Aquaponics, a symbiotic cultivation of fish and plants, is emerging as an innovative solution to address the urgent global challenges of food security and climate change. By merging aquaculture and hydroponics, this innovative system offers a sustainable and efficient approach to food production.
A recent study published in the journal Resources, Conservation and Recycling by researchers from Ben Gurion University of the Negev (Israel), Wageningen University and Research (Netherlands), and the Israel Oceanographic and Limnological Research Institute delved into the comparative performance of different aquaponics models, including a novel system that incorporates in situ anaerobic treatment. The results are impressive.
Overcoming the Challenges of Traditional Aquaponics
While aquaponics holds great promise, traditional systems, including coupled and decoupled aquaponics, face limitations. These systems often struggle with nutrient imbalances, water management, and fish sludge disposal. To address these issues, researchers have developed a novel approach: coupled aquaponics with an anaerobic digester (CAP-AD).
The CAP-AD System: A Game-Changer
The CAP-AD system represents a significant advancement in aquaponics. By incorporating an anaerobic digester, it effectively treats fish sludge, recovering valuable nutrients such as nitrogen and phosphorus. These recovered nutrients can be recycled back into the system, further enhancing its efficiency and sustainability.
The CAP-AD system aligns with the principles of the circular economy, emphasizing resource efficiency and waste minimization. By closing the nutrient loop and optimizing water use, this innovative approach contributes to the United Nations Sustainable Development Goals.
A Quantum Leap in Nutrient Efficiency
The study revealed a significant breakthrough. The new system demonstrated an impressive nitrogen recovery of 41% and phosphorus recovery of 36%, eclipsing the 21% and 16% rates of conventional decoupled systems, and even surpassing the 24% and 18% of coupled systems. This higher nutrient efficiency translates into a remarkable overall nutrient utilization of 76% for nitrogen and 80% for phosphorus, mainly attributed to the effective nutrient recovery from fish sludge.
Boosting Productivity While Conserving Resources
Beyond nutrient management, the novel aquaponics system showed superior performance in other key metrics. Plant productivity increased 1.6 times compared to conventional systems. Additionally, it achieved a 2.1-fold reduction in water consumption and a 16% decrease in energy expenditure per kilogram of food.
Projections suggest that if scaled up to around one ton of fish, the system could operate without external energy requirements, with a water turnover of less than 1%, negligible waste production, and significant carbon capture. These figures underscore the system’s efficiency in optimizing resource utilization.
A Circular Economy Solution for Arid Regions
The study posits that aquaponics combined with anaerobic digestion presents a compelling model for a circular economy, particularly in arid regions characterized by high radiation and temperature. By effectively recycling nutrients and minimizing waste, this system offers a sustainable pathway for food production in challenging environments.
“Feeding the planet’s more than 8 billion people and reducing greenhouse gas emissions will require innovative technologies. Those that combine two functions in one are obviously preferable. Fish is a sustainable source of high-quality protein with a much smaller carbon footprint than most other sources. Combining fish growth with vegetable production and avoiding waste is a win-win situation,” says Professor Amit Gross, Director of the Zuckerberg Institute for Water Research at the Jacob Blaustein Institutes for Desert Research at Ben-Gurion University.
The Road Ahead
While the CAP-AD system shows great potential, further research is needed to fully understand its nutrient dynamics and optimize its performance in diverse arid environments.
Thus, the findings of this research illuminate the immense potential of aquaponics as a transformative technology. By optimizing nutrient cycling, enhancing productivity, and conserving resources, this innovative approach can significantly contribute to global food security and climate change mitigation.
The study was funded by the ICA Foundation, the British Council, and the China MUST project, the PRIMA program funded by the EU, and the BlueCycling project funded by EU Horizon 2020.
Contact
Amit Gross
Zuckerberg Institute for Water Research, Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev
Sde Boker Campus, Midreshet Ben Gurion 84990, Israel
Email: amgross@bgu.ac.il
Reference
Zhu, Z., Yogev, U., Keesman, K. J., & Gross, A. (2024). Promoting circular economy: Comparison of novel coupled aquaponics with anaerobic digestion and conventional aquaponic systems on nutrient dynamics and sustainability. Resources, Conservation and Recycling, 208, 107716. https://doi.org/10.1016/j.resconrec.2024.107716
