Below are a few of the different MBBR media types:
Sponge-type carriers: Sponge-type MBBR media carriers have high mechanical strength, a high specific surface area, and a rough surface texture optimal for biofilms to take hold on. Their spongy materials are incredibly flexible, though they tend to wear down more easily than other types.
Chip-type carriers: Chip-type carriers are thin and have a high concentration of fine pores. They are flexible as well, and they offer robust resistance to wear and tear.
Coin-shaped carriers: Thin, coin-shaped media carriers provide the advantage that wastewater can filter into them from either side of the media, so they are minimally susceptible to fouling. Some thin chip-type media carriers are coin-shaped.
Tube-shaped carriers: Long, narrow tube-shaped carriers offer an extended MBBR media surface area for microorganism growth. Their shape also helps them suspend evenly within the water column instead of stacking on top of one another. Because of their hollow forms, though, they can sometimes become susceptible to fouling.