PVDF/HMO mixed matrix membrane coated with l-dopa via spray coating method

Abstract

Day by day, the amount of oily wastewater keeps on growing as oily wastes are discharged from numerous sources. This phenomenon needs to be remedied to reduce water pollution. Generally, the issues regarding the membrane to be applied in oily wastewater treatment are the fouling problem and membrane’s lifetime. In this study, mixed matrix membrane (MMM), 18 wt% of polyvinylidene fluoride (PVDF) incorporated with 10 wt% of hydrous manganese dioxide (HMO) was coated via spray coating at 0.5 bar with levodopa (L-DOPA) to enhance the water flux performance of the membrane. The flux performances of the membranes were compared using oil/water emulsion at concentration of 1000 ppm. The mixed matrix membrane L-DOPA (MMM LA) showed a slight difference in pure water flux value (423.33 L/m2·h), however the oil rejection is comparable with current technology. The coated membrane attained a smoother surface which led to better antifouling properties where MMM LA exhibited a surface roughness value of 23 nm, almost 82% smoother than that of MMM. The membranes were operated for 120 min with a feed of 1000 ppm, which resulted in flux values of 37.89 and 45.84 L/m2·h for MMM and MMM LA, respectively. The MMM LA exhibited good wetting properties with high hydrophilicity and oleophobicity and so as the flux and antifouling performance compared to the unmodified MMM.