Photocatalytic removal of 17ß-estradiol from water using a novel bimetallic NiCu/Nb2O5 catalyst.

The development of effective photocatalytic materials is essential for removing emerging pollutants from aqueous media, such as the hormone 17ß-estradiol (E2). In this study, a novel photocatalyst based on niobium pentoxide (Nb2O5) functionalized with nickel (Ni) and copper (Cu) was synthesized for E2 removal. The NiCu/Nb2O5 photocatalyst was prepared using a facile wet impregnation method and characterized by various techniques. The incorporation of Ni and Cu into Nb2O5 reduced the band gap energy from 3.3 to 2.8 eV, enabling efficient utilization of visible light. Moreover, NiCu/Nb2O5 exhibited the highest E2 removal efficiency (82%) under UV-A-assisted conditions at a concentration of 1.5 g L-1. The reaction kinetics were found to follow a second-order model with a rate constant of k = 0.0020 L g-1 min-1, and a plausible reaction mechanism was proposed. Through the study of radical elimination, it was proven that the radical oxidation reaction mechanism predominated in the reaction. The results of the toxicity assays, combined with the TOC parameter, demonstrated the efficacy of photocatalytic degradation in reducing E2. These findings demonstrate the great potential of the NiCu/Nb2O5 photocatalyst for removing persistent pollutants.

Extraction Methods, Chemical Characterization, and In Vitro Biological Activities of Plinia cauliflora (Mart.) Kausel Peels.

Plinia cauliflora (Mart.) Kausel, popularly known as jabuticaba, possesses bioactive compounds such as flavonoids, tannins, and phenolic acids, known for their antioxidant, antibacterial, wound healing, and cardioprotective effects. Therefore, this study aimed to standardize the P. cauliflora fruit peel extraction method, maximize phenolic constituents, and evaluate their antioxidative and antimicrobial effects. Various extraction methods, including vortex extraction with and without precipitation at 25, 40, and 80 °C, and infusion extraction with and without precipitation, were performed using a completely randomized design. Extraction without precipitation (E - P) showed the highest yield (57.9%). However, the precipitated extraction (E + P) method displayed a yield of 45.9%, higher levels of phenolic derivatives, and enhanced antioxidant capacity. Major compounds, such as D-psicose, D-glucose, and citric acid, were identified through gas chromatography-mass spectrometry (GC-MS) analysis. Ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis identified citric acid, hexose, flavonoids, tannins, and quercetin as the major compounds in the extracts. Furthermore, the extracts exhibited inhibitory effects against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli bacteria. In conclusion, the E + P method efficiently obtained extracts with high content of bioactive compounds showing antioxidant and antimicrobial capacities with potential application as a dietary supplement.

Hydroxychloroquine Adsorption in Aqueous Medium Using Clinoptilolite Zeolite.

The presence of drugs on a large scale in aquatic matrices raises concern and requires the study of efficient technologies to remove these compounds. This study investigated the adsorption capacity of the natural zeolite clinoptilolite (CP) in removing the drug hydroxychloroquine (HCQ). Zeolite was characterized by BET, XRD, FT-IR, SEM, and pHpzc techniques. The kinetic model that best fits the experimental data was the pseudo-first-order and the SIPS isotherm provided the best fit. The Langmuir isotherm RL separation factor (> 0.01) indicated that the adsorption process was favorable and the Freundlich isotherm (n > 1) suggested that the adsorption mechanism occurred mainly by physisorption, with intraparticle diffusion as the step limiting the process. The process was spontaneous (ΔG°ads < 0), endothermic (ΔH°ads > 0), and with increased randomness at the solid-solution interface (ΔS°ads > 0). The initial pH variation of the effluent was not favorable for the adsorption process and the zeolite was easily regenerated for later use. The ecotoxicological tests with Artemia salina and Lactuca Sativa proved that the final effluent did not show toxicity after the adsorption treatment. Based on the results obtained in this work, clinoptilolite zeolite is a potential adsorbent for reducing HCQ toxicity in aquatic matrices. Supplementary Information: The online version contains supplementary material available at 10.1007/s11270-022-05787-3.

Photocatalytic degradation of hydroxychloroquine using ZnO supported on clinoptilolite zeolite.

The objective of this work was to evaluate the photocatalytic activity of zinc oxide catalysts supported on natural zeolite clinoptilolite for photocatalytic degradation of the drug hydroxychloroquine, used in the treatment of malaria and which has been tested in the treatment of COVID-19. To synthesize 10%ZnOCP and 15%ZnOCP catalysts, the wet impregnation methodology was used. The raw and synthesized catalysts were characterized by XRD, SEM, XRF, BET, DRS, PCZ, FT-IR and PL. The degradation of hydroxychloroquine was calculated using UV-vis absorption from the samples before and after the photocatalytic process. The maximum percentage of degradation (96%) was obtained with the operational parameters of C0 = 10 mg L-1; Ccat = 2 g L-1 of 15%ZnOCP; pH = 7.5; UV-A radiation. Ecotoxicological tests against the bioindicators Lactuca sativa and Artemia salina confirmed the reduction of effluent toxicity after treatment.

A critical review on environmental presence of pharmaceutical drugs tested for the covid-19 treatment.

On March 11, 2020, the World Health Organization (WHO) declared COVID-19 a pandemic. The outbreak caused a worldwide impact, becoming a health threat to the general population and its professionals. To date, there are no specific antiviral treatments or vaccines for the COVID-19 infection, however, some drugs are being clinically tested. The use of these drugs on large scale raises great concern about their imminent environmental risk, since the elimination of these compounds by feces and urine associated with the inefficiency of sewage treatment plants in their removal can result in their persistence in the environment, putting in risk the health of humans and of other species. Thus, the goal of this work was to conduct a review of other studies that evaluated the presence of the drugs chloroquine, hydroxychloroquine, azithromycin, ivermectin, dexamethasone, remdesivir, favipiravir and some HIV antivirals in the environment. The research indicated the presence of these drugs in the environment in different regions, with concentration data that could serve as a basis for further comparative studies following the pandemic.

Toxicity reduction of persistent pollutants through the photo-fenton process and radiation/H2O2 using different sources of radiation and neutral pH.

The presence of toxic compounds in aquatic bodies is of great concern, and the Fenton, photo-Fenton and radiation/H2O2 processes can be applied in the remediation of these compounds due to their efficiency and advantages. However, these processes need to be investigated to make them more viable and environmentally friendly. Thus, the reduction of toxicity was evaluated, through ecotoxicological tests with Artemia salina and Lactuca sativa, of the compounds 2,4-D, diazepam, nicotine and paracetamol (acetaminophen) by the Fenton, photo-Fenton and radiation/H2O2 process with UVC, UVA and natural solar radiation at neutral pH with low concentrations of Fe2+ and H2O2. The UVC/H2O2 process was efficient in the degradation of nicotine (74%), the photo-Fenton process was more efficient in the degradation of 2,4-D (82%), diazepam (27%) and paracetamol (85%) using solar radiation, UVA and UVC respectively. The toxicity and total organic carbon (TOC) tests showed a reduction in the toxicity of the compounds after treatment, except for diazepam, which was more resistant to the process, leading to a higher mortality of Artemia salinas (92%) and less relative seed germination of Lactuca sativa (40%).