Zinc Ion Removal on Hybrid Pectin-Based Beads Containing Modified Poly(Methyl Methacrylate) Waste

Abstract

A new hybrid sorbent in the form of round beads containing modified poly(methyl methacrylate) (PMMA) waste immobilized in pectin and crosslinked with calcium ions was prepared. A previously obtained and characterized powdered poly(methyl methacrylate)–based sorbent was used. Batch and column studies on the new material’s sorption-desorption properties were performed. Two kinetic models (pseudo-first- and pseudo-second-order) and three isotherms (Langmuir, Langmuir bisite and Freundlich) were used to describe the results. Breakthrough and elution curves were also obtained. Nitric, hydrochloric, and sulfuric acid of various concentrations were used in the desorption studies. Higher sorption affinity of zinc(II) ions to hybrid sorbent than to pectin alone, reflected by higher values of the Langmuir and Freundlich model parameters, was observed. The maximum sorption capacities, calculated based on the best-fitted models, were 50.2 mg/g (Langmuir bisite) and 42.2 mg/g (Langmuir) for hybrid and only pectin beads, respectively. The stripping of Zn ions using 0.1 M solutions of mineral acids was similarly effective in the case of both sorbents. The mass balance calculated for the column studies showed about 100% recovery of zinc in a sorption-desorption cycle. By applying the hybrid sorbent under the studied conditions it is possible to purify Zn in water to the level permitted by law and concentrate Zn(II) ions by about 60 times.

Synthesis and appraisal of a hydroxyapatite/pectin hybrid material for zinc removal from water

“…These results were consistent with the previous investigations on HAP 6,11,27 and pectin. 28,29 However, under the same experimental conditions, the capacity of ve different HAP/pectin hybrids averaged more than 225 mg Zn 2+ per gram of adsorbent. By adjusting the mass ratio of HAP and pectin; and modifying the synthesis procedure (with or without ethanol dehydration treatment), the best performing hybrid (6H1P) achieved 285.6 AE 3.3 mg Zn 2+ per gram of hybrid adsorbent.…”

“Functional upcycling” of polymer waste towards the design of new materials

“…Furthermore, this sorbent was immobilised on pectin-based beads to conduct column-scale removal of Zn 2+ ions and a slightly decreased adsorption capacity was recorded (50.2 mg g −1 ). 449 Compared to commercially available materials (clinoptilolitic zeolite and granulated activated carbon), PMMA-based sorbents achieved higher sorption capacities under neutral pH conditions (4–7). 498…”

“…For instance, hydroxylated PMMA surfaces can be modified using common organosilanes 6)), 445,451,454,472,473,481,482 by transesterification with diethanolamine (Fig. 16d and Table 7( 7)), 449,483 alkylation for further functionalisation (Fig. 16e and Table 7(5)), 450 and radical graft polymerisation (Fig.…”

“…489 Fig. 16 Functionalisation of PMMA: (a) direct aminolysis, 447 (b) hydrolysis, 448 followed by (c) amination, 448 (d) esterification, 449 (e) alkylation, 450 (f) silanisation 451 and (g) grafting/cross-linking; 452 (h) modification by high reactive radicals; 453 and (i) physical and chemical activation. 454 This journal is © The Royal Society of Chemistry 2023 Despite the prevalence of the two-step methods, the application of diazonium salts 453,495,496 or nitrene precursors 497 has been developed as a direct approach to introduce the functional groups (Fig.…”

Hybrid Pectin-Based Sorbents for Cesium Ion Removal

“…Pectin biosorbents were used for removal of various heavy metals, e.g., Pb(II), Cd(II), and Cu(II), from water and wastewater [25,26]. It was also proved that pectin may be a good matrix material for the immobilization of other sorption substances, e.g., titanium dioxide or modified poly(methyl methacrylate) waste [27,28]. There is no information concerning immobilization of Prussian blue in pectin matrix to create sorption beads.…”