Catalytic Denitrification in a Trickle Bed Reactor: Ion Exchange Waste Brine Treatment. Issue 5 (1st May 2017)

• Record Type: Journal Article
• Authors: Bergquist, Allison M.; Bertoch, Madison; Gildert, Gary; Strathmann, Timothy J.; Werth, Charles J.
• Is Part Of: Journal ‐ American Water Works Association. Volume 109:Issue 5(2017)
• Page Start: E129
• Page End: E151
• Publication Date: 2017-05-01
• Subjects: activated carbon -- brine reuse -- catalysis -- drinking water treatment -- ion exchange -- palladium‐indium -- trickle bed reactor; Ion Exchange -- Mass Transfer -- Velocity -- Reactors -- Brines -- Denitrification -- Reuse -- Activated Carbon Treatment; Water-supply -- United States -- Periodicals; Water-supply engineering -- United States -- Periodicals; 363.61097305
• DOI: 10.5942/jawwa.2017.109.0055
• Languages: English
• ISSNs: 0003-150X

Abstract

Abstract : Catalytic reduction of nitrate in ion exchange (IX) waste brine for reuse is a promising option for reducing IX costs and environmental impacts. A recycling trickle bed reactor (TBR) was designed and optimized using 0.5 percent by weight (wt%) palladium–0.05 wt% indium catalysts supported on US mesh size 12 × 14 or 12 × 30 activated carbon particles. Various liquid superficial velocities (Ur ) and hydrogen gas superficial velocities (Ug‐H2 ) were evaluated to assess performance in different flow regimes; catalyst activity increased with Ug‐H2 at all Ur for both catalysts and was greatest for the 12 × 30 catalyst at the lowest Ur (8.9 m/h). The 12 × 30 catalyst demonstrated up to 100% higher catalytic activity and 280% higher mass transfer rate compared with the 12 × 14 catalyst. Optimal TBR performance was achieved with both catalysts in the trickle flow regime. The results indicate that the TBR is a promising step forward, and continued improvements are possible to overcome remaining mass transfer limitations.