Subscriber access provided by TULANE UNIVERSITY
Remediation and Control Technologies
In situ growth of Metal-Organic Frameworks in ThreeDimensional Aligned Lumen Arrays of Wood for Rapid and Highly Efficient Organic Pollutants Removal Ruixue Guo, Xiaohui Cai, Hanwen Liu, Zi Yang, Yajie Meng, Fengjuan Chen, Yiju Li, and Baodui Wang Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.8b06564 • Publication Date (Web): 06 Feb 2019 Downloaded from http://pubs.acs.org on February 7, 2019
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 49
Environmental Science & Technology
In situ growth of Metal-Organic Frameworks in 3-Dimensional Aligned Lumen Arrays of Wood for Rapid and Highly Efficient Organic Pollutants Removal Ruixue Guo1†, Xiaohui Cai1†, Hanwen Liu1, Zi Yang1, Yajie Meng 1, Fengjuan Chen1*, Yiju Li2*, Baodui Wang1*
1
State Key Laboratory of Applied Organic Chemistry and Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University, Lanzhou, 730000, P. R. China 2 Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, P. R. China *Email:
[email protected];
[email protected];
[email protected] †These authors contributed equally to this work.
ACS Paragon Plus Environment
1
Environmental Science & Technology
Page 2 of 49
Table of Content
ACS Paragon Plus Environment
2
Page 3 of 49
Environmental Science & Technology
1
Abstract
2
Organic contaminants in water have become one of the most serious environmental problems
3
worldwide. Adsorption is one of the most promising approaches to remove organic pollutants
4
from water. However, the existing adsorbents have relatively low removal efficiency, complex
5
preparation process and high cost, which limit their practical applications. Here,we developed a
6
three-dimensional (3D) zirconium metal-organic frameworks (MOFs) encapsulated in a natural
7
wood membrane (UiO-66/wood membrane) for highly efficient organic pollutants removal from
8
water. UiO-66 MOFs were in situ growth in the 3D low-tortuosity wood lumens by a facile
9
solvothermal strategy. The resulting UiO-66/wood membrane contains the highly mesoporous
10
UiO-66 MOFs structure as well as many elongated and open lumens along the direction of the
11
wood growth. Such unique structural feature improves the mass transfer of organic pollutants
12
and increases the contact probability of organic contaminants with UiO-66 MOFs as the water
13
flows through the membrane, thereby improving the removal efficiency. Furthermore, the
14
integrated multilayer filter consisting of three pieces of UiO-66/wood membranes exhibits a high
15
removal efficiency (96.0%) for organic pollutants such as rhodamine 6G, propranolol, and
16
bisphenol A at the flux of 1.0×103 L∙m-2∙h-1. The adsorbed capacity of UiO-66/wood for Rh6G
17
(based on the content of UiO-66 MOFs) is calculated to be 690 mg∙g-1. We believe that such
18
low-cost and scalable production of UiO-66/wood membrane has broad applications for
19
wastewater treatment and other related pollutants removal.
20
Keywords: Metal organic frameworks, water treatment, organic pollutants removal, in situ
21
growth, lumen arrays
ACS Paragon Plus Environment
3
Environmental Science & Technology
Page 4 of 49
22
Introduction
23
Organic pollutants in water resources, such as organic dyes, pesticides, and pharmaceuticals,
24
have attracted great attention because of their potential negative impact on ecological
25
sustainability and human health.
26
methods for organic pollutants removal. So far, a variety of sorbents have been developed for
27
organic pollutants removal, including activated carbon, modified polymer,3 chelating resins,4
28
natural materials5 and so on. Among these adsorbents, activated carbon has been widely used as
29
a commercial material because of its high adsorption capacity and removal efficiency for some
30
organic pollutants.6 However, this material still suffers from several deficiencies, such as slow
31
treatment rate and poor removal efficiency for hydrophilic pollutants. Therefore, it is still
32
necessary to develop new materials with high efficiency, low cost and recyclability to rapidly
33
remove organic pollutants from aqueous solution. 5,7
34
MOFs with an abundant microporous structure, a large surface area, and high thermal stability 8,9
35
have triggered tremendous attention due to their various potential applications in molecular
36
separation,10 gas capture,11 chemical sensors,12 catalysis,13 and drug delivery.14,15 Recently,
37
water-stable MOFs have been used for the removal of organic contaminants including dyes,16
38
benzenes,17 phenols,18 hydrochloric acid, and acetic acid from aqueous solutions19,20 and
39
displayed great adsorption capacities in a laboratory scale. However, there are still facing issues
40
used as pollutant absorbents on a practical scale. Generally, MOFs particles are usually filled in
41
pipes in the form of powders, which can block mass transfer pathways and make it difficult to
42
recycle. Therefore, it is urgent to prepare MOFs based freestanding membranes with open,
43
porous, and low-tortuosity microstructure.
1,2
Adsorption is thought to be one of the most promising
ACS Paragon Plus Environment
4
Page 5 of 49
Environmental Science & Technology
44
Wood is a widely used natural material in our daily lives. 21 Because of its large number of 3D
45
openings and low bending lumen (channels) along the growth direction,22-24 wood is an ideal
46
substrate for diverse applications, including solar steam generation,25 transparent building
47
materials,26,27 and green chemical reactors28,29 etc. We envisaged that a composite membrane
48
with high transport and adsorption properties can be obtained by growing MOFs materials in situ
49
in wood channels. However, so far, there have been no reports on the use of MOFs/wood
50
membrane to remove organic pollutants from aqueous solutions.
51
Herein, we developed a 3D Zr-MOFs/wood (UiO-66/wood) composite membrane for rapid and
52
highly efficient organic removal by in situ growth of water-stable UiO-66 MOFs in the 3D wood
53
channel arrays. Cellulose is the major constituent of wood cell walls, which contains a large
54
number of hydroxyl groups30 that can coordinate zirconium ions (IV, Zr4+). The coordinated Zr4+
55
ions in wood channels further reacted with organic ligands to form 3D UiO-66/wood membrane.
56
Due to the open and aligned structure of wood channels,31 the contact probability between
57
organic pollutants and the modified UiO-66 MOFs nanoparticles is increased, which leads to the
58
efficient adsorption of organic pollutants. Additionally, the high natural abundance of wood
59
helps to reduce the cost of organic pollutant removal and achieve large-scale treatment in
60
practical applications. As a proof of concept, we designed an all-in-one filter by assembling three
61
pieces of UiO-66/wood membranes for efficient removal of several organic pollutants in water.
62
The efficiency of the UiO-66/wood membrane was over 96.0% for all organic pollutants tested at
63
a flux of 1.0 ×103 L∙m-2∙h-1, showing broad application prospects for the practical water treatment.
64
32, 33
ACS Paragon Plus Environment
5
Environmental Science & Technology
Page 6 of 49
66
Materials and Methods
67
Materials and chemicals. All reagents and solvents were used without further purification
68
unless otherwise mentioned. The basswood used in this study was obtained from the Chenlin
69
Wood Company. Terephthalic acid (TPA, 98.5%) and propranolol hydrochloride were purchased
70
from the J&K Scientific Ltd. 1-naphthyl amine (1-NA), Bisphenol A (BPA), Bisphenol S (BPS),
71
zirconium (IV) chloride (ZrCl4, 98%), acetic acid (HAc, 99%), rhodamine 6G (Rh6G), methanol,
72
and N, N-dimethyl formamide (DMF) were obtained from Tianjin Med.
