Modification of ceramic microfilters with colloidal zirconia to promote the adsorption of viruses from water

• Published in: Water research (Oxford) Vol. 42; no. 6; pp. 1726 - 1734
• Main Authors: Wegmann, Markus, Michen, Benjamin, Luxbacher, Thomas, Fritsch, Johannes, Graule, Thomas
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2008; Elsevier Science
• Subjects: Adsorption; animal pathogens; Applied sciences; bacteriophages; Ceramics; Colloidal zirconia; colloids; Colloids - chemistry; Diatomaceous earth; Exact sciences and technology; filters; Filtration; heat treatment; isoelectric point; micropores; microporous ceramic filters; Microscopy, Electron, Scanning; Other industrial wastes. Sewage sludge; Pollution; Virus filter; viruses; Viruses - isolation & purification; Wastes; water filters; Water Microbiology; water treatment; Water treatment and pollution; Zeta potential; zirconia; zirconium; Zirconium - chemistry; zirconium dioxide; Adsorption; Diatomaceous earth; Colloidal zirconia; Zeta potential; Virus filter; Surface charge; Filter medium; Heat treatment; Filtration; Adsorption capacity; Microporosity; Isoelectric point; Bacteria; Electrokinetic potential; Ceramic materials
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2007.10.030

The purpose of this study was to test the feasibility of modifying commercial microporous ceramic bacteria filters to promote adsorption of viruses. The internal surface of the filter medium was coated with ZrO 2 nanopowder via dip-coating and heat-treatment in order to impart a filter surface charge opposite to that of the target viruses. Streaming potential measurements revealed a shift in the isoelectric point from pH <3 to between pH 5.5 and 9, respectively. While the base filter elements generally exhibited only 75% retention with respect to MS2 bacteriophages, the modified elements achieved a 7 log removal (99.99999%) of these virus-like particles. The coating process also increased the specific surface area of the filters from ≈2 m 2/g to between 12.5 and 25.5 m 2/g, thereby also potentially increasing their adsorption capacity. The results demonstrate that, given more development effort, the chosen manufacturing process has the potential to yield effective virus filters with throughputs superior to those of current virus filtration techniques.