MICRODYN-NADIR explains that when operating wastewater treatment plants using MBR technology, factors such as energy saving, reduction of the chemical demand or minimisation of the total costs of a plant is of major interest. However, the company adds that increasingly one other criterion is becoming important. The membranes built into submerged modules and installed in a WWTP have to be of the highest quality in order to ensure, amongst others, compliance with international water standards when looking at effluent quality and turbidity.A damaged membrane is one of the worst things that can happen to an operator of a wastewater treatment plant and consequently for the manufacturer of the membrane module. For example, screw drivers or other tools falling into the filtration chamber of a plant can damage the membranes severely.MICRODYN-NADIR has introduced a self-healing mechanism for BIO-CEL® sheets, which represents the core part of the BIO-CEL® MBR module. Due to its sandwich-like and self-supporting structure the membrane ‘heals’ itself and closes any scratch or cut immediately.Several tests have proven that even under worst case conditions, such as very low MLSS concentrations and significant damage of the sheet, the BIO-CEL® module offers turbidity values which are compliant with existing international regulations for water reuse.