The initiative emerged to tackle the intertwined environmental and socio-economic challenges confronting rural communities in Jordan and across the Mediterranean basin. Olive mill effluent—generated during fruit washing and oil extraction in both traditional presses and two- or three-outlet centrifugal systems—carries high loads of toxic organic compounds, exhibits low pH, and demands elevated chemical oxygen consumption (COD). If discharged untreated, this wastewater poses serious threats to soil health, surface waters, and groundwater reserves. At the same time, livestock farmers endure scarcity and steep costs for quality animal feed, especially during the October–February olive-pressing season.
A multidisciplinary team from Al-Ahliyya Amman University’s Agricultural Technology and Genetic Engineering Department joined forces with researchers at Pablo de Olavide University (Seville, Spain) and Jaén University (Jaén, Spain) to develop a holistic, nature-based solution. Central to this approach is the aquatic fern Azolla, which grows rapidly on the surface of unaltered olive mill effluent. By cultivating Azolla directly in the effluent—without any chemical pretreatment—the initiative simultaneously remediates the wastewater and generates valuable biomass.
During pilot implementation, ten experimental ponds were installed adjacent to olive mills in the Balqa, Jerash, and Irbid governorates. Wastewater samples were classified by origin (fruit-wash versus oil-wash) and extraction technology (centrifugal decanter versus traditional press). Initial analysis revealed elevated concentrations of phenolic compounds, organic acids, carbohydrates, and dissolved minerals—components that, if left untreated, would degrade local ecosystems.
Over a three-week period, Azolla cultivation achieved remarkable pollutant removal, reducing COD by more than 70%. The treated effluent consistently met Jordanian standards for safe agricultural reuse, enabling nearby farmers to irrigate crops without ecological harm. Meanwhile, the harvested Azolla biomass was valorized in two key ways. First, annual yields surpassed 20 tonnes of a protein-rich feed supplement suitable for cattle, sheep, and poultry. By replacing commercial feeds with this on-farm product, feed costs dropped by up to 40%, markedly improving farmers’ profitability and food security. Second, lipid extraction from the residual biomass yielded over 5 tonnes of biofuel per year. This renewable fuel powers small-scale generators, cutting greenhouse-gas emissions and reducing dependency on fossil fuels.
Community engagement has been integral: more than 150 smallholder farmers took part in hands-on workshops and field demonstrations focused on pond operation, Azolla cultivation techniques, and straightforward maintenance protocols. Memoranda of understanding with local farmers’ associations guarantee ongoing management, knowledge transfer, and a roadmap for scaling up to additional mills in future seasons.
Aligned with the United Nations’ Sustainable Development Goals, this initiative drives progress on zero poverty (SDG 1) by creating new income streams and lowering input costs; on clean water and sanitation (SDG 6) through effective wastewater remediation and reuse; on affordable and clean energy (SDG 7) by supplying locally produced biofuel; and on industry, innovation, and infrastructure (SDG 9) by introducing a replicable, low-cost biotreatment technology. By fusing environmental restoration with economic empowerment, this project offers a scalable model for sustainable agriculture and circular-economy practices across the Mediterranean region.
