Jointly meeting global challenges Annual report 2012


Clean membranes for efficient drinking water

13 October 2012BTO

KWR develops a new test that quickly and cost-effectively identifies the optimal cleaning method for membrane filters fouled with biofilms.

Een biofilm. Rood zijn de actieve bacteriën, groen extracellulair materiaal.

Microscopic image of a biofilm. The active bacteria are red and the extracellular material is green.

Membrane filtration plays an important role in drinking water production. Membranes work like a screen and remove undesirable substances and pathogens from the drinking water. Bacteria can grow on the surface of the membranes, where they accumulate and form a biofilm. The biofilm also secretes and adsorbs a wide variety of substances, which is known as extracellular material. Since biofilm reduces the effectiveness of the treatment installation, the membranes need to be cleaned regularly. Selecting the most appropriate cleaning process (cleaning products, conditions) is in practice time-consuming and costly, and is therefore not usually done.

A test that water companies can implement

In response, KWR has developed a testing method within the framework of the water sector’s joint research programme (BTO). A large number of biofilm samples are produced in a test set-up with water recirculation, fed with drinking water or the local feed water of a membrane installation. These biofilm samples are then exposed to different cleaning conditions (product, temperature, time). A measurement is then made of the amount of biofilm (bacteria and extracellular material) remaining on the membrane. Water companies can carry out the test to optimise the performance of their membrane installation by better and more efficient cleaning procedures.

© 2018 KWR Watercycle Research Institute

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