73
Preparation of the UiO-66/wood membrane. A piece of natural basswood (diameter: 13 mm,
74
thickness: 5 mm) was immersed in 30 mL DMF containing 366 mg ZrCl4, 258 mg terephthalic
75
acid, and 2.68 mL acetic acid. Then, the mixture was transferred into a sealed autoclave and
76
placed in a muffle at 120℃ for 24 h. The UiO-66 MOFs nanoparticles were formed in-situ in the
77
wood matrix.
78
methanol (MeOH) to remove free UiO-66 and excessive precursors. The Zr content of the UiO-
79
66/wood membrane was tested by inductively coupled plasma mass spectrometry (ICP-MS,
80
Perkin-Elmer Elan DRC II). The content of UiO-66 MOFs in the prepared membrane was 2.22
81
wt%.
82
Water treatment measurements. Pollutants (propranolol, 1-NA, BPA, BPS) were dissolved
83
directly in deionized filtered water (DI water) to prepare the water samples polluted with the
84
organic molecule (0.1 mmol·L-1). Rh6G-polluted water (10 mg·L-1) was used to investigate the
85
absorption isotherm and the kinetic process. The pH of the mixture solution was adjusted using
86
HCl or NaOH solutions (0.1 mol·L-1). The Rh6G, propranolol, 1-NA, BPA, and BPS contents of
87
the water before and after treatment with the UiO-66/wood membrane were determined by UV-
34,35
Finally, the prepared UiO-66/wood membrane was washed with DMF and
ACS Paragon Plus Environment
6
Page 7 of 49
Environmental Science & Technology
88
visible adsorption spectroscopy (UV-vis). The removal efficiency was calculated using the
89
following equation: 6,36
90
Removal efficiency (%) = 100*(C0-C)/C0
(1)
91
where C0 is the initial concentration of pollutant and C is the pollutant concentration after
92
filtration. An all-in-one three-layer filter was designed by assembling three pieces of UiO-
93
66/wood membranes together. A syringe pump was used to control the flux. The removal
94
efficiency of the three-layer filter for various organic pollutants (Rh6G, propranolol, 1-NA, BPA
95
and BPS) was evaluated.
96
Characterization. X-ray diffraction (XRD) patterns were recorded using the Cu Ka radiation
97
(λ=1.5418 Å) on a Bruker AXS D8 advance diffractometer. The morphology of the samples was
98
investigated by field-emission scanning electron microscopy (FE-SEM, FEI, Sirion 200). The
99
UV-vis curves were obtained with a UV 1750 spectrometer.
100 101
Results and Discussion
102
The schematic of the in situ synthesis UiO-66 MOFs nanoparticles in 3D wood microchannels
103
for rapid and highly efficient organic pollutants removal is shown in Figure 1. A piece of natural
104
basswood was immersed in the precursor solution of UiO-66 MOFs until adsorption saturation
105
was reached (Figure 1a). The UiO-66 MOFs nanoparticles are in-situ formed in the wood matrix
106
after heating at 120 0C for 24 hours
107
enlarged schematic of the UiO-66/wood membrane exhibits the numerous elongated and open
108
lumens that are uniformly decorated with the UiO-66 MOFs nanoparticles. As shown in Figure
109
1c, an all-in-one filter device was designed by assembling three pieces of the UiO-66/wood
110
membranes together for scalable applications. Furthermore, the prepared UiO-66/wood
34,35
and the color of wood turns brown (Figure 1b). The
ACS Paragon Plus Environment
7
Environmental Science & Technology
Page 8 of 49
111
membrane can be readily regenerated by cleaning with methanol several times and can be scaled
112
up by adjusting the number of layers of the UiO-66/wood membrane for industrial applications.
113 114
Figure 1. Schematic showing the synthesis process of the UiO-66 MOFs in a 3D wood membrane for rapid
115
and highly efficient organic pollutants removal. (a) A piece of natural wood is absorbed with the precursor
116
solution of UiO-66 MOFs, which contains ZrCl4, TPA, DMF, and HAc. (b) UiO-66 MOFs nanoparticles in situ
117
formed in the 3D wood matrix through a solvothermal treatment. The zoomed-in image shows the microstructure of
118
the UiO-66/wood membrane uniformly decorated with the UiO-66 MOFs nanoparticles in the numerous aligned and
119
open microchannels. (c) All-in-one device for large-scale organic pollutants removal is built by assembling three
120
pieces of UiO-66/wood membranes into a filter.
121
A piece of basswood with a diameter of 13 mm and a thickness of 5 mm was cut along its growth
122
direction to prepare the UiO-66/wood membrane. Figure S1 shows the microstructure of natural
123
basswood. Figure 2a shows the photo images of the natural basswood (yellow) and UiO-66/wood
124
membrane (brown). Figure 2b shows the SEM image of the UiO-66/wood membrane. There are
125
numerous aligned and open microchannels in the wood framework, which are highlighted with
126
red dash lines. As shown in Figure S2, FT-IR spectra showed that a new absorption band at
127
around 660 cm−1 was observed, which is assigned to Zr-O stretching vibration.
ACS Paragon Plus Environment
37
The XPS
8
Page 9 of 49
Environmental Science & Technology
128
spectra shows that the bonding energy of O 1s shifts from 531.2 eV for natural wood to 531.6 eV
129
for Zr-wood (Figure S3), indicating that the bond of Zr-O was formed. 38,39 The coordinated Zr4+
130
ions in wood channels further reacted with organic ligands, thus to achieve the in situ synthesis
131
of UiO-66 MOFs nanoparticles within the aligned microchannels. Magnified SEM image of the
132
UiO-66/wood membrane shows that the UiO-66 MOFs nanoparticles are uniformly decorated on
133
the surface of the multiple wood channels (Figure 2c, Figure S4). The content of elemental Zr in
134
UiO-66/wood membrane is 0.73 wt% from the ICP-MS test. In addition, the loading amount of
135
UiO-66 MOFs in wood based on the Zr6O4(OH)4(bdc)6 formula, is 2.22 wt% (Table S1). The
136
size of the UiO-66 MOFs nanoparticles is approximately in the range of 130 ± 10 nm (Figure 2d,
137
Figure S5). The transmission electron microscopy (TEM) image shows that the morphology of
138
the UiO-66 MOFs nanoparticles is cubic (inset of Figure 2d). The elemental maps show the
139
coexistence of Zr, C, and O in the UiO-66/wood membrane (Figure 2e), which was further
140
confirmed by the Energy-Dispersive X-ray (EDX) spectra (Figure S6). In addition, the uniform
141
distribution of Zr in the wood microchannels further confirmed the uniform distribution of UiO-
142
66 nanoparticles in the wood matrix. The structure of the UiO-66/wood composite was
143
determined by the X-ray diffraction (XRD) analysis. The results demonstrate that the XRD
144
pattern of the UiO-66/wood composite is in good agreement with the standard patterns of UiO-
145
66 MOFs and wood (Figure 2f). 40,41 Furthermore, the stability of UiO-66/wood composite was
146
investigated in solution at different pH values (pH =1, 7 or 14) and characterized using XRD.
