Patent ID: 7080828

Claim:
Settling basin membrane ( 1 ) made of polymer material, which is gas-permeable by means of a perforation ( 2 ), whereby with regard to permanent gas permeability of the polymer material, an inhibitor that is biologically active for waste water is added to the polymer material, which inhibitor is difficult to dissolve in water, and is distributed in the polymer material in essentially uniform manner, wherein the inhibitor is an inhibitor system, formed by a microorganism inhibitor and an algae inhibitor, whereby in reference to the total mass of the polymer material, the proportion of the inhibitor system is 0.1 to 5.0 wt.-%; and that the polymer material is a vulcanized rubber mixture, specifically on the basis of an ethylene-propylene-diene mixed polymerizate (EPDM), of nitrile rubber (NBR), or silicone rubber, each of them uncut, or on the basis of an EPDM/NBR blend, whereby with reference to the total mass of the polymer material, the proportion of the polymer or rubber or blend component is 10 to 50 wt.-%.