Phragmifiltre® is the first reed bed technology in the UK that provides complete treatment of macerated or raw sewage in one wetland system, with no pre-settlement using little to no power. This signifies a major change in thinking towards a natural and sustainable alternative for sewage treatment in the UK where reed beds have been traditionally used as a secondary treatment after settlement and as tertiary treatment to polish effluent prior to discharge.
Developed in France, the Phragmifiltre® requires no pre-settlement, only screening and/or maceration of raw sewage . The system has in the design two stages. The first stage filter has three or more beds and de-waters the solids from the raw sewage on the surface of the reed bed. Macerated/screened sewage is fed to each bed in rotation thereby allowing all the beds to have a rest period. The filtrate passes down through the beds which act as a typical vertical flow reed bed reducing BOD primarily but also undertaking nitrification of ammonia.
The second stage of vertical flow reed beds provides additional BOD reduction and completes the nitrification of ammonia prior to discharge. The design incorporates siphon technology where possible for dosing at both stages, thus minimising any power requirement.
Information about this new technology can be obtained from ARM Group Ltd, Rydal House, Colton Road, Rugeley, Staffordshire, WS15 3HF. 01889 583 811