Aerated reed beds
Buffalo Airport is in Washington State (USA) and generates significant loads of runoff contaminated with anti-freeze. This had been a difficult issue to resolve in wintertime, as large volumes of runoff and snow melt required treating prior to discharge from site.
The glycol-based antifreeze reaches very high loading levels of up to 15,000 mg/l CBOD5.
The contaminated runoff was effectively treated by an engineered wetland system using the patented ARM Forced Bed Aeration™. The extent of CBOD5 degradation by this system is illustrated in Fig.1.
Eichten Cheese Factory generates very highly loaded effluents, between 3,000-7,000 CBOD5 mg/l.
BOD levels were effectively controlled with a reed bed with Forced Bed Aeration™. The extent of CBOD5 degradation by this system is illustrated in Fig.2.
Uffington Waste Water Treatment Works serves a population of 700-800 and receives an average flow of 174 m3/d.
It had been operating within a 5mg/l ammonia consent which was lowered to a 3 mg/l.
Two aerated vertical beds with a total area of 550m2 were constructed for the provision of tertiary treatment on site. Fig.3 indicates the impact aeration had on the treatment capacity and consistency, especially with reference to lower temperatures seen in winter.