Application of Modern Research Methods for the Physicochemical Characterization of Ion Exchangers

Abstract

Ion exchange technique as the reversible exchange of ions between the substrate and the surrounding medium can be an effective way of removing traces of ion impurities from the waters and wastewaters and obtaining a product of ultrapure quality. Therefore, it can be used in analytical chemistry, hydrometallurgy, purification and separation of metal ions, radioisotopes and organic compounds, and it also finds great application in water treatment and pollution control. In the presented paper, the new trends for ion exchanger characteristics determination and application are presented. Special attention is paid to the ion exchangers with multifunctionality for heavy metal ions removal. They show superior actions such as sorption capacity values with excellent resistance to fouling and the possibility of application in the co-current or modern packed bed counter-current systems, as well as for the condensate polishing or the conventional mixed bed systems in combination with other resins. The results of the paper are expected to help researchers to establish a powerful strategy to find a suitable ion exchanger for heavy metal ions removal from waters and wastewaters. It is important because the best ion exchangers are selected for a specific application during laboratory tests taking into account the composition of the feed solution, pH, type of ion exchangers and then the column breakthrough tests. Therefore, the optical profilometry and the X-ray photoelectron spectroscopy can prove beneficial for this purpose in the case of three different ion exchangers such as Dowex M 4195, Amberlite IRA 743 and Purolite Arsen Xnp.

Polymeric and inorganic sorbents as a green option to recover critical raw materials at trace levels from sea saltwork bitterns

“…3a-c), it was observed that quaternary amine sorbents (A500Plus, MP500, K6362, and IRA904) did not show affinity toward any of the target elements of interest for the project (removals <10%) and that only appreciable Ga and Ge sorption (25-30%) was achieved by A500Plus with bittern 1 and IRA904 with bittern 3 (25-35%). This would be in accordance with the explanation of Yi-Gong Chen et al (2021), 64 where it is said that strong basic anion exchangers with quaternary ammonium groups could have good kinetics and short rinses but, in contrast, not a very high exchange efficiency. Among tertiary amine sorbents, IRA94 did not show affinity toward any element, but A100 was able to sorb around 67%, 62%, and 52% Co for bitterns 1, 2, and 3, respectively.…”

“…K3 and K5 belong to fibrous sorbents with carboxylic acid functional groups but with amines on their structure. These kind of fibrous ion exchangers, due to their mechanical strength and flexibility, 70 are applied for air purification, 64 but they could also be used to extract several metals from water. 71 Independent of which bittern was tested (Fig.…”

“…Both sorbents were also able to sorb about 86% Ga and 93% Ge when bittern 1 was evaluated. Yi-Gong Chen et al (2021) 64 reported that large operating capacity and regeneration efficiency are characteristics of tertiary amine sorbents, while Silva et al (2018) 65 described mixed anion exchangers (those combining, for example, quaternary ammonium groups with tertiary amines, such as MP64) as sorbents with good metal selectivity and loading capacity.…”

Ion-Imprinted Polymeric Materials for Selective Adsorption of Heavy Metal Ions from Aqueous Solution

“…Sorbents bearing various chelating ligands were prepared by two main strategies: (i) post-functionalization of commercially available [ 12 , 13 , 14 , 15 , 16 ] or homemade [ 12 , 17 , 18 , 19 , 20 ] cross-linked copolymers; (ii) “bottom-up” design of specialized materials by the free radical polymerization of monomers endowed with adequate pre-existing heteroatomic moieties, such as –COOH, –OH, –SH, –NH 2 , =NH, –N=, –SO 3 H, and –PO 3 H, in the presence of a cross-linker [ 18 , 20 , 21 ], or by the condensation of monomers containing a high density of reactive functional groups [ 12 , 22 ]. Even so, all the sorbents described above have weak selectivity.…”

Reductive Cr(VI) Removal under Different Reducing and Electron Donor Conditions—A Soil Microcosm Study

“…Throughout the years, various pump and treat physicochemical technologies have been employed to remediate Cr(VI) polluted soil and groundwater (ion exchange, chemical precipitation, adsorption, membrane filtration, etc.) [5][6][7][8]. However, these technologies present certain disadvantages, such as secondary pollution, high operational and maintenance cost, and low effectiveness [9,10].…”