Valorization of Eichhornia crassipes into iron-modified activated biochar for sustainable removal of diclofenac and ciprofloxacin from water: adsorption mechanisms, techno-economic, and phytotoxicity assay analysis.

The increasing presence of pharmaceutical contaminants in water has necessitated the development of sustainable and efficient adsorbents for water remediation. In this study, Eichhornia crassipes biomass was used to prepare magnetic activated biochar through the co-precipitation method for the removal of ciprofloxacin (CIP) and diclofenac (DF) from water. Various characterization techniques such as FTIR, XRD, FESEM, BET, and VSM were used to evaluate the surface morphology, crystalline structure, surface area, and magnetic properties. Batch adsorption experiments were performed to study the impact of input parameters: pH, initial DF and CIP concentration, adsorbent dose, time, and temperature. The maximum Langmuir adsorption capacities of MAB for CIP and DF were found to be 135.33 mg/g and 119.72 mg/g, respectively. To study the reliability and predictive accuracy of the models, error analysis was conducted using RMSE, SSE, HYBRID, ARE, and χ2. Furthermore, the phytotoxicity assessment using Vigna radiata showed a reduced toxicity after adsorption treatment, indicating the environmental safety of the treated water. The reusability of MAB over 5 cycles demonstrated 62% and 64% removal efficiency for both DF and CIP, respectively. The cost benefit analysis highlighted the economic feasibility of MAB for large scale treatment of water. Overall, the findings suggested that the material is eco-friendly, cost-efficient, sustainable and effective for the removal of pharmaceuticals from water.