Anaerobic Reactors

1. Description: The UASB reactors (Up flow Anaerobic Sludge Blanket), also known as Upward Flow Anaerobic Reactor are a type of tubular bioreactor operating in a continuous regime and flow upward, i.e., the inflowing liquid enters from the bottom of the reactor, flows through all the longitudinal profile, and exits at the top. Anaerobic reactors are those in which microorganisms are grouped, forming bio granules. All aerobic biological reactors contain biological growth that remains in suspension within the reactor. For this reason they are referred to as reactors for biological growth in suspension.

2. Ranges of design: technology for anaerobic treatment of heavy loads is a mature technology. There have been at least 1,200 plants registered on an industrial scale in the world for industrial effluents treatment (currently it is estimated that there are about 2,500). The range of applications of this technology is very broad, since the anaerobic treatment of wastewater is not limited solely to degradation of organic pollution in wastewater.

Important factors to consider in the design are:

     a) Nutrients.

     b) Temperature.

     c) pH.

     d) Absence of OD.

     e) Configuration.

     f) Means of support.

     g) Hydraulic retention time.

     h) Organic load.

     i) Surface speed.

     j) Useful volume.

     k) Efficiency.

     l) Final effluent quality.

3. Applications: Industrial plants (metallurgical, chemical, petrochemical, pharmaceutical, etc.).

4. Benefits:

     a. Low power consumption, contribution of O₂ is not required.

     b. Ability to retrieve and use CH₄ as fuel (expensive).

     c. Obtained sludge is already an stabilized sludge.