147
Figure S7 shows that the samples maintain their crystalline structure after immersion in the
148
solution at different pH values for 24 hours.
ACS Paragon Plus Environment
9
Environmental Science & Technology
Page 10 of 49
149 150
Figure 2. Characterizations of the UiO-66/wood membrane. (a) Photos of the natural basswood and UiO-
151
66/wood membrane. The color of the basswood turns brown due to the formation of UiO-66 MOFs nanoparticles
152
within the wood framework. The inside of the UiO-66/wood membrane is brown, indicating that the UiO-66 MOFs
153
nanoparticles are evenly distributed throughout the entire wood matrix. (b) SEM image of the UiO-66/wood
154
membrane showing the numerous elongated and low-tortuosity microchannels. The microchannels are highlighted
155
with red dash lines. (c) SEM image showing the UiO-66 MOFs nanoparticles anchored in the wood microchannels.
156
(d) Magnified SEM image of the UiO-66 MOFs nanoparticles. The inset shows the TEM image of the UiO-66
157
MOFs nanoparticle. (e) SEM image and corresponding elemental maps of the UiO-66/wood. (f) XRD patterns of the
158
natural wood, UiO-66 MOFs, and UiO-66/wood membrane.
159
Rh6G (molecular structure shown in Figure S8) is a potential carcinogen. In our study, Rh6G
160
was selected as a pollutant to test the removal efficiency of the UiO-66/wood membrane. Firstly,
161
we studied the kinetics of the adsorption process. As shown in Figure S9a, the concentration of
162
Rh6G in the solution reduced from 10 mg∙L-1 to 0.0096 mg∙L-1 within 5 min. The removal
163
efficiency reached 98.8%. The distribution coefficient (Kd) is 2.6×106 mL∙g-1, which shows that
ACS Paragon Plus Environment
10
Page 11 of 49
Environmental Science & Technology
164
the UiO-66/wood membrane had excellent affinity for Rh6G. 42 Adsorption kinetics studies show
165
that the adsorption process fits well with a pseudo-second-order model, which confirms that the
166
interaction between the UiO-66/wood membrane and Rh6G is mainly controlled by a chemical
167
processes. 43,44 The adsorption isotherm analysis indicates the adsorption mechanism between the
168
Rh6G and UiO-66/wood composite follows the Langmuir model, which confirms that the
169
adsorption is a single-layer pattern process (Figure S9 and S10).44,45 The maximum adsorption
170
capacity of UiO-66/wood based on the Rh6G content of the UiO-66 MOFs is 690 mg∙g-1, which
171
is much higher than other UiO-66 based membranes.
172
water transport within a single vessel was also studied based on an advection-diffusion
173
phenomenon. 5
174
Taking advantage of the open and aligned microstructure of wood, the UiO-66/wood membrane
175
can be used as a filter for efficient pollutants removal from water by filtration. Figure 3a exhibits
176
the images of natural wood and UiO-66/wood membranes for water treatment. The orange
177
aqueous Rh6G solution becomes colorless after flowing through the UiO-66/wood membrane. In
178
contrast, when the aqueous Rh6G solution flows through the natural wood, there is no obvious
179
color change in aqueous solutions containing Rh6G. This result indicates that the UiO-66/wood
180
membrane has efficient removal ability for Rh6G. The structure of crystal unit cell of the UiO-66
181
MOFs is shown in Figure 3b. The blue, red, and white spheres represent the Zr, O, and C atoms,
182
respectively. H atoms on the ligands are omitted for clarity. The large yellow sphere in the
183
middle represents the void cage inside the framework. The UiO-66 MOFs with the
184
Zr6O4(OH)4(bdc)6 (bdc=1,4-benzenedicarboxylate) formula have an fcu topology (Figure S11). 48
185
The maximum diameter of the octahedral cavity of the UiO-66 MOFs is 12.3 Å, which is large
186
enough to adsorb various organic molecules (Table S2). Zeta potential was measured to
46,47
In our previous work, the polluted
ACS Paragon Plus Environment
11
Environmental Science & Technology
Page 12 of 49
187
determine the surface charge state of the UiO-66 MOFs. As shown in Figure S12, the UiO-66
188
MOFs have a positive potential from pH = 1 to 6 and a negative potential from pH = 7 to 10. The
189
polar surface of the UiO-66 MOFs helps capturing organic molecules and binding with the polar
190
functional groups through electrostatic attraction.49,37 The schematic adsorption process of
191
organic pollutants in the UiO-66/wood membrane is shown in Figure 3c. The uniformly
192
distributed UiO-66 MOFs nanoparticles on the surface of the aligned and low-tortuosity wood
193
microchannels increase the contact area with the organic pollutants, thereby enhancing the
194
extraction of the organic molecules. The unique open and elongated wood channels facilitate the
195
mass transfer of polluted water, which is essential for rapid and highly efficient organic
196
contaminant uptake from water. The adsorption ability of the UiO-66/wood membrane towards
197
Rh6G is further confirmed by the UV-vis spectra (Figure 3d). The characteristic absorbance peak
198
of Rh6G (525 nm) completely disappears after the aqueous Rh6G solutions are treated with the
199
UiO-66/wood membrane. However, there is only a rarely decrease after aqueous Rh6G solutions
200
are treated with natural wood. The UiO-66/wood membrane displays high removal efficiency
201
(98%) for the different concentrations of Rh6G. The removal efficiency of UiO-66/wood
202
membrane decreases only slightly when the concentration of Rh6G is higher than 12 mg L-1
203
(Figure 3e). We also investigated the adsorption properties of the UiO-66/wood membrane for
204
Rh6G solutions at different pH values. As shown in Figure S13, the removal efficiency is
205
dramatically increased when the pH is higher than 4, demonstrating that a weak acid or alkaline
206
environment facilitates the adsorption of Rh6G on the UiO-66/wood membrane. Rh6G is a kind
207
of cationic dye 50 which is easily adsorbed by UiO-66 MOFs in the wood microchannels through
208
electrostatic attraction in the higher pH range since the UiO-66 MOFs have a negative potential
209
in the high pH range.
ACS Paragon Plus Environment
12
Page 13 of 49
Environmental Science & Technology
210 211
Figure 3. Rh6G removal performance of the UiO-66/wood membrane. (a) Comparison of the Rh6G (10 mg∙L-1)
212
adsorption efficiency of the natural wood and the UiO-66/wood membrane. (b) Crystal unit cell of the UiO-66
213
MOFs. (blue: Zr; red: O; white: C; H atoms on ligands are omitted for clarity. The large yellow sphere represents the
214
void cage inside the framework. (c) Schematic showing the absorption process of the organic molecules as the
215
polluted water flows through the UiO-66/wood filter. (d) UV-vis spectra of the Rh6G-contaning solution before
216
(black) and after treatment with natural wood (red) and the UiO-66/wood membrane (blue). (e) Removal efficiency
217
of the UiO-66/wood membrane for different Rh6G concentrations.
