The Fluidized aerobic Bioreactor (FAB) is an advance hybrid biological system primarily designed to reduce the footprint area required and to make effortless installation and trouble free operation while increasing the treatment efficiency.
Most of attached growth process has the media packing fixed in reactor tank and wastewater passed the biofilm . However the FAB process calls for the media is moving inside the reactor continuosly. Air bubbles through diffused aeration and influent wastewater keeps the media in fluidized condition. FAB is an advanced high –efficient, compact biological wastewater treatment process with ease of operation. It is designed to treat any organic waste stream amenable to biological treatment, mainly for BOD removal including domestic wastewater but it can also be applied (for removal of nitrogen)to improve volumetric nitrification rates and to accomplish denitrification in aeration tanks by having anoxic zones within the bio-film depth.
The typical FAB process consists of pretreatment like screening followed by one or more FAB tanks, where the degradation process of soluble matter takes place and the final stage of the treatment is normally particle separation. The FAB tank consists of various components such as earators , spray nozzles, bio-media, grids/sieves, and other integral parts, which makes it a complete successful system. The wastewater after primary settling or screening flows directly in to the FAB reactor through pumping or under gravity.
In this system the organic pollutants of wastewater are decomposed with the help of both attached & suspended growth microorganisms. The COOLFloat polypropylene media used as a medium for the attached bio growth occupies around 30-50% of the tank volume. The rest of the portion of the reactor is utilized for suspended growth aeration system. This lightweight media (of density 0.97gm/cc) is in constant circular motion trough out the tank due to diffused aeration system placed at the bottom.
The perforated aeration grid is mounted at the bottom of the reactor tank and connected to high efficiency blower, to produce fine air bubbles to fulfill the desired oxygen requirements for aerobic treatment. The upward air current keeps media in continues floating movement in the wastewater and thoroughly mix it throughout the tank. As the microorganisms are retained in the tank for the longer period this helps in maintaining the sufficient MLSS concentrator in the tank. This also eliminates the need of recycling of the return sludge. The maintained MLSS concentration helps the system to handle shock loads, keeps sludge generation low and a mineralized one.
Pure FAB reactor
Combination of FAB and Activated sludge process
Pure FAb followed by Activated sludge process.
Deployment of new plants or upgrading existing plants simply involves deployment of the FAB media without the need for supporting structures. In addition there is no need to remove the media or empty the tank to attend air treatment.
COOLFloat media is sturdy & heavy and manufactured with virgin Poly Propylene material, UV stabilized. Results shows, no damage to media found due to rubbing during the process. In any case the life media shall be more than 20 years.
The COOLfloat FAB media provides around 400 m2/m3 of extra active surface area for biofilm to develop thus keeping high MLSS concentration in the reactor. The design of the media is such that it is free from clogging. This non-clog feature of the media helps thin, fresh bacterial layer over the surface thus increases the treatment efficiency.
A high concentration of biomass remains in the reactor, which helps in handling uncertain shock loads. In most cases, nosludge re-circulation is required. However provision for minimum sludge recirculation will enhance process efficiency. Media being inert do not react with industrial wastewater. The outer fins of the media reduce the loss of biofilm growth on outer surface due to rubbing/friction action keeping the ratio of PSA/TSA maximum.
Lightweight of the media and higher void rationof > 80% helps the media in continuous movement inside the reator. ‘Continuos Movement’ of this floating media driven by air bubbles supplied inside the reactor by means on air diffusers.
The media increase the available surface area in given volume of tank thus reducing the volume of the tank and thus reducing the basin size. Incase of older conventional tank capacity gets increased with simple addition of COOLFloat media to the tank.