Biological filter structures

摘要

A biological filter element includes a support element of generally ellipsoidal configuration. The support element has two opposite polar regions and includes a medial ring intermediate the two opposite polar regions and a plurality of arcuate ribs extending from the medial ring to each polar region. Adjacent arcuate ribs are angularly spaced to provide access to an interior space of the support element. A cohesive body of biologically active material surrounds the support element and penetrates the interior space of the support element.