Enhanced fouling resistance of organosilane-grafted ceramic microfiltration membranes for water treatment

Abstract

A facile surface modification technique for imposing antifouling properties on ceramic microfiltration (MF) membranes was developed based on the chemical conjugation of organosilane molecules on ceramics. The ceramic MF membranes (pore size: approximately 0.1¯m) were fabricated using conventional dip coating in an alumina slurry with nano-sized particles. The membranes were subsequently subjected to organosilane grafting with different molar concentrations (25, 50, and 100 mM). The physicochemical analysis of the organosilane-grafted membranes revealed a small decrease in pore size/roughness, which resulted from the new formation of organosilane multilayers (i.e., pore-filling effect). The pure water permeability was also diminished to some extent while exhibiting minimal influence on the permeation flux. Because of the electrostatic repulsion force between the surface-modified MF membranes and the model foulants, serious foulant adsorption followed by flux decline was significantly alleviated. In particular, the lowest organosilane concentration (25 mM) showed the greatest flux performance. This was mostly attributed to the reduced effect of pore-size restriction and electrostatic repulsion forces. We therefore achieved the optimum organosilane-grafting conditions for ceramic MF membranes, which not only minimized the alteration of surface morphology/pore size and hydraulic permeability but also remarkably improved the antifouling properties.

A Mini Review on Treatment of Wastewater with Membrane Technology

“…For industrial applications where particles larger than 0.1 µm must be stayed in a mixed solution, micro-filtration is the preferred approach and a fairly well-established technology [21]. Micro-filtration membranes is making significant progress in the wastewater sector, concentrating on removing particles from wastewater, in sewage treatment, but also in a number of other types of industries like semiconductor fabrication that produce heavily polluted wastewater that requires extensive treatment due to toxic substances and metals [35].…”

Ceramic Microfiltration Membranes in Wastewater Treatment: Filtration Behavior, Fouling and Prevention

“…Examples (Table 2) include sterilization and clarification of numerous different genres of mixtures and solutions, in the food, feed and pharmaceutical industry which until recently were the main industrial applications [75]. MF is gaining great grounds in the water and wastewater industry, focusing in removing particles from water and wastewater, in sewage treatment but also in several other types of industries such as semiconductor fabrication that generate heavily polluted wastewater that needs extensive treatment due to toxic substances and metals [63].…”

Effect of SiO₂ coating on alumina microfiltration membranes on flux performance in membrane fouling process

“…Previous studies on organic surface modification have also revealed a correlation between the pore size and the pure water permeability of alumina MF membranes. 25) An increase of the extent of surface grafting (or coating) leads to a reduction of the pore size, surface roughness, and water permeability. In spite of the many merits of organic/ inorganic surface modification, it sometimes gives rise to a reduction in the flux level owing to the "pore-filling" effect.…”