TY - JOUR
T1 - Scaling Resistance in Nanophotonics-Enabled Solar Membrane Distillation
AU - Rice, Douglas
AU - Ghadimi, Shahrouz J.
AU - Barrios, Ana C.
AU - Henry, Skyler
AU - Walker, W. Shane
AU - Li, Qilin
AU - Perreault, François
N1 - Funding Information:
This work was supported by the Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (EEC-1449500). We acknowledge Zhiwei Xiao for the streaming potential measurements, Pratiksha Dongare and Bernie Kellogg for supplying CB-PVDF membranes, and Charles Dahill for the initial modeling work. We gratefully acknowledge the use of the characterization facilities within the LeRoy Eyring Center for Solid State Science at ASU.
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/2/18
Y1 - 2020/2/18
N2 - This study compares the scaling behavior of membrane distillation (MD) with that of nanophotonics-enabled solar membrane distillation (NESMD). Previous research has shown that NESMD, due to its localized surface heating driven by photothermal membrane coatings, is an energy-efficient system for off-grid desalination; however, concerns remained regarding the scaling behavior of self-heating surfaces. In this work, bench-scale experiments were performed, using model brackish water, to compare the scaling propensity of NESMD with MD. The results showed NESMD to be highly resistant to scaling; a three times higher salt concentration factor (c/c0) was achieved in NESMD compared to MD without any decline in flux. Analyses of the scaling layer on NESMD membranes revealed that salt deposition was 1/4 of that observed for MD. Scaling resistance in NESMD is attributed to its lower operating temperature, which increases the solubility of common scalants and decreases salt precipitation rates. Precipitation kinetics measurements revealed an order of magnitude faster precipitation under heated conditions (62 °C, k = 8.7 × 10-2 s-1) compared to ambient temperature (22 °C, k = 7.1 × 10-3 s-1). These results demonstrate a distinct advantage of NESMD over MD for the treatment of high scaling potential water, where scaling is a barrier to high water recovery.
AB - This study compares the scaling behavior of membrane distillation (MD) with that of nanophotonics-enabled solar membrane distillation (NESMD). Previous research has shown that NESMD, due to its localized surface heating driven by photothermal membrane coatings, is an energy-efficient system for off-grid desalination; however, concerns remained regarding the scaling behavior of self-heating surfaces. In this work, bench-scale experiments were performed, using model brackish water, to compare the scaling propensity of NESMD with MD. The results showed NESMD to be highly resistant to scaling; a three times higher salt concentration factor (c/c0) was achieved in NESMD compared to MD without any decline in flux. Analyses of the scaling layer on NESMD membranes revealed that salt deposition was 1/4 of that observed for MD. Scaling resistance in NESMD is attributed to its lower operating temperature, which increases the solubility of common scalants and decreases salt precipitation rates. Precipitation kinetics measurements revealed an order of magnitude faster precipitation under heated conditions (62 °C, k = 8.7 × 10-2 s-1) compared to ambient temperature (22 °C, k = 7.1 × 10-3 s-1). These results demonstrate a distinct advantage of NESMD over MD for the treatment of high scaling potential water, where scaling is a barrier to high water recovery.
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U2 - 10.1021/acs.est.9b07622
DO - 10.1021/acs.est.9b07622
M3 - Article
C2 - 31971783
AN - SCOPUS:85080872101
SN - 0013-936X
VL - 54
SP - 2548
EP - 2555
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 4
ER -