Biofouling detection is difficult to in an early stage in an operating membrane installation. Biofouling detection starts normally at the leading elements, which will not result in an increased pressure drops over the total first stage. Only when severe biofouling has occurred it will be detectable with the equipment normally installed to control the first stage of the installation. Biofouling is one of last hurdles to overcome in membrane technology. (Paul, 1991; Flemming et al., 1997; Ridgway, 2003). As scaling is a predictable process, biofouling however is still poorly understood even when factors that contribute and influence it are well known. In all membrane processes as Reversed Osmosis and Nano filtration, it leads to an increase of pressure drop and consequently to higher costs of plant operation.
Biofouling Detection and the Membrane Fouling Simulator
In order to detect biofouling in an early phase a instrument has been designed. The Membrane Fouling Simulator (MFS) has been developed and tested over the last decade by Dr. Hans Vrouwenvelder, currently Technical University Delft and KAUST. Its sensitivity has been proven in lab tests and on full scale installations which the MFS is used for biofouling detection. The MFS can be used to evaluate the biofouling tendencies of different water sources, of dosed chemicals or as an early warning device.
Biofouling Detection and Global Membrains
Global Membrains offers the MFS to simulate the fouling under the same conditions that are present in the lead element of a plant. It can be used in pre-studies for biofouling detection potential of different available feed water qualities. Furthermore, it can be used to evaluate different kind of pre-treatments for the feed water of a membrane plant even without the plant actually being there.
The possibilities of the MFS such as biofouling detection instruments are not limited to membrane technology. It can be used to monitor biofouling in cooling water systems and to control a biocide program. It also can be used as a detector to monitor the biofouling in a complex drinking water distribution system.