Innovative eco-sustainable reishi mushroom-based adsorbents for progesterone removal and agricultural sustainability

The pervasive presence of endocrine-disrupting chemicals (EDCs), particularly progesterone, in aquatic ecosystems poses significant ecological and human health risks, necessitating the development of sustainable and efficient removal strategies. This study introduces an innovative, eco-friendly approach utilizing non-edible reishi mushroom (<i>Ganoderma lucidum</i>) and its calcined form as natural adsorbents for progesterone removal while simultaneously exploring the potential of the formed composites as sustainable agricultural amendments. The adsorption efficiency of both reishi mushroom powder and its calcined form was systematically optimized under varying pH, adsorbent dose, temperature, and contact time conditions. The adsorption capacities of reishi mushroom and its calcined form for progesterone were assessed using nine non-linear isotherm models. Among these, the Langmuir and Freundlich models provided the best fit to the experimental data (<i>R</i> ² ∼ 0.99), demonstrating high adsorption capacities of 90.52 mg g^-1 for reishi mushroom and 118.10 mg g^-1 for calcined reishi mushroom under optimal conditions (pH 3, 25 °C, 0.1 g and 0.075 g doses, respectively) following pseudo-second-order and mixed-order kinetic models. Both materials were fully characterized before and after the adsorption process using XRD, FTIR, and SEM techniques. Thermodynamic analysis revealed the process to be exothermic, spontaneous, and highly ordered, driven by hydrophobic interactions and van der Waals forces. Molecular docking analysis shows that ganoderic acid A and progesterone bind strongly to key plant hormone receptors (GID1, TIR1, BRI1), indicating their potential to enhance plant growth by influencing gibberellin, auxin, and brassinosteroid signaling pathways. Beyond environmental remediation, the formed composites exhibited exceptional potential in enhancing agricultural productivity. Composite treatments, particularly progesterone adsorbed on calcined reishi mushroom, significantly improved seed germination rates (95%), shoot-to-root elongation (2.5 : 1), and overall plant growth (39 cm height, 200 g fresh weight). Soil quality assessments revealed increased organic matter content and improved fertility, highlighting the dual benefit of these adsorbents in environmental remediation and sustainable agriculture. The greenness profile of the proposed method, evaluated using NEMI, AGP, and Modified GAPI metrics, further underscores its eco-sustainability, with an eco-scale score of 94 and a BAGI blueness score of 75, affirming its alignment with green analytical chemistry principles. This study introduces a novel, cost-effective, and eco-friendly method for progesterone removal while pioneering the use of waste-derived adsorbents in circular agriculture. By utilizing reishi mushroom and its calcined form, this research addresses both water contamination and sustainable farming, advancing eco-friendly technologies.