Biofiltration of WWTP sludge composting emissions at contact times of 2-10Â s by structured/unstructured packing materials

- Operation of a BTF for composting emissions at 10 s gas contact time.
- Polyurethane foam cubes and a structured packing were compared as packing material.
- Average ECs of 13 g N m−3 h−1 and 3.3 g C m−3 h−1 were achieved for 8 months.
- Water make-up flow rate affects NH3 removal and nitrification rate.
- A large packing surface area only proved useful to accelerate reactor start-up.