R2π Project: Circularity in Aquaponics

May 30th, 2018

Designing Food Production Systems for Circularity – Aquaponics

Paul Wolf, Sylvie Geisendorf, Alexis Figeac

Waste describes materials or products that are no longer of use. In a linear economy, waste accumulates as an undesired by-product of economic activity. A circular economy, on the other hand, sees intrinsic value in such flows and re-routes them back into the economic process. The case of aquaponics exemplifies this by inherently designing the production process from the start, to improve key elements of circularity. Compared to traditional industrial farming operations where circularity might be added at the end in terms of better reuse or recycling, aquaponics is circular by design. The entire business idea is based on a well-balanced combination of different farming products in order to allow a circular symbiosis between them. The process is based on nature´s template and controlled by technology. In contrast to many circular ideas where the conversation of circularity often revolves purely around product design and even more only around end of life takeback, aquaponics switches gears to a more integrated level in addressing circularity of more parts of the product life cycle with a focus on the circular design of production1, (see Figure 1 for orientation of the circular economy core framework).

Figure 1 Circular Economy Framework: Geisendorf & Pietrulla (2017).

The R2Pi project team is working closely with an advanced and innovative aquaponics start-up, to analyse how the business model and production processes are oriented to improve circularity in the food sector. With this aquaponics case study, they are investigating the business models of a promising new area of technology based on biological processes in the progression of circular thinking and design, as well as uncovering corresponding challenges. For example, aquaponics businesses operate in a vague policy environment for both aquaculture and agriculture separately, rather than one that has been designed for aquaponics, resulting in a web of bureaucracy that must be disentangled. The results of the case study will be available as the research is completed. For now, here is a bit of background about this innovative food production system and the immediate benefits it provides for the circular economy.

What exactly is it? Aquaponics is a nascent agricultural production concept that combines elements of aquaculture—fish farming, and hydroponics—plant farming with controlled water systems. While some aquaculture may be performed in the natural environment with submerged cages, aquaponics adopts the closed system approach where a fish nursery is carefully harmonized with a closed hydroponic production system in which plants such as herbs, salads, or tomatoes are grown. These two separate but dependent systems are designed, balanced, and technologically controlled to reduce environmental impacts while improving productivity of the physical space—in this case, an urban environment.

How these benefits are derived can best be understood by a comparison with traditional aquaculture systems. In these cases, fish produces high levels of nitrates and phosphorus, which has to be purged from the system and replaced with fresh water to maintain healthy water for the fish. However, by flushing this nutrient-rich fish wastewater into the environment, ecosystems may be damaged by effects of eutrophication; and in an urban environment results in costs of treatment through the municipal sewage system. Furthermore, these same nutrients are required for plant cultivation—and in the case of nitrates—they are, for the non- naturally occurring variety, primarily derived from natural gas.

An aquaponics system takes the would-be waste-output of highly nutrient water, and delivers it directly to plants, thereby effectively cleaning the water, reducing the need on artificial (and transported) fertilizer. Furthermore, the most advanced aquaponics systems can be 90% more water efficient than traditional field farming, and requiring less than 3% of system water each day (e.g. some lost in evaporation, some absorbed in the plants)2. The state-of-the-art system designs strive to achieve greater circularity of resources e.g., aiming to capture condensate and reduce water loss to less than 1%, as well as processing unused organic by-products in a bioreactor to power the system.3 The water that is maintained in the system, continuously circulates and is cleaned mechanically and biologically. This effectively reduces water needs and the dependency on fossil fuel for transportation—particularly when the reduced need for fertilizer and the proximity to market for the final food products is considered.

“Food miles” are not only a contributor to GHG-emissions but are also part of a phenomenon of anonymisation of food production and of detaching the consumer from the production source. Sustainable urban farming through aquaponics thus becomes more practical. Whereas urban farming primarily provides a source of plant-based fibre, vitamins and minerals, aquaponics is able to deliver the missing dietary link, namely animal protein; indeed, the aquaculture is far more efficient and practical in this respect than any form of livestock breeding in an urban environment. Moreover, it is achieved in an odourless manner and with an extremely small physical footprint.

Considering these features of aquaponics, this new concept opens new alleys for further measures of circularity and eases the challenges associated with the global trends of increased population—need for sustainable protein, urbanization—need to transport food, clean water scarcity, and environmental hazards related to traditional farming—e.g. eutrophication and carbon emissions from fossil fuels and derivative inputs.

In the framework of circularity as established by the R2Pi project, the case of aquaponics leverages primarily the co-product recovery business model pattern, a form of industrial symbiosis in which waste becomes a raw material for another production process. This is evident in the technological and biological design of the processes utilized in the system, where fish effluent that would otherwise be discarded and purged from the system as an environmentally hazardous waste, is considered a raw material source and organically processed into a natural fertilizer for horticulture. Such a business model has the further social benefit of bringing advanced farming jobs to urban areas, as well as producing food that can be free of herbicides, pesticides, hormones, antibiotics, and microplastics,3 as well as being close to the consumer.

In a typical deployment of aquaponics, it may be categorized as a micro-level economic activity in the circular economy, however, there may be further opportunities to develop synergetic meso-level activities—e.g. in partnerships with other local circularity focused businesses to provide more opportunities to close the loops. These are uncovered by investigating the system inputs and outputs along value chains of the business, in line with the framework for circular economy business models. The results of the aquaponics case study, as well as of further cases analysed by R2Pi, will be available in the full report of the R2Pi project, and disseminated within the curriculum of ESCP Europe Business Schools to give our next generation of business leaders the inspiration and knowledge to accelerate the transition to a circular economy!

1 Geisendorf, S., & Pietrulla, F. (2017). The circular economy and circular economic concepts—a literature analysis and redefinition. Thunderbird International Business Review.

2  Kloas, W., Groß, R., Baganz, D., Graupner, J., Monsees, H., Schmidt, U., … & Wuertz, S. (2015). A new concept for aquaponic systems to improve sustainability, increase productivity, and reduce environmental impacts. Aquaculture environment interactions, 7(2), 179-192.

3 Estim, A., Saufie, S. & Mustafa, S. (2018). Water quality remediation using aquaponics sub-systems as biological and mechanical filters in aquaculture. Journal of Water Process Engineering. https://doi.org/10.1016/j.jwpe.2018.02.001

Originally publishd for the R2Pi project at http://www.r2piproject.eu/aquaponics-case-circular-design/