Synthesis and characterization of nano magnetic wheat straw for lead adsorption

Abstract

In this study, an attempt was made for the first time to remove Pb(II) ions from aqueous solutions using magnetic wheat straw (MWS). MWS was synthesized using in situ co-precipitation method and characterized by BET, SEM, TEM, X-ray diffraction, Fourier transform infrared, and vibrating sample magnetometer methods. The biosorption characteristics of Pb(II) ions onto the wheat straw (WS) and MWS were studied with respect to some effective parameters, including solution pH, initial Pb(II) concentration, and dose of adsorbent. The initial solution pH and contact time for MWS were optimized to be 5.0 and 30 min, respectively. The equilibrium process was satisfactorily described by the Langmuir isotherm model with maximum sorption capacities of 50.76 and 41.15 mg g⁻¹ for MWS and WS, respectively. Kinetic studies for MWS indicated that both pseudo-first-order and pseudo-second-order kinetic models were able to describe the process with correlation coefficients of 0.978 and 0.9997, respectively.

Keywords:

• Magnetic wheat straw
• Lead
• Biosorption
• Fe₃O₄ nano-particles