Sulfadiazine removal using green zero-valent iron nanoparticles: A low-cost and eco-friendly alternative technology for water remediation

Oocyte maturation, fertilization, and embryo development in vitro by green and chemical iron oxide nanoparticles: a comparative study

Oxidative stress is considered one of the main challenges for in vitro maturation (IVM) and makes assisted reproductive technology (ART), including IVF and embryonic development less effective. Reducing free radicals via biocompatible nanoparticles (NPs) is one of the most promising approaches for developing IVM. We investigated the comparative effect of green and chemically synthesized iron oxide nanoparticles (IONPs) with an aqueous extract of date palm pollen (DPP) on oocyte parameters related to the IVM process. To this end, IONPs were synthesized by chemical (Ch-IONPs) and green methods (G-IONPs using DPP) and characterized. The mature oocyte quality of the Ch-IONPs and G-IONPs groups was evaluated by JC1 and Hoechst staining, Annexin V-FITC-Propidium Iodide, 2', 7'-dichlorofluorescein diacetate, and dihydroethidium staining compared to the control group. Eventually, the mature oocytes were fertilized, promoted to blastocysts (BL), and evaluated in vitro. Compared with the control and G-IONPs groups, the Ch-IONPs-treated group produced more hydrogen peroxide and oxygen radicals. Compared with the Ch-IONPs group, the fertilization rate in the G-IONPs and control groups increased significantly. Finally, the G-IONPs and control groups exhibited a significant increase in the 2PN, 2-cell, 4-cell, 8-cell, compacted morula (CM), and BL rates compared with the Ch-IONPs group. Green synthesis of IONPs can reduce the toxicity of chemical IONPs during the IVM process. It can be concluded that G-IONPs encased with DPP compounds have the potential to protect against exogenous reactive oxygen species (ROS) production in an IVM medium, which can have a crucial effect on oocyte maturation and fertilization efficiency.

Iron oxide nanoparticles synthesized usingMentha spicataextract and evaluation of its antibacterial, cytotoxicity and antimigratory potential on highly metastatic human breast cells

Iron oxide nanoparticles (Fe2O3NPs) were synthesized utilizingMentha spicatasourced from Cyprus as a stabilizing agent. The study delved into assessing the antimicrobial, cytotoxic, anti-proliferative, and anti-migratory potential of Fe2O3 NPs through disc diffusion, trypan blue, and 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, respectively. Characterization of the synthesized Fe2O3 NPs was conducted using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), UV-vis spectroscopy (UV-vis), scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDX). The FTIR, XRD, and SEM-EDX spectra confirmed the successful formation of Fe2O3 NPs. The analysis of UV-vis spectra indicates an absorption peak at 302 nm, thereby confirming both the successful synthesis and remarkable stability of the nanoparticles. The nanoparticles exhibited uniform spherical morphology and contained Fe, O, and N, indicating the synthesis of Fe2O3NPs. Additionally, the Fe2O3NPs formed through biosynthesis demonstrated antimicrobial capabilities againstEscherichia coliandBacillus cereus. The significant anti-migratory potential on MDA-MB 231 human breast cancer cells was observed with lower concentrations of the biosynthesized Fe2O3NPs, and higher concentrations revealed cytotoxic effects on the cells with an IC50of 95.7μg/ml. Stable Fe2O3NPs were synthesized usingMentha spicataaqueous extract, and it revealed antimicrobial activity onE. coliandB. cereus, cytotoxic, anti-proliferative and anti-migratory effect on highly metastatic human breast cancer cell lines.

Underwater bubbling plasma assisted with persulfate activation for the synergistic degradation of tetracycline hydrochloride

The performance and mechanism of persulfate consisting of peroxymonosulfate (PMS) and peroxydisulfate (PDS) activation by underwater bubbling plasma (UBP) for the synergistic removal of tetracycline hydrochloride (TCH) were comparatively investigated. Both PMS and PDS addition significantly promoted the removal of TCH in UBP system, indicating persulfate exhibited highly synergistic effect with UBP. Furthermore, enhancing the persulfate dosage, peak voltage and pulse frequency, as well as reducing initial TCH concentration were favorable for the elimination of TCH. Compared with neutral condition, acidic and alkaline condition were advantageous to TCH removal. The presence of coexisting substances including Cl-, SO42- and humic acid (HA) had an adverse effect on TCH degradation, while Fe2+ could improve the removal of TCH. The degradation of ciprofloxacin and metronidazole proved the applicability for other antibiotics degradation of the reaction system. SO4-·, ·OH, ·O2-, hydrated electrons, O3 and H2O2 were the active substances responsible for TCH removal. The reduction of aqueous O3 concentration and enhancement of H2O2 concentration were observed after persulfate addition. UV-vis spectra and TOC analysis illustrated the addition of PMS or PDS facilitated the degradation and mineralization of TCH. 3D-EEMF spectra visually displayed the degradation process of TCH. Plausible degradation routes were deduced based on LC-MS and the toxicities of TCH and its intermediates were evaluated by Toxicity Estimation Software Tool.

