CHED 1055 |
| N-Nitrosodimethylamine (NDMA) and related N-nitrosamines are a class of potent carcinogens that are generated as byproducts of wastewater and drinking water disinfection with combined and free chlorine. Recent work from our laboratory shows that NDMA is rapidly reduced by porous Raney-type nickel catalysts in water using H2 as an electron donor. However, Raney Ni is pyrophoric, so more stable alternatives are sought for treatment applications. This work examines the kinetics of NDMA reduction in water by H2 in combination with nanophase nickel-boron (Ni-B) catalysts that are non-pyrophoric. Ni-B catalysts are highly active for NDMA reduction, with metal-normalized pseudo first order rate constants as high as 200 L gNi-1 h-1, which is significantly more active than Raney Ni (81 L gNi-1 h-1) and 5% Pd/Al2O3 (6 L gPd-1 h-1). The influence of solution pH and the Ni:B ratio on reaction rates will also be discussed. Nickel-boron's higher stability in the presence of oxygen combined with the low costs of nickel and boron suggest that Ni-B materials may be viable alternatives to Raney Ni and more expensive precious metal catalysts. |
|
Undergraduate Research Poster Session: Environmental Chemistry
2:00 PM-4:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster
Division of Chemical Education |