The Eco-SAF™ module is based on proven Submerged Aerated Filter (SAF) technology and has been manufactured by us since 1996. Originally designed to treat domestic sewage to a good quality discharge standard it has been successfully developed further over the years as an advanced ammonia removal system, total N (nitrogen) removal system, and as part of a process to treat a wide variety of Industrial effluents. Individual modules are available to treat wastewater from the equivalent of 50pe to a maximum of 1000pe. Where multiple modules are required a flow splitter tank can be installed to distribute the wastewater evenly. 
It is an upflow bioreactor which is a well-proven, extremely robust and efficient biological treatment process which is used to biodegrade organic matter. It is generally installed as an integral part of a complete packaged wastewater treatment solution. It can also be configured to enhance existing treatments to reduce the nitrogen in the wastewater. The Eco-SAF will produce a treated wastewater that exhibits a very low levels of BOD, COD, Total Suspended solids and. It has been developed to handle fluctuations in flows and loads making it a good solution where intermittent loading occurs. To optimize performance the Eco-SAF is designed with a minimum of 3 cells and in the standard sewage treatment installation attains discharge standards in mg/lt better than: BOD5.:20 / TSS:30 / NH4-N:10 (95%ile). 

How does it work? 

The Eco-SAF process is a very simple:- 
Wastewater is distributed across the base of the cell and flows vertical up through the cells in sequence. 
Air that includes the necessary oxygen is provided from an air compressor via the diffuser membrane system that is located at the base of the cells. 
The mixture of the wastewater and the fine bubbles of air travels upwards through the voidage of the plastic media that is fitted in the cells. 
Biomass that is grown on the media surfaces carries out the biological oxidation. 
Anoxic and Anaerobic cells and zones are used for enhanced optional processes. 

Internal configuration 

Our Eco-SAFs are available in fully protective coated carbon steel or in stainless steel and are suitable for above or below ground applications. Internal dividing walls create individual aeration, anoxic and anaerobic cells or zones (there is a minimum of 3 cells in each module) and also acts to eliminate the risk of shortcuts. The cells are filled with the high efficiency cross or vertical flow fixed film plastic media specified for the particular process the Eco-SAF has been designed for.The media provides the large surface area on which the bacteria attach themselves to grow and live. To understand how much area the bacteria would have available to attach to, a typical 700pe Eco-SAF would provide the same surface area of media to cover a football pitch. 

Why rectangular tank and not circular? 

The rectangular design of the Eco-SAF ensures that there is maximum oxygen transfer efficiency. Why? 1. We utilise the full cell floor for coverage of the aeration as described above. 2. Oxygen transfer is more efficient the further the bubbles have to travel. In a circular tank design there will be areas at the side that cannot be aerated, the lower the aeration in the tank the narrower the bubble track and lower sludge holding capacity, try to raise the aeration and the bubbles will not have as far to travel to reach the surface so oxygen transfer efficiency is reduced. Typically a 2.5m wide x 3m high Eco-SAF will have approx. 65% more aeration efficiency than a 2.5m diameter tank. 
The Eco-SAF is suitable for the following applications: 
Secondary: Eco-SAF 
For settled wastewater from primary settlement tanks. 
Carbonaceous and nitrifying applications 
Segmented filter with first segments containing 150 m2/m3 media (roughing)and subsequent section containing 240 m2/m3 media 
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