Removal of yttrium (III) from aqueous solution using surface metal sequestration methodology by 3‑azo‑phenolate salicylic acid

Yttrium immobilization through biomineralization with phosphate by the resistant strain Mesorhizobium qingshengii J19

AIMS

Yttrium (Y) holds significant industrial and economic importance, being listed as a critical element on the European list of critical elements, thus emphasizing the high priority for its recovery. Bacterial strategies play a crucial role in the biorecovery of metals, offering a promising and environmentally friendly approach. Therefore, gaining a comprehensive understanding of the underlying mechanisms behind bacterial resistance, as well as the processes of bioaccumulation and biotransformation, is of paramount importance.

METHODS AND RESULTS

A total of 207 Alphaproteobacteria strains from the University of Coimbra Bacteria Culture Collection were tested for Y-resistance. Among these, strain Mesorhizobium qingshengii J19 exhibited high resistance (up to 4 mM Y) and remarkable Y accumulation capacity, particularly in the cell membrane. Electron microscopy revealed Y-phosphate interactions, while X-ray diffraction identified Y(PO3)3·9H2O biocrystals produced by J19 cells.

CONCLUSION

This study elucidates Y immobilization through biomineralization within phosphate biocrystals using M. qingshengii J19 cells.

Nanoscale Pisum sativum pods biochar encapsulated starch hydrogel: A novel nanosorbent for efficient chromium (VI) ions and naproxen drug removal

Assembly of novel ecofriendly and sustainable (N-PSPB/SHGL) nanosorbent was fabricated based on encapsulation of derived nanoscale spherical biochar from Pisum sativum pods (N-PSPB) with starch hydrogel (SHGL). The mass ratio between starch and N-PSPB was examined and 2% (w/w) was selected as the optimum percentage for fabrication of the assembled hydrogel. High swelling capacity was characterized by N-PSPB/SHGL nanosorbent (500.0%) at room temperature (25 °C), excellent stability for ten cycles with respect to regeneration by 0.1 mol L-1 HCl. Additionally, characterizations of N-PSPB/Starch nanosorbent were established by SEM and BET measurement to characterize surface area (226.94 m2/g) and pore volume (9.88 cm3/g). The N-PSPB/SHGL nanosorbent was subjected to extensive investigations to evaluate its efficiency for removal of naproxen drug (NAP) and chromium (VI). The Cr(VI) and NAP drug adsorptions were fitted to pseudo-second kinetic and correlated with Langmuir isotherm. The adsorption processes were spontaneous and endothermic based on thermodynamic study.

Encapsulation of starch hydrogel and doping nanomagnetite onto metal-organic frameworks for efficient removal of fluvastatin antibiotic from water

Growing interests and efforts have been recently focused on design and assembly of novel hydrogel nanosorbents for removal of drugs from wastewater. Therefore, this work is aimed to immobilize and encapsulate starch hydrogel matrix onto metal organic frameworks (MOFs) and dope with nanomagnetite. The magnetic MOFs-Starch hydrogel (NFe₃O₄@Zn(GA)/Starch-Hydrogel) was synthesized via microwave irradiation process and characterized with high surface area (528.39 m²/g), mesoporous with pore size 2.90 nm and highly crystalline structure. The maximum swelling ratio (1000.0 %) was optimized at pH 10, 180 min and 25 °C. The validity of NFe₃O₄@Zn(GA)/Starch-Hydrogel for adsorptive removal of Fluvastatin statin drug provided maximum equilibrium adsorption capacity 782.05 mg g^-1. The Langmuir isotherm and pseudo-second kinetics models were correlated well with the computed correlation coefficient values 0.9991 and 0.9997, respectively. The validity of NFe₃O₄@Zn(GA)/Starch-Hydrogel for removal of FLV statin drug from real water matrices was confirmed in the range 96.15-99.99 %.

Amino-decorated magnetic metal-organic framework as a potential novel platform for selective removal of chromium (Vl), cadmium (II) and lead (II)

In this work, the -NH₂ functional group via 3-aminopropyltrimethoxysilane (APTMS) was selected to anchor onto the pore surface of magnetic metal organic framework using microwave green chemical process. The prepared nanocomposite was investigated for potential and fast removal of cationic Cd(II), Pb(II) as well as anionic Cr(VI) species via batch adsorption. Six kinetics models were applied in order to examine the adsorption mechanisms; the obtained data confirmed that the investigated metal ions followed the pseudo-second order model. The adsorption processes were fitted to the Langmuir model and the maximum adsorption capacities of cadmium (II), lead (II) and chromium (VI) ions were 693.0, 536.22 and 1092.22 mg g^-1. In addition, thermodynamic study confirmed the endothermic and spontaneous adsorption reactions. The nFe₃O₄@MIL-88A(Fe)/APTMS was easily regenerated and the adsorptive removal values were decreased by only 3% after five consecutive recycling processes. The recovery values from tap water, sea water and wastewater were identified as Cd(II) (98.49, 96.22 and 94.73), Pb(II) (96.88, 93.31 and 91.81) and Cr(VI) (99.69, 98.01 and 95.46), respectively.