In-situ Manipulation of Gel Layer Fouling into Gel Layer Membrane Formation on Porous Supports for Water Treatment

Abstract The inaccessibility of clean water is one of the growing issues of this era. Indeed, cost-effective and sustainable methods for recycling wastewater are essential. Although membrane separation is an efficient technology for the recycling and purification of water, membrane fouling is still a major drawback of this technology. This work is aimed to develop a dynamic method to form gel layer membranes (GLMs) by manipulating the irreversible fouling process itself as a problem-solving approach. A microporous polyvinylidene fluoride (PVDF) support is subjected to gel layer formation by applying a supernatant of industrial aerobic sludge (containing soluble extracellular polymeric substances EPS) as a feed. Retention of polysaccharides and calcium during the filtration and the topographical analysis after the filtration show that EPS uniformly formed a gel layer on the PVDF support. No further decline in permeability is observed (i.e. remained around 27-33 L/m2.hr) when the formed GLM is subjected to fouling under similar conditions. Moreover, the percent flux recovery ratio (FRR) of the GLM is also significant (i.e. 90.1 ±2.71). The retention ability, hydrophilicity, porosity, and water uptake capability of the formed GLM also increased significantly. These results suggest that the newly developed GLM operating at room temperature (RT) under neutral pH and sub-critical trance membrane pressures (TMP), is viable for preparing fouling resistant membranes with high retention efficiency. In addition, this approach can be used for membrane manipulation via gel layer formation for wastewater treatment.