Sequential Batch Reactor – SBR
MiCroBial Technologies along with the supply of microbial culture, we do provide Design, Fabricate, Supply, Erection and Commissioning Sewage Treatment Plants (STP), Effluent Treatment Plant for treating sewage/effluent generated by Industry, large colonies, Hotels, Hospitals, IT Parks and commercial buildings.
Now a days the Sewage Treatment Plant (STP) became a statutory requirement of all the State Pollution Control Boards, everybody, whether Hotelier or Industrialist were looking for an economical, easy to install and operate compact type Sewage Treatment Plant. Since the land is extremely expensive, very few industries could afford the large treatment units as recommended by most of the Consultants.
The sequential batch reactor is operated in a batch reactor mode. A batch reactor is a perfect reactor, which ensures 100% treatment. Sufficient number of modules shall be provided to ensure continuous treatment. The complete process takes place in a single reactor, within which all biological treatment steps take place sequentially.
Sequential batch reactor is operated in a batch reactor mode. A batch reactor is a perfect reactor, which ensures 100% treatment. Sufficient number of modules shall be provided to ensure continuous treatment. The complete process takes place in a single reactor, within which all biological treatment steps take place sequentially.
The complete biological operation is divided into cycles. Each cycle is of 4 – 8 hrs. duration, during which all treatment steps take place.
Process Description – Sequential Batch Reactor
The air-saturated water stream is recycled to the front of the float tank and flows through a pressure reduction valve just as it enters the front of the float tank, which results in the air being released in the form of tiny bubbles. Bubbles form at nucleation sites on the surface of the suspended particles, adhering to the particles. As more bubbles form, the lift from the bubbles eventually overcome the force of gravity. This causes the suspended matter to float to the surface where it forms a froth layer which is then removed the complete biological operation is divided into cycles. Each cycle is of 4-8 hrs. duration, during which all treatment steps take place.
Basic cycle comprises of 5 phases of operation:
- Mix fill phase (preparation for new cycle)
- React fill phase (alimentation with/without aeration)
- React phase (aeration and/or mixing)
- Settle phase (sedimentation)
- Decant phase (discharge treated water and excess sludge)
Mix fill phase
During the period of a cycle, the influent valve is opened and the liquid is raw influent is filled in the SBR basin up to a set operating water level. Mixers are started for proper mixing of the raw influent contents in absence of aeration. This causes anaerobic conditions that facilitate the removal of nitrates and nitrites through de-nitrification. This phase is extended for the removal of phosphorus by phosphorus accumulating organisms (pao) through luxury uptake, in cases where phosphorus reduction is required. Anoxic conditions also help in restricting the growth of many filamentous organisms.
Fill phase
In this phase the mixers and the aerators both are in operation. The influent thus undergoes both mixing and aeration. Intermittent aeration promotes both aerobic and anoxic conditions. Biological carbon degradation (BOD/COD reduction) takes place along with ammonical nitrogen reduction along with “luxury uptake of phosphorus” takes place under aerobic conditions. Anoxic conditions promote the reduction of nitrogen oxides.
Use of separate systems for aeration and mixing (diffusers and mixers) allows aeration system to be turned down during low flow conditions and thus save energy and the flexibility of the system allows nitrification and denitrification to be managed easily
React phase
Influent flow in this phase is terminated and a true batch condition is thus created. In absence of influent flow the mixing and the aeration process continues thus causing BOD/COD reduction along with nitrogen reduction under aerobic conditions. Oxygen requirement as needed is controlled by do probes while maintaining complete mix conditions. Thus, it is the polishing stage before the effluent and sludge are separated by settling to achieve the desired effluent quality. Focus can be also brought to the requirement of:
Dissolved oxygen control
The SBR process uses measurement of dissolved oxygen (DO) levels in the basin to enhance treatment efficiency and optimize power consumption. The DO concentration in the basin is continuously monitored using a DO sensor. Once DO level is measured in the basins, a variable frequency drive automatically alters the aeration blower rpm to maintain desired DO levels in the basin. This methodology provides a true in-basin method for the efficient use of energy.
Settle Phase
With the influent line closed this phase doesn’t allow the new raw influent to enter into the reactor. Mixing and aeration are also terminated causing suitable quiescent conditions to take over. Solid-liquid separation takes place takes place due to perfect quiescent conditions. Adjustable time values allow settling time to match prevailing process conditions.
Decant Phase
In this phase no influent enters the reactor. Aeration and mixing systems continue to remain off. Decant able volume of the effluent is removed by subsurface withdrawal by highly effective floating decanters. Floating decanters follow the liquid level, maximizing distance between withdrawal point and the sludge blanket. Small amount of sludge is wasted at end of each cycle. Following the above phase, the reactor goes into ideal mode and prepares itself for receiving the next batch of raw influent into the system.
Automization of system
About sensors for single basin reactor (SBR)
TSS sensor
Total suspended solids (TSS) are a measurement of the total solids in a water or wastewater sample that are retained by filtration.
Why is it important?
TSS is an important water quality parameter measure for wastewater treatment operations and environmental health. Wastewater contains large quantities of suspended organic and inorganic material that must be removed through screening, filtration or settling/flotation methods prior to environmental discharge. TSS will also have adverse effects on UV disinfection blocking/scattering UV light bound for pathogen disinfection or alternatively requiring higher intensity for proper disinfection, increasing energy costs. If TSS is not removed properly through treatment, high concentrations can lower the water quality in the receiving environment. The suspended solids absorb light, causing increased water temperature and decreased oxygen which create an unfavorable environment for aquatic life. It is also advantageous to monitor TSS in conjunction with bod and cod as part of the bod/cod is in the TSS form.
Dissolved Oxygen Sensor
This is a dissolved oxygen sensor kit, which is compatible with microcontrollers. This product is used to measure the dissolved oxygen in water, to reflect the water quality. It is widely applied in many water quality applications, such as aquaculture, environment monitoring, and natural science and so on. This product is used to measure the dissolved oxygen in water, to reflect the water quality. This sensor kit helps you quickly to build your own dissolved oxygen detector. The probe is a galvanic probe, no need of polarization time, and stays available at any time. The filling solution and membrane cap is replaceable, leading to the low maintenance cost. The signal converter board is plug and play, and has the good compatibility. It can be easily integrated to any control or detecting system
PH Sensor
It’s used for monitoring and maintaining the PH of system.
Unique Feature of SBR Technology
It is highly operator friendly due to maximum automation and minimum human intervention. Due to PLC based monitoring and control system, it is an advanced and smart system.
The system is flexible by supporting continuous feed as well as true batch operations flow control strategies.
Meets effluent discharge limits consistently.
It is advantageous than other systems as far as the initial capital investment versus operational cost is concerned. Thus, it offers the best life cycle.
Application and Usability
Due to high versatility and cost-effectiveness, SBR sewage treatment plant is widely used in:
- Personal bungalows, houses and weekend homes
- Industries effluent treatment, Municipal wastewater treatment
- Hotels, resorts and holiday homes
- Hospitals, Malls and shopping centers
- Airports and railway stations
- Commercial, residential complexes & Project sites
- Schools, colleges, and other institutions
- Small, medium and large manufacturing units
- Sports complexes
- Other public places
Click here to download data sheet required for designing of SBR Technology-based STP/ETP