What is MBR?
Membrane bioreactor (MBR) technology is an efficient hybrid of traditional biological wastewater treatment and modern membrane processes that is used in both municipal and industrial wastewater treatment. As in legacy activated sludge processes, it uses microorganisms to degrade organic pollutants, but instead of using a bulky clarifier, it uses advanced membranes to reject suspended solids.
MBR technology is widely used across various sectors, including municipal wastewater treatment plants, industrial facilities, and decentralized treatment systems. Its versatility makes it suitable for applications ranging from small-scale to large-scale projects.
Benefits of MBR Technology
Membrane bioreactor systems offer many advantages over legacy processes. They include:
- Efficient treatment and quality effluent: MBR systems excel in removing contaminants for enhanced treatment efficiency. Membrane filtration maintains high water quality by removing solids, pathogens, and pollutants.
- Space optimization and adaptability: MBR’s compact design, sans secondary clarifiers, suits installations with limited space. Easy expansion and modification options offer flexibility in system design.
- Sustainable operation: Reduced sludge production lowers disposal costs and lessens environmental impact, promoting operational efficiency. Membrane filtration minimizes the need for certain chemicals, contributing to sustainable and cost-effective operation.
- Resourceful water reuse: MBRs produce high-quality effluent suitable for nonpotable applications. They can play a crucial role in direct potable reuse (DPR) systems, promoting water reuse.
- Consistent performance and environmental compatibility: MBRs ensure consistent treatment performance, meeting regulatory standards even with varying influent conditions. Generating less odor and noise, MBR systems are environmentally friendly and community-conscious.
How Does an MBR System Work?
The MBR process begins with a pretreatment stage to minimize membrane fouling. Then, aerobic microorganisms break down organic matter in the MBR tank. An aeration system delivers air bubbles to the tank to keep the bacteria active as they break down organic pollutants.
A pumping system mixes water in the bioreactor tank and moves it through a module, where semipermeable membranes filter out suspended solids and microorganisms. MBR membranes are fibers or flat sheets made of polyethylene or polyvinylidene fluoride.
Chemical or backwash cleaning systems are used to minimize biofilm fouling of the membrane, supporting performance and long life. To save water, a backwash recovery system can be used to collect and recover the cleaning backwash water.
During the process, sensors and monitoring devices keep track of effluent parameters in real time as a control system simultaneously adjusts operational settings to optimize treatment.
MBRs generate sludge as a byproduct of the biological treatment process. A sludge management system separates and handles the excess sludge, which may be treated further or dewatered for efficient disposal.
Finally, a system collects the resulting permeate once it passes through the membrane.
Membrane Bioreactor Frequently Asked Questions (FAQ)
What is the quality of MBR treated water?
MBR-treated water demonstrates minimal levels of contaminants, including phosphorus, bacteria, total suspended solids (TSS), and biochemical oxygen demand (BOD). This enhanced water quality allows for effective high-level disinfection. The resulting MBR effluents are suitable for safe discharge into water bodies or can be repurposed for applications like irrigation. Learn more about the quality of MBR-treated water.
What is the removal efficiency of MBR?
MBRs feature excellent removal efficiency for contaminants. One 2022 study in the Journal of Environmental Management found that MBRs demonstrated exceptional removal rates for total suspended solids (>99%) and chemical oxygen demand (>91%), achieving notable removal efficiencies for a range of microcontaminants (>68.3–>99.7%).
What is the retention time of an MBR tank?
The retention time in an MBR tank, including solids retention time (SRT) and hydraulic retention time (HRT), varies but is generally longer than in traditional activated sludge systems. It typically ranges from days to weeks.
What is the difference between MBR and the activated sludge process?
Is MBR better than SBR?
MBR Wastewater Treatment Plants Built to Last
While MBR offers multiple advantages over legacy processes, it is a sophisticated process that requires expertise and specialized resources at every stage.
To take full advantage of MBR’s performance without devoting organizational resources, consider Seven Seas’ Water-as-a-Service® WaaS®, which keeps the entire MBR project in-house. Seven Seas takes care of planning, financing, construction, compliance, and long-term operations and maintenance. Under performance-based WaaS® contracts, Seven Seas owns and operates MBR systems for the long term, providing wastewater services at a guaranteed price and quality.
Because Seven Seas owns and operates the MBR system, plants are built for reliability, aligning interests of customer and provider, maintaining industry-leading plant availability, and lengthening the long list of customers who opt to renew their WaaS® agreements when contract terms end.
Request a Quote for MBR Wastewater Treatment
Contact Seven Seas to explore the possibilities of MBR under financing arrangements that are tailored to your needs. Our experts can work with you to design the right MBR wastewater treatment system for your situation.
Seven Seas Water Group and its affiliates are dedicated to protecting our team members and the environment where we work, live, and operate. See what we’re doing to meet U.N. Sustainable Development Goals and achieve carbon net-zero status.
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