UIO-66-NH2 DOPED ORGANOSILICON HIGH SALINITY WASTEWATER TREATMENT MEMBRANE AND A PREPARATION METHOD THEREOF

Abstract

The invention belongs to the technical field of composite membrane, and in particular discloses a UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane and a preparation method thereof. The membrane is formed into UIO-66-NH.sub.2/organosilicon hybrid membrane on the prefabricated ceramic support surface through the dip-coating method by doping the UIO-66-NH.sub.2 metal-organic framework material into the organosilicon polymeric sol. The UIO-66-NH.sub.2/organosilicon hybrid membrane prepared by the present invention exhibits high water permeability (up to 1.6×10.sup.−10 m.sup.3/(m.sup.2 s Pa) and high salt retention (NaCl retention rate is more than 99.9.%) in the application of pervaporation desalination, and maintains stable membrane structure in the treatment process of TDS>5 wt % high salinity wastewater.

Claims

1. A UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane, which is characterized in that the wastewater treatment membrane thereof is formed into UIO-66-NH.sub.2/organosilicon hybrid membrane on the prefabricated ceramic support surface through the dip-coating method by doping the UIO-66-NH.sub.2 metal-organic framework material into the organosilicon polymeric sol.

2. A preparation method of UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane, wherein the method is characterized in that the preparation steps are as follows: (1) the silicon source precursor and the hydrochloric acid catalyst are hydrolyzed and polymerized with water in ethanol solution to obtain the organosilicon polymeric sol; (2) the UiO-66-NH.sub.2 crystal is added into the organosilicon polymeric sol and subjected to ultrasonic mixing and uniform dispersion to prepare the UiO-66-NH.sub.2/organosilicon hybrid sol; (3) the UiO-66-NH.sub.2/organosilicon hybrid sol is coated on the ceramic support of the sillica-zirconia nanometer transition layer through the dip-coating method, and then is flash burned in air to obtain the UiO-66-NH.sub.2/organosilicon hybrid membrane.

3. The preparation method of UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane according to claim 2, wherein the method is characterized in that: the silicon source precursor according to the step (1) is 1,2-Bis(triethoxysilyl)ethylene, abbreviated as BTESEthy.

4. The preparation method of UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane according to claim 2, wherein the method is characterized in that: the molar ratio of silicon source precursor, water and hydrochloric acid according to the step (1) is 1:60:0.2, the temperature of hydrolytic-polymeric reaction is 40 DEG C., and the time of hydrolytic-polymeric reaction is 2 h.

5. The preparation method of UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane according to claim 2, wherein the method is characterized in that: the preparation process of UiO-66-NH.sub.2 crystal according to the step (2) is as follows: ZrCl.sub.4 and 2-amino-1,4-benzenedicarboxylic acid are dissolved in N,N-dimethylformamide and subjected to ultrasonic agitation for 10 min, then the acetic acid is added and subjected to ultrasonic agitation for 10 min, and the mixture is put into the preheated 130 DEG C. oven for 24 h, finally the product UiO-66-NH.sub.2 is washed with N, N-dimethylformamide and methanol, and dried overnight at 100 DEG C. to obtain the UiO-66-NH.sub.2 crystal; wherein, the molar ratio of ZrCl.sub.4, BDC-NH.sub.2, HAC and DMF is 1:1:50:500.

6. The preparation method of UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane according to claim 2, wherein the method is characterized in that: the weight ratio (UB-n) of UiO-66-NH.sub.2 and organosilicon in the hybrid sol according to the step (2) is 0.2-1.

7. The preparation method of UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane according to claim 2, wherein the method is characterized in that: the ultrasonic time according to the step (2) is 30 min.

8. The preparation method of UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane according to claim 2, wherein the method is characterized in that: the support according to the step (3) is α-Al.sub.2O.sub.3 ceramic membrane.

9. The preparation method of UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane according to claim 2, wherein the method is characterized in that: the ceramic support comprising the sillica-zirconia transition layer according to the step (3) is soaked in the sillica-zirconia sol for 10-60 s, and then dried at room temperature for 5-10 min and calcined for 15-30 min. The calcination temperature is 500-600 DEG C., and the calcination atmosphere is air. The process is repeated 2-3 times.

10. The preparation method of UIO-66-NH.sub.2 doped organosilicon high salinity wastewater treatment membrane according to claim 2, wherein the method is characterized in that: the flash-burning temperature according to the step (3) is 250 DEG C., and the flash-burning time is 20 min.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 depicts the water flux and the salt retention rate of BTESEthy membrane and UiO-66-NH.sub.2/BTESEthy composite membrane in 6.5 wt % NaCl solution at 70° C.

