A compressible biomass carrier for use in fluid treatment systems is disclosed. The biomass carrier includes an extruded circumferential mesh-like structure and elongated elements positioned in a space confined by the circumferential mesh-like structure and at least some of the elongated elements are joined to an inner portion of the mesh-like structure.

A packing element for use in a heat exchange or mass transfer tower includes a barrel and a plurality of fins spaced around a circumference of the barrel, each fin having a height approximately equal to a height of the barrel and a length extending radially from the barrel, a proximate end of each fin attached perpendicularly to the barrel. A protrusion extends outward from the distal end or each fin along its height. A method for mass transfer includes passing fluids through a vessel packed with randomly arranged packing elements.