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PollutionEngineering November 2012 : Page 43

Advertorial Caustic Soda Pumps for Acidic Groundwater Acidic Groundwater Presents Corrosion Problems Over time, acidic groundwater adversely affects piping, valves and other components in residential water distribution systems. For many water districts, which have acidic groundwater, the solution is to inject caustic soda, (49 % sodium hydroxide solution), at the well site to raise the pH to approximately 7.8 to 8.4. For years, many water districts have been using diaphragm pumps to meter the caustic soda on order to raise the pH. The struggle has been with issues of varying accuracy and ongo-ing pump maintenance. Diaphragm pumps have check valves, which need to be routinely serviced. Also, the pump’s flexible diaphragm wears and deforms over time, causing accu-racy drift between maintenance periods, and requires recalibration. Fluid Metering Inc. offered a solution by replacing the diaphragm pumps with Fluid Metering’s Model CTS Valveless Piston Pump system. FMI’s patented CeramPump® pumping FLUID METERING principle uses one moving part, a rotating and reciprocation ceramic piston, for all fluid con-trol functions in the pump. Eliminating check valves eliminates all of the associated rebuild-ing maintenance and downtime. The sapphire-hard, ceramic internals are dimensionally stable, eliminating accuracy drift and the need for recalibration. maintenance, was virtually eliminated. The dimensionally stable internal components pro-vide drift free accuracy of better than 1 % for millions of cycles without recalibration. The CTS also uses considerably less power, has a smaller footprint, and comes housed in a pro-tective enclosure suitable for wall mounting. Fluid Metering is a major manufacturer of Dispensers and Metering Pumps for Water, Wastewater, Laboratory, Industrial and OEM applications. These unique piston-type posi-tive-displacement units feature no valves, low-dead volume, 1 % accuracy and a ceramic/ fluorocarbon fluid path. Flows from 2.5 µl/ dispense to flows of 4,600 ml/min with pres-sures to 200 psig. For complete information on the FMI Model CTS system and additional solutions to Water/Wastewater treatment, go to: The Results Have Been Dramatic Downtime, resulting from check-valve or HOWTO: • (732) 970-6696 • GEO-CLEANSE INTERNATIONAL, INC. Produce Chemical Oxidants and Reductants Utilizing a ‘Combined Oxidant ’ concentrations, such as DNAPL interfaces; thus the catalyst is precipitated directly with the targeted contaminants. A phosphate buf-fer solution stabilizes the reaction of the peroxide with MnO 2 to produce superoxide radicals and results in destruction of CT and other compounds that cannot be oxi-dized. Hydrogen peroxide also reacts with naturally occurring transitions metals (e.g., iron) to produce hydroxyl radicals, enabling treatment of mixed plumes of CT with com-pounds that can only be oxidized. Geo-Cleanse has conducted bench-scale treatability studies and a pilot-scale appli-cation to further enhance the effectiveness and efficiency of this remedial approach. Full-scale application of this technology is currently underway at the former chemical plant, and is expected to be complete by 2013. For additional information regarding this novel and sustainable “combined oxi-dant” in-situ remedial approach, please feel free to contact our office. 43 In-Situ Remediation Approach for Comingled Plumes A former chemical plant was demolished and the property has laid dormant for two decades in an economically depressed area in central New Jersey. Soil and groundwater in part of the site were impacted with VOCs (primarily chlorobenzene, carbon tetra-chloride (CT) and its breakdown products, including a DNAPL phase) and pesticides. An initial remedial design for the DNAPL-impacted areas called for sheet pilling, dewa-tering, and soil excavation. However, this type of a design would consist of high reme-dial costs, large sustainability implications, and transport of thousands of truckloads of heavily contaminated soil through urban and residential areas. Based upon previous academic research, Geo-Cleanse developed an approach utiliz-ing a combined oxidant in-situ remediation plan to treat the heavily impacted com-ingled plumes at this large 100-acre site. This combined oxidant concept is capable of oxidizing and reducing the contaminants present in situ without excavating the haz-ardous material. This novel in-situ treat-ment approach utilizes permanganate to precipitate manganese dioxide (MnO 2 ), which contains Mn(IV), to catalyze hydro-gen peroxide at circum-neutral pH pro-ducing superoxide radicals. The permanga-nate reduced by the reaction with organics precipitates the MnO 2 catalyst preferen-tially in zones with the highest organic NOVEMBER 2012

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