Kinetic and thermodynamic investigation into the lead adsorption process from wastewater through magnetic nanocomposite Fe3O4/CNT

Abstract

In this study, magnetic nanocomposite Fe 3 O 4 / CNT was synthesized through chemical precipitation and was used for uptake of lead from wastewater. The nanocomposite was characterized by XRD, TEM, and FTIR spectroscopy. Batch adsorption experiments were performed to investigate the effects of such various parameters as the pH of solution, the contact time, and the adsorbent dosage on the adsorption efficiency of Fe 3 O 4 / CNT. The maximum lead adsorption was observed in pH = 3, 0.16 g of nanosorbent, the contact time of 40 min, and the temperature of 30°C. The maximum removal percentage of Pb ions in optimal conditions by Fe 3 O 4 /CNT was 95.5%. Despite the fact that the optimum pH = 3, the bath adsorption experiments were performed at pH = 6 ± 0.5. For water with high alkalinity, a problem related to microbiologically induced corrosion may occur. However, high acidic water can accelerate the corrosion rate by increasing the reaction rates or causing physical damage to the pipes. The pseudo-first order and pseudosecond order were used to evaluate the kinetic models and the mechanism of the adsorption. The results indicated that the pseudo-second-order kinetic model resulted in a satisfactory fit for the experimental data (R 2 = 0.99). The adsorption isotherms were analyzed using Langmuir and Freundlich models. The Freundlich isotherm proved to have a little better correlation compared with that of the Langmuir isotherm. The thermodynamic parameters indicate that there was a spontaneous endothermic reaction. The process was successfully applied in the treatment of battery wastewater where the presence of organic compounds, copper, lead, zinc, nickel, and cadmium is hardly influenced the removal efficiency of lead ions even after five successive cycles. The results also show that the nanocomposite has a high efficiency of lead removal from wastewater resources.

Nanomaterials for the Removal of Heavy Metals from Wastewater

“…The fabrication of these magnetic nanocomposites could be achieved mainly through three approaches: (1) Surface modification of magnetic iron/iron oxide nanoparticles by functional groups such as –NH 2 , –SH etc., which has been discussed in the previous chapter; (2) encapsulating the iron/iron oxide nanoparticles with other materials, such as humic acid, polyethylenimine, polyrhodanine, MnO 2 , polypyrrole, etc. to make a core-shell structure [139,172,250,251,252]; (3) coating the iron/iron oxide nanoparticles on some porous materials such as graphene oxide, CNTs, and so on [253,254]. Recently, Huang et al synthesized a novel magnetic composite in which the nanosized Fe 3 O 4 @SiO 2 served as the core while the amino-decorated Zr-based metal-organic frameworks (Zr-MOFs) acted as the shell [255].…”

Kinetic and Isotherm Studies of Adsorption of the Metribuzin Herbicide on an Fe3O4/CNT@PDA Hybrid Magnetic Nanocomposite in Wastewater

“…The Fe 3 O 4 /CNT magnetic nanocomposite was initially synthesized relying on a previous study . Second, a polymer layer of PDA was coated on the Fe 3 O 4 /CNT surface using an oxidative polymerization of dopamine under alkaline conditions.…”

Carbon Nanotube Membranes in Water Treatment Applications

“…Magnetic functionalized CNTs have also been employed to remove heavy metals from water, mainly due to the easy magnetic retrieval by an external magnetic field for recycling. [135,136] In this case, magnetic CNTs are prepared and then retrieved by magnetic separation after the adsorption process (Figure 9), which is an effective way to recycle the CNTs.…”