Adsorption of Pb(II) and Hg(II) ions from aqueous single metal solutions by using surfactant-modified ostrich bone waste

In this paper, the application of a stable immobilized cetyltrimethylammonium bromide (cationic surfactant) and laundry detergent (anionic surfactant) on the surface of a biological origin support (ostrich bone waste) was reported as the novel bio-adsorbents for the removal of Pb(II) and Hg(II) ions from aqueous solution. The synthesized bio-materials were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Brunnauer-Emmett-Teller, SEM-EDX, thermal gravimetric, and point of zero charge. The removal efficiency of the bio-adsorbent was investigated as a function of contact time, pH, initial ion concentration, temperature, adsorbent dosage, and chemical modification process. Equilibrium, kinetics, and thermodynamic studies were also performed for design and evaluate the bio-adsorbents in removing Pb(II) and Hg(II) ions from aqueous solution. The modified ostrich bone with anionic surfactant indicated remarkable capability to remove Pb(II) and Hg(II) ions from aqueous solution. The results showed that the majority of Pb (91.9%) and Hg (87.7%) ions were removed within the first 0-60 min contact with the B-Detergent bio-adsorbent. Langmuir-Freundlich isotherm type model satisfactorily described the Pb(II) and Hg(II) experimental data. The adsorption process was spontaneous and endothermic in nature and followed pseudo-second-order kinetic model.