Mcdowellchambers0935

The aim of the present research is to investigate the efficiency of surface-modified magnetic nanoparticles for photocatalytic degradation of PCBs from transformer oil. Therefore, CMCD-Fe3O4@TiO2 was successfully produced via grafting of carboxymethyl-β-cyclodextrin (CM-β-CD) onto the core-shell titania magnetic nanoparticles surface. The photocatalytic efficiency of CMCD-Fe3O4@TiO2 for degradation of PCBs was systematically evaluated using an experimental design and the process parameters were optimized by response surface methodology (RSM). The central composite design (CCD) with four experimental parameters was used successfully in the modeling and optimization of photocatalytic efficiency in removing PCBs from transformer oil. ANOVA analysis confirmed a high R-squared value of 0.9769 describing the goodness of fit of the proposed model for the significance estimation of the individual and the interaction effects of variables. The optimal degradation yields of PCBs was achieved 83 % at a temperature of 25 °C, time of 16 min, the dosage of the catalyst of 8.35 mg and oil ethanol ratio of 15. These findings encourage the practical use of CM-β-CD-Fe3O4@TiO2 as a promising and alternative photocatalyst on an industrial scale for the cleaning of organic pollutants such as PCBs due to its environmental friendliness, the benefit of magnetic separation and good reusability after five times. Two-dimensional (2D) nanosheet-based nanocomposites have attracted intensive interest owing to the unique electronic and optical properties from their constituent phases and the synergistic effect from the heterojunctions. In this study, an interfacial coupled TiO2/g-C3N4 2D-2D heterostructure has been prepared via in situ growth of ultrathin 2D-TiO2 on dispersed g-C3N4 nanosheets. This strongly coupled 2D-2D TiO2/g-C3N4, different from the weakly bonded 2D-TiO2/g-C3N4 heterostructures produced by mechanical mixing, has unique electronic structures and chemical states due to strong interlayer charge transfer, confirmed by both experimental and theoretical analyses. Significantly enhanced visible-light responses have been observed, indicating a great potential for visible-light induced photosynthesis and photocatalysis. For benzylamine coupling reactions under visible-light irradiation, 80 % yield rate has been achieved, superior to ∼30 % yield rate when adopting either 2D-TiO2 or g-C3N4 structure. The enhanced photocatalytic activity can be attributed to the adequate separation of photo-generated electrons at the strongly coupled 2D-2D heterojunction interfaces. ABT-888 ic50 In this study, superparamagnetic β-CD-MnFe2O4 with a large surface area was synthesized via a facile co-precipitation method, with β-cyclodextrin (β-CD) acting as a coating agent. The as-prepared β-CD-MnFe2O4 exhibited better catalytic performance than bare MnFe2O4 in terms of activating peroxymonosulfate (PMS) to degrade 2,4-dichlorophenol (2,4-DCP) over a broad pH range of 5-11. Electron spin resonance spectroscopy (ESR) and free radical quenching experiments indicate that various active species (SO4-/OH/O2-/1O2) are generated in the β-CD-MnFe2O4/PMS system and that pollutants trapped in the cyclodextrin cavity are quickly degraded. Various reaction parameters of the β-CD-MnFe2O4/PMS system and the stability of β-CD-MnFe2O4 were also investigated. The results indicate that β-CD-MnFe2O4 is promising for use in water purification owing to its excellent magnetic separation and recovery properties and good resistance to humic acid (HA). Metallic 1T phase of MoS2 (1T-MoS2) has aroused great concern for decontamination of heavy metal ions from water. Herein, ultrastable 1T-MoS2 was successfully achieved via a gentle two-stage solvothermal strategy utilizing water and ethanol as solvent for efficient removal of Cr(VI). Notably, nearly 100 % 1T-MoS2 was obtained, and it remained highly stable in air even for 360 days. Electron paramagnetic resonance analysis showed that sulfur vacancies were in situ formed on the 1T/2H mixed phase MoS2 (M-MoS2) under the induction of ethanol, which is critical to promote the transformation of 2H to 1T phase. Molecular dynamic simulation revealed that there was strong interaction between ethanol and MoS2 surface, which could decrease the total energy of MoS2 for strengthening stability of 1T phase. Moreover, 1T-MoS2 shows superior sorption capacity (200.3 mg·g-1) for removal of Cr(VI), twice more than that of M-MoS2 and 2H phase MoS2 under the same condition. Significantly, the stable phase structure of 1T-MoS2 and chromium adsorption capacity still remained even after five cycles of chromium adsorption. The study of Cr(VI) adsorption mechanism revealed that the chromium adsorption was attributed to the undercoordinated Mo(IV) as active site and coupled with redox reaction during removal process. Mixed micelles of linear alkylbenzene sulfonic acid (LAS) and ether sulfate-based surfactants (SLEnS) can be added in household products and cleaning agents. SLEnS with higher ethylene oxide (EO) units in the head groups have economic and environmental advantages. This work aims to assess the influence of the number of EO units in the ecotoxicity of seven variants of SLEnS-LAS micelles (0-50 EO units) in soils. Ecotoxicological tests were carried out to assess emergence and growth of four plants species and reproduction of collembolans. Most of the variants inhibited plants growth at the highest concentrations (1237.5 μg SLEnS kg-1 of soildw). For reproduction, lower number of EO units resulted in EC50 from 924.2 (95 % CL 760.7-1063.4) to 963.2 (95 % CL 676.9-1249.6) μg SLEnS kg-1 of soildw, whereas for higher number of EO units (50 and 30) no inhibition was reported. Based on these results, we suggest that a higher number of EO units contribute to less hazardous formulations, confirming that different designs of surfactants may contribute to changes in the responses of terrestrial organisms. Therefore, we demonstrate that standardized ecotoxicological assays may contribute to more sustainable and effective formulations, when used upstream, prior to manufacture and marketing.