Native wetland and marginal plants grown in Wales, United Kingdom

The Growing Solution To Water Pollution

Reeds from Seeds

Reeds from Seeds

Advantages

• Low maintenance
• Low capital and operational costs
• No operational noise
• Aesthetically better than traditional plant equipment
• Capable of treating very low/intermittent flows
• Capable of treating flows from residences/businesses not connected to main sewerage system

 

Disadvantages

 

• Land area required may be greater than that required by traditional processes
• Not a tried and trusted methodology on a wide variety of industrial effluents
• Design procedures not standardised

 

Application and Performance

 

Some advantages of reed beds are specific to municipal systems. Reed beds have also been successfully applied to specific industrial effluent treatment. Effluents such as landfill leachate, mine drainage, various chemical and pharmaceutical effluents, refinery effluents, pulp and paper wastewaters, food processing and textile dyeing wastewaters have all been treated or partially treated using reed beds.

 

Reed beds are not  a single biological entity. Reed beds are a community in which exist, fungi, algae, bryophytes and aquatic invertebrates. The reeds (macrophytes) are an integral part of the system, they provide oxygen and within the root zone provide surfaces on and to which other organisms can grow and proliferate. This complex community displays certain contaminant removal mechanisms which are simply not present in standard treatment processes. With specific reference to fungi, there are certain species capable of degrading a range of synthetic recalcitrant chemicals including pesticides and chlorinated hydrocarbons. Fully mature reed beds have been used to remove phenols, methanol, acetone and amines from a range of industrial effluents.

 

Industrial wastewaters may have very specific characteristics with regard to their composition and contaminants. Pilot studies are advisable to ensure that systems designed will function adequately. Reed beds will remove specific contaminants either biologically as a direct result of the reedbed uptake, e.g. nutrients, soluble, organics and trace elements, chemically via complexation and precipitation reactions, or by physical filtration, sedimentation and adsorption.

 

Cation exchange has also been demonstrated using reed beds and this cation exchange ability appears to stem from the presence of carboxyl groups in the cellular layers of the reed. Additionally this cation exchange ability appears to function pathogenically when the plant material has died back, as well as during the active growing season.