Removal of nano and microparticles by granular filter media coated with nanoporous aluminium oxide

Abstract

Conventional filtration was designed to achieve high levels of particle and pathogen removal. Previous studies have examined the possibility of modifying filtration media to improve their ability to remove microorganisms and viruses. Although these studies have evaluated filter media coatings for this purpose, none have evaluated nanoscale particle suspensions as coating materials. The overall goal of this paper is to describe the preliminary test results of nanoporous aluminium oxide coated media that can be used to enhance filtration of nano and microparticles. Filtration tests were carried out using columns packed with uncoated and coated forms of granular anthracite or granular activated carbon. A positive correlation between isoelectric pH of filter media and particle removal was observed. The modified filter media with a higher isoelectric pH facilitated better removal of bacteriophage MS2 and 3 microm latex microspheres, possibly due to increased favorable electrostatic interactions.

Nanostructured surface modification of microporous ceramics for efficient virus filtration

“…12 These and other studies of electropositive filter media 13,14 generally show that the strongest contribution to the adsorption process is made by electrostatic forces, i.e. the attraction of charged particles to an oppositely charged surface.…”

Adsorption and separation properties of positively charged ZrO2nanofibrous membranes fabricated by electrospinning

“…7,8 Nanoporous Al 2 O 3 coatings prepared on the surface of activated carbon particles can increase the isoelectric point of the surface and the removal efficiency of Escherichia coli MS2. 9 In a previous study, positively charged ZrO 2 or Y 2 O 3 nanocoating was loaded on diatomite by impregnation and sintering; 10,11 the coating showed a removal rate of 99% for E. coli MS2 but exhibited a low specic surface area (8 m 2 g À1 ), which led to low adsorption capacity for other bacteria and viruses. Hence, micro/ nanoporous ceramic membranes with high porosity, specic surface area, and adsorption capacity 12,13 should be used as adsorbent materials to effectively separate and remove negatively charged viruses and bacteria.…”

Virus removal from drinking water using modified activated carbon fibers

“…11,16,19 AC can also be modied with metal species/metal oxides in order to increase the amount adsorbed of the target species from both the gas and liquid phase. [20][21][22][23] AC is not commonly used for virus removal, exhibiting rather low affinity towards them. [23][24][25][26] Conversely, Matsushita et al reported up to 4 log 10 reduction value (LRV) in long-term batch studies using grained powdered activated carbon (PAC).…”