Background
Over the past 100 years, activated sludge treatment has become the industry standard for the treatment of domestic sewage. Very little has changed in the technology. The core principles of the activated sludge process are however what also make it undesirable from a human interaction perspective.
One of the main disadvantages of activated sludge treatment is the psychological footprint of the technology. The technology requires large concrete reactors that look terrible from an aesthetic viewpoint. Furthermore, it is associated with unpleasant odours that impact on neighbouring areas. This has resulted in the requirement of a zone sanitaire around sewage works in order to distance communities from the units, enable the dilution of the odorous air and to prevent the potential spread of diseases.
Psychological Footprint
Our FCR sewage treatment technology has changed activated sludge processing to a more aesthetically pleasing product, that achieves the required treatment standards, while reducing the operating costs.
Interior
Technology Summary
Fixed Bed Activated Sludge leverages the use of natural (plant roots) and engineered media to provide a fixed habitat for a diverse fixed-film bacterial culture which metabolizes the contaminants in waste water. These populations of organisms live in an attached form on fixed bed media inside the reactors, as opposed to being in constant motion as is the case with conventional activated sludge. Providing a stationary habitat allows an incredibly diverse and robust biofilm to grow, offering significantly improved nutrient removal, energy efficiency, sludge reduction and resiliency to shock loads in less space than conventional processes.
The biological process takes place in a series of cascade reactors, with standard pre-treatment at the beginning, and phase separation and disinfection at the end. As water flows through from one reactor zone to the next, different ecologies will grow and adapt to the conditions in each stage. This configuration allows the “food chain effect” to develop, as higher level organisms become predators on the simpler organisms.
Features
The technology provides a unique look and feel, drastically reducing the psychological footprint when compared to conventional activated sludge. The system results in reduced odour emissions and requires up to 60% less plot area than conventional activated sludge. The negative impact on surrounding real estate values is removed.
Although the equivalent biomass concentration increases (10 – 18 kg/m3) compared to activated sludge MLSS (2 – 5 kg/m3), the suspended biomass decreases (< 0.3 kg/m3), resulting in improved oxygen transfer efficiency which in turn results in a 20 – 50 % reduction in electricity consumption. The attached biomass results in a more resilient and stable biomass, that handles peak flow variations and pollution incidents much better. The attached growth results in increased endogenous respiration, as well as the predator effect, resulting in a 20 – 35% reduction in waste activated sludge. These factors combine to give an operating cost reduction of typically greater than 30%.
Diagram – Energy Saving
Applications
The main application is in the municipal WWTP market with more than 50 installations of up to 80 000 m3/d. Due to the improved oxygen transfer efficiency it can also be utilised in the WWTP upgrade and debottlenecking market.
Warm Climate Solution
Industrial applications are in sectors producing organically polluted effluents that are biodegradable, such as the food and beverage sectors.
Smaller units are also used in commercial developments e.g. airports, rest stops, schools, shopping malls, etc. with on-site recycling of grey water to irrigation, toilet flushing, cooling towers, etc.
A small containerised Bluehouse version has been developed for smaller applications where the aesthetic appeal of the FCR is important in residential estates or corporate office parks, etc.
Containerised BlueHouse Unit
Video
Watch a video clip on our FCR technology:
Watch a video clip with a TEDx discussion our FCR technology: