What is Anaerobic Treatment?
It is a biological process wherein organic wastes are broken down by anaerobic microorganisms in the absence of dissolved oxygen.  As BOD is removed, biogas, containing energy-rich methane, is produced.  A small amount of stable sludge is also produced which is beneficial for agricultural purposes.
Anaerobic technology is well suited for pretreating warm, high-strength wastewater.

  Advantages

 - Low sludge production saves on disposal and dewatering costs.
-  Energy consumption is very low.
-  Fuel costs can be reduced by using biogas as a renewable energy source.
 

 
 The Hybrid reactor is a high-rate system that combines two anaerobic processes - the UASB (upflow anaerobic sludge blanket) on bottom and UFF (upflow fixed-film) on top - and retains the process advantages of each.  It also requires less space than other treatment methods.

The reactor circumvents one major shortfall of the UASB, namely, the need to generate and maintain dense, granular sludge (essential of process stability).  Overlying media intercepts solids, promotes flocculation, and returns solids to the sludge bed below.

The advantages of combining UASB and UFF processes are high loading rates (10-20kg COD/m3d) and excellent hydraulic characteristics and substrate-bios contact.  The additional biosolids inventory increases the reactor's removals, process stability, and ability to handle toxic shocks.

BOD removals can reach 90-95 percent at 30-35oC, and effluent SS levels are usually low because of the overlying media.  This reactor process a consistent high-quality effluent because of its ability to maintain a high biological solids inventory.