Testing method helps determine activated carbon remaining service

Problem: Operators at the drinking water plant in Corvallis, Oregon, were unable to determine the remaining life of their eight activated carbon adsorbers.

Solution: Activated Carbon Services - PACS deployed its aqueous-phase carbon adsorber remaining service as a definitive test to answer the question. The test method is based on the Polanyi adsorption model and uses a gravimetric adsorption energy distribution full characterization to provide critical data for remaining service life. The device measures distribution of adsorption energies and associated pore volumes. By comparing starting carbon and used carbons, it can reveal the pores that are filled with adsorbate and no longer available.

Result: The remaining life method helped Corvallis learn that the adsorbers needed replacing. The method continues to obtain estimated carbon remaining service time before change-outs. 724/457-6576; www.pacslabs.com.

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Analyzer allows plant to decrease use of aluminum sulfate

Problem: The Fond du Lac (Wisconsin) Regional Wastewater Treatment Plant was spending a large amount on aluminum sulfate to keep effluent total phosphorus under 1 mg/L. Industrial discharges were contributing to highly variable phosphorus in the wastewater. The mode of operation was to make sure enough chemical was added to address the fluctuations.

Solution: Tom Kruzick of William Reid recommended the ChemScan mini oP analyzer from ASA Analytics. The unit was used as a monitoring device, allowing the aluminum sulfate to be manually adjusted once or twice a day. The analyzer is connected to the chemical feed pump via a SCADA system and is controlled automatically. The setpoint is currently 0.6 mg/L ortho phosphorus.

Result: Since installation of the analyzer in 2012, the plant has saved about $100,000 per year on aluminum sulfate using manual control. The plant recently moved toward biological phosphorus removal with chemical polishing. Effluent total phosphorus is consistently around 0.8 mg/L. The plant is on pace to save $50,000 more per year above the savings from manual adjustment, for a total of $150,000. 262/717-9500; www.asaanalytics.com.

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Platform enables city to organize monitoring data

Problem: The City of Richmond, California, was having trouble organizing its environmental monitoring data into a single web platform. The network included meters from Isco, Telog and ADS. The lack of a single platform made data reporting and graphing tedious and time-consuming.

Solution: The city deployed a FlowWorks platform on the advice of George Elaro and the Infrastructure Engineering Corporation.

Result: FlowWorks has helped the city bring its data into one platform, keep it organized and easily run reports and generate graphs. This has simplified day-to-day tasks. The engineering and management teams now have access to all the flow monitors in the system as well as the SCADA data from the wastewater treatment operations. Combined sewer overflow events and potential spills are identified using an accurate system with alarm capabilities. 206/859-6999; www.flowworks.com.

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Intuitive pump control solves drive fault issues

Problem: Repeated random pump failures in a Connecticut community in the Catskills were caused by the drive faulting out on a phase loss. Water is pumped uphill from a 100-foot well into large storage tanks for distribution to the community. “The environment and landscape played a role in our challenge,” says David Dretel, D&S Pump and Supply Co. “The problem was difficult to troubleshoot because power loss was happening randomly. Sometimes it would only occur once a week. The power faults also would happen during certain weather conditions and peak demand — not really things we could plan for.”

Solution: Experts from Goulds Water Technology, a Xylem brand, teamed with distributor D&S and Foley’s Pump Service. Installing the Aquavar Intelligent Pump Controller on the input of the SPD provided a more robust line filter (3.6 percent electrical impedance versus 3 percent). Xylem employees discovered that the drives were running without a pressure transducer. The system was also using a chlorinator when the drive ran full speed and was hooked up to the relay output. This meant the IPC would need to be used in a different setup. The team quickly configured the new controller.

Result: After setting up the new pump controllers, Xylem experts remained on site to test them and train the customers on features, data analysis and maintenance. The customer has seen improved performance and is providing a reliable water supply. 866/325-4210; www.goulds.com.

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Rural water plant finds leak with clamp-on flowmeter

Problem: A rural village water treatment plant in the Southwestern United States treats, stores and distributes 325,000 gpd. The village consumes an average of 125,000 gpd and can store up to 1 million gallons. The treatment plant was losing 210,000 gpd due to a leak.

Solution: The water authority brought in a portable SITRANS FUP1010 clamp-on ultrasonic flowmeter from Siemens to help find the leak. Workers checked the flow from the well and compared the readings to the line feeding the storage tank. The 8-inch pipe was buried in the side of a mountain. The differences in the clamp-on meter readings indicated the leak was on that line. The supervisor had plant personnel uncover the line in various sections and narrowed the search to the pipe section believed to be leaking. The leak was found and the 30-year-old pipe was repaired.

Result: By using the flowmeter to find the leak, the village avoided wasting more time and water and did not have to spend money for a consultant. Thousands of gallons in daily water loss was avoided, and the village was able to end water rationing. 800/365-8766; www.usa.siemens.com.

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Online monitoring of ammonium and nitrate helps facility meet strict discharge limits

Problem: Daily maximum discharge limits for ammonia and total inorganic nitrogen require exceptional performance at the Littleton Englewood (Colorado) Wastewater Treatment Plant. Operators needed a solution to monitor and control nitrification and denitrification in real time across a multistage biological process.

Solution: The plant team chose the IQ SensorNet 2020 XT system from YSI, a Xylem Brand, for its accurate results and low operator attention. DO, ammonium and nitrate sensors were installed at critical locations to monitor the process and control distribution of wastewater for the most efficient treatment. Optical nitrate sensors are deployed at the influent and effluent of the solids contact tanks, where the objective is to remove BOD and push nitrification downstream to the nitrifying trickling filters. Ammonium ion-selective electrode sensors are installed in the centrate return to control transfer of stored centrate and avoid overloading biological treatment. Ammonium sensors in the prechlorination tanks control the bypass of ammonia-rich secondary effluent around the nitrification process, maintaining the critical ammonia-to-chlorine ratio for efficient operation of the effluent chloramination disinfection process.

Result: The network configuration and modularity of the equipment means the monitoring system could easily be expanded to help solve problems with nitrification and denitrification. The system continues to provide real-time monitoring. 800/765-4974; www.ysi.com.