Adsorptive removal of lead (II) ion from water and wastewater media using carbon-based nanomaterials as unique sorbents: A review.

Carbon-based nanomaterials and its derivatives such as carbon nanotubes, graphene, reduced graphene oxide, and graphene oxide have been widely used as unique sorbents for removal of both organic and inorganic contaminants due to unique physical and chemical properties. In the review, application of the carbon-based nanomaterials or nanocomposites is considered with particular focus on the lead(II) removal from water and wastewater samples. Moreover, various procedures of synthesis and functionalization of each class of carbon-based nanomaterials were reviewed. A critical review has been given to the adsorption behavior of these nanomaterials and interaction type between the sorbent and lead(II) ion s due to changes in their surface structure and functional group modification for the removal of lead(II)ions. The adsorption capacity, the sorbent selectivity and structure, and the adsorption mechanism for lead(II) ion adsorption with these sorbents were studied and compared. Specific consideration is devoted to effecting of pH of samples as a critical factor in the adsorption of lead(II)ions on each class of carbon-based nanomaterials. Also, the advantages and disadvantages of the nanomaterials or nanocomposites for the adsorption of lead(II) ion were evaluated in detail. In this way, the paper will contribute to presenting suggestions for the preparation of new sorbents to researchers for future study, as well as the remaining research challenges in this field.

Magnetic ethylene diamine-functionalized graphene oxide as novel sorbent for removal of lead and cadmium ions from wastewater samples.

In this paper, magnetic ethylene diamine-functionalized graphene oxide (MDFGO) as a novel sorbent was synthesized and applied for removal of Pb(II) and Cd(II) from real wastewater samples. The morphology and molecular structure of MDFGO were studied by different analytical methods. The effective parameters in adsorption efficiency of Pb(II) and Cd(II) were studied and optimized using experimental design. Under the optimal condition, the effective parameters including pH, sorbent dosage, shaking rate, and adsorption time were 6.2, 33.0 mg, 500 rpm, and 11 min, respectively. Mechanism of adsorption kinetic was investigated using the Lagergren pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. It was found that adsorption of lead and cadmium ions in the MDFGO sorbent followed from pseudo-first-order and pseudo-second-order models, respectively. Thermodynamic parameters (ΔG°, ΔH°, and ΔS°) for the lead and cadmium ions uptake onto the MDFGO sorbent were calculated and indicated that the adsorption processes were spontaneous and endothermic in nature for both cations. In order to investigate the isotherm model for adsorption of Pb(II) and Cd(II), the experimental data were studied using the Langmuir, Freundlich, and Harkins-Jura isotherm models. The results fitted well with Freundlich model for both metal ions. The new sorbent (MDFGO) was applied to remove Pb(II) and Cd(II) from battery wastewater and electroplating wastewater. The removal percentage of Pb(II) and Cd(II) were 99.6±0.5 and 99.4±0.6, respectively, and demonstrated that the new sorbent was very suitable for removal of lead and cadmium ion from the real wastewater samples.

Development of a novel ultrasonic-assisted magnetic dispersive solid-phase microextraction method coupled with high performance liquid chromatography for determination of mirtazapine and its metabolites in human urine and water samples employing experimental design.

Ultrasonic-assisted magnetic dispersive solid-phase microextraction coupled with high performance liquid chromatography has been developed for extraction and determination of mirtazapine, N-desmethyl mirtazapine, and 8-hydroxy mirtazapine in human urine and water samples. Magnetic graphene oxide-polyaniline nanocomposite (MGOPA) as a novel SPME sorbent was synthesized and used for the microextraction process. The analytical performance of MGOPA was compared with magnetic graphene oxide nanocomposite and indicated that the new sorbent was quite effective for extraction of mirtazapine, N-desmethyl mirtazapine, and 8-hydroxy mirtazapine. A two-stage experimental design approach, Plackett-Burman screening design and Box-Behnken optimization design, was used for screening and optimizing of significant variables in the microextraction process. The practical applicability of the proposed method was assessed by studying the linearity, intra-day and inter-day accuracy, enrichment factor, and precision. This method can be satisfactorily applied to the determination of mirtazapine and its metabolites in human urine and environmental water samples. Graphical Abstract Magnetic graphene oxide-polyaniline nanocomposite.