UASB & UAFB Process

Among these recently developed technologies, UASB & UAFB (up flow anaerobic sludge blanket) package is ideally suited to treat industrial wastewater containing medium to high concentrations of soluble organics (i.e. BOD in excess of 1000 mg/L).

 In order to improve the treatment facilities, Mojan Co. has applied modern technology to manufacture UASB and UAFB modular systems for biological treatment of industrial effluents.

Process description:


In a Mojan manufactured UASB-reactor, the accumulation of influent suspended solids and bacterial activity and growth lead to the formation of a sludge blanket near the reactor bottom, where all biological processes take place. Wastewater enters the bottom of the reactor vessel through the inlet distribution system and passes upwards through the dense anaerobic sludge blanket. Soluble COD is readily converted to biogas which is rich in methane and an upward circulation of water and gasborne sludge is established. As the combination of gas, water and sludge passes upward, In order to prevent unwanted sludge discharge, separation devices (deflectors) are installed that prevent the further upward movement of the sludge and force it to sink back into the bed.

Thus, the dense granular sludge particles now devoid of attached gas bubbles sink back to the bottom establishing a return downward circulation. The gas is collected in gas holders installed in the upper part of the reactor; for gas rising close to the reactor walls, an additional one may be installed. The upward flow of gasborne sludge through the blanket combines with the return downward flow of degassed sludge and creates continuous convection. This insures effective sludge to wastewater contact without the need for any energy consuming mechanical or hydraulic agitation within the reactor. While the sludge should remain in the reactor, purified water, like the produced gas, leaves the reactor.


Mojan prefabricated UASB & UAFB units can be used to treat different kinds of industrial waste streams. Some examples come here in below:

Sugar production

Pulp & Paper

Fruit and juice production

Food industries

Pharmaceutical industries

Beverage production facilities


Wood panel mills  


 Features and Advantages:

Some of  the Mojan Co. UASB & UAFB systems features are as follows:

Low energy requirement

Low operation and maintenance costs

Lower skill required for operation and supervision

Accommodating a wide range of flows and COD strengths due to a modular design

Adjusting wastewater PH through the addition of nutrients if required 

Fully accessible for inspection and cleaning

No odor emission

Long trouble free life