Fabrication of magnetic manganese ferrite-loaded sugar cane bagasse/peanut peel biochar adsorbents for the adsorptive removal of phosphorus from aqueous solution

Adsorption has the potential to be a highly effective and selective method for recovering and adsorbing phosphate from wastewater and water, which can serve as secondary sources of phosphorus. The objectives of this study were to synthesize manganese ferrite (MF) nanoparticles which are fabricated and studied alone and loaded on sugar cane bagasse and peanut peels biochar (BC) adsorbents (Mn@Fe₃O₄@BC) by in-situ growth method, which in turn applied to evaluate their capabilities for phosphorus adsorption from aqueous solutions. Batch experiments were conducted to determine the optimum adsorption conditions for different process parameters such as pH, adsorbent dose, and initial phosphorus concentration. The maximum phosphorous removal efficiency using MF, MFBC_b, and MFBC_p was obtained at adsorbent doses 0.2 and 0.3 g/L, and initial phosphorous concentrations of 20, 40, and 60 mg/L, respectively. The optimum retention time was obtained at 120 min for MF and MFBC_b, and 150 min for MFBC_p. The optimum rotation speed and temperature were 120 rpm and 25 °C for all adsorbents. The maximum removal efficiencies obtained are 98.5% and 99% for MF and MFBCs, respectively. Different characterization analyses; including SEM, EDX, and FTIR; were applied to investigate surface morphology, elemental composition, and chemical properties of the adsorbents before and after the adsorption process. Adsorption kinetics, isotherms, capacity, mechanisms, and thermodynamic studies were studied to evaluate the adsorption process. And finally, adsorbents were regenerated using their magnetic properties and a second successive adsorption cycle was evaluated showing promising results for MFBC adsorbents which can affect the expected costs of the adsorption process.