Pharmaceuticals, industrial chemicals and other endocrine disruptors, even at low concentrations can cause severe damage to aquatic ecosystems and potentially lead to infertility of entire fish cultures. If drinking water is obtained from these waters, damage to humans cannot be ruled out. Since current wastewater treatment plants do not sufficiently break down these micropollutants, research is conducted on various methods of micropollutant removal. The combination of adsorptive processes with membrane separation is considered particularly promising.
Membranes have become indispensable in technology: they, for instance, separate clean water from impurities, and their functional principle is similarly simple as the one of a classic coffee filter. The small but significant difference between a generally known filter and a membrane lies in the pore size. For an ultrafiltration membrane, this is less than a tenth of a micrometer, i.e. around 500 times smaller than a human hair. Activated carbon – the main representative of adsorptive processes – is characterized by a very large specific surface area. Just a few grams correspond to the area of a soccer field. Through its large surface, activated carbon excellently binds the problematic micropollutants from waste water.
In this project, which is supported by the “Tiroler Wissenschaftsförderung”, a novel combination method will be investigated. Activated carbon is embedded directly into the membrane matrix of so-called phase inversion membranes – a membrane form produced by a special process – which allows for a one-step process combining adsorption and membrane filtration. This "Activated Membrane" will first be tested and optimized under laboratory conditions with selected micropollutants. Subsequently, the separation efficiency with real wastewater samples will be tested. Further important questions are the regenerability of this hybrid membrane after loading and the fouling properties (the timespan before the membrane starts to "foul" and has to be backwashed).
First results are still pending, but "Activated Membrane" could be a promising concept for the elimination of micropollutants and finally for the reduction of the environmental impact of anthropogenic wastewater streams.
For further information, please get in touch with:
Jan BackLecturer+43 512 2070 – 3259jan.back@mci.edu
Scanning electron microscopy of “Activated Membranes“ with increasing activated carbon content. Photo: MCI.
Different variations for combinations of adsorptive processes and membrane technology: (a) Two-step process with upstream activated carbon contactor, (b) One-step process with “Activated Membrane”. Photo: MCI.
