TY - JOUR
T1 - Functionalized carbon nanotube immobilized membrane for low temperature ammonia removal via membrane distillation
AU - Intrchom, Worawit
AU - Roy, Sagar
AU - Mitra, Somenath
N1 - Funding Information:
This study was partially supported by a grant from the Chemical, Bioengineering, Environmental, and Transport Systems Division, National Science Foundation, USA (Grant no. CBET-1603314). The authors also acknowledge the use of instrumentation at the Otto York Center for membrane characterization, and funding from the Ada Fritts Chair position at New Jersey Institute of Technology. The authors declared that there is no conflict of interest.
Funding Information:
This study was partially supported by a grant from the Chemical, Bioengineering, Environmental, and Transport Systems Division, National Science Foundation, USA (Grant no. CBET-1603314 ). The authors also acknowledge the use of instrumentation at the Otto York Center for membrane characterization, and funding from the Ada Fritts Chair position at New Jersey Institute of Technology.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/3/18
Y1 - 2020/3/18
N2 - Enhanced ammonia separation via direct contact membrane distillation (DCMD) using carbon nanotube immobilized membranes (CNIMs) is presented. The CNIMs were prepared using raw carbon nanotubes (CNTs) as well as more polar carboxylated carbon nanotubes referred to as f-CNTs. The ammonia removal by both CNIMs were markedly superior to that of the original PTFE membrane, while functionalized CNIM (CNIM-f) showed the best performance in terms of flux, mass transfer coefficients and selectivity. The flux with f-CNTs was 63% higher than the PTFE membrane and 22% higher than raw CNTs. Similar trends were observed for ammonia removal efficiency and mass transfer coefficients that were also significantly higher for the f-CNTs. The ammonia selectivity with respect to water vapor decreased with temperature for the PTFE and CNIM with raw CNTs, but in the presence of f-CNTs the selectivity did not show any decrease with temperature. The enhancement in ammonia removal with f-CNTs is attributed to the favored chemisorption of ammonia on the f-CNTs which was evident from contact angle measurements that showed a dramatic decrease for aqueous ammonia in the presence of the carboxylic groups.
AB - Enhanced ammonia separation via direct contact membrane distillation (DCMD) using carbon nanotube immobilized membranes (CNIMs) is presented. The CNIMs were prepared using raw carbon nanotubes (CNTs) as well as more polar carboxylated carbon nanotubes referred to as f-CNTs. The ammonia removal by both CNIMs were markedly superior to that of the original PTFE membrane, while functionalized CNIM (CNIM-f) showed the best performance in terms of flux, mass transfer coefficients and selectivity. The flux with f-CNTs was 63% higher than the PTFE membrane and 22% higher than raw CNTs. Similar trends were observed for ammonia removal efficiency and mass transfer coefficients that were also significantly higher for the f-CNTs. The ammonia selectivity with respect to water vapor decreased with temperature for the PTFE and CNIM with raw CNTs, but in the presence of f-CNTs the selectivity did not show any decrease with temperature. The enhancement in ammonia removal with f-CNTs is attributed to the favored chemisorption of ammonia on the f-CNTs which was evident from contact angle measurements that showed a dramatic decrease for aqueous ammonia in the presence of the carboxylic groups.
KW - Ammonia separation
KW - Carbon nanotube immobilized membranes (CNIMs)
KW - Direct contact membrane distillation (DCMD)
KW - Flux enhancement
UR - http://www.scopus.com/inward/record.url?scp=85073689370&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85073689370&partnerID=8YFLogxK
U2 - 10.1016/j.seppur.2019.116188
DO - 10.1016/j.seppur.2019.116188
M3 - Article
AN - SCOPUS:85073689370
SN - 1383-5866
VL - 235
JO - Separation and Purification Technology
JF - Separation and Purification Technology
M1 - 116188
ER -