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Remediation of actual groundwater polluted with nitrate by the catalytic reduction over copper–palladium supported on active carbon

Paper ID Volume ID Publish Year Pages File Format Full-Text
42463 45926 2009 7 PDF Available
Title
Remediation of actual groundwater polluted with nitrate by the catalytic reduction over copper–palladium supported on active carbon
Abstract

Catalytic reduction of nitrate (NO3−) in groundwater over a Cu–Pd catalyst supported on active carbon was investigated in a gas–liquid co-current flow system at 298 K. Although Cu–Pd/active carbon, in which the Cu/Pd molar ratio was more than 0.66, showed high activity, high selectivity for the formation of N2 and N2O (98%), and high durability for the reduction of 100 ppm NO3− in distilled water, the catalytic performance decreased during the reduction of NO3− in groundwater. The catalyst also irreversibly deactivated during the reaction in groundwater. The organic species in the groundwater caused the decrease in the catalytic performance and the irreversible catalyst deactivation. Ozone-treatment of the groundwater to remove the organic species substantially helped to maintain the catalytic activity and to halt the irreversible deactivation of the catalyst. Chloride ion (Cl−) in the groundwater also caused the decrease in the activity and selectivity, but the effects of Cl− were reversible. Sulfate ion (SO42−) and cations, including Mg2+, Ca2+ and K+, had little or no effect on the catalytic performance of Cu–Pd/active carbon, though they were present in the groundwater sample. More than an allowable level of NH3 (NH4+) was formed during the catalytic reduction of NO3− in the groundwater, but was completely removed by the cation-exchange process using Na-mordenite.

Graphical abstractOzone-treatment of actual groundwater polluted with NO3− substantially helped to maintain the catalytic activity of Cu–Pd/active carbon due to removal of organic compounds in the groundwater. While Cl− in the groundwater caused the decrease in the activity and selectivity, a process of ozone pre-treatment, catalytic reduction using Cu–Pd/active carbon, and ion-exchange with Na-mordenite remediated the actual groundwater.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Nitrate; Groundwater; Catalytic reduction; Copper–palladium bimetal catalyst; Humic acid; Ion-exchange
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Remediation of actual groundwater polluted with nitrate by the catalytic reduction over copper–palladium supported on active carbon
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 361, Issues 1–2, 20 June 2009, Pages 123–129
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us