Reed beds now able to treat stronger effluents in smaller footprints

Reed bed technology has always been seen as a sustainable sewage treatment solution however it does have limitations in terms of the effluent strengths it can treat and the size of footprints versus alternative solutions. Reed bed technologies have moved forward and offer a far more flexible and feasible solution for a wider array of applications.

Higher energy costs and the drive to reduce carbon footprints are all contributing to make reed beds a more viable option compared with the alternative chemical and mechanical treatment technologies.

Recent advances in reed bed technology mean the treatment of high strength pollutants such as petrochemicals, agricultural wastewaters and capped landfill leachate with high ammonia concentrations are now proven.

The market leader in natural wastewater treatment, ARM, has collaborated with its US partner, Naturally Wallace which developed Forced Bed Aeration (FBA) technology for which ARM has sole UK distribution rights. It has a wide range of applications across many industries but the advantages are most considerable for the water industry.

In reed beds fitted with FBA, a network of aeration pipes is laid beneath the gravel media. Air is pumped through the pipes, it then bubbles up through the reed bed and greatly increases the oxygen availability which intensifies the loads which the reed bed is then capable of treating.

Micro-organisms attach themselves to media and plant roots. These organisms degrade the pollutants using the oxygen available in the reed bed. The more oxygen available to the organisms, the more pollutants they can remove.

Due to the increased oxygen availability in FBA systems, micro-organisms degrade pollutants aerobically and this can boost treatment capability by at least ten times that of a traditional passive reed bed.

The increased treatment capacity due to oxygen availability also has several other benefits. It allows for far deeper reed beds meaning FBA systems can have a smaller footprint. It also means FBA reed beds can handle stronger pollutants such as wastewater containing high concentrations of ammonia than traditional, passive systems.

Complete nitrogen removal can be achieved by dividing reed beds into aerobic and anoxic zones to allow both nitrification and denitrification. FBA technology can be retro-fitted to existing systems.