Packaged plant provides turnkey solution for private utility company

Problem:

Windy Hill Utility is an investor-owned water and wastewater utility provider in Hays County, Texas, that provides services to a residential housing development. The utility needed a turnkey package with a small footprint that could meet the strict permit requirements.

Solution:

The chosen Active Water Solutions packaged system had to meet effluent limits of 5 mg/L BOD and TSS, 2 mg/L NH4-N, and 1 mg/L total phosphorus for the 30,000-gpd phase one of the project. To maintain ease of operation, the process train was made for reliability and simplicity by incorporating Active Water Solutions’ submerged fixed-bed biofilm reactor method for BOD oxidation and nitrification. To further minimize moving parts and repair costs, clarification is handled by a tube settler rather than a mechanized system, while the chemical feed for phosphorus removal is introduced to a static mixer located between the aeration process and clarification. The facility includes an integrated chlorine contact basin. Waste is periodically moved from the clarifier via pump to a holding tank, to be hauled as needed.

Result: 

The cost-effective, packaged treatment system meets strict permit requirements while maintaining the resiliency and ease of use needed by utility providers. 832-571-1111; www.activewatersolutions.com

Mixing panels keep grit removal system running

Problem:

Southport Advanced Wastewater Treatment Plant in Indianapolis sought a solution that would maintain solids to prevent buildup in its grit removal system for a dry weather flow of 70 mgd. “The pulsed air mixing system is provided in Junction Structure 101B to suspend solids, which settle out following grit removal so they can pass on downstream for further removal or treatment,” says Gary Ruston, senior project engineer. “Keeping solids from accumulating in JS 101B will minimize or eliminate the need to periodically take JS 101B out of service for cleaning, which would be a major undertaking.”

Solution:

Wessler Engineering was tasked with developing the system. They worked with Pulsed Hydraulics to provide 24 bubble forming plates located in the channels and basin pursuant with the CFD model. The company supplied three four-valve mixing panels with an Allen-Bradley PLC and two rotary screw 20 hp compressors. “The pulsed air system was selected due to its higher mixing energy and better ability to keep or resuspend solids throughout the entire tank,” Ruston says. “The system can be operated on a continuous basis or may be operated intermittently, based on operator preference.”

Result: 

Requirements met and verified by customer’s engineer. 800-641-1726; www.phiwater.com

Anaerobic Membrane Bioreactor (AnMBR) pilot demonstrates superior performance in brewery

Problem:

The continued growth in popularity of craft beer and demand for its special brews, promoted Deschutes Brewery in Oregon to step up production. The company’s focus on sustainability, combined with economics, regulations, and space limitations, influenced Deschutes Brewery’s choice to find a system to treat the brewery’s wastewater and produce biogas in the process.

Solution:

Deschutes Brewery initiated a pilot study to verify if the anaerobic MBR technology using the Pentair X-Flow Helix membranes can handle the levels of COD and TSS created by spent hops and yeast residuals. In addition, the pilot helped identify the organic loading rate, the MLSS concentration, and ideal sludge retention time. This information was to minimize the footprint of a full-scale version, without sacrificing effluent quality and membrane performance.

Result: 

The six-month pilot proved the system’s performance. The external setup and Helix flux enhancement technology controlled any issues with fouling. As a result, the membranes provide a durable and reliable barrier for many years of demanding operation. The almost absolute separation between solids and fluids keeps the biomass in the reactor and delivers a superior effluent quality. 815-986-0391; www.xflow.pentair.com

Mixer provides efficiency and energy

Problem:

The Bellozanne Sewage Treatment Works on the island of Jersey in the Channel Islands — a crown dependency of Great Britain — sought a mixer system that would provide efficiency and energy.

Solution:

Utilizing its chopper pump to break down particle size, Landia’s externally mounted GasMix digester mixing system was successfully installed. “We certainly agreed straightaway that for the three new anaerobic digesters, all pipework and moving parts should be on the outside of the tank,” says Michelle Macleod, principal mechanical engineer for Doosan Enpure, who delivers water, wastewater, and renewable energy solutions. “Externally mounted equipment would also improve health and safety by eliminating the need for working at height and confined-space entry.” Bellozanne and Doosan Enpure also chose Landia pumps for three separate tanks containing digested biosolids, thickened biosolids (fed to the digesters via pasteurizers), and unthickened biosolids that comes off the final clarifiers, which are then thickened and added to the thickened tank to maximize overall residence time.

Result: 

Dave Garnett, technical specialist (wastewater) at Doosan Enpure added that Bellozanne is achieving high volatile solids destruction at an average of around 60 percent. “The pasteurizers must help,” he says. “Good mixing is critical with the high temperature feed to the digesters to make sure that everything is distributed properly. GasMix is working very well because we’re seeing plenty of energy produced by the CHP, making a big reduction in operating expense.” 919-466-0603; www.landiainc.com

Phosphorus recovery alleviates struvite buildup

Problem:

High levels of orthophosphates in the biosolids at Madison Metropolitan Sewerage District’s Nine Springs Wastewater Treatment Plant in Wisconsin caused struvite issues in the methane digester, as well as increased the polymer consumption during dewatering and reduced the plant’s biosolids dewaterability. The high orthophosphate levels also posed challenges for meeting the facility’s National Pollutant Discharge Elimination System permit.

