Unlocking Efficiency and Sustainability in Wastewater Treatment
The treatment of municipal wastewater often involves using microorganisms present in the wastewater. While these methods can be effective, they do have drawbacks, such as the challenge of cultivating specific types of microorganisms and the need for a large tract of land to accommodate the system.
Microfiltration membrane bioreactors (MBRs), which combine a suspended growth biological reactor with solids removal via filtration, address many of the constraints associated with traditional wastewater treatment.
A Different Kind of Treatment
In an MBR wastewater system, the membrane cassette consists of multiple membrane modules, each containing fine-pore membranes. These membranes act as barriers, allowing clean water to pass through while retaining suspended solids, bacteria, and contaminants.
MBRs differ from traditional polishing processes where the membrane is used as an advanced step during tertiary treatment, and there is no reintroduction of the active biomass into the biological process. Most commercial membrane bioreactor systems use the membrane as a filter to eliminate solids produced by the biological process, yielding a clarified and disinfected effluent.
A membrane bioreactor is effectively a modern, more streamlined version of the conventional activated sludge treatment system. While a conventional activated sludge system employs a secondary clarifier or settlement tank to separate solids and liquids, an MBR system uses a membrane to achieve this.
This offers advantages in process control and the quality of the produced water. Some of the benefits MBRs offer in wastewater treatment and water reclamation processes include operational efficiency, highly efficient treatment, space efficiency, flexibility, and environmental sustainability.
Operational Efficiency
MBRs offer better process control and automation options compared with conventional treatment methods. This results in improved operational efficiency and treatment that is stable and reliable. MBRs typically require fewer chemicals for treatment, resulting in cost savings and a reduced environmental impact.
MBRs also produce less sludge. Because smaller volumes of sludge are easier and more cost-effective to dewater, handle, and dispose of, this results in a significant reduction in disposal costs.
Membrane bioreactors are extremely efficient at removing solids, organic matter, and contaminants such as nitrogen, phosphorus, pathogenic microorganisms, and biochemical oxygen demand from wastewater. The use of membranes results in high-quality effluent that meets stringent environmental standards and regulatory requirements, making it suitable to be reused or safely discharged into the environment without health risks or contributing to eutrophication in receiving waters.
While the capital costs to install an MBR system may be higher initially than conventional wastewater treatment technologies, MBRs can have lower long-term operational costs due to improved efficiency and reduced need for downstream treatment.
Less Space is Required
Because membrane filtration allows a higher concentration of microbes to be maintained, smaller bioreactors can be used. MBR systems are therefore compact and require less space compared to traditional wastewater treatment systems. They can also be installed below ground, freeing up surface space for other purposes. Additionally, an MBR system can replace the secondary clarifier and sand filters typically used in a conventional activated sludge treatment system. This makes them particularly suitable for sites where space is limited.
MBR systems can be customized to suit various applications, from small-scale decentralized systems to large municipal or industrial wastewater treatment. They are also resilient to variability in flow rates as they can adapt to fluctuating influent flows and loads, making them well-suited for industries or locations with variable wastewater characteristics.
Environmental Sustainability of Membrane Bioreactors
MBRs offer a more sustainable approach to wastewater treatment by producing high-quality effluent and reducing the environmental impacts often associated with wastewater treatment. The effluent produced by MBRs can be safely discharged or recycled for water reuse, thereby conserving freshwater resources while also preserving aquatic ecosystems.
MBR wastewater treatment technology offers numerous advantages, making it a preferred choice for such applications as municipal sewage treatment, industrial wastewater management, and water reclamation projects.
Contact Seven Seas’ team of wastewater treatment experts to learn more about MBRs and other wastewater treatment options, and how our Water-as-a-Service® partnerships and Lease Plant Program can help you finance the water infrastructure you need.