218
To demonstrate a practical application, an all-in-one filter was designed and assembled by
219
integrating 3 pieces of the UiO-66/wood membranes in a plastic kettle (Figure 4a). The set-up for
220
organic pollutant removal is shown in Figure 4b. A syringe pump is used to control the water
221
flux. The flux of the treatment is calculated with equation (2):
222
W = V/S
(2)
223
Where V is the solution flux of the syringe pump (L∙h-1), S is the effective area of the UiO-
224
66/wood membrane (m2), and W is the treatment flux (L∙m-2 ∙h-1).
225
Propranolol (molecular structure shown in Figure S14) is a common medicine against
226
hypertension and is hardly removed by common wastewater treatment systems.
227
evaluated the adsorption ability of the three-layer filter for a propranolol solution (0.1 mmol∙L-
ACS Paragon Plus Environment
32
We firstly
13
Environmental Science & Technology
Page 14 of 49
228
1).51
229
with the all-in-one three-layer filter. The characteristic peak of the propranolol solution at 290
230
nm is absent after treatment, indicating efficient removal. The influence of the flux on the
231
removal efficiency of the three-layer filter was further investigated. As shown in Figure 4d, a
232
high removal efficiency over 97% was maintained even when the flux reached 1.0×103 L∙m-2∙h-1,
233
which is significantly higher than previous reports.33 The rapid and highly efficient removal of
234
propranolol from water using the proposed three-layer filter originates from three elements. First,
235
the fine UiO-66 MOFs nanoparticles with a high surface area are uniformly distributed
236
throughout the aligned wood lumens, which enhances the full utilization of UiO-66 MOFs.
237
Secondly, the elongated and irregular multi-channels in the wood matrix contribute to creating
238
sufficient contact between the UiO-66 MOFs nanoparticles and the organic contaminants in
239
water. Finally, the low-tortuosity and aligned microchannels with a favorable hydrophilic
240
property (Figure S15) can facilitate the fast transport of polluted water without significantly
241
sacrificing the removal efficiency. The reusability of water treatment materials is a crucial factor
242
for practical applications. The designed three-layer filter can be readily regenerated by washing
243
with methanol (3×5 mL) and DI water (10 mL). The removal efficiency of the three-layer filter
244
for propranolol was over 95.0% even after 6 cycles of regeneration (Figure 4e, Figure S16). The
245
results demonstrate the excellent reproducibility and reusability of the three-layer filter based on
246
the UiO-66/wood membranes. The stability of the three-layer filter was investigated by SEM. As
247
shown in Figure S17, the morphology and average size of the UiO-66 MOFs nanoparticles is
248
well maintained even after 6 cycles. The XRD pattern of the UiO-66 MOFs is also in good
249
agreement with the standard patterns of UiO-66 MOFs after 6 cycles, demonstrating its excellent
250
structural stability (Figure S18). In addition, the weight loss of Zr in the UiO-66/wood membrane
Figure 4c shows the UV-vis spectra of the propranolol solution before and after treatment
ACS Paragon Plus Environment
14
Page 15 of 49
Environmental Science & Technology
251
after 6 regeneration cycles was measured by ICP-MS and was less than 0.1 wt%, confirming the
252
superior stability of our three-layer filter. Figure 4f compares the removal efficiency for
253
propranolol of activated carbon,32 UV-treated carbon (UV-C),33 natural wood, and our three-
254
layer filter based on the UiO-66/wood membranes. The removal efficiency of our three-layer
255
filter is significantly higher than the other materials.
256 257
Figure 4. Removal performance for propranolol of the all-in-one three-layer filter based on the UiO-66/wood
258
membrane. (a) Photographs of the three-layer filter using three pieces of UiO-66/wood membranes. (b)
259
Experimental set-up for organic contaminants removal using the all-in-one three-layer filter. (c) UV-vis spectra of
260
the propranolol solution before (red) and after (black) treatment using the three-layer filter (flux: 1.0×103 L∙m-2∙h-1).
261
(d) Removal efficiency for propranolol of the three-layer filter at different flux. (e) Removal efficiency for
262
successive regeneration cycles. (f) Comparison of the removal efficiency of activated carbon, UV-C, natural wood,
263
and our three-layer filter.
264
Besides Rh6G and propranolol, we also investigated the adsorption performance of the three-
265
layer filter for other common organic pollutants (Figure 5a). The selected organic contaminants
266
were: 1-NA, a known carcinogen and an azo-dye precursor,51 BPA, an endocrine disrupting
267
chemical present in plastic products,53,54 and BPS, a substitute of BPA in many polycarbonates
ACS Paragon Plus Environment
15
Environmental Science & Technology
Page 16 of 49
268
suspected to be an endocrine disruptor with greater environmental persistence.55,56 The physical
269
and chemical properties of the selected organic pollutants are shown in Table S3. The removal
270
performance of the three-layer filter for these organic contaminants at different flux was
271
evaluated (Figure 5b, Figure S19-21). The proposed all-in-one three-layer filter displays a high
272
efficiency ( ≥ 96%) for each organic contaminant at a flow rate of 1.0×103 L∙m-2∙h-1, which
273
shows highly outperforms natural wood and pure UiO-66 MOFs particles in powder form
274
(Figure 5c). In addition, we have compared the organic pollutants removal efficiency of UiO-
275
66/wood membrane with other systems such as B-ZnO nanoparticles, zeolitic imidazolate
276
framework-9
277
Fe3O4@SiO2-β-cyclodextrin (Fe3O4@SiO2-PGMACD), and porous β-CD-containing polymer
278
(P-CDP)42, 57-60. As shown in Table S4, the organic pollutants treatment performance of the UiO-
279
66/wood membrane is higher than for other systems. In this work, we proposed a UiO-66/wood
280
membrane for highly efficient organic pollutants removal from water. A three-layer filter was
281
designed, which shows a high removal efficiency over 96.0% for various organic contaminants
282
in water at a treatment flow rate of 1.0×103 L∙m-2∙h-1. The use of the three-layer filter based on
283
the UiO-66/wood membrane offers a scalable, renewable, and cost-effective strategy for rapid
284
and efficient water treatment.
(ZIF-9),
porous
β-cyclodextrin
polymer@cotton
ACS Paragon Plus Environment
(CD-TFP@COTTON),
16
Page 17 of 49
Environmental Science & Technology
285 286
Figure 5. Removal performance of the all-in-one three-layer filter for other organic pollutants. (a)
287
Constitutional formulas of the organic pollutants tested. (b) Removal efficiency of the designed three-layer filter for
288
each organic pollutant at different flow rates. (c) Comparison of the removal efficiency of the three-layer filter,
289
natural wood, and pure UiO-66 MOFs particles in a powder form for several organic pollutants at a flow rate of 1.0
290
×103 L∙m-2∙h-1.
291 292 293
Acknowledgement
294
X. Guo and X. Cai contributed equally to this work. The work was supported by the National
295
Natural Science Foundation of China (21876072). We would like to thank Dr. Mingwei Zhu for
296
the SEM measurement, Dr. Zonglei Zhang for the ICP-MS test. We acknowledge Dr. Wei Dou,
297
Dr. Aijiang Lu and Dr. Weihua Han contributed technical knowledge and understanding of the
298
subject. We thank the Electron Microscopy Centre of Lanzhou University for the microscopy
299
and micro-analysis of our samples.
