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.
One of the major focuses in the field of sewage is the development of low-pressure driven and high-efficiency filtration membrane, particularly for removing extremely low-concentration heavy metals cations. A new type of polyvinyl chloride (PVC) blended ultrafiltration (UF) membrane was fabricated to reject heavy metal cations (e.g., Cd 2+ , Co 2+ , Ni 2+ , Cu 2+ , and Zn 2 + ) from simulated waters using micellar enhanced ultrafiltration (MEUF) in this research. The positively charged PVC UF membrane was fabricated by blending PVC and amphiphilic poly (methyl methacrylate- co- dimethylaminoethyl methacrylate) (PMD) which was in-situ quaternized by methyl iodide (CH 3 I), then the PVC/PMD blended membrane was fabricated via nonsolvent induced phase separation (NIPS) process. The membranes' pore morphology, surface chemical compositions, surface charge, water contact angle, mechanical strength and water flux were investigated in detail. The influence of pH, transmembrane pressure, sodium dodecylbenzene sulfonate (SDBS) concentration on the filtration of pure SDBS solution was studied. SDBS was subsequently used as surfactant to remove heavy metal ions by micellar enhanced ultrafiltration (MEUF). For a molar ratio of 40:1 (SDBS: metal cation), the rejection of feed solution containing 10 ppm metal cations (e.g., Cd 2+ , Co 2+ , Ni 2+ , Cu 2+ , and Zn 2+ ) surpassed 96% with MEUF method. The results showed that the prepared membrane had low-pressure driven and high-efficiency performance, which provided a potential solution for the high-efficiency removal of trace heavy metals cations.
危险品化学品经营许可证（带存储）