[0023] FIG. 2 depicts the isothermal curves of nitrogen adsorption for BTESEthy, UiO-66-NH.sub.2/BTESEthy and UB-0.5 membranes.

[0024] FIG. 3A depicts the SEM images of top view for UB-0.5 membrane; and FIG. 3B depicts the SEM images of cross-section view for UB-0.5 membrane.

[0025] FIG. 4 depicts the desalination hydrothermal stability test of UB-0.5 membrane.

DETAILED DESCRIPTION:

[0026] The present invention further illustrates the technical features of the present invention by combining the following embodiments, but the protection scope of the present invention is not limited to the embodiments.

Embodiment 1

[0027] The preparation method for the embodiment is as follows, including the following steps:

[0028] (1) 1,2-Bis(triethoxysilyl) ethylene (BTESEthy) (as silicon source precursor) and hydrochloric acid (as catalyst) are hydrolyzed and polymerized with water in ethanol solution. The molar ratio of BTESEthy, water and hydrochloric acid is 1:60:0.2, and the solution is subjected to agitation at 40° C. for 2 h to obtain the BTESEthy polymeric sol.

[0029] (2) ZrCl.sub.4 and 2-amino-1,4-benzenedicarboxylic acid are dissolved in N,N-dimethylformamide and subjected to ultrasonic agitation for 10 min, then the acetic acid is added and subjected to ultrasonic agitation for 10 min (the molar ratio of ZrCl.sub.4, BDC-NH.sub.2, HAC and DMF is 1:1:50:500). The mixture is put into the preheated 130 DEG C. oven for 24 h. Finally, the product UiO-66-NH.sub.2 is washed with N,N-dimethylformamide and methanol, and dried overnight at 100 DEG C. to obtain the UiO-66-NH.sub.2 crystal.

[0030] (3) The UiO-66-NH.sub.2 crystal is added into the BTESEthy polymeric sol and subjected to ultrasonic mixing and uniform dispersion for 30 min to prepare the UiO-66-NH.sub.2/BTESEthy hybrid sol. The UiO-66-NH.sub.2/BTESEthy sample of different composition is designated as UB-n (n=0.2, 0.5, 0.8 or 1) to indicate the weight ratio of UiO-66-NH.sub.2 and BTESEthy in solution.

[0031] (4) The UiO-66-NH.sub.2/BTESEthy hybrid sol is coated on the α-Al.sub.2O.sub.3 ceramic support comprising the sillica-zirconia nanometer transition layer through the dip-coating method, wherein the ceramic support comprising the sillica-zirconia transition layer is soaked in the sillica-zirconia sol for 40 s, and then dried at room temperature for 7 min and calcined for 20 min. The calcination temperature is 500 DEG C., and the calcination atmosphere is air. The process is repeated 2-3 times. After coating, the flash burning is carried out in air at 250 DEG C. for 20 min to obtain the UiO-66-NH.sub.2/BTESEthy hybrid membrane. The membrane prepared is applied to the pervaporation desalination system.

Embodiment 2

[0032] The preparation method for the embodiment is as follows, including the following steps:

[0033] (1) 1,2-Bis(triethoxysilyl)ethylene (BTESEthy) (as silicon source precursor) and hydrochloric acid (as catalyst) are hydrolyzed and polymerized with water in ethanol solution. The molar ratio of BTESEthy, water and hydrochloric acid is 1:60:0.2, and the solution is subjected to agitation at 40° C. for 2 h to obtain the BTESEthy polymeric sol.

[0034] (2) ZrCl.sub.4 and 2-amino-1,4-benzenedicarboxylic acid are dissolved in N,N-dimethylformamide and subjected to ultrasonic agitation for 10 min, then the acetic acid is added and subjected to ultrasonic agitation for 10 min (the molar ratio of ZrCl.sub.4, BDC-NH.sub.2, HAC and DMF is 1:1:50:500). The mixture is put into the preheated 130 DEG C. oven for 24 h. Finally, the product UiO-66-NH.sub.2 is washed with N, N-dimethylformamide and methanol, and dried overnight at 100 DEG C. to obtain the UiO-66-NH.sub.2 crystal.

