(559c) Integration of Catalytic Membranes and Bio-Hydrogen for Water Detoxification

The integration of nanostructured catalytic materials (such as, Pd) in microfiltration type functionalized membranes or creating metal-polymer composite membranes can create immense value in the area of pollutant remediation from water. Reductive processes with Pd containing catalyst in membranes require dilute hydrogen source for reductive dehalogenation. If one can produce hydrogen through photobacteria (near IR light) by converting waste organic acids to hydrogen, then we can integrate Pd-containing membranes for reductive degradation of water pollutants. The presentation will include: (a) Hydrogen generation by photo-responsive bacteria (Rhodopseudomonas palustris). We used NIR light sources and optically resonant gold-silica nanoparticles to increase light utilization of the bacteria to convert waste organic acids, such as acetic and maleic acids, to hydrogen (RSC Adv, 2019; Int. J. Hydrogen Energy, 2021). We demonstrated > 2.5 fold increases in hydrogen production when grown under a NIR source compared to a broad-band light source at equal light intensity (130 W/sqm). The use of the of the biohydrogen with functionaized membranes (PVDF-PAA-Pd, and Fe/Pd) containing Pd particles showed over 90% conversion of PCB-1 to biphenyl for water detoxification, indicating excellent hydrogenation reaction; (b) Use of composite membranes (porous Pd film on UF membrane for PCB degradation. Magnetron sputtering was used to deposit thin films of tantalum and MgPd alloy on top of polysulfone (PSf) membranes 100 nm thick (J. Mat. Res, 2021). A dealloying step in water removes the Mg component of the film creating a nanoporous (np) film of Pd. PCB’s were dechlorinated while permeated in a water solution under pressurization with 5% H₂ gas (remainder Argon). Over 60% of PCB-1 was degraded in solution with a single pass (under 4 bar pressure) through the composite membrane at 40 liter/m^2 h. This research has been supported by NIH-NIEHS-SRP, NSF-EAGER, and Southern Company.