Solution:

Centrisys/CNP conducted an extensive pilot of the scalable phosphorus recovery system, CalPrex. The system recovers phosphorus at a high rate in the form of brushite, diverting over 50 percent of the phosphorus from the digesters. The recovered brushite is a valuable phosphate fertilizer that can be utilized as an agricultural nutrient. 

Result: 

The pilot achieved orthophosphate reduction of over 90 percent and resulted in a fully scalable process. A Tailored Collaborative research pilot in collaboration with The Water Research Foundation, Milwaukee Metropolitan Sewerage District, Metro Wastewater Reclamation District of Denver, Madison Metropolitan Sewerage District, and Massachusetts Water Resources Authority is currently underway. 262-654-6006; www.cnp-tec.com

Reclaimed water station combats extreme drought

Problem:

During an extreme drought, the city of Brenham, Texas, struggled to conserve potable water. With nonessential needs like construction, toilet flushing, and dust control draining their supply, the city set off to find a solution but found most options to be cost-prohibitive. 

Solution:

With permission from the Texas Commission on Environmental Quality, the city procured a 210 Reuse Authorization, which allowed them to divert effluent water from their wastewater treatment plant to be used for nonessential needs. EleMech installed a Portalogic FS-22 bulk water filling station at the plant, which is monitored remotely by management software installed on personal computers in the administration office. After installation, EleMech also provided training for the city’s employees on the use of the station and software.

Result: 

The station not only enabled the city to drastically reduce potable water consumption, but also added a source of revenue. Haulers now purchase reclaimed water at the station, which is tracked via customer accounts in the management software. The station is open full time and has proven convenient and easy to use for numerous contractors. 630-499-7080; www.portalogic.info

Winery solves odor issues with aeration

Problem:

Ste. Chapelle Winery in Caldwell, Idaho, was experiencing odors from its 300-by-200-foot evaporative lagoon. These odors were generating complaints from retail customers and threatening the feasibility of a planned outdoor concert venue. A high BOD load of 2,100 mg/L was consuming all the oxygen in the water. Undigested process solids including grape pulp and skins were becoming septic and releasing pungent odors. The lagoon had less than 1 foot of water depth, and solids were building up around the inlet.

Solution:

Triplepoint Environmental assessed the pond with the engineers and site management and determined that nearly 5 feet of available freeboard would support a higher water level in the lagoon. They advised the winery that raising the water level to a minimum of 2.5 feet would allow an AeroHub Fine-Bubble Lagoon Aeration System to be installed to maintain dissolved oxygen levels, digest volatile solids and mitigate odors. Twelve fine-bubble units were installed onto the lagoon floor. Irrigation water was used to fill the lagoon to the recommended minimum depth of 2.5 feet. Because they are powered by an onshore blower, there are no moving parts in the water to malfunction, ensuring reliability and saving on operation and maintenance.

Result: 

The AeroHubs nestled into the process solids; significant surface foam demonstrated that they had immediately started oxidizing the solids. After a couple of weeks of acclimation, the foam dissipated, and the odors are under control. 800-654-9307; www.tpenv.com

Moving bed biofilm reactor system allows town to meet effluent limits

Problem:

An existing wastewater treatment plant in Ladysmith, British Columbia, provided treatment before discharging to the Ladysmith Harbor. The plant removed primarily particulate matter and suspended solids to be driven to a composting site. The system met some needs, but would not be able to achieve the future BOD and TSS effluent limits proposed to the town. The town needed an upgraded system that would minimize its biological and separation footprint while also meeting proposed effluent limits of 15 mg/L for both BOD and TSS on an average monthly basis.

Solution:

Ideal MBBR-DAF technology from World Water Works was selected. It combines moving bed biofilm reactor and dissolved air flotation technology to provide removal of BOD and TSS. The reactor degrades organic matter resulting in BOD removal, and the DAF component separates the biomass and solids from the water. This duo system allows the town to remove BOD and TSS with a small footprint. The system was designed with future flexibility for nitrification and denitrification. The 2.66 mgd secondary wastewater treatment plant treats mainly domestic sources, is designed to service a population of 17,000 and will treat the town’s wastewater for at least the next 20 years.

Result: 

The system was completed in the summer of 2016. The town was able to minimize its ecological footprint, and during the system’s performance test, it met an average of 8 mg/L BOD and 11 mg/L TSS. 800-607-7973; www.worldwaterworks.com 

Plant utilizes efficient mixing technology 

Problem:

The DTE Tonawanda wastewater treatment plant in Buffalo, New York, cleaned membranes in its ultrafiltration system with a two-step cleaning process using caustic soda followed by a citric acid wash. Less-than-acceptable results were met after three to four wash cycles. In addition, the caustic cleaners were highly corrosive and were hazardous to the operators.

Solution:

The plant manager switched to Micro-90 concentrated cleaning solution from International Products. It is a nonhazardous, water-based concentrate. A 1 percent solution removed the organics and metals that blind the membranes, and it has allowed them to eliminate the previous two-step cleaning process using caustic material. 

Result: 

The single cleaning cycle provides savings through reduced energy use, reduced chemical use and less downtime. The plant achieves 100 percent recovery after every wash, thus extending the life of their membranes to 11 years. 609-386-8770; www.ipcol.com