A lot has been said about rewilding waterways and urban creeks. However, Hydroflux has found inspiration in nature to partner with Organica Water to provide a product that implements bio-films.
The Organica Food Chain Reactor (FCR) is a compact and seamlessly integrated wastewater treatment facility that minimises wastewater treatment’s technological, architectural, and environmental impact in residential and commercial settings.
Organica’s FCR has been validated by over 120 projects worldwide, showcasing the practical advantages of the technology.
“These facilities are designed for implementation in diverse climates,” said Hydroflux director Andrew Miley. “They can handle volumes ranging from 1000 to 200,000 cubic metres per day.”
Integrated Fixed Film Activated Sludge Plants (IFAS) rely on a media where biofilm is grown, resulting in a compact footprint as most of the biomass is fixed to a high surface area instead of being suspended.
The development of a variation of IFAS Plants by Organica Water has been to combine naturally occurring plants with engineered media. Simply put, a botanical garden is placed on top of the IFAS reactors, with the plant roots penetrating the reactors.
“The interaction of enzymes and various organic acids from the plant roots to the bio-media creates a diverse biology,” Miley said. “It leads to increased process stability, less sludge production, and lower energy demand than conventional activated sludge plants. The sewage treatment plant looks like a botanical garden.”
Bio-film technology
Bio-film technology in wastewater treatment has been available since the 1970s as moving bed biofilm reactor (MBBR) systems or IFAS. In general, most of the developments in this field relate to increased surface area, scouring and bio-film growth.
Generally, the media used in either MBBR or IFAS is a non-metallic surface. Both systems provide benefits such as reduced reactor size, high total available biomass inventory, high tolerance against biomass washout and simultaneous nitrification-denitrification within the biofilm layer.
Organica’s FCR combines naturally occurring plants with an IFAS-based process. A greenhouse or shaded structure typically houses the process, creating an aesthetically pleasing treatment system.
The FCR is generally configured as a continuous multistage cascade process with an anoxic zone and internal recycling from the last stage as part of the nitrogen removal loop.
Benefits of bio-films
The multistage cascade FCR provides several operational benefits. That includes the independent development of biomass and ecology within each stage. It also features an increase in the diversity of biomass speciation. That comes from the interaction between the plants and the biomass.
“The bio-film growth results in a much higher total biomass inventory,” said Miley. “We have also seen higher sludge retention time and a reduced biomass yield. That comes from the higher sludge retention time.”
The lower free MLSS means the phase separation step post-FCR can be designed with a lower loading. Rather than using secondary clarifiers, phase separation can occur in a horizontal disc filter, which has a tenth of the footprint of a conventional clarifier.
In addition, the lower MLSS results in a higher diffuser alpha factor, meaning that less air is required to provide the process oxygen needed, thus a lower energy demand.
“We’ve also found that there is not as much odour around the plant,” he said. “There’s also no need to return activated sludge (RAS) in the process design.”
Diversity of biomass speciation results in adaptive ecologies forming in each FCR stage. As opposed to 300 to 400 species commonly present in activated sludge plants, the FCR exhibits up to 3000. This diversity creates a stable process, which is tolerant to shock loads. In the last stage, the presence of eukaryotes results in the consumption of decayed bacteria.
Operating data has demonstrated the robustness of the FCR systems, as well as consistent effluent quality. The discharge quality that can be achieved can be designed to match any conventional activated or MBR process.
The total observed biomass within the FCR system is typically 16,000 milligrams per litre, three to four times that of conventional systems.
Aesthetics
The FCR can be housed within a greenhouse or shading structure, resulting in a wastewater treatment plant resembling a garden or greenhouse facility, with low odour emissions and an aesthetically pleasing look. Due to this unique feature, in some installations, buffer zones around the treatment plant have been reduced from 350 m to 50 m, freeing up additional land for development and providing a net positive attitude from local communities.
Bio-film technology provides several advantages around footprints, biomass inventory, capital, and operational cost savings.
The natural plants do not treat the wastewater but provide nutrients, organic acids, and enzymes, creating a diverse biology within the plant roots and IFAS modules. A denser biofilm is produced compared to other IFAS systems or MBBR processes.
A reduced footprint can be achieved with an observed total biomass concentration three times that of conventional systems. Savings in energy demand and sludge disposal are two other benefits of the process, particularly over MBR-based systems with similar space-saving features. Full-scale installations as large as 80 MLD have demonstrated the technology’s application within the municipal and industrial wastewater field.
The aesthetically pleasing look of the Organica FCR has changed the local community’s attitude towards wastewater treatment. It has provided a place for communities to interact positively with the process.
As rapid urban growth continues in many cities worldwide, this technology has demonstrated its use as a decentralised facility that can be constructed in the middle of a dense urban landscape. It can relieve the load on existing sewer systems and enable water reclamation in these environments.
Hydroflux Epco is the exclusive ANZ-Pacific representative for Organica Water’s Food Chain Reactor process.
For more information, visit https://www.hydroflux.au/
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