was used for the preparation of titanium dioxide modified polyvinylidene fluoride ultrafiltration membrane. Structure and properties of the membrane a

- 1 511458 2 518055 - ph - ph 4.5 - X 703 A Study on Treatment of Surfactant Wastewater by Coagulation and Membrane Separation Integrated Process WANG Jianming 1 WANG Hanbin 1 ZHONG Xiaoqing 2 SONG Hongchen 1 1 ( Guangdong Key Lab of Membrane Material and Membrane Separation, Guangzhou Institute of Advanced Technology, Chinese Academy of Sciences, Guangzhou 511458, China ) 2 ( Water Science Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China ) Abstract Surfactants have complex compositions and low molecular weights, which usually leads to the eutrophication of waterbodies. For the treatment of wastewater that contains surfactants, the membrane separation technology is usually adopted. However, the membrane is easily polluted and the cleaning process is usually laborious. In this work, a new surfactants wastewater processing technology was investigated by combining the coagulation and membrane separation techniques. Firstly, the phase inversion technique 2015-08-26 2016-04-15 21307146 2015B090901018201506010024 JCYJ20150401145529053 E-mail hc.song@giat.ac.cn

was used for the preparation of titanium dioxide modified polyvinylidene fluoride ultrafiltration membrane. Structure and properties of the membrane are tested by several instrumentations, like the scanning electron microscopy, fourier transform infrared spectroscopy, and contact angle instrument. Secondly, using sodium dodecyl benzene sulfonate solution and polymerization aluminum chloride as surfactant wastewater and coagulant respectively, the treatment effect is evaluated with respect to ultraviolet light intensity, water flow rate and ph values. By observation, the modified membrane has dense-selective layer on the surface, and its cross-section is composed with finger holes and spongy structures. By the analysis of fourier transform infrared spectroscopy, polyethylene glycol and titanium dioxide in the modified membrane can cover apart of infrared absorption of polyvinylidene fluoride. The modified membrane has relative small contact angle and its performance is also insensitive to the change of ultraviolet light intensity and water flow rate. Moreover, the process can reach best performance while the wastewater with ph value of 4.5. The proposed surfactants wastewater process technique has distinct advantages of high efficiency and low-cost, which makes it with great potentials in the application of large scale industrial and domestic wastewater processing. Keywords coagulation; membrane separation; titanium dioxide; sodium dodecyl benzene sulfonate 1 1 2 Linear Alklybezene Sulfonates LAS 72% 3 / ph 4 1.0 ml/l 20 Sodium Dodecyl Benzene Sulfonate SDBS 96% 4 LAS LAS 65% 5 / 1 200 mg/l 150 mg/l 80 m 3 /h 6 DK2540 95% 1 -

7-10 Polyaluminum Chloride PAC 11 Titanium Dioxide TiO 2 12 TiO 2 - SDBS ph - 2 2 2.1 TiO 2 5 Polyvinylidene Fluoride PVDF Polyethylene Glycol PEG 6 000 Da80 4 TiO 2 2.2 1 Table 1 Technologies and characters of surfactant waste water treatment 2 Table 2 Experiment reagents and instruments

4 cm 2 700 1 500 cm 1 1 cm 2 3 μl 2.3 0.1 MPa 30 10 2 1 SDBS 224 nm 13 2 SDBS 0.8 0.6 0.4 0.2 0.0 y 0.0283x 0.0049 R 2 0.9987 5 10 15 20 25 (mg/l) 2 Fig. 2 Standard curve of sodium dodecyl benzene sulfonate solution 1 1 J L m 2 h 1 V m 3 A m 2 h 2 2 R C filtration g/l C bulk g/l 1 Fig. 1 The flow chart of cross-flow ultrafiltration experiment

3 3.1 3.1.1 Scanning Electron Microscope SEM 3 4 TiO 2 TiO 2 TiO 2 14 C C C 840 cm 1 CH 2 β 763 cm 1 CF 2 796 cm 1 CH 2 975 cm 1 α 15 PEG TiO 2 β α 875 763 840 796 PVDF+TiO 2 +PEG PVDF+PEG PVDF 1 070 975 1 180 1 275 1 404 800 1 000 1 200 (cm 1 ) 1 400 5 3 SEM Fig. 3 SEM picture of the membrane surface Fig. 5 Infrared spectra of the membrane 3.1.3 TiO 2 6 7 0.5 wt% TiO 2 79.3 66.5 14 TiO 2 PVDF TiO 2 4 SEM Fig. 4 SEM picture of the membrane cross-section 3.1.2 PEG- 6000 TiO 2 5 1 404 cm 1 CH 2 1 180 cm 1 CF 2 875 cm 1 79.3 6 TiO 2 Fig. 6 Contact angle of the membrane without TiO 2

1 wt% PVDF 95 83 TiO 2 TiO 2 66.5 7 TiO 2 Fig. 7 Contact angle of the membrane with TiO 2 3.2 0.1 MPa SDBS 100 mg/l PAC 10 mg/l ph - 3.2.1 10 mg/l PAC 300 ml/min ph 4.5 8 9 1.0 0.8 0 0.6 1.0 mw/cm 2 0.4 1.5 mw/cm 2 0.2 min 8 Fig. 8 Effect of different ultraviolet radiation intensity on the flux of membrane ultrafiltration 20 60 80% 1.0 mw/cm 2 TiO 2 16-1.0 mw/cm 2 100 80 60 40 0 1.0 mw/cm 2 1.5 mw/cm 2 20 min 9 Fig. 9 Effect of different ultraviolet radiation intensity on the rejection rate of membrane ultrafiltration 3.2.2 10 11 17

300 ml/min 80% 300 ml/min 0.8 100 ml/min 0.6 300 ml/min 500 ml/min 0.4 0.2 min 10 Fig. 10 Flux changes with different influent flow 100 ph SDBS SDBS ph 4.5 ph 2.5 ph 7 ph 2.5 30 ph 4.5 ph 7 1.0 80 60 40 20 100 ml/min 300 ml/min 500 ml/min 0.8 0.6 0.4 0.2 ph 2.5 ph 4.5 ph 7 min 11 Fig. 11 Rejection changes with different influent flow 3.2.3 ph 12 13 ph 7 ph 4.5 ph ph 4.5 PAC 18 ph 2.5 PAC Al H 2 O 6 3+ ph 7 PAC min 12 ph Fig. 12 Flux changes with different ph 100 80 60 40 20 ph 2.5 ph 4.5 ph 7 min 13 ph Fig. 13 Rejection changes with different ph

ph 7 3.3 3 3 [19-26] Table 3 Characteristics of integrated membrane separation technology

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