The Fabrication of Calcium Alginate Beads as a Green Sorbent for Selective Recovery of Cu(Ⅱ) from Metal Mixtures

Abstract

Calcium alginate (CA) beads as a green sorbent were easily fabricated in this study using sodium alginate crosslinking with CaCl2, and the crosslinking pathway was the exchange between the sodium ion of α-L-guluronic acid and Ca(II). The experimental study was conducted on Cu(II), Cd(II), Ni(II) and Zn(II) as the model heavy metals and the concentration was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The characterization and sorption behavior of the CA beads were analyzed in detail via using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The adsorption experiments demonstrated that the CA beads exhibited a high removal efficiency for the selective adsorption of Cu(II) from the tetra metallic mixture solution and an excellent adsorption capacity of the heavy metals separately. According to the isotherm studies, the maximum uptake of Cu(II) could reach 107.53 mg/g, which was significantly higher than the other three heavy metal ions in the tetra metallic mixture solution. Additionally, after five cycles of adsorption and desorption, the uptake rate of Cu(II) on CA beads was maintained at 92%. According to the properties mentioned above, this material was assumed to be applied to reduce heavy metal pollution or recover valuable metals from waste water.

Competitive Interaction of Phosphate with Selected Toxic Metals Ions in the Adsorption from Effluent of Sewage Sludge by Iron/Alginate Beads

“…For the tested systems, the affinity of the Fe_Alg for metal ions was in the following decreasing order: Pb 2+ > Cu 2+ > Cd 2+ > Zn 2+ in DW_PM, and Cu 2+ > Pb 2+ > Cd 2+ > Zn 2+ in SW_PM. Metals’ adsorption in the DW_PM solution is consistent with other reports, in which the adsorption of these metals on calcium-crosslinked alginate adsorbents [ 49 , 50 ], on alginate modified by the grafting of urea maintained [ 51 ] and on activated carbon-containing alginate adsorbent [ 52 ] was studied. An affinity of Fe_Alg for number of metal ions found in the study are consistent with the ability of sodium alginate to bind to multivalent cations following the sequence of Pb 2+ > Cu 2+ > Cd 2+ > Ba 2+ > Sr 2+ > Ca 2+ > Co 2+ > Ni 2+ > Zn 2+ > Mn 2+ [ 53 ].…”

“…The adsorption experiments demonstrated that the beads exhibited a high removal efficiency for the selective adsorption of Cu 2+ . It was due to better bond stability with Cu 2+ compared to other metals [ 50 ]. Research conducted by Chen et al [ 42 ] showed that the nature of lead uptake was the typical ion exchange between Ca 2+ and Pb 2+ at the carboxylate anionic site, whereas the copper uptake took place through the ion exchange between Ca 2+ and Cu 2+ as well as the formation of the coordination complex.…”

Physical Properties, Chemical Analysis, and Evaluation of Antimicrobial Response of New Polylactide/Alginate/Copper Composite Materials

“…Sodium alginate with abundant carboxylate and hydroxyl groups [ 71 ], reacts with divalent cations such as Cu(II) [ 72 ], and others [ 73 , 74 , 75 ], to form cross-linked hydrogels, existing in reticular structures called “egg box” structures [ 76 , 77 ]. In transition metal-alginate systems, the sol-gel transition is characterized by a complex formation in which only the carboxyl groups in both M and G residues are coordinated to the metal ions [ 78 ].…”

Removal of Cadmium from Aqueous Solutions by Saccharomyces cerevisiae–Alginate System

“…The decrease in peak vibration intensity in the region between 3000 and 3600 cm −1 indicated that Cd 2+ interacts with -OH formed in alginate beads. Hydroxyl groups were also designated as binding sites for Cu 2+ and Zn 2+ on the surface of alginate beads [55].…”