By Maricel Pastor-Soltes – Coffey
Continuing our series on the various wastewater treatment technology options available in the industry. Last week, the Sequencing Batch Reactor process was discussed. The Moving Bed Biofilm Reactor (MBBR) is a wastewater treatment technology which is discussed in today’s blog post.
The Conventional Activated Sludge (CAS) system is the most popular and widely implemented wastewater treatment system. This success can be attributed to the system flexibility in design, good effluent quality, easy to operate, very stable system, and low in cost. This somehow requires a bigger reactor volume due to the limited biomass concentration in the reactor.
In the quest to reduce the footprint of a traditional activated sludge system, many biological processes have emerged aiming to increase the biomass concentration in the reactor. The Moving Bed Biofilm Reactor (MBBR) is a wastewater treatment technology which has successfully proven its capability to improve the effluent quality and significantly reduce the footprint of a wastewater treatment plant by reducing the reactor volume and eliminating the need for a final settlement tank. However, there are several factors to be considered in using MBR system such high capital and operational cost, membrane fouling and use of chemicals in membrane cleaning, and the requirement for a skilled operator. It is an excellent alternative where footprint and/or stringent effluent criteria is a consideration.
Another alternative of reducing the reactor volume is to use biofilm to support the biomass growth. Several known attached growth process are trickling filters, RBC, submerged fixed media, and fluidized bed reactors. Due to the known disadvantages of the attached growth system such as blocking of the filter bed, channeling, odour issue, mechanical failure, and instability. The particular attached growth biofilm process that will be focused in this article is the moving bed biofilm configuration. The process combines the CAS and attached growth processes eliminating the problems related to channeling, clogging, and influent distribution. In the MBBR process, the media which support the growth of the biofilm are kept suspended in the reactor by aeration/mixing depending on the treatment application it is used for. The biomass is attached to the carrier media, thus, partly protected from the environment giving the system more flexibility in varying influent conditions such as pH, temperature and in the events of toxicity.
The MBBR carrier media are typically a low-density plastic media (with density slightly lower that of water) of approximately 950kg/m3 and slightly higher in the non-aerated reactors. The reactor is typically filled by media at about 50-65%. The media must be evenly distributed in the reactor and typically medium bubble diffusers are used, with the DO to be maintained between 2 –3 mg/l depending on the plant performance requirements. The outlet of the MBBR reactors need sieves/screens to hold the media within the reactors.
Moving Bed Biofilm Reactor (MBBR) is a Wastewater Treatment Technology with a degree of flexibility – MBBR can be used as the main treatment process, pre-treatment to an activated sludge process, IFAS hydrid, and post-treatment of another biological process.
At Coftec, we provide wide range of wastewater treatment solutions. We can provide you with an MBBR system that is practically suitable to your treatment requirements. Our multi-disciplinary team of engineers and experts offer a proven track record of leveraging their expertise and experience in providing the most practical solutions to treat your wastewater.
Contact Coftec whether designing a new facility or refurbishing, expanding, or bringing an existing facility up to regulatory standards to discuss how we can help in your project.
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