Removal of water pollutants using plant-based nanoscale zero-valent iron: A review

Nanotechnology has been increasingly explored for the treatment of various waste streams. Among different nanoparticles, nanoscale zerovalent iron (nZVI) has been extensively investigated due to its high reactivity and strong reducing power. However, conventional methods for the synthesis of nZVI particles have several limitations and led to the green synthesis of nZVI using plant-based materials. Plant extracts contain various reducing agents that can be used for nZVI synthesis, eliminating the need for toxic chemicals, and reducing energy consumption. Additionally, each plant species used for nZVI synthesis results in unique physicochemical properties of the nanoparticles. This review paper provides an overview of plant-based nZVI particle synthesis, its characteristics, and its application for the removal of different classes of pollutants such as dyes, heavy metals, nutrients, and trace organic pollutants from water. The review shows that continued research on plant-based nZVI particles to fully understand its potential in wastewater treatment, especially for the removal of a wider variety of pollutants, and for improving sustainability and reducing the cost and environmental impact of the process, is necessary.

Molybdenum disulfide co-catalysis boosting nanoscale zero-valent iron based Fenton-like process: Performance and mechanism

The conventional Fenton process has the drawbacks of low efficiency of Fe³⁺/Fe²⁺ conversion, low utilization of H₂O₂, and narrow range of pH. In this paper, molybdenum sulfide (MoS₂) was used as a co-catalyst to boost the nanoscale zero-valent iron (nZVI) based heterogeneous Fenton-like process for the degradation of Rhodamine B (RhB). The catalytic performance, influences of parameters, degradation mechanism, and toxicity of intermediates were explored. Compared with the conventional like-Fenton process, the existence of MoS₂ accelerated the decomposition of H₂O₂ and the RhB degradation rate constant of MoS₂/nZVI/H₂O₂ reached more than six times that of nZVI/H₂O₂. In addition, the effective pH range of MoS₂/nZVI/H₂O₂ was broadened to 9.0 with 84.9% of RhB being removed within 15 min. The co-catalytic system of MoS₂ and nZVI was stable and had high reusability according to the results of four consecutive runs. Quenching tests and electron paramagnetic resonance (EPR) demonstrated that hydroxyl radical (·OH), superoxide anions (·O₂^-), and singlet oxygen (¹O₂) were all involved in MoS₂/nZVI/H₂O₂. Compared with nZVI/H₂O₂ system, MoS₂ not only increased the corrosion of nZVI but also accelerated the conversion of Fe³⁺/Fe²⁺. ECOSAR analysis suggested that the overall acute and chronic toxicity of the degradation products decreased after treatment. Hence, this MoS₂ co-catalytic nZVI based Fenton-like process can be used as a promising alternative for the treatment of organic wastewater.

Effect and mechanism of norfloxacin removal by guava leaf extract in the ZVI/H2O2 system

To overcome the bottlenecks of the conventional zero-valent iron Fenton-like (ZVI/H₂O₂) process, such as low reagent utilization, low applicable pH, and iron sludge contamination, guava leaf extract (GLE) was used as a green promoter to enhance ZVI/H₂O₂ process in this study. Compared with the ZVI/H₂O₂ system, the removal rate and k_obs of norfloxacin by the ZVI/H₂O₂/GLE system were increased by 33.76% and 2.19 times, respectively. The experimental investigation of the mechanism showed that the attack of reactive oxygen species was the main pathway for the removal of pollutants, and three types of reactive oxygen species (¹O₂, O₂^-,·OH) generations in the ZVI/H₂O₂/GLE system were effectively promoted by the introduction of GLE. The reactivity improvement was mainly due to the decrease of pH. At the same time, the chelation of iron ions by GLE promoted the Fe(III)/Fe(II) cycle on the catalyst surface was also a minor mechanism to improve the reactivity. This study provides a crucial reference for the practical application of guava leaf to promote the ZVI/H₂O₂ process in environmental pollution control.

Recent Advances on Membranes for Water Purification Based on Carbon Nanomaterials

Every year the problem of water purification becomes more relevant. This is due to the continuous increase in the level of pollution of natural water sources, an increase in the population, and sharp climatic changes. The growth in demand for affordable and clean water is not always comparable to the supply that exists in the water treatment market. In addition, the amount of water pollution increases with the increase in production capacity, the purification of which cannot be fully handled by conventional processes. However, the application of novel nanomaterials will enhance the characteristics of water treatment processes which are one of the most important technological problems. In this review, we considered the application of carbon nanomaterials in membrane water purification. Carbon nanofibers, carbon nanotubes, graphite, graphene oxide, and activated carbon were analyzed as promising materials for membranes. The problems associated with the application of carbon nanomaterials in membrane processes and ways to solve them were discussed. Their efficiency, properties, and characteristics as a modifier for membranes were analyzed. The potential directions, opportunities and challenges for application of various carbon nanomaterials were suggested.