Yong Chen,Tao Wan,Yanjun Huang,Yi Wang,Guozhi Fan,Lei Zhang,Shengxuan Fan,Xueling Liu
The amount of substation accident oil pool wastewater (SAOPW) generated has been increasing due to the successive addition and renovation of substations, and the discharge of untreated or incomplete treatment outside the station will cause serious environmental pollution problems. In this study, a polyethersulfone (PES) composite ultrafiltration membranes were fabricated using phase inversion method and evaluated them for oil removal from SAOPW. The morphology and functional groups of PES composite membranes before and after filtration were characterized and compared through scanning electron microscopy and Fourier-transform infrared spectroscopy. The effects of operating pressure, feed temperature, initial oil concentration and operating time were systematically investigated using flux recovery and oil removal rate as the indexes of investigation, and the process economy was studied and evaluated. The results showed that the PES composite membrane had a relatively high-water flux of 260.2 (L·m –2 ·h –1 ) and a high oil removal rate (≥90%), which could effectively remove oil from water. Besides, its high flux recovery ratio (≥90%) after four filtration and cleaning cycles indicated the excellent performance of this PES composite membrane in the separation of oil–water emulsions. This study confirms the applicability of PES composite membrane for oil removal from SAOPW, providing a promising treatment method for the SAOPW treatment.
Usually seen as a waste with low chemical value and limited commercial potential, lignin produced in large quantity from paper industry performs abundant valuable hydrophilic groups which make it a potential hydrophilic assistant. In this contribution, in order to improve hydrophilicity and antifouling properties of PVC ultrafiltration membrane, lignin was doped into PVC to prepare a uniform sol under strengthening heat and mass transfer process, and then PVC/lignin ultrafiltration membranes were prepared via phase inversion strategy. The resulted PVC/lignin ultrafiltration membranes were characterized by SEM, FT-IR, XPS , DSC and were also tested by oily wastewater. According to the results of SEM, XRD and DSC analyses, PVC is compatible with lignin and the homogeneous PVC/lignin sol can be formed. The hydrophilicity of membrane is significantly enhanced with water contact angle (WCA) decreasing from 106.73° to 41.53°. Particularly, the PVC/lignin ultrafiltration membranes exhibit attractive properties with oil rejection of 97.36% and oily wastewater permeation flux of 156.55 L m −2 h −1 (0.1 MPa), nearly 2.5 times that of pure one (65.06 L m −2 h −1 ). Lignin suggests to be a superior additive to improve hydrophilic and anti-fouling properties of PVC membranes, and the lignin-modified membranes are promising candidates for cleaning oily wastewater and sewage.
Hailin Yu,Huili Zhang,Zhengnan Sun,Yingjun Wang,Hongsheng Liu,Yanbin Tong,Lingmin Wu,Jinjun Deng,Liqun Sun
When the amount of anionic polyacrylamide (APAM) and petroleum sulphonate in polymer-flooding oily sewage increases, a stable emulsification system forms. This makes the treatment of oily sewage increasingly difficult. To better develop high-efficiency coagulants from scratch, this study first determined the structure and carbon number of petroleum sulphonate using 1 H NMR and 13 C NMR spectroscopy. Then, hydrophobic monomers with different chain lengths were copolymerised with aluminium salts to prepare inorganic polymer coagulants with different hydrophobic association abilities. Three novel coagulants were successfully prepared, as verified by FTIR and hydrodynamic radius detection, and their coagulation mechanism and performance in oily sewage were investigated and compared with (polyaluminium silicate sulphate) PASSi. The particle size and morphology of flocs after the addition of coagulant were detected by laser particle size analysis and scanning electron microscopy. The structure-activity relationship between emulsifiers and coagulants with different chain lengths was studied via the second virial coefficient A 2 . Polyaluminium silicate sulphate-hexadecyltrimethoxy (PASSi-C16) was determined to have the best coagulation effect by turbidity , oil removal rate and Zeta potential detection. This may have been due to PASSi-C16 containing a similar lipophilic group to the carbon chain structure of petroleum sulphonate, which could easily destroy the emulsion layer. These results provide insights into methods to improve the hydrophobic association capacity and for the targeted use of associative coagulants in large-scale applications.
危险品化学品经营许可证（带存储）