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Vision to Environment
 

Moving Biofilm Reactor based wastewater Treatment:

INTRODUCTION
 
 

When communities of microorganisms grow on surfaces, they are called biofilms.Microorganisms in a biofilm wastewater treatment process are more elastic to process disturbances compared to other types of biological treatment processes. Thus, biofilm wastewater treatment technologies can be considerably more robust especially when compared to conventional technologies like activated sludge.The very first biofilm process, the trickling filter, was invented towards the end of the19th century. The trickling filter can be reliable and stable but does suffer from one serious drawback; it easily becomes clogged and septic even under moderate loading conditions.In the MBBR biofilm technology the biofilm grows protected within engineered plastic carriers, which are carefully designed with high internal surface area. These biofilm carriers are suspended and thoroughly mixed throughout the water phase.With this technology it is possible to handle extremely high loading conditions without any problems of clogging, and treat industrial and municipal wastewater on a relatively small footprint.

SYSTEM DESCRIPTION

Moving-Bed-Bio-Reactor-Technology
 

The Moving Bed Bio-Reactor (MBBR) includes a tank in any shape filled up with small carrier elements. The elements are specially developed materials of controlled density such that they can be fluidized using an aeration device. A bio-film develops on the elements, which move along with the effluent in the reactor. The movement within the reactor is generated by providing aeration with the help of diffusers placed at the bottom of the reactor. The thin bio-film on the elements enables the bacteria to act upon the bio-degradable matter in the effluent and reduce BOD/COD content in the presence of oxygen from the air that is used for fluidization.Treated water flows from reactor through a grid or a sieve, which retains the MBBRbio-carriers in the reactor.

The process consists of adding small cylindrical shaped polyethylene carrier rings (specific density of about 0.96 kg/m3) in aeration tanks to support the biofilm growth. The bio-media when dumped inside the aeration tank, occupies about 25-30% of the tank volume. The fluidized bio media ensures optimum contact time & eliminates the fouling tendencies of fixed film media. The biofilm carriers are maintained inside the reactors by use of perforated plate at the outlet. As the effluent gets in contact with this media, the attached biomass degrades the organic matter. During this process, ammonia contained in the effluent is also oxidized to nitrates.

The process has a very high ‘BOD removal: aeration tank volume’ ratio. Since the biofilm is attached & grows on the biomedia, the FAB process generates very little sludge compared with conventional processes & does not require high sludge recirculation rates.

BENEFITS
   
 
  • Odourless operations, with a self-regulating system
  • High bio-film surface area, compact plants with high loading rates
  • Reduced power consumption
  • Simple to operate, low maintenance requirements
  • Non-clogging design, better oxygen transfer efficiency
  • Attached growth process, low sludge production.
  • The advantages of MBBR are that it occupies lower area and lower power consumption vis--vis activated sludge or extended aeration plant. This is because the aeration tank detention time is about 4 hours of average flow. This reduces blower power.
 
 
APPLICATIONS
 
 
  • Commercial complexes
  • Hotels
  • Hospitals
  • Industry
  • Institutes
  • IT parks
  • SEZ
  • Residential colonies