Environmental friendly FeOOH adsorbent materials preparation, characterization and mathematical kinetics adsorption data

Goethite (FeOOH) nano-material was prepared via precipitation process by using an aqueous solution (pH: 12) of ferric nitrate and potassium hydroxide at different aging time (1, 24, 72, 120, 168 h), to be used as an adsorbent for removing the heavy toxic metals. The structural characterization and morphology of the prepared adsorbents have been studied by different techniques. X-ray diffraction analysis established the growth of the goethite particles with the increase in the aging time. High-resolution transmission electron microscopy inferred the formation of the nano-rods like structure that increase in length with the increase in the aging time. The adsorption of the lead (II) on using the prepared adsorbent goethite material (168 h) studied as a function of pH, adsorbent amount and contact time with lead concentration in the range of 100–500 mg/L. The results revealed that the lead uptake is increased with the increase in contact time until 45 min and then it reached equilibrium. Adsorption kinetics described by the pseudo-second order kinetic equation. The high correlation coefficient obtained for Langmuir model hence it was best-fitted isotherm under the experimental conditions. The high adsorption efficiency for the lead removal was attained on using the prepared goethite (168 h days), as compared with the natural one.