TY - JOUR
T1 - Stable dechlorination of Trichloroacetic Acid (TCAA) to acetic acid catalyzed by palladium nanoparticles deposited on H2-transfer membranes
AU - Cai, Yuhang
AU - Long, Xiangxing
AU - Luo, Yi Hao
AU - Zhou, Chen
AU - Rittmann, Bruce E.
N1 - Funding Information:
This work was supported by the generous donations from the Swette Family Endowment, the National Science Foundation (EEC-1449500) Nanosystems Engineering Research Center on Nanotechnology-Enabled Water Treatment, the Nanotechnology Collaborative Infrastructure Southwest (NNCI-ECCS-1542160), and ASU's Fulton Chair of Environmental Engineering. We gratefully acknowledge the use of electron microscopic facilities supervised by Mr. David Lowry in the School of Life Science, and by Mr. Karl Weiss and Dr. Manuel Roldan Gutierrez in the LeRoy Eyring Center for Solid State Science, both at Arizona State University. Yuhang Cai also gratefully acknowledges the financial support from China Scholarship Council (No. 201906680080 ).
Publisher Copyright:
© 2021
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/3/15
Y1 - 2021/3/15
N2 - Trichloroacetic acid (TCAA) is a common disinfection byproduct (DBP) produced during chlorine disinfection. With the outbreak of the Coronavirus Disease 2019 (COVID-19) pandemic, the use of chlorine disinfection has increased, raising the already substantial risks of DBP exposure. While a number of methods are able to remove TCAA, their application for continuous treatment is limited due to their complexity and expensive or hazardous inputs. We investigated a novel system that employs palladium (Pd0) nanoparticles (PdNPs) for catalytic reductive dechlorination of TCAA. H2 was delivered directly to PdNPs in situ coated on the surface of bubble-free hollow-fiber gas-transfer membranes. The H2-based membrane Pd film reactor (H2−MPfR) achieved a high catalyst-specific TCAA reduction rate, 32 L/g-Pd/min, a value similar to the rate of using homogeneously suspended PdNP, but orders of magnitude higher than with other immobilized PdNP systems. In batch tests, over 99% removal of 1 mM TCAA was achieved in 180 min with strong product selectivity (≥ 93%) to acetic acid. During 50 days of continuous operation, over 99% of 1 mg/L influent TCAA was removed, again with acetic acid as the major product (≥ 94%). We identified the reaction pathways and their kinetics for TCAA reductive dechlorination with PdNPs using direct delivery of H2. Sustained continuous TCAA removal, high selectivity to acetic acid, and minimal loss of PdNPs support that the H2−MPfR is a promising catalytic reactor to remove chlorinated DBPs in practice.
AB - Trichloroacetic acid (TCAA) is a common disinfection byproduct (DBP) produced during chlorine disinfection. With the outbreak of the Coronavirus Disease 2019 (COVID-19) pandemic, the use of chlorine disinfection has increased, raising the already substantial risks of DBP exposure. While a number of methods are able to remove TCAA, their application for continuous treatment is limited due to their complexity and expensive or hazardous inputs. We investigated a novel system that employs palladium (Pd0) nanoparticles (PdNPs) for catalytic reductive dechlorination of TCAA. H2 was delivered directly to PdNPs in situ coated on the surface of bubble-free hollow-fiber gas-transfer membranes. The H2-based membrane Pd film reactor (H2−MPfR) achieved a high catalyst-specific TCAA reduction rate, 32 L/g-Pd/min, a value similar to the rate of using homogeneously suspended PdNP, but orders of magnitude higher than with other immobilized PdNP systems. In batch tests, over 99% removal of 1 mM TCAA was achieved in 180 min with strong product selectivity (≥ 93%) to acetic acid. During 50 days of continuous operation, over 99% of 1 mg/L influent TCAA was removed, again with acetic acid as the major product (≥ 94%). We identified the reaction pathways and their kinetics for TCAA reductive dechlorination with PdNPs using direct delivery of H2. Sustained continuous TCAA removal, high selectivity to acetic acid, and minimal loss of PdNPs support that the H2−MPfR is a promising catalytic reactor to remove chlorinated DBPs in practice.
KW - Catalytic dechlorination
KW - Disinfection byproducts
KW - Hollow fiber membrane
KW - Palladium nanoparticle (PdNP)
KW - Trichloroacetic acid (TCAA)
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U2 - 10.1016/j.watres.2021.116841
DO - 10.1016/j.watres.2021.116841
M3 - Article
AN - SCOPUS:85099855779
VL - 192
JO - Water Research
JF - Water Research
SN - 0043-1354
M1 - 116841
ER -