World’s Largest Aquaponics Project, in China’s Third Largest Aquaculture Lake

Posted October 14, 2014 by Tom Duncan& filed under Aquaculture, Biological Cleaning, Fish, Plant Systems.

Lake Taihu experienced its worst ever algal bloom at the height of summer, pushing researchers to search for new solutions. They decided to try a new technology, Aqua Biofilter, that is designed to remove nutrients that fuel algal blooms. An ambitious aspect of the project was to launch the world’s largest aquaponics system, over 4 acres in size, using new technologies in combination with old world bamboo that is used in traditional Chinese building. Experiments growing rice on fish ponds provided a foundation for scaling up to lakes and larger water bodies for earth and water repair.

The technology is part of the new wave of products that biomimics nature, using biomaterials that can remediate and restore nature’s balance with non-toxic and sustainable processes. The concept was adapted from natural wetlands that process nutrients and pollutants with plants. Mature wetland ecosystems often develop self-sustaining floating wetlands that mop up pollutants. Most lakes and urban wetlands are highly modified or recently built, with polluted inflows, making it necessary for human intervention, taking the best of what nature has developed naturally to tackle pollutants that run-off from urban and industrial areas.

Algal bloom removal shown in water samples, Lake Taihu (Credit Dr Kangmin Lee)

Lake Taihu has extensive aquaculture industry that suffered mass die offs and threatened the future of the industry. The research team chose plant species that would beautify the lake, and also provide rapid root growth which serve as habitat for native fish to spawn and provide refuge from the toxic algal bloom.
Three months after project implementation, the water cleared completely with no visible algae and water transparency improved by 250%. The plants had soaked up the excess nutrients, cutting off the nutrient supply that algal blooms require to grow. Roots exert a strong biofilm that captures nutrients and pollutants, and de-nitrifies the water allowing natural balance to be restored.
Some 200 square foot of Aqua Biofilter provides a root biofilm surface area of 1 acre, delivering incredible rates of nutrient and pollutant removal, at zero cost once installed. The lack of operational expenses makes the technology attractive to local governments and water managers who need quick results at an affordable price. The benefits of floating wetlands go beyond improving water quality, by also serving as habitat for diverse water fauna, enabling complete restoration of aquatic ecosystems.
Company CEO Tom Duncan has done some interesting Aqua Biofilter projects including growing rice on floating reedbeds, and writing Chinese characters with plants in urban developments on waterways in Nanjing to promote water conservation for urban apartment dwellers and skyscrapers viewing the waterways below.