Membrane straws lead to improved drinking water

Research by Joris de Grooth from the University of Twente’s MESA+ research institute in the Netherlands has led to the possibility of purifying water in a single step without the need for preliminary treatment.

The process can also improve the removal of increasing amounts of micropollutants such as medicines, pesticides and hormones in surface water which in turn produces cleaner drinking water.

The selective membrane is applied to thin porous straws with holes of about five nanometres in diameter. Multiple thin layers of polymer coating are applied over the holes by means of a chemical process. The number and density of the layers can be varied depending on the application.

On the inside of the straws, the contaminated water flows to the inside while on the outside of the membrane, clean water flows through the fibre, with the contaminants remaining behind.

Overall it makes water treatment cheaper and the process can improve the possibility of processing clean water in remote areas such as developing countries.

Mr De Grooth has been awarded a doctorate for his research which was partly carried out at Pentair. The company is taking over further product development of the membrane.