ACS Paragon Plus Environment
17
Environmental Science & Technology
Page 18 of 49
301
References
302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345
(1) Schwarzenbach, R. P.; Escher, B. I.; Fenner, K.; et al. The Challenge of Micropollutants in Aquatic Systems. Science, 2006, 313 (5790), 1072-1077. (2) Murray, K. E.; Thomas, S. M.; Bodour, A. A. Prioritizing Research for Trace Pollutants and Emerging Contaminants in The Freshwater Environment. Environ. Pollut. 2010, 158 (12), 3462-3471. (3) Arkas, M.; Allabashi, R.; Tsiourvas, D.; et al. Organic/Inorganic Hybrid Filters Based on Dendritic and Cyclodextrin “Nanosponges” for the Removal of Organic Pollutants from Water. Environ. Sci. Technol. 2006, 40 (8), 2771-2777. (4) Morin-Crini, N.; Crini, G. Environmental Applications of Water-insoluble β-cyclodextrinepichlorohydrin Polymers. Prog. Polym. Sci. 2013, 38 (2), 344-368. (5) Chen, F. J.; Gong, A. S.; Zhu, M.; et al. Mesoporous, Three-Dimensional Wood Membrane Decorated with Nanoparticles for Highly Efficient Water Treatment. ACS Nano. 2017, 11 (4), 4275-4282. (6) Zhang, W. J.; Yang, X. Y.; Wang, D. S. Complete Removal of Organic Contaminants from Hypersaline Wastewater by the Integrated Process of Powdered Activated Carbon Adsorption and Thermal Fenton Oxidation. Ind. Eng. Chem. Res. 2013, 52 (16), 5765-5771. (7) Chen, Y. F.; Chen, F.; Zhang, S. H.; et al. Facile Fabrication of Multifunctional Metal– Organic Framework Hollow Tubes to Trap Pollutants. J. Am. Chem. Soc. 2017, 139 (46), 16482-16485. (8) Farha, O. K.; Eryazici, I.; Jeong, N. C.; et al. Metal-Organic Framework Materials with Ultrahigh Surface Areas: is the Sky the Limit? J. Am. Chem. Soc. 2012, 134 (36), 1501615021. (9) Alaerts, L.; Maes, M.; Giebeler, L.; et al. Selective Adsorption and Separation of OrthoSubstituted Alkylaromatics with the Microporous Aluminum Terephthalate MIL-53. J. Am. Chem. Soc. 2008, 130 (43), 14170-14178. (10) Zhu, G. W.; Ng Cheng, W.; Lin, W. Y.; Koh, S. N.; Wang, C. H. Effective Recovery of Vanadium from Oil Refinery Waste into Vanadium-Based Metal-organic Frameworks. Environ. Sci. Technol. 2018, 52 (5), 3008-3015. (11) Creamer, A. E.; Gao, B. Carbon-based Adsorbents for Postcombustion CO2 Capture: A Critical Review. Environ. Sci. Technol. 2016, 50 (14), 7276-7289. (12) Mondloch, J. E.; Katz, M. J.; Isley III, W. C.; et al. Destruction of Chemical Warfare Agents Using Metal-organic Frameworks. Nat. Mater. 2015, 14 (5), 512. (13) Liu, K.; Gao, Y. X.; Liu, J.; Wen, Y. F.; Zhao, Y. C.; Zhang, K. Y.; Yu, G. Photoreactivity of Metal-organic Frameworks in Aqueous Solutions: Metal Dependence of Reactive Oxygen Species Production. Environ. Sci. Technol. 2016, 50 (7), 3634-3640. (14) Horcajada, P.; Chalati, T.; Serre, C.; et al. Porous Metal-organic Framework Nanoscale Carriers as a Potential Platform for Drug Delivery and Imaging. Nat. Mater. 2010, 9 (2), 172. (15) Tong, M.; Liu, D.; Yang, Q.; et al. Influence of Framework Metal Ions on the Dye Capture Behavior of MIL-100 (Fe, Cr) MOF Type Solids. J. Mater. Chem. A, 2013, 1 (30), 85348537. (16) Jhung, S. H.; Lee, J. H.; Yoon, J. W.; et al. Microwave Synthesis of Chromium Terephthalate MIL-101 and Its Benzene Sorption Ability. Adv. Mater. 2007, 19 (1), 121124.
ACS Paragon Plus Environment
18
Page 19 of 49
346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391
Environmental Science & Technology
(17) Liu, B. J.; Yang, F.; Zou, Y. X.; et al. Adsorption of Phenol and P-nitrophenol from Aqueous Solutions on Metal-organic Frameworks: Effect of Hydrogen Bonding. J. Chem. Eng. Data, 2014, 59 (5), 1476-1482. (18) Han, S.; Lah, M. S. Simple and Efficient Regeneration of MOF-5 and HKUST-1 via Acidbase Treatment. Cryst. Growth. Des. 2015, 15 (11), 5568-5572. (19) Bhunia, M. K.; Hughes, J. T.; Fettinger, J. C.; et al. Thermochemistry of Paddle Wheel MOFs: Cu-HKUST-1 and Zn-HKUST-1. Langmuir, 2013, 29 (25), 8140-8145. (20) Russell, A. P.; Richard, L. G. Formation and Structure of Wood. Am. Chem. Soc. Washington, DC, 1984. (21) Zhu, H. L.; Luo, W.; Ciesielski, P. N.; et al. Wood-derived Materials for Green Electronics, Biological Devices, and Energy Applications. Chem. Rev. 2016, 116 (16), 9305-9374. (22) Zhu, H. L.; Fang, Z. Q.; Wang, Z.; et al. Extreme Light Management in Mesoporous Wood Cellulose Paper for Optoelectronics. ACS Nano. 2015, 10 (1), 1369-1377. (23) Chen, C.; Zhang, Y.; Li, Y.; et al. Highly Conductive, Lightweight, Low-tortuosity Carbon Frameworks as Ultrathick 3D Current Collectors. Adv. Energy Mater. 2017, 7 (17), 1700595. (24) Chen, C. J.; Li, Y. J.; Song, J. W.; et al. Highly Flexible and Efficient Solar Steam Generation Device. Adv. Mater. 2017, 29 (30), 1701756. (25) Yu, Z.; Yao, Y.; Yao, J.; et al. Transparent Wood Containing CsxWO3 Nanoparticles for Heat-shielding Window Applications. J. Mater. Chem. A, 2017, 5 (13), 6019-6024. (26) Zhu, M. W.; Song, J. W.; Li, T.; et al. Highly Anisotropic, Highly Transparent Wood Composites. Adv. Mater. 2016, 28 (26), 5181-5187. (27) Zhu, M.; Wang, Y.; Zhu S, et al. Anisotropic, Transparent Films with Aligned Cellulose Nanofibers. Adv. Mater. 2017, 29 (21), 1606284. (28) Wang, Y.; Sun, G.; Dai, J.; et al. A High-performance, Low-tortuosity Wood-carbon Monolith Reactor. Adv. Mater. 2017, 29 (2), 1604257. (29) Zhu, M. W.; Li, T.; Davis, C. S.; et al. Transparent and Haze Wood Composites for Highly Efficient Broadband Light Management in Solar Cells. Nano Energy, 2016, 26, 332-339. (30) Kong, W. Q; Wang, C. G; Jia, C; et al. Muscle-Inspired Highly Anisotropic, Strong, IonConductive Hydrogels. Adv. Mater. 2018, 30 (39), 1801934. (31) Sjostrom, E. Wood Chemistry: Fundamentals and Applications. Gulf professional publishing. 1993. (32) Valenzano, L.; Civalleri, B.; Chavan, S.; et al. Disclosing the Complex Structure of UiO-66 Metal Organic Framework: A Synergic Combination of Experiment and Theory. Chem. Mater. 2011, 23 (7), 1700-1718. (33) Zhu, H.; Yang, X.; Cranston, E. D.; et al. Flexible and Porous Nanocellulose Aerogels with High Loadings of Metal-organic Framework Particles for Separations Applications. Adv. Mater. 2016, 28 (35), 7652-7657. (34) Aguilera-Sigalat, J.; Bradshaw, D. A Colloidal Water-stable MOF as A Broad-range Fluorescent pH Sensor via Post-synthetic Modification. Chem. Commun. 2014, 50 (36), 4711-4713. (35) Kandiah, M.; Nilsen, M. H.; Usseglio, S.; et al. Synthesis and Stability of Tagged UiO-66 Zr-MOFs. Chem. Mater. 2010, 22 (24), 6632-6640. (36) Sirés, I.; Oturan, N.; Oturan, M. A. Electrochemical Degradation of β-blockers. Studies on Single and Multicomponent Synthetic Aqueous Solutions. Water research, 2010, 44 (10), 3109-3120.
