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Antibiotic abuse, particularly the excessive use of tetracycline (TC), a drug with significant environmental risk, has gravely harmed natural water bodies and even posed danger to human health. In this study, a three-dimensional self-supported MoS2/MXene nanohybrid with an expanded layer spacing was synthesized via a facile one-step hydrothermal method and used to activate peroxydisulfate (PDS) for the complete degradation of TC. The results showed that a stronger •OH signal was detected in the aqueous solution containing MoS2/MXene, demonstrating a superior PDS activation effect compared to MoS2 or Ti3C2TX MXene alone. Under the conditions of a catalyst dosage of 0.4 g/L, a PDS concentration of 0.4 mM, and pH = 5.0, the MoS2/MXene/PDS system was able to fully eliminate TC within one hour, which was probably due to the presence of several reactive oxygen species (ROS) (•OH, SO4•−, and O2•−) in the system. The high TC degradation efficiency could be maintained under the influence of various interfering ions and after five cycles, indicating that MoS2/MXene has good anti-interference and reusability performance. Furthermore, the possible degradation pathways were proposed by combining liquid chromatography–mass spectrometry (LC-MS) data and other findings, and the mechanism of the MoS2/MXene/PDS system on the degradation process of TC was elucidated by deducing the possible mechanism of ROS generation in the reaction process. All of these findings suggest that the MoS2/MXene composite catalyst has strong antibiotic removal capabilities with a wide range of application prospects. [ABSTRACT FROM AUTHOR]

Transition metals and their oxide compounds exhibit excellent chemical reactivity; however, their easy agglomeration and high cost limit their catalysis applications. In this study, an interpolation structure of a Myriophyllum verticillatum L. biochar-supported Mn/Mg composite (Mn/Mg@MV) was prepared to degrade triphenyl phosphate (TPhP) from wastewater through the activating periodate (PI) process. Interestingly, the Mn/Mg@MV composite showed strong radical self-producing capacities. The Mn/Mg@MV system degraded 93.34% TPhP (pH 5, 10 μM) within 150 min. The experimental results confirmed that the predominant role of IO3· and the auxiliary ·OH jointly contributed to the TPhP degradation. In addition, the TPhP pollutants were degraded to various intermediates and subsequent Mg mineral phase mineralization via mechanisms like interfacial processes and radical oxidation. DFT theoretical calculations further indicated that the synergy between Mn and Mg induced the charge transfer of the carbon-based surface, leading to the formation of an ·OH radical-enriched surface and enhancing the multivariate interface process of ·OH, IO3, and Mn(VII) to TPhP degradation, resulting in the further formation of Mg PO4 mineralization. [ABSTRACT FROM AUTHOR]

Microwave-absorbing materials have attracted extensive attention due to the development of electronic countermeasures. In this study, novel nanocomposites with core–shell structures based on the core of Fe-Co nanocrystals and the shell of furan methylamine (FMA)-modified anthracite coal (Coal-F) were designed and fabricated. The Diels-Alder (D-A) reaction of Coal-F with FMA creates a large amount of aromatic lamellar structure. After the high-temperature treatment, the modified anthracite with a high degree of graphitization showed an excellent dielectric loss, and the addition of Fe and Co effectively enhanced the magnetic loss of the obtained nanocomposites. In addition, the obtained micro-morphologies proved the core–shell structure, which plays a significant role in strengthening the interface polarization. As a result, the combined effect of the multiple loss mechanism promoted a remarkable improvement in the absorption of incident electromagnetic waves. The carbonization temperatures were specifically studied through a setting control experiment, and 1200 °C was proved to be the optimum parameter to obtain the best dielectric loss and magnetic loss of the sample. The detecting results show that the 10 wt.% CFC-1200/paraffin wax sample with a thickness of 5 mm achieves a minimum reflection loss of −41.6 dB at a frequency of 6.25 GHz, indicating an excellent microwave absorption performance. [ABSTRACT FROM AUTHOR]

Highlights: nZVI/MXene@CNTs with a three-dimensional intercalation structure was successfully synthesized. nZVI/MXene@CNTs exhibited a high adsorption and catalytic oxidation capacity for As(III). nZVI/MXene@CNTs showed good anti-interference ability. nZVI/MXene@CNTs possessed excellent recyclability and reusability. Transition metal compounds demonstrated good performance in the removal of environmentally harmful contaminants, such as arsenic, while the aggregation propensity and poor chemical stability should be noticed. In this study, the nZVI/MXene@CNTs was adequately prepared by liquid reduction precipitation method for adsorption and oxidation of As(III) from the aqueous solution. The results of batch removal experiments showed that the maximum removal capacity of the nZVI/MXene@CNTs for As(III) was 443.32 mg/g with the pH = 3.0 at 25 °C. The effects of initial pH, dosage of materials and ionic strength on As(III) removal were explored. According to the various characterization analyses, the most plausible mechanisms of As(III) removal were the surface complexation, solid phase precipitation and the catalytic oxidation by the •OH. Furthermore, the nZVI/MXene@CNTs could be readily activated and reused via leaching with 0.1 M NaOH solution, due to the three-dimensional mesh intercalation structure. Therefore, it is a potential nanocomplex for removing and recovering As(III) from water with excellent capacity and environmental friendliness. [ABSTRACT FROM AUTHOR]

Water pollution has caused the ecosystem to be in a state of imbalance for a long time. It has become a major global ecological and environmental problem today. Solving the potential hidden dangers of pollutants and avoiding unauthorized access to resources has become the necessary condition and important task to ensure the sustainable development of human society. To solve such problems, this review summarizes the research progress of nanomaterials in the field of water aimed at the treatment of water pollution and the development and utilization of new energy. The paper also tries to seek scientific solutions to environmental degradation and to create better living environmental conditions from previously published cutting edge research. The main content in this review article includes four parts: advanced oxidation, catalytic adsorption, hydrogen, and oxygen production. Among a host of other things, this paper also summarizes the various ways by which composite nanomaterials have been combined for enhancing catalytic efficiency, reducing energy consumption, recycling, and ability to expand their scope of application. Hence, this paper provides a clear roadmap on the status, success, problems, and the way forward for future studies. [ABSTRACT FROM AUTHOR]

A constructed wetland system, consisting of a surface-flow wetland cell connected in series with three vertical subsurface-flow wetland cells, was tested for treatment of domestic sewage from rural families in southern China. Diatomite, vermiculate, zeolite and hydrotalcite, were used, respectively, as filler adsorbents in the sequenced subsurface-flow cells for adsorption of organic, cationic and anionic pollutants. Selected trees, shrubs and annual herbs were planted to form a wetland plant community. The total treatment capacity, hydraulic loading rate and water retention time were 2 m3/d, 0.5 m/d and 48 h, respectively. Experimental data obtained from a year operation confirmed that the treatment process followed the dynamic pathway of pollutant transformation. The constructed system was effective to remove TSS, CODCr and BOD5 and their effluent concentrations met the first grade of the discharge standards legislated in China. The removal rates of TN, NH3-N and TP were relatively lower, and their effluent concentrations fell within the range between the first and second grade of the standards. An increase in initial pollutant loading and a decrease in temperature in winter caused apparent accumulation of TN, NH3-N and TP in the system. Discharge of sludge at adequate intervals was shown to be effective to enhance the treatment efficiency. [ABSTRACT FROM AUTHOR]