The physicochemical properties of nanocomposite was characterized by X-ray diffraction analysis (XRD), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDAX), Thermo-gravimetric analysis (TGA), Vibrating Sample Magnetometery (VSM) and Fourier-transform infrared spectroscopy (FT-IR) analysis. In this method, the batch removal process were designed by response surface methodology (RSM) based on a central composite design (CCD) model. The results indicated that the highest efficiency of Pb(II) removal was obtained from the quadratic model under optimum conditions of prominent parameters (initial pH 6.0, adsorbent dosage 7 mg, initial concentration of lead 15 mg L −1 and contact time 27.5 min). Adsorption data showed that lead ions uptake on nanocomposite followed the Langmuir isotherm model equation and pseudo-second order kinetic model. High adsorption capacity (558.2 mg g −1) and easy magnetic separation capability showed that the synthesized nanocomposite has great potential for the removal of Pb(II) ions from contaminated wastewaters.ĭisposal of industrial effluents and wastewaters is considered as one of the most important challenges in the industrial world today. Due to the toxic ingredients of these effluents such as, heavy metal ions and dyes, they are the main cause of pollution of rivers, lakes and underground waters 1, 2. Unlike organic pollutants, heavy metal ions are not only degradable or decomposable but also can accumulate in biotic and abiotic systems through the food chain, drinking water and air, resulting in serious damage to the environment and human safety 3. The most notorious heavy metals that cause significant environmental pollution are lead, chromium, mercury, cadmium, arsenic, zinc, copper, and nickel. The concentration of some of them have reached dangerous levels both for the environment and humans. Accordingly, reduction of such pollutants is one of the most significant steps in wastewater treatment 4. Among the various toxic metal ions, lead is a highly toxic pollutant that is released into the environment due to industrial activities, including mining, plating, battery production, metal smelting, oil refining, printing, and so on. Accumulation of Pb(II) ions in the human body lead to various health consequences, such as: anorexia, gastrointestinal colic, anemia, neurasthenia, kidney and liver damage, and even cancer 5. Therefore, in order to environmental clean-up, it is absolutely essential to design appropriate technologies and prepare effective materials for complete removal or reduction of Pb 2+ ions to an acceptable level, before discharge 6. It should be notified that careful sensing of pollutants and chemicals are also beneficial 7. There are many traditional methods for removing lead, including ion exchange, chemical precipitation, electrodeposition, membrane filtration and reverse osmosis 8. However, these techniques usually suffer from some limitations including complexity and high cost of their operation, potential secondary pollution, difficulty in recycling and poor efficiency in low concentration of lead 9, 10. Among the various treatment technologies, adsorption is currently preferred as a non-hazardous method for the removal of heavy metal ions due to its cheapness, selectivity, high efficiency, simple processes, reusability, flexibility in design and availability of different adsorbents 11. Generally, an ideal adsorbent should have a high surface area and also adsorption sites, so that the adsorption process takes place in a short equilibrium time 11, 12. In the last two decades, by the development of novel nanotechnologies and the advent of nanomaterials 13, 14, scientists have been attracted to this field and various novel adsorbents have been emerged 15. Due to various advantageous in which appears by reducing the size of the adsorbent to nanometers and increasing the surface area and thus increasing the active sites, the adsorption capacity of these materials increases significantly 16, 17. Quite recently some novel strategies have been proposed for lead removal or adsorption via nanomaterials.
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