APTMS-BCAD modified magnetic iron oxide for magnetic solid-phase extraction of Cu(II) from aqueous solutions

Fe₃O₄@SiO₂-3-aminopropyltrimethoxysilane-1,8-bis (3-chloropropoxy) anthracene-9,10-dione was synthesized as a new, sustainable, and environmentally friendly adsorbent for magnetic solid-phase extraction of Cu(II) from aqueous solutions. The structure of the adsorbent was characterized by FTIR, XRD, SEM, EDX, and TEM analysis. Optimum conditions for Cu(II) adsorption were determined as adsorbent dose 0.04 g, pH 5.0, contact time 120 min, and beginning concentration of 30 mg/L in the adsorption process. The adsorption capacity for Cu(II) ions was 43.67 mg/g and the removal efficiency was 84.72 percent. The Langmuir isotherm and the pseudo-second-order model fit the experimental data better. Adsorption was a spontaneous and endothermic process based on the obtained thermodynamic properties such as ΔG°, ΔH°, and ΔS°. The results showed that the sorbent has good selectivity in the presence of competing ions. The method was determined to be accurate and effective using real water samples and CRM.

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Magnetic Fe₃O₄@SiO₂-3-aminopropyl-trimethoxysilane-1,8-bis(3-chloropro-poxy) anthracene-9,10-dione was synthesized as a new, sustainable, and environmentally friendly adsorbent for magnetic solid-phase extraction of Cu(II) from aqueous solutions.

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The results showed that the presence of competitor ions did not have a significant effect on the sorption of Cu(II) ion and the sorbent had good selectivity.

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Using real water samples and CRM, the method was found to be accurate and effective.

Adsorption performance of activated carbon synthesis by ZnCl2, KOH, H3PO4 with different activation temperatures from mixed fruit seeds

In this study, new activated carbons (ACs) were synthesized from a mixture of lemon and orange seeds (LOS) for toxic metal removal from aqueous solutions. Adsorbents have been produced by chemical activation with different activation agents (with H₃PO₄, ZnCl₂ and KOH) and activation temperature (600°C, 700°C, 800°C). The elemental analysis, FT-IR, XRD and SEM analyses were performed to determine the characterization of the ACs. A series of batch adsorption experiments were done to research the influence of various parameters such as pH, adsorbent dosage, contact time, temperature, the complexing agents on the toxic metal ions (Cu(II), Cr(III) and Ni(II)) removal capacity of ACs. Adsorption equilibration time was 60 min, the adsorption capacity was 118.02 mg/g for Ni(II) ions, 146.03 mg/g for Cr(III) ions and 150.45 mg/g for Cu(II) ions. The adsorption of toxic metal ions was observed as a maximum at pH = 5 on AC-ZnCl₂ (600°C) produced under N₂ atmosphere. The adsorption process was fitted with a Langmuir isotherm model and a pseudo-second-order kinetic equation, showing the metal ions adsorption on AC was monolayer coverage. Thermodynamic studies show that the adsorption is endothermic and spontaneous in nature. AC produced from the LOS mixture has not been encountered in the literature. A simple, easy-to-apply method has been developed for a new adsorbent prepared from a mixture of LOS with environmentally friendly, easy to produce, reusable, cost-effective, non-toxic and with good adsorption-desorption capacity. Therefore, this study will contribute to the world economy in terms of environmental and wastewater cleaning.