ACS Paragon Plus Environment
19
Environmental Science & Technology
392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437
Page 20 of 49
(37) Han, Y; Liu, M.; Li, K.; et al. In situ synthesis of titanium doped hybrid metal–organic framework UiO-66 with enhanced adsorption capacity for organic dyes. Inorg.Chem. Front. 2017, 4 (11), 1870-1880. (38) BE Lookup Table for Signals from Elements and Common Chemical Species. XPS international, Inc. 1999. (39) Wagner, C. D.; Riggs, W. M.; Davis, L. E.; et al. Handbook of X-ray Photoelectron Spectroscopy. Perkin Elmer: Eden Prairie, MN, 1979. (40) http://muchong.com/html/201709/9767241.html. (41) Chowdhury, P.; Mekala, S.; Dreisbach, F.; et al. Adsorption of CO, CO2 and CH4 on CuBTC and MIL-101 metal organic frameworks: Effect of Open Metal Sites and Adsorbate Polarity. Microporous and Mesoporous Materials, 2012, 152, 246-252. (42) Shin, Y. S; Fryxell, G. E.; Um, W.; et al. Sulfur-Functionalized Mesoporous Carbon. Adv.Funct.Mater. 2007, 17 (15), 2897-2901. (43) Zou, Y. D.; Wang, X. X.; Ai, Y. J.; et al. β-Cyclodextrin modified graphitic carbon nitride for the removal of pollutants from aqueous solution: experimental and theoretical calculation study. J. Mater. Chem. A. 2016, 4 (37), 14170-14179. (44) Yu, D. Y.; Wang, L. L.; Wu, M. H.; Simultaneous removal of dye and heavy metal by banana peels derived hierarchically porous carbons. J. Taiwan Inst. Chem. Eng. 2018, 93, 543-553. (45) Wang, B.; Jiang, Y. S; Li, F. Y; et al. Preparation of biochar by simultaneous carbonization, magnetization and activation for norfloxacin removal in water. Bioresour Technol. 2017, 233, 159-165. (46) Tian, C; Xiang, X; Wu, J; et al. Facile Synthesis of MoS2/CuS Nanosheet Composites as an Efficient and Ultrafast Adsorbent for Water-Soluble Dyes. Journal of Chemical & Engineering Data 2018, 63 (10), 3966-3974. (47) Liu, F. Z; Leung, Y. H.; Djurišić, A. B.;et al. Native Defects in ZnO: Effect on Dye Adsorption and Photocatalytic Degradation. J. Phys.Chem. C 2013, 117 (23), 12218-12228. (48) Bajpai, A; Mukhopadhyay, A.; Krishna, M. S.; et al. A Fluorescent Paramagnetic Mn Metal–organic Framework Based on Semi-rigid Pyrene Tetracarboxylic Acid: Sensing of Solvent Polarity and Explosive Nitroaromatics. IUCrJ, 2015, 2 (5), 552-562. (49) Yang, Y.; Hu, G.; Chen, F.; et al. An Atom-scale Interfacial Coordination Strategy to Prepare Hierarchically Porous Fe3O4-graphene Frameworks and Their Application in Charge and Size Selective Dye Removal. Chem. Commun. 2015, 51 (76), 14405-14408. (50) Yang, Y. M; Hu, G. W; Chen, F. J; et al. An atom-scale interfacial coordination strategy to prepare hierarchically porous Fe3O4-graphene frameworks and their application in charge and size selective dye removal. Chem Commun 2015, 51 (76), 14405-14408. (51) Dantas, R. F.; Rossiter, O.; Teixeira, A. K. R.; et al. Direct UV Photolysis of Propranolol and Metronidazole in Aqueous Solution. Chem. Eng. J. 2010, 158 (2), 143-147. (52) Kandiah, M.; Nilsen, M. H.; Usseglio, S.; et al. Synthesis and Stability of Tagged UiO-66 Zr-MOFs. Chem. Mater. 2010, 22 (24), 6632-6640. (53) Occupational Safety and Health Administration (OSHA) Standard, USA. Toxic and Hazardous Substances: 13 Carcinogens (4-Nitrobiphenyl, etc.). Standard number 1910.1003. http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id =10007, 2012. (54) Vandenberg, L. N.; Hauser, R.; Marcus; M.; et al. Human Exposure to Bisphenol A (BPA). Reprod. Toxicol. 2007, 24 (2), 139-177.
ACS Paragon Plus Environment
20
Page 21 of 49
438 439 440 441 442 443 444 445 446 447 448 449 450 451 452
Environmental Science & Technology
(55) Liang, L.; Zhang, J.; Feng, P.; et al. Occurrence of Bisphenol A in Ssurface and Drinking Waters and Its Physicochemical Removal Technologies. Front. Environ. Sci. Eng. 2015, 9 (1), 16-38. (56) Ke, M.; Chen, M. Y.; Danzl, E.; et al. Biodegradation of A Variety of Bisphenols under Aerobic and Anaerobic Conditions. Water Sci. Technol. 2006, 53 (6), 153-159. (57) Liu, F.; Leung, Y. H.; Djurišić, A. B.; et al. Native Defects in ZnO: Effect on Dye Adsorption and Photocatalytic Degradation. J. Phys.Chem. C. 2013, 117 (5), 12218-12228. (58) Alzate-Sánchez, D. M.; Smith, B. J.; Alsbaiee, A.; et al. Cotton Fabric Functionalized with a β-Cyclodextrin Polymer Captures Organic Pollutants from Contaminated Air and Water. Chem. Mater. 2016, 28 (22), 8340-8346. (59) Kang, Y.; Zhou, L.; Li, X.; Yuan, J., β-Cyclodextrin-modified hybrid magnetic nanoparticles for catalysis and adsorption. J. Mater. Chem. 2011, 21 (11), 3704. (60) Alsbaiee, A.; Smith, B. J.; Xiao, L. L.; et al. Rapid removal of organic micropollutants from water by a porous beta-cyclodextrin polymer. Nature, 2016, 529 (7585), 190-194.
