A collaborative research initiative between the Massachusetts Institute of Technology (MIT) D-Lab and Keo Fish Farms in the United States is advancing the integration of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More into commercial aquaculture systems. This partnership focuses on developing regenerative water-quality solutions for the Arkansas Delta, where engineering student Kiyoko Hayano is leading the design of low-cost filtration models. By utilizing biochar as a primary remediation medium, the project aims to establish a closed-loop infrastructure that addresses both chemical contaminants and nutrient recovery. This effort represents a significant shift toward applying decentralized engineering solutions to domestic food security challenges within the American agricultural heartland.

The central challenge addressed by this collaboration is the presence of elevated iron levels in groundwater, which has led to increased fish mortality at the Keo facility during peak summer conditions. Traditional well systems tapping into specific geological strata in the Delta region often introduce high mineral concentrations that compromise the health of sensitive species, such as hybrid striped bass and triploid grass carp. Beyond the immediate biological risk, the farm faced the economic burden of high-cost infrastructure upgrades. There was a critical need for a filtration system that was not only effective at sequestering minerals but also financially viable within the operational constraints of a large-scale commercial fish farm.

To mitigate these risks, the MIT D-Lab team evaluated and implemented a multi-stage water treatment strategy featuring biochar-based media. The solution leverages biochar’s high porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More and surface area to bind iron and other impurities before the water enters the holding vats. Furthermore, the long-term vision for the site includes a circular economy component: producing biochar on-site using local agricultural residues, such as rice hulls, which are abundant in the region. This localized production ensures a steady supply of filtration media while simultaneously managing waste from nearby row-crop operations, effectively turning a waste stream into a functional input for aquaculture health.

The outcomes of this project demonstrate a successful pathway for regenerative aquaculture that balances environmental stewardship with industrial productivity. By improving water quality through biochar filtration, the farm expects to enhance fish survival rates and overall health across its annual production of 150 million fish. Additionally, the project provides a blueprint for nutrient recovery, as the spent biochar—now enriched with minerals and organic matter—can be repurposed as a high-value soil amendmentA soil amendment is any material added to the soil to enhance its physical or chemical properties, improving its suitability for plant growth. Biochar is considered a soil amendment as it can improve soil structure, water retention, nutrient availability, and microbial activity.   More for local terrestrial farming. This interdisciplinary approach not only secures the farm’s commercial viability but also positions the Arkansas Delta as a site for innovation in sustainable, carbon-negative food systems.