[0035] (3) The UiO-66-NH.sub.2 crystal is added into the BTESEthy polymeric sol and subjected to ultrasonic mixing and uniform dispersion for 30 min to prepare the UiO-66-NH.sub.2/BTESEthy hybrid sol. The UiO-66-NH.sub.2/BTESEthy sample of different composition is designated as UB-n (n=0.2, 0.5, 0.8 or 1) to indicate the weight ratio of UiO-66-NH.sub.2 and BTESEthy in solution.

[0036] (4) The UiO-66-NH.sub.2/BTESEthy hybrid sol is coated on the α-Al.sub.2O.sub.3 ceramic support comprising the sillica-zirconia nanometer transition layer through the dip-coating method, wherein the ceramic support comprising the transition layer is soaked in the sillica-zirconia sol for 40 s, and then dried at room temperature for 7 min and calcined for 20 min. The calcination temperature is 500 DEG C., and the calcination atmosphere is air. The process is repeated 2-3 times. After coating, the flash burning is carried out in air at 250 DEG C. for 20 min to obtain the UiO-66-NH.sub.2/BTESEthy hybrid membrane. The membrane prepared is applied to the pervaporation desalination system.

[0037] Comparative 1

[0038] (1) 1,2-Bis(triethoxysilyl)ethane (BTESEthy) (as silicon source precursor) and hydrochloric acid (as catalyst) are hydrolyzed and polymerized with water in ethanol solution. The molar ratio of BTESEthy, water and hydrochloric acid is 1:60:0.2, and the solution is subjected to agitation at 40° C. for 2 h to obtain the BTESEthy polymeric sol.

[0039] (2) The BTESEthy sol is coated on the α-Al.sub.2O.sub.3 ceramic support comprising the sillica-zirconia nanometer transition layer through the dip-coating method, wherein the ceramic support comprising the transition layer is soaked in the sillica-zirconia sol for 40 s, and then dried at room temperature for 7 min and calcined for 20 min. The calcination temperature is 500 DEG C., and the calcination atmosphere is air. The process is repeated 2-3 times. After coating, the flash burning is carried out in air at 250 DEG C. for 20 min to obtain the BTESEthy membrane. The membrane prepared is applied to the pervaporation desalination system.

[0040] Comparative 2

[0041] (1) 1,2-Bis(triethoxysilyl)ethane (BTESEthy) (as silicon source precursor) and hydrochloric acid (as catalyst) are hydrolyzed and polymerized with water in ethanol solution. The molar ratio of BTESEthy, water and hydrochloric acid is 1:60:0.2, and the solution is subjected to agitation at 40° C. for 2 h to obtain the BTESEthy polymeric sol.

[0042] (2) The 0.160 ZrCl.sub.4 and the 0.124 g 2-amino-1,4-benzenedicarboxylic acid are dissolved in 10 mL N,N-dimethylformamide and subjected to ultrasonic agitation for 10 min, then 2 mL acetic acid is added and subjected to ultrasonic agitation for 10 min (the molar ratio of ZrCl.sub.4, H.sub.2BDC, HAC and DMF is 1:1:50:500). The mixture is put into the preheated 130 DEG C. oven for 24 h. Finally, the product UiO-66 is washed with N,N-dimethylformamide and methanol, and dried overnight at 100 DEG C. to obtain the UiO-66 crystal.

[0043] (3) The UiO-66 crystal is added into the BTESEthy polymeric sol and subjected to ultrasonic mixing and uniform dispersion for 30 min to prepare the UiO-66/BTESEthy hybrid sol. The weight ratio of UiO-66 and BTESEthy is 0.5.

[0044] (4) The UiO-66/BTESEthy hybrid sol is coated on the α-Al.sub.2O.sub.3 ceramic support comprising the sillica-zirconia nanometer transition layer through the dip-coating method, wherein the ceramic support comprising the transition layer is soaked in the sillica-zirconia sol for 40 s, and then dried at room temperature for 7 min and calcined for 20 min.

[0045] The calcination temperature is 500 DEG C., and the calcination atmosphere is air. The process is repeated 2-3 times. After coating, the flash burning is carried out in air at 250 DEG C. for 20 min to obtain the UiO-66/BTESEthy hybrid membrane. The membrane prepared is applied to the pervaporation desalination system.

[0046] The experimental results of above embodiments and comparatives are shown in Table 1.

TABLE-US-00001 TABLE 1 Flux Retention rate Membrane 10.sup.−11 m.sup.3/(m.sup.2 s Pa) (%) Embodiment 1 7.4 99.98 Embodiment 2 7.3 99.98 Comparative 1 5.7 99.97 Comparative 2 6.1 99.98