453
454
455 456 457 458 459 460 461 462 463 464 465 466 467 468 469
ACS Paragon Plus Environment
21
Environmental Science & Technology
Page 22 of 49
SUPPORTING INFORMATION
470 471 472
In situ growth of Metal-Organic Frameworks in Three-Dimensional Aligned Lumen
473
Arrays of Wood for Rapid and Highly Efficient Organic Pollutants Removal
474 475
Ruixue Guo1†, Xiaohui Cai1†, Hanwen Liu1, Zi Yang1, Yajie Meng 1, Fengjuan Chen1*, Yiju Li2*,
476
Baodui Wang1*
477 478 479 480 481 482 483 484 485 486
1
State Key Laboratory of Applied Organic Chemistry and Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University Gansu, Lanzhou, 730000, P. R. China 2 Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, P. R. China *Email:
[email protected];
[email protected];
[email protected] 487 488 489 490
†These authors contribute equally to this work.
ACS Paragon Plus Environment
22
Page 23 of 49
Environmental Science & Technology
491 492 493
Figure S1. (a) SEM image of natural wood. There are numerous long and irregular
494
microchannels in wood. (b) High resolution SEM image of wood channels. (c, d) SEM images
495
showing the top view of the natural wood.
496 497 498 499 500 501 502 503
ACS Paragon Plus Environment
23
Environmental Science & Technology
Page 24 of 49
504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529
Figure S2. Infrared spectrum of the natural wood and Zr-wood.
ACS Paragon Plus Environment
24
Page 25 of 49
Environmental Science & Technology
530 531 532
Figure S3. XPS spectra of O 1s in (a) natural wood and (b) Zr-wood.
533 534 535 536 537 538 539 540 541 542 543 544 545 546
ACS Paragon Plus Environment
25
Environmental Science & Technology
Page 26 of 49
547 548 549
Figure S4. SEM image of UiO-66 MOFs nanoparticles in the microchannels of UiO-66/wood
550
membrane.
ACS Paragon Plus Environment
26
Page 27 of 49
Environmental Science & Technology
552
553 554 555
Figure S5. (a) SEM image of the UiO-66 MOFs nanoparticles in wood channels. (b) Size
556
distribution of the UiO-66 MOFs nanoparticles. The average size of the UiO-66 MOFs
557
nanoparticles is about 130 ± 10 nm.
ACS Paragon Plus Environment
27
Environmental Science & Technology
Page 28 of 49
558
559 560 561
Figure S6. Energy dispersive X-ray spectroscopy (EDX) spectrum of the UiO-66/wood
562
membrane.
ACS Paragon Plus Environment
28
Page 29 of 49
Environmental Science & Technology
563 564
Figure S7. XRD patterns of UiO-66/wood composites showing the stability after immersed in
565
solution with different pH values for 24 hours.
566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582
ACS Paragon Plus Environment
29
Environmental Science & Technology
583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614
Page 30 of 49
Figure S8. Molecular structure of Rh6G.
ACS Paragon Plus Environment
30
Page 31 of 49
Environmental Science & Technology
615
Contaminant Adsorption experiments
616
Rh6G sorption kinetics. The adsorption kinetic was performed at 25 °C. A piece of UiO-
617
66/wood membrane (20 mg, UiO-66 MOFs: 2.22 wt %) was cut to chips and then added to a 100
618
mL beaker, which included 50 mL aqueous solution of Rh6G (10 mg∙L-1). The mixture was
619
shaken for 2 hours. The supernatant was taken out at different specific time periods and filtered.
620
The concentration of Rh6G in filtrate was analyzed by UV-vis spectra (λ = 525 nm).
621
The distribution coefficient Kd is an important parameter to measure the performance of the
622
adsorbents. The value of Kd can be determined by 39
623
Kd = (Ci-Cf)/Cf × (V/m)
(1)
624
where Ci indicates the initial concentration of the contaminant (mg∙L-1), Cf indicates the final
625
equilibrium concentration of the contaminant (mg∙L-1), m is the mass of the adsorbent (g), and V
626
is the volume of the tested liquid (mL).
627
the adsorbed amount for Rh6G (qt) was determined by the below equation.
628 629
qt= (Co-Ct)/m × V
(2)
630 631
where Co and Ct are the concentration of the Rh6G (mg∙L-1) initially and at time t, respectively, V
632
is the volume solution used (L), and m is the mass of UiO-66 MOFs (g).
633
Mathematical Models.The adsorption kinetics of pseudo-first-order rate equation and pseudo-
634
second-order rate equation was used to investigate the adsorption process. The adsorption kinetic
635
equations are given as Eq 3 and Eq 4, respectively.1,2
636 637
Log (qe - qt) = logqe –k1t
(3)
638
t/qt =1/(k2qe2) + t/qe
(4)
639 640
where qe and qt are the amount of Rh6G adsorbed at equilibrium and time t (min), and k1 (min-1)
641
and k2 (g∙mg-1∙min-1) are the rate constant of the pseudo-first-order adsorption and the pseudo-
642
second-order rate constant, respectively.
643
Rh6G adsorption isotherm. The adsorption isotherm of Langmuir and Freundlich models was
644
used to further understand the adsorption mechanism. The adsorption isotherm equations are
645
given as Eq 5 and Eq 6, respectively.3,4
ACS Paragon Plus Environment
31
Environmental Science & Technology
Page 32 of 49
646 647
Ce/qe = 1/(kLqm) + Ce/qm
(5)
648
logqe = logKf + (1/n)logCe
(6)
649 650
where qe and qm represent the equilibrium and the maximum adsorption capacity (mg∙g-1),
651
respectively. Here, Ce is the Rh6G concentration (mg∙L-1) at equilibrium, and KL (L∙mg-1) is the
652
Langmuir constant. Also, Kf (L∙mg-1) and n are the Freundlich parameters related to adsorption
653
capacity and adsorption intensity, respectively.
654
According to the above equations, conclusion can be drawn that:
655
(1) The Kd values of the UiO-66/wood membrane for Rh6G can reach 2.6 × 106 mL∙g-1.
656
(2) The pseudo-second-order rate model and the Langmuir model were selected as the adsorption
657
kinetic and the adsorption isotherm between Rh6G and UiO-66/wood composite.
658
(3) The adsorbed capacity of UiO-66/wood based on the content of UiO-66 MOFs for Rh6G is
659
up to 690 mg∙g-1.
