Abstract: A filtration apparatus (2) includes a pressurized cylindrical pressure vessel (4) having a longitudinal axis (X) and a shaft (8) having a longitudinal axis (Y) extending parallel to the longitudinal axis (X). A plurality of rotatable membrane filter discs (6) are arranged along the shaft (8). The membrane filter discs (6) are spaced-apart from each other, attached to the shaft (8) and oriented transverse to the longitudinal axis (Y) of the shaft (8). An interior (10) of the membrane filter discs (6) are in fluid communication with a permeate discharge channel (12) extending parallel to the longitudinal axis (X) of the pressure vessel (4). The pressure vessel (4) has a cylindrical inner geometry without any significant obstruction elements. The longitudinal axis (X) of the pressure vessel (4) is laterally offset from the longitudinal axis (Y) of the shaft (8) and/or the membrane filter discs (6) are oval-shaped.

Abstract: The present invention relates to a resilient member (FIG. 7b) and combination of resilient members into resilient devices. Particular embodiments of the present invention relate to a bio film reactor comprising a stack of bio film discs formed as a resilient member thereby allowing the stack of bio film discs to be self compensative at least partially for expansion of the stack as a result of e.g. changes in temperature. Furthermore, the resilient member and device according to the present invention provide a great flexibility as to the actual choice of material for the member and device. The male protrusions (4) of one resilient member (1) are introduced into the voids (5) of the female protrusions (3) of a similar or identical member (1). Male protrusions (4) of a second kind do not abut the bottom of the voids (5).

Abstract: The invention relates to an aeration device (20) for aeration of a liquid. The aeration device comprises a plate (30) of a first material, said first material being permeable to air, said plate having inlet means (31) for inletting air into the plate and means for creating a flow of liquid across the plate of the first material, when said aeration device is immersed or submerged in a liquid. The plate of first material is stationary within the aeration device. The aeration device may moreover comprise a disc (12) arranged for being placed in parallel to the plate, but leaving a gap between the plate and the disc member, and the means for creating a flow of liquid across the plate of the first material may comprise means for rotating the disc member around a central axis through the disc member. Small or very small bubbles of air may be generated by the combination of air permeable material and creation of a flow across the plate.