How Fluidized Bed Bioreactor Works?

Fluidized Bed Bioreactor

Fluidized Bed Bioreactor Treatment process. The reasons are as follows. Due to the FBBR Media, the Surface area of the Bacteria to the Effluent water is higher by 10 times. Due to attached growth of the Bacteria, the Bacteria count known as MLSS is very high compared to conventional Biological treatment plant. In the conventional process, the Bacteria count MLSS is 2500mg/L, whereas in the FBBR process the Bacteria count MLSS is 10,000 to 12,000mg/L. The FBBR process is easy to maintain and does not get collapsed due to variations in the load or temperature or SVI (Sludge Volume Index)  Big civil tanks for Aeration, and Secondary Clarifier are not needed in this FBBR process.  The retention time in FBBR process is 4 – 6 Hours, whereas in the Conventional Biological process, the retention time is 28 – 36 Hours.

Main use of FBBR Reactor

• To Reduce the BOD and COD up to 50 to 60 percentage
• To increase the Dissolved Oxygen in the outlet effluent
• To remove partially color from fluidized bed bio reactor
• To remove the odor in the effluent
• To increase the efficiency of Electro-Coagulation system
• To reduce the current and electrode consumption in EC system
• To remove the ammonia and all other Hazardous gas

Fluidized Bed Bioreactor Advantages

• Less Civil Area for fluidized bed bioreactor
• Attached Bacteria growth.
• High MLSS.
• Highly Reliable Process which is less prone to Collapse.
• Easy to Maintain.
• Long life of the FBR Media.
• No need of Secondary Clarifier.

Fluidized Bed Bioreactor Biological Treatment

• pH Correction
• Reduces the BOD and COD levels in the Raw Effluent.
• Increases the Dissolved Oxygen Content.
• Removes the odour.
• 2 types of process, Fluidized Bed Bio-Reactor & Activated Sludge Bio-Reactor.

Secondary Clarification

• Maine use of Secondary Clarifier:
• To Recirculation the Bacteria to the FBBR system
• To reduce the suspended solids in the effluent
• To avoided the Bacteria escape to other system
• To remove the odor in the effluent
• To increase the efficiency of Electro-Coagulation system
• To reduce the current and electrode consumption in EC system
• To increase the efficiency of FBBR system

Fluidized Bed Bioreactor Process description

• Initially raw effluent is collected in collection storage tank of 1500mm *1500mm *1500mm (1.5 Hours Capacity). The Effluent is pumped to Equalization tank in which the Effluent is homogenized. The volume of equalization tank is 3000mm* 3600mm* 2400mm (12 Hours Capacity).
• After equalization process the Effluent is fed to the Biological process. The pH Neutralization is done before the Biological Process.
• The activated sludge process and After Filtration process, the treated water quality is as per Bangladesh Pollution Control Board Regulations ( COD < 200 mg/litre, TSS < 30 mg/litre & etc).
• tank volume is 3000mm*3000mm*2400mm (12 Hours Capacity). The retention time is 12 hrs for full capacity of 40m3/Day. The Activated Sludge Process is proposed to be converted to FBBR by addition of FBBR Media in future when the ETP Flow rate will reach the full Capacity of the plant. The COD value is reduced by 40-50% from input (raw effluent). The parameters of SV-30 as 300 ml-500 ml/litre, PH as 6.5 to 7.5 and DO as 1.5 to 2.5 mg/litre and SVI value is 100 to 150 mg/litre are maintained.
• After the biological process, the BOT outlet is fed into the secondary clarifier where the bio sludge is settled and Re- circulated to the BOT tank.
• The superannuated liquid is fed into EC-I feed tank followed by EC process. The COD value is reduced minimum  40% and  maximum 60 %  from the  input .
• After EC process, the treated water fed into flash mixer, anionic polymer flocculent is dosed and then passed to the Sludge Settling clarifier  having the volume of  3600mm* 3300mm* 2400mm. The sludge particles are settled in this Clarifier and SUPERNATED CLEAR LIQUID is fed into  filter feed tank
• ( 3000* 3300* 2400HT).
• From the filter feed tank the treated effluents are fed into MULTIGRADE SAND FILTER (Dia-1800mm * 2100mm Height).
• Bio sludge and EC sludge are fed into sludge thickener having the volume of Dia- 1500 * 2400 HT.
• After Filtration process, the treated water quality is as per Bangladesh Pollution Control Board Regulations ( COD < 200 mg/litre, TSS < 30 mg/litre & etc).
• From the sludge thickener sludge’s are separated using FILTER PRESS  and stored in sludge storage area of fluidized bed bioreactor