,â Cullen notes.
Durham uses Grundfos digital dosing pumps for hypochlorite and caustic and specified them for magnesium chloride in the Ostara system. âThe pumps are now part of Ostaraâs standard design because of their smooth delivery and Profibus control link,â says Baur.
A NEXTChem online analyzer measures phosphorus in the Ostara effluent, which is basically centrate. âIn spite of all the solids in the sample, the NEXTChem analyzer does not use a filter,â says Baur. âThe turbid sample, which could not be analyzed colorimetrically, is measured with a titration using a pH electrode.
âThe sample is titrated to pH 4 and lanthanum nitrate is added. The lanthanum reacts with the phosphorus to release nitric acid, and the pH drops. The sample is titrated back up to pH 4. The amount of titrant is proportional to the initial phosphorus concentration. The online data is used to monitor reactor operation.â
In fact, Baur and Cullen say the only issue with the Ostara process was tying the remote operation of the system into the plantâs SCADA network. It was necessary to work around stringent internal security protocols that do not allow Internet access to the plant SCADA system.
The Durham facility is highly automated, using GE-Intellution iFix software and ChemScan analyzers (ASA Analytics) to measure nitrites, nitrates, ammonia and phosphorus in the secondary effluent. Sixteen critical alarm signals, with voice-over, are annunciated over the facilityâs radio system.
RETURN ON INVESTMENT
The plant receives revenue from the struvite, and Baur anticipates a seven-year payback on the system. Other benefits are already apparent. The plant is using 40 percent less alum for phosphorus removal, since the Ostara system recovers about 85 percent of the phosphorus in the centrate. Biosolids contain less phosphorus and are easier and less expensive to manage.
Ostara provided 30 days of concentrated training to acquaint staff with the operation of the nutrient recovery system. âThey had staff on site, conducting formal training with each of our shifts,â Baur says. âThey had to make 20 tons of product within the 30-day period for substantial completion of the construction contract.
âBrett Laney, one of our operators, really got involved with it, so we now have him dedicated to the process. He stays in touch with Ostara, giving them feedback and interfacing with them. Brett is also involved with piloting and implementing modifications to the nutrient removal system.
âWe used to treat the same phosphorus over and over again due to the heavy recycle load. But not anymore. The system has improved our biological phosphorus removal, itâs reduced our operating cost, and itâs producing revenue. Itâs been fun.â
PDF download:
2011-08-15-TPO_0

Ostara and Oakley Sign Letter of Intent for Purchase of Oakleyâs St. Louis Granulation Facility and Long-term Terminal Services

Ostara Nutrient Recovery Technologies Inc. & City of Atlanta Announce Official Launch of Nutrient Recovery Facility

Ostara Nutrient Recovery Technologies Inc. and ICL Specialty Fertilizers Expand Distribution of Recycled Nutrients into New Territories

Ostara Provides Corporate Update: Additional Growth Capital from Equity Funding and New Credit Facility; New Board Director, Monty Bayer

Reimagining the Future of Phosphates at Symphos 2019; Phosphorus Recovery, Sustainability and the Circular Economy.

Ostara Raises up to US$16.5 Million with Existing Investors to Support Production Scale-up and Accelerate Global Growth

Ostara Enters into Long-Term Granulation Tolling Agreement in Response to Increasing Crystal Green Sales Demand

Shafdan Wastewater Treatment Plant will be the first in the region to install an Ostara Nutrient Recovery Facility

City of St. Cloud to Install Ostaraâs Nutrient Recovery Technology as Key Part of the Cityâs Nutrient Recovery and Reuse Project

Ostara to Deliver City of Atlanta Nutrient Recovery Facility Through Unique Alternative Finance Model

Ellen MacArthur Foundation | Case Study: Ostara Nutrient Recovery Technologies – Closing the Nutrient Loop

Treatment Plant Operator | Water Environment Federation Presents Awards for Operational and Design Excellence

The MWRD of Greater Chicagoâs Nutrient Recovery Facility earns Top Honor from Water Environment Federation

Executive Voice Publishing | The Best of Canada Report: Honoring Canada’s 150 year Legacy of Commercial Success (as seen in Bloomberg and The Wall Street Journal)

SDTC SUCCESS STORY | Partnering for real results. Meeting environmental goals. Moving cleantech to market.

