Bioremediation of Modified Phosphogypsum to Cultivable Anthrosol via Peanut Growth

Phosphogypsum stacks have become a global environmental concern due to their massive annual production. While their primary application lies in construction, the scale of utilization pales in comparison to the production volume, necessitating the exploration of expansive, innovative applications. This study pioneers a simple and efficient strategy for phosphogypsum bioremediation, transforming modified phosphogypsum into a sustainable anthrosol. The strategy involved treating fresh phosphogypsum with calcium oxide at a 100:5 mass ratio, successfully reducing fluoride ion concentrations in the leachate to below 15.0 ppm, while maintaining an ambient pH of around 7.6. Employing peanut growth as our bioremediation model, we cultivated using 100% modified phosphogypsum. The germination rate soared to 96.0%, with a 16-week seedling average height of 19.5 cm, mirroring growth metrics in natural soil. Throughout the cultivation, notable enhancements in the total organic carbon (TOC) and total nitrogen (TN) were observed in the modified phosphogypsum. A thriving microecosystem was gradually established and characterized by the proliferation of microbial species such as gammaproteobacteria, cyanobacteria, and alphaproteobacteria. These results illuminate a transformative pathway to mitigate the challenge of phosphogypsum surplus by converting it into recyclable anthrosol, setting a precedent for potential bioremediation strategies across various industrial solid industrial wastes.