Abstract: A gas diffuser including a grid of aeration pipes spaced apart and in parallel alignment within a horizontal plane is provided. The aeration pipes have improved discharge hole placement along their lengths and around their circumferences to provide improved performance and reduced fouling of membrane filtration systems associated therewith.

Abstract: A gas diffuser comprises a grid of aeration pipes spaced apart and in parallel alignment with each other within a common horizontal plane and a manifold in fluid communication with the aeration pipes. A given aeration pipe (12) includes: a length (L) extending between two ends and defining an axis (Z), a hydrodynamic diameter (Dh),an elliptical cross-sectional area defining a vertical plane comprising a vertical (Y) and horizontal (X) axis intersecting through a center (C) which are perpendicular to axis (Z), an outer circumference defined by a first arc (20) comprising 30° located below the (X) axis and bisected by the (Y) axis, and a second arc (22) comprising 330° which is non-overlapping with the first arc (20.