Melamine-based dendrimer amine-modified magnetic nanoparticles as an efficient Pb(II) adsorbent for wastewater treatment: Adsorption optimization by response surface methodology. (December 2017)

• Record Type: Journal Article
• Authors: Jiryaei Sharahi, Fatemeh; Shahbazi, Afsaneh
• Is Part Of: Chemosphere. Volume 189(2017)
• Page Start: 291
• Page End: 300
• Publication Date: 2017-12
• Subjects: Magnetic nanocomposite -- Heavy metal -- Multivariate optimization -- Adsorption modeling -- Desorption–regeneration; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2017.09.050
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Magnetic Fe3 O4 nanoparticles with an average diameter of 64 nm was synthesized solvothermically and subsequently modified with melamine-based dendrimer amine (MDA–Fe3 O4 ) via grafting method. The synthesized materials were characterized using DLS, SEM, XRD, FTIR, VSM, TGA and elemental analysis techniques. The MDA–Fe3 O4 was employed for the efficient removal of Pb(II) ions from an aqueous solution. The adsorption efficiency was investigated in relation to the independent variables of Pb(II) concentration (80–250 mg L −1 ), pH of the solution (3–7), adsorbent dosage (0.1–0.5 g L −1 ) and temperature (10–40 °C) via a central composite design (CCD) using response surface methodology (RSM). The significance of independent variables and their interactions was tested using ANOVA at a 95% confidence limit ( α = 0.05). A second-order quadratic model was established to predict the adsorption efficiency. Under the optimum condition (initial Pb(II) concentration = 110 mg L −1, MDA-Fe3 O4 dosage = 0.49 g L −1, pH = 5 and temperature = 30 °C) a removal percentage of 85.6% was obtained. The isotherm data fitted well to the Freundlich model within the concentration range of the experimental study. A maximum adsorption capacity of 333.3 mg g −1 was predicted by the Langmuir model. The adsorption rate of Pb(II) ions onto MDA–Fe3 O4 was in good agreement with the pseudo-second-order model (R 2 = 0.999; k 2 = 4.7 × 10 −4 g mg −1 min −1 ). Thermodynamically, adsorption was spontaneous and endothermic. The MDA–Fe3 O4 was successfully regenerated using 0.3 M HCl with little loss of adsorption capacity (≈7%) for five successive adsorption cycles. Highlights: Magnetic iron oxide nanoparticles was modified by dendrimer amine. Adsorption mechanism of MDA-Fe3 O4 was evaluated using Pb(II) as a target pollutants. The excellent adsorption was attributed to robust surface complexation of MDA-Fe3 O4. MDA-Fe3 O4 can be used effectively towards the remediation of Pb(II).