Stable anti-oil fouling of spray coated L-DOPA/APTES on mixed matrix membrane

Abstract

Oily wastewater poses a significant environmental concern as it has adverse effects on both ecosystems and human health. The development of highly efficient and robust antifouling membranes for oily emulsion is in great demand to prevent these serious issues in oil/water emulsion filtration. Moreover, fouling was inevitable when dealing with membrane separation. In order to overcome the addressed matters, this paper reported sprayed hydrophilic surface coating using commercialized levodopa (L-DOPA). The coated solution was mixed with 3-amino-propyltriethoxysilane in various ratios to obtain a smooth coated layer. Based on the results, the highest pure water flux and rejection efficiency of 586.51 ± 23.95 L/m2?h and 98.22% was achieved in this study, respectively. The abundant hydroxyl and carboxyl functional groups on the membrane surface from L-DOPA benefit the membrane in many ways, especially the membrane wetting properties. The water and oil contact angles of the coated membrane increased by approximately 75% and 85%, respectively. The fouling behaviors are influenced by the presence of the coated layer, resulting in the attainment of 90% fouling resistance ratio (FRR). This is mostly due to the reduction in adherence of oil droplets on the membrane surface, hence enhancing the effectiveness of the anti-oil fouling membrane. Additionally, this provides excellent properties of the membrane to be applied in oily wastewater treatment.