Impact of insufficient membrane and filter properties: Fouling and functionalization

B. Arlt*, Anton Paar Germany GmbH, Germany; T. Luxbacher, Anton Paar GmbH, Austria

In this presentation we will focus on promising methods for membrane and filter characterization in order to improve the filtration efficiency and to increase the life time of these materials. Exemplarily, we will point on two showcases: the fouling behavior of a nanofiltration (NF) membrane and the functionalization of depth filters based on diatomaceous earth (DE).

  1. Identifying the fouling behavior of NF membranes

Employment of polymer membranes for purification and separation processes experiences a steadily growing popularity. Besides their classical application in water purification, polymer membranes become increasingly attractive for the separation and up-concentration of products in the fields of food, biotechnology and pharmacy.

Despite of these versatile application areas, there are restrictions for the optimum use of polymer membranes. The deposition of dissolved or dispersed matter from the feed on the membrane surface, known as membrane fouling, represents an often unresolved challenge especially for polymer membranes and pressure-driven filtration processes (such as nanofiltration and reverse osmosis).

Beside the conventional methods to monitor fouling, such as the monitoring of the transmembrane pressure, we present a highly sensitive method, which is the zeta potential analysis [1]. This parameter at the interface between the membrane surface and the surrounding aqueous solution enables early detection of fouling processes.

  1. Analyzing the modification of water filters

Potable water production requires an efficient and cost-effective technology of drinking water treatment. Depth filters based on diatomaceous earth are widely used for bacteria removal.

Bacteria are unable to penetrate the pores of a microporous DE filter, whereas the significantly smaller viruses can easily pass the filter and harm the consumer. These contaminants can only be completely removed by electrostatic attraction of the virus on the filter pore surface.

As both, the filter and the virus, show negative surface charges, the filter surface has to be modified. Thereby, the zeta potential analysis is a proven tool for measuring the surface charge in a wide pH range.

Session: M4 - Ceramic Membranes and Fouling
Day: 23 October 2019
Time: 10:45 - 12:00 h

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