Cross-flow for wastewater revamp


ASHFORD Wastewater Treatment Works has undergone a £12.6 million redevelopment.

To ensure the high standard of service was maintained and able to accommodate a 30% increase in flows and loads, Southern Water specified the best suppliers to meet its high expectations through design workshops in which Hewitech successfully showcased its range of cross-flow media. All products had to contribute towards achieving National Environmental Programme (NEP) consent requirements while ensuring that the installation process wouldn’t affect the live water works and Southern Water customers.
Constructing a fourth nitrifying trickler filter (NTF) was essential in increasing the water works processing capacity. The NTF facilitates the nitrification of the wastewater to remove ammonia, a vital process, as it is not only toxic to aquatic life but also places a high oxygen demand on receiving waters as well as promoting algal blooms.
Hewitech’s CF 15 PP Cross flow was specified for the application as the NTF media of its structure provided a suitable surface for the growth of the bacterial film necessary in the nitrification process. The polypropylene 190m2/m3 model was applied in 1733m3 quantity, providing a large surface area through which a substantial volume of water can be filtered.