Immobilization of bimetallic nanoparticles on microfiltration membranes for trichloroethylene dechlorination.

Highly reactive nanoscale Ni/Fe nanoparticles were synthesized on microfiltration membranes for dechlorination of 20 mg/L trichloroethylene (TCE). Complete degradation of TCE was achieved within 25 min by Nylon 66 membrane with the production of ethane as a major degradation product, depicting that hydrodechlorination is the major reaction mechanism for TCE dechlorination. In addition, the carbon mass balance can be reached to 93%. The surface-area-normalized rate constant (kSA) for TCE degradation by Ni/Fe immobilized on Nylon 66 was 0.172 L h(-1) m(-2), which is higher than that by Ni/Fe in solution. Further TEM and SEM-EDS analyses show that Nylon 66 can retain higher amounts of Ni on the surface of membrane. In addition, the efficiency and rate for TCE dechlorination increased upon increasing mass loading of Ni from 2.5 to 20 wt%. Results obtained in this study clearly demonstrate that the use of Nylon 66 as the support for immobilization of bimetallic Ni/Fe nanoparticles has a good catalytic activity for dechlorination of TCE.