ACS Paragon Plus Environment
32
Page 33 of 49
Environmental Science & Technology
660 661
Figure S9. (a) The adsorption kinetic of UiO-66/wood composite for Rh6G at the initial
662
concentration of 10 mg∙L-1. (b) Adsorption curve of Rh6G versus contact time using UiO-
663
66/wood composite. Inset: Pseudo-second-order kinetic plot for Rh6G adsorption. (c) Adsorption
664
isotherm of UiO-66/wood composite for Rh6G. (d) Linear regression by fitting the data with
665
Langmuir adsorption model.
666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681
ACS Paragon Plus Environment
33
Environmental Science & Technology
Page 34 of 49
682 683 684
Figure S10. (a) Pseudo-first-order kinetic plot and (b) Freundlich isotherms for the adsorption
685
mechanism between Rh6G and UiO-66/wood composite (Rh6G concentration: 10 mg∙L-1).
686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709
ACS Paragon Plus Environment
34
Page 35 of 49
710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736
Environmental Science & Technology
Figure S11. The structure of UiO-66 constructed with Zr6 cluster and BDC ligand.
ACS Paragon Plus Environment
35
Environmental Science & Technology
Page 36 of 49
737 738 739
Figure S12. Zeta potential of UiO-66/wood composite in aqueous solution with different pH
740
values.
741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760
ACS Paragon Plus Environment
36
Page 37 of 49
Environmental Science & Technology
761 762
Figure S13. The removal efficiency of the three-layer filter (Flux: 1.0×103 L∙m-2∙h-1) towards
763
Rh6G (10 mg∙L-1) at different pH values.
764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786
ACS Paragon Plus Environment
37
Environmental Science & Technology
Page 38 of 49
787 788
789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810
Figure S14. Molecular structure of the propranolol.
ACS Paragon Plus Environment
38
Page 39 of 49
811 812 813 814 815 816 817
Environmental Science & Technology
Figure S15. Water contact angle of UiO-66/wood membrane.
ACS Paragon Plus Environment
39
Environmental Science & Technology
Page 40 of 49
818
819 820 821
Figure S16. The UV-vis spectra of the propranolol solution before and after treated with the
822
UiO-66/wood membrane for different cycles.
ACS Paragon Plus Environment
40
Page 41 of 49
Environmental Science & Technology
823 824
Figure S17. Different magnified SEM images of the UiO-66/wood membrane after 6 recycle.
825
Inset shows the size distribution of UiO-66 MOFs after 6 recycle.
ACS Paragon Plus Environment
41
Environmental Science & Technology
826 827 828 829 830 831 832 833 834 835 836 837 838
Page 42 of 49
Figure S18. XRD patterns of simulated UiO-66 and UiO-66/wood membrane after 6 cycles.
ACS Paragon Plus Environment
42
Page 43 of 49
Environmental Science & Technology
839
840 841 842
Figure S19. UV-vis spectra of the BPS solution (0.1 mmol∙L-1) before (in black) and after (in
843
colors) the treatment using the UiO-66/wood membrane based three-layer filter at different flux
844
rate.
ACS Paragon Plus Environment
43
Environmental Science & Technology
Page 44 of 49
845
846 847 848
Figure S20. UV-vis spectra of the 1-NA solution (0.1 mmol∙L-1) before (in black) and after (in
849
colors) treated using the UiO-66/wood membrane based three-layer filter at different flux rate.
ACS Paragon Plus Environment
44
Page 45 of 49
Environmental Science & Technology
850
851 852 853
Figure S21. UV-vis spectra of the BPA solution (0.1 mmol∙L-1) before (in black) and after (in
854
colors) the treatment using the UiO-66/wood membrane based three-layer filter at different flux
855
rates.
856 857 858 859 860 861 862 863 864 865
ACS Paragon Plus Environment
45
Environmental Science & Technology
866
Page 46 of 49
Table S1. ICP analysis for the content of Zr and the calculated UiO-66 loading amount. Molar mass of Zr (g∙mol-1)
Molar mass of UiO-66 (g∙mol-1)
Content of Zr (wt%)
Loading amount of UiO-66 (wt%)
91.2
1662.0
0.73
2.22
867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904
ACS Paragon Plus Environment
46
Page 47 of 49
905
906
Environmental Science & Technology
Table S2. The molecular size of various pollutants. 5 Pollutant
molecular size (Å)
1-NA
16.3×9.5×5.8
BPA
12.5×7.9×6.7
BPS
12.5×7.2×6.7
Propranolol Rhodamine 6G
16.2×9.4×6.0 16.7×12.5×11.4
The present molecular size was calculated with Gaussian 09w.
907
908
909
910
911
912
913
914
915
916
917 918
ACS Paragon Plus Environment
47
Environmental Science & Technology
919
Page 48 of 49
Table S3. Physical and chemical properties of the selected organic pollutants. 6 Selected target molecular weight solubility
Rh6G 479.01 Soluble in water
logKow catogery
7.22550 Dye
toxicity in terms of LD50 (mg∙Kg-1) 400
BPA 228 Slightly soluble in water 3.4 Endocrine disruptor
BPS 250.27 Soluble in water
Propranolol 259.01 Soluble in water
3.01140 Endocrine disruptor
2.96840 Beta-blocker
1-NA 143.19 Slightly soluble in water 3.00320 Carcinogen
2000-5000
2830
9.334-9.450
779
920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952
ACS Paragon Plus Environment
48
Page 49 of 49
Environmental Science & Technology
953
Table S4. The organic pollutants removal efficiency of UiO-66/wood membrane compared to
954
other materials reported in literature.
955 956 957 958 959 960 961 962 963 964 965 966 967 968
Materials
Pollutants
Recycling
Reference
Rh6G BPA BPS 1-NA Propranolol
Removal efficiency (%) 98 98 98 98 98
UiO-66/wood membrane
6 6 6 6 6
Our work
B-ZnO nanoparticles
Rh6G
80.7
Not mentioned
Ref 57
Z9-600
Rh6G
91
4
Ref 54
CD-TFP@cotton
BPA
60
4
Ref 55
Fe3O4@SiO2PGMACD
BPA
89
5
Ref 56
P-CDP
BPA BPS 1-NA Propranolol
95 85 92 96
5 5 5 5
Ref 58
Reference (1) Ho, Y. S. Citation review of Lagergren kinetic rate equation on adsorption reactions. Scientometrics. 2004, 59 (1), 171-177. (2) Ho, Y. S.; Ng, J. C. Y.; McKay, G. Kinetics of pollutant sorption by biosorbents: review. Sep. Purif. Rev. 2000, 29 (2), 189-232. (3) Langmuir, B. I. The Constitution and fundamental properties of solids and liquids. J. Am. Chem. Soc. 1916, 38 (11), 2221-2295. (4) Andjelkovic, I.; Tran, D. N. H.; Kabiri, S.; et al. Graphene aerogels decorated with α-FeOOH nanoparticles for efficient adsorption of arsenic from contaminated waters. ACS Appl. Mater. Interfaces. 2015, 7 (18), 9758-9766. (5) Gaussian 09, Revision B.01: Frisch, M. J. et al. Gaussian, Inc.: Wallingford, CT, 2009. (6) https://www.wikipedia.org/?tdsourcetag=s_pctim_aiomsg
ACS Paragon Plus Environment
49