Black & Veatch | Worldâs largest nutrient recovery facility produces valuable, environmentally friendly fertilizer

AQUA STRATEGY | A growth opportunity – how recovery of phosphorus from wastewater is bringing success for Ostara

ESEM | Wastewater converted to ecofriendly fertilizer with the help of dewatering, classifying screeners

WATER ONLINE | Measuring The Impact Of Phosphorus Recovery â From The Midwest To The Gulf Of Mexico

VANCOUVER SUN | Vancouver’s Ostara aims to harvest from municipal waste rather than mining phosphorus

WATER BRIEFING | Dutch Waterboard opens Europeâs first nutrient recovery facility at Amersfoort WwTW

DUTCH WATER SECTOR | Next-step sludge treatment integrates three advanced technologies at wwtp Amersfoort, the Netherlands

SUSTAINABLE BRANDS | Chemical Plant, Nutrient Recovery Facility Bring Circular Economy One Step Closer

Metropolitan Water Reclamation District of Greater Chicago and Ostara Open Worldâs Largest Nutrient Recovery Facility to Help Recover Phosphorus and Protect Mississippi River Basin

Dutch Waterboard Vallei en Veluwe and Ostara to produce high-value fertiliser, Crystal GreenÂŽ at Amersfoort WWTP

Ostara is named in the 2015 Global Cleantech 100: Recognized as a Pioneer in Shaping the Future of Resource Recovery

ACWA Services partners with Ostara to offer Phosphorus Recovery Revenue Stream for UK Water Companies

Ostara is Named in the 2014 Global Cleantech 100 for 6th Straight year: Recognized as Market Leader in Waste to Wealth Technology

Ostara Sees Improved Dewaterability and Reduced Biosolids Production with Waste-activated Sludge Stripping Technology

Madison Metropolitan Sewerage District and Ostara Help Dane County Lead the Way in Reducing Nutrient Pollution

What operational benefits and political motivation persuade utilities to install nutrient recovery systems?

Ostara Nutrient Recovery Technologies wins Technology Green 15⢠Award at the 2013 Deloitte Technology Fast 50⢠Awards

Come, friendly bombs, don’t fall on Slough. It’s doing good for humans now: Berkshire town to launch ÂŁ2m nutrient-recovery reactor

BBC World News Horizons explores why human waste is one of biggest public health issues facing world today

Ostara Named to 2013 Global Cleantech 100 List: Recognized as Market Leader in Technology with World-Changing Impact

Ostara Named to 2013 Global Cleantech 100 List: Recognized as Market Leader in Technology with World-Changing Impact

Robert F. Kennedy Jr. and Chicagoâs Metropolitan Water Reclamation District Discuss Nutrient Recoveryâs Crucial Role in Combatting Water Pollution

Black & Veatch and Ostara to Design-Build New Nutrient Recovery System for Worldâs Largest Water Reclamation Plant

Black & Veatch and Ostara to Design-Build New Nutrient Recovery System for World’s Largest Water Reclamation Plant

Clean Water Services and Ostara Nutrient Recovery Technologies Open World’s Largest Municipal Nutrient Recovery Facility

Hampton Roads Sanitation District and Ostara Win National Council of Public-Private Partnerships Award

Madison Metropolitan Sewerage District and Ostara Partner to Install Commercial Nutrient Recovery Facility

Virginia Wastewater Treatment Plant First In Chesapeake Bay Watershed to Recover Nutrients and Transform Them into âGreenâ Commercial Fertilizer

Media Alert: Unveiling of New Nutrient Recovery Facility That Will Protect Chesapeake Bay, with Keynote Speaker Robert F. Kennedy, Jr.

World’s Only Slow Release, Renewable Fertiliser Begins Commercial Production – Crystal GreenÂŽ Proven Effective for Turf, Nursery, Specialty Markets

HRSD Treatment Plant to Build Full-Scale Nutrient Recycling Facility Nutrients will be Recycled into âGreenâ Commercial Fertilizer

Severn Trent First in Europe to Recycle Nutrients into âEnvironmentally Friendlyâ Commercial Fertiliser

VantagePoint Venture Partnerâs Portfolio Companies Take Top Rankings in Guardianâs Global CleanTech 100

Oregon Wastewater Treatment Plant First in the U.S. to Recycle Nutrients Into ‘Green’ Commercial Fertilizer

SFPUC and Ostara Demonstrate Innovative Technology That Recycles Harmful Sewage Byproduct to Environmentally-safe Fertilizer

SFPUC and Ostara Demonstrate Innovative Technology That Recycles Harmful Sewage Byproduct to Environmentally-Safe Fertilizer

Ostara Nutrient Recovery Technologies Raises U.S. $10.5 Million to Accelerate Commercialization of CleanTech Water Treatment Process

Ostara Nutrient Recovery Technologies Inc.: Oregon Wastewater Treatment Plant Is the First in U.S. to Recycle Nutrients Into “Green” Commercial Fertilizer

Edmonton Reveals World’s First Industrial Scale Sewage Treatment Facility to Recycle Nutrients Into Environmentally-Safe Commercial Fertilizer

Clean Water Servicesâ wastewater treatment facility conducts trials of new environmentally-friendly technology from Canadian company
Â
Š 2020 Ostara Nutrient Recovery Technologies Inc. Home | Technology | Nutrients | Contact UsÂ
Â