Surface Properties of Halloysite-Carbon Nanocomposites and Their Application for Adsorption of Paracetamol

Effective removal of selected pharmaceuticals from sewerage treatment plant effluent using natural clay (Na-montmorillonite)

The consumption of pharmaceuticals has rapidly increased on a global scale due to the serious increase in Covid-19, influenza and respiratuar sinsityal virus, which is called "triple epidemic" in the world. The use of non-prescription analgesic and anti-inflammatory drugs (AAIDs), especially paracetamol, is higher compared to pre-pandemic. This increased the AAIDs load discharged to the aqueous media through sewerage treatment plant (STP). Therefore, simple and effective treatment options for removing AAIDs from STP effluents are needed. The aim of the study was to remove AAIDs (paracetamol, acetylsalicylic acid, codeine, diclofenac, ibuprofen, indomethacin, ketoprofen, mefenamic acid, naproxen, and phenylbutazone) from STP effluents by nearly pure natural clay Na-montmorillonite. The Na-montmorillonite taken from the Ordu region in the northern part of Turkey. Surface area of the Na-montmorillonite is 99.58 m2/g and CEC is 92.40 meq/100 g. The removal efficiencies of AAIDs using Na-montmorillonite were between 82 ± 5% (ibuprofen) and 94 ± 4% (naproxen). Paracetamol was used as a model compound in kinetic and isotherm model studies. Freundlich isotherm model and the pseudo second order kinetic model were the best-fit using the obtained experimental data. Film diffusion governed its rate mechanism. The paracetamol adsorption capacity was acquired as 244 mg/g at 120 min contact time at pH 6.5 at 25 °C. With this study, it could be shown that montmorillonite can be used effectively to eliminate paracetamol from STP effluent. Natural clay can be used as a simple, inexpensive and effective adsorbent for removing AAIDs from STP effluents.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13201-023-01930-5.

Sustainable Mitigation of Paracetamol with a Novel Dual-Functionalized Pullulan/Kaolin Hydrogel Nanocomposite from Simulated Wastewater

In the present investigation, a novel, green, and economical dual-functionalized pullulan/kaolin hydrogel nanocomposite (f-PKHN) was fabricated and subsequently applied for the liquid-phase decontamination of paracetamol (PCT), a pharmaceutical pollutant. Pullulan and kaolin were functionalized with l-asparagine and gallic acid, respectively. The physicochemical facets of the functionalized pullulan/kaolin hydrogel nanocomposite and its interactive behavior with PCT were elucidated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), and elemental mapping. The process parameters along with the isotherm, kinetics, and thermodynamics were methodically appraised via a batch technique to unveil the adsorption performance of the as-fabricated hydrogel nanocomposite. The adsorption isotherm and kinetics of PCT uptake by f-PKHN conform well to Freundlich and pseudo-second-order models, respectively. Relying on hydrogen bonding, n-π, and van der Waals interactions, the maximum adsorption capacity was 332.54 mg g^-1, higher than for most of the previous adsorbents reported in the literature for PCT removal. Thermodynamic calculations corroborated endothermic, spontaneous, and feasible adsorption phenomena. The maintenance of a high uptake percentage (69.11%) in the fifth consecutive adsorption-desorption cycle implied the significant reusable potential of f-PKHN. Swelling studies exhibited 90% swelling within 200 min, indicating the successful fabrication of a cross-linked hydrogel network. The real water (distilled water, tap water, and river water) samples spiked with PCT specified a significant uptake of PCT (>85%), and the minor influence of ionic strength on the adsorptive potential of f-PKHN validated its potentiality for the decontamination of real effluents. In conclusion, f-PKHN with substantial adsorption capacity, green characteristics, and excellent reusability can be reckoned with as a promising adsorbent for the de-escalation of PCT from aquatic sources as well as at the industrial level.

Bimetallic modified halloysite particle electrode enhanced electrocatalytic oxidation for the degradation of sulfanilamide

The treatment of antibiotics wastewater by electrocatalytic oxidation has attracted much attention. In the paper, a novel halloysite bimetallic (HLS-Cu-Mn) particle electrode material was prepared and a bench-scale electrocatalytic reaction tank was designed. A three-dimensional electrocatalytic oxidation reactor composed of HLS-Cu-Mn and a bench-scale electrocatalytic reaction tank was used to degrade Sulfanilamide (SA) wastewater. Characterization of the synthesized material was conducted with Scanning electron microscopy (SEM), X-ray polycrystalline powder diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET). The electron spin resonance spectroscopy test results confirmed that HLS-Cu-Mn produced a large number of •OH. The electrochemical workstation confirmed that HLS-Cu-Mn had strong electrocatalytic activity and repolarization ability. Under the optimum preparation conditions and degradation process parameters, the removal efficiency of SA and TOC was 99.84% and 88.95% respectively. The method also has good degradation efficiency for aniline, phenol, herbicides, antibiotics, and dyeing wastewater. It was found that 4 main intermediates appeared in the degradation process by Ultra-high performance liquid chromatography/triple tandem quadrupole mass spectrometry (LC-MS). In sum, it was believed that this work provides a new vision and idea for water treatment.