A new magnetic amino-functionalized polymeric sorbent based on glycidyl methacrylate was synthesized and used in the separation of chromium Cr(VI) oxyanions sorption from aqueous solutions in a static batch system. The kinetic and isothermal parameters of the sorption process were determined. The experimental data were best fitted by a pseudo-second-order model with R² = 0.994 and χ² = 0.004. The sorption process of Cr(VI) removal by amino-functionalized sorbent was controlled by both intraparticle diffusion and liquid film diffusion. The equilibrium results showed that the sorption process is best described by the Freundlich model, followed closely by the Sips isotherm model, with a maximum sorption capacity of 64 mg/g. Quantum chemical modeling revealed that the sorption sites on the sorbent surface are fragments with diethylenetriamine and aminopropyl silane groups that coated the magnetic nanoparticles. The calculations showed that Cr(VI) oxyanions (Cr₂O₇²⁻, CrO₄²⁻ and HCrO₄⁻) bind to both sorption sites, with diethylenetriamine centers slightly favored. The X-ray photoelectron spectroscopy (XPS) spectra demonstrate that the chromium bound to the sorbent in the form of Cr(III), indicating that the Cr(VI) can be converted on the surface of the sorbent to a less harmful form Cr(III) due to the sorbent’s chemical composition.

A core-shell amino-functionalized glycidyl methacrylate magnetic molecularly imprinted polymer (MIP) was synthesized by the suspension polymerization/surface imprinting method and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), mercury porosimetry, nitrogen gas adsorption–desorption, and elemental analysis. This MIP was used as the sorbent in dispersive solid-phase microextraction (DSPME) of aniline from textile wastewater prior to high-performance liquid chromatography-mass spectrometry (HPLC-MS) measurements. Since aniline is toxic and a probable human carcinogen, its determination in water is of great significance. This is a challenging task because aniline is usually present at trace levels. The effects of different DSPME variables on the preconcentration efficiency have been studied by using the Plackett–Burman screening design of experiments (DoE) followed by response surface methodology optimization using the Box-Behnken design. Thus, DoE enabled the investigation of several variables simultaneously. Under optimized conditions, aniline was effectively and selectively separated by a small amount of the DSPME sorbent and detected in real textile wastewater samples. The method detection limit of 1 ng mL⁻¹ was attained, with good method linearity and acceptable recovery and precision. The results showed that the studied MIP could be a reliable DSPME sorbent for efficiently analyzing trace aniline in real wastewater samples.

An amino-functionalized magnetic macroporous copolymer of glycidyl methacrylate (GM) and ethylene glycol (E) dimethacrylate (m-poly(GME)-deta) was synthesized, fully characterized, and used to investigate the adsorption of vanadium (V) oxyanions from aqueous solutions (Ci = 0.5 mM) in a batch system at room temperature (298 K). Pseudo-first-order (PFO), pseudo-second-order (PSO), Elovich, and intra-particle diffusion (IPD) models were used to analyze the kinetic data. The study showed that sorption is rapid, i.e., the sorption half-time is approximately one minute. Initially, the sorption process primarily involved surface sorbent particles, and it was best described by the PSO model. However, after saturation of the surface active sites is attained, the sorption rate decreases significantly because of limitations of the diffusion rate, which is then primarily controlled by the IPD process. The sorption process is favorable in the pH range of 3–6 due to the strong electrostatic interactions between the absorption centers of copolymer and vanadium (V) oxyanions. In the stated pH range, deta absorption centers with two and three protonated N atoms are in equilibrium as studied by quantum chemical modeling. Among V(V) species present in diluted aqueous media, the adsorption of H₂VO₄⁻ ions dominates.

A novel porous gold polymer composite was prepared by the functionalization of a glycidyl methacrylate-based copolymer (pGME) with ethylene diamine (pGME-en), and activation by gold (pGME-en/Au), in a simple batch adsorption procedure in an acid solution, at room temperature. Detailed characterization of the pGME-en before and after activation was performed. The main focuses of this research were the design of a method that can enable the recovery of gold and the reuse of this multipurpose sorbent as an antimicrobial agent. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis pointed out amine groups as the primary binding sites for Au activation, while hydroxyl groups also contributed to the chelation reaction. pGME-en exhibited fast gold adsorption with an adsorption half-time of 5 min and an equilibrium time of 30 min. The maximal adsorption capacity was about 187 mg/g. The analysis of sorption experimental data with a non-linear surface reaction and diffusion-based kinetic models revealed the pseudo-second-order and Avrami model as the best fit, with unambiguous control by liquid film and intra-particle diffusion. The biological activity studies against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Candida albicans revealed moderate activity of pGME-en/Au against different bacterial and fungal species. pGME-en/Au was stable in a saline solution, with a release of approximately 2.3 mg/g after 24 h.

A previously synthesized and functionalized magnetic glycidyl methacrylate-based nanocomposite, mPGMT-deta, was tested as a sorbent for Re(VII) oxoanions in Mo(VI)-containing solutions. The effect of pH on the removal efficiency and the separation factor was examined in the range of 2 to 9. A maximum separation factor (β_Re/Mo) of 8.85 was observed at pH 6. The nature of rhenium oxoanions binding to the active sites of mPGMT-deta was analyzed using density functional theory (DFT). The calculations indicated that the formation of MoO₄²⁻//hedetaH₂²⁺ adduct is electrostatically favored at pH 6, while the inclusion of solvation effects makes the formation of ReO₄⁻//hedetaH₂²⁺ adduct thermodynamically more favorable. Solvation played a dominant role in determining the selectivity of oxoanion sorption to the nanocomposite. The adsorption isotherm, kinetics, and thermodynamics of Re(VII) onto mPGMT-deta were determined. The equilibrium data were best-fitted using the Langmuir adsorption model (R² = 0.999), with a maximum sorption capacity for Re(VII) of 0.43 mmol/g. The uptake kinetics of the sorption process obeyed the pseudo-second-order model, with the influence of diffusion and external mass transfer. Based on the thermodynamic parameters, Re(VII) sorption was spontaneous and endothermic.

The presented research includes the preparation, characterization, and implementation of magnetic biosorbent (Fe₃O₄/RWB), obtained from ragweed (Ambrosia artemisiifolia) biomass. Fe₃O₄/RWB was examined for the removal of a hazardous dye, malachite green (MG), from an aqueous solution in a batch system. The effects of the experimental parameters—initial dye concentration (10–300 mg/L), contact time (0–120 min), biosorbent dose (1–5 g/L), initial pH (2–10), ionic strength (0–1 mol/L), and temperature (298–318 K) on dye biosorption—were studied. The results showed that increases in biosorbent dose, contact time, and initial pH led to an increase in biosorption efficiency, while the increase in initial dye concentration, the ionic strength, and temperature had the opposite effect. The biosorption kinetics for MG on Fe₃O₄/RWB were analyzed with pseudo-first-order, pseudo-second-order, and Elovich kinetic models, while the Langmuir, Freundlich and Temkin isotherm models were used for equilibrium data analysis. It was observed that the MG biosorption followed the pseudo-second-order kinetic model, whereas the Langmuir model was the best fit for the equilibrium biosorption data of MG, with a Q_max of 34.1 mg/g. the desorption of MG from Fe₃O₄/RWB indicated reusability in five adsorption/desorption cycles, good performance, and potential in practical applications.