Passive Aeration Leads to Huge Energy Savings
Membrane aerated biofilm Reactor (MABR) technology provides a revolutionary improvement in aerobic wastewater treatment for a number of reasons, particularly its high energy efficiency and increased treatment capacity, compared to traditional wastewater treatment systems.
Much of the energy used in aerobic treatment is tied to aeration, the introduction of air bubbles into wastewater via pumps, paddles, and other mechanisms to feed the aerobic bacteria that digest waste. Aeration can be very inefficient.
Fluence’s Innovation Advisor Eytan Levy told Sharon Udasin ofThe Jerusalem Post that wastewater treatment “is a massive energy consumer […] We’re trying to find technological ways to minimize this power consumption.”
MABR represents one such technological breakthrough. MABR systems passively circulate oxygen through a spirally wound membrane at atmospheric pressure. MABR’s self-respiring membrane allows bacteria to consume oxygen more readily for a 90% reduction in energy used for aeration.
What’s more, the membrane surface quickly accumulates a biofilm of bacteria that establishes a simultaneous nitrification-denitrification (SND) process to produce a high-quality, low-nitrogen effluent suitable for reuse in irrigation. The MABR process is low-maintenance. All of these advantages add to an overall reduction in energy use.
One important aspect of MABR is that its low energy consumption allows it to be used in areas far from centralized treatment plants without the expense of distribution infrastructure. The plants are so efficient that they can be operated off the electrical grid with the use of solar energy. The process is low-odor and low-noise, making it neighborhood friendly.
The first municipal installation of Fluence MABR provides a good illustration of its potential. HaYogev, a dairy farming community of about 1,000 homes in Israel’s Jezreel Valley, needed to replace its existing pond treatment system in order to treat its high-nutrient wastewater to meet state-level standards.
A 125 m3/d MABR plant was installed using the existing pond structure at a competitive capital outlay. The effluent meets all quality standards and is suitable for agricultural reuse.
Another example can be found in the United States Virgin Islands, in the Bordeaux section of the island of St. Thomas, which includes about 200 homes. Bordeaux’s old plant didn’t meet regulations or industry standards.
Within seven months of receiving the order, Fluence and its partner, SD&C Inc., built the MABR-based wastewater treatment system using existing pieces of equipment salvaged from the old plant. The plant’s 25,000 GPD capacity is expandable, and the effluent is suitable for discharge into the environment, which is vital in an area that relies on tourism. And, energy use is very low, an important consideration on the island.
This decentralized approach proved its worth after Hurricane Irma devastated St. Thomas in September 2017. The plant was confirmed operational within hours of the storm’s passage.
MABR’s Installation Flexibility
Flexibility is a key to MABR’s potential. Freestanding modules can be installed in a new, dedicated plant. They can be used in conjunction with existing infrastructure or in a purpose-built concrete tank with a clarifier and mechanical mixing for phosphorus removal. MABR can be supplied in containerized solutions (C-MABR) for quick deployment and plug-and-play operability. Scalability can be easily achieved through the addition of modules.
Decentralized use is an important application of MABR, but an exciting new development is the use of submerged arrays of the modules (SUBRE) to upgrade existing centralized treatment plants. MABR expands the treatment capacity of the plants and enables them to meet higher nitrogen discharge standards without the addition of dangerous chemicals like methanol.
Fluence recently was awarded its first contract to upgrade Mayanot Ha-Amakim’s Mayan Zvi wastewater treatment plant in Israel. MABR will increase the capacity of the 6,000 m3/d plant by 15 to 20%.
The Wave of the Future
Commercial use of MABR began only in 2016, but commercialization of MABR has exceeded original expectations.
Fluence, which has established core operations in the Americas, Europe, the Mideast, and China, is preparing for an enormous global market for MABR.
Fluence is slated to produce 7,500 of the modules annually out of its fully-operational production facility in Changzhou, China and predicts they will be commercially available by the second quarter of 2018. With strategic partnerships covering more than 70% of China, Fluence is already receiving orders in Henan and Guizhou provinces, and is ready to respond to China’s 5-Year Plan, which prioritizes infrastructure upgrades in rural communities, as well as an enormous Chinese retrofit and turnkey market that is just coming online.