Polybrominated diphenyl ethers (PBDPEs) and, for the first time, methoxy-polybrominated diphenyl ethers (MeO-PBDPEs) have been positively identified and quantified in various biotic samples including herring, salmon, seal, man (only PBDPEs), and commercial fish oils. The presence of these compounds was confirmed in the above samples by mass spectra and accurate mass determinations and verified by comparisons to gas chromatographymass spectrometry (GC-MS) of available reference material. Concentrations were measured by GC-MS and found to vary from the low to moderate nanogram per gram of lipid range, with the highest levels in seal blubber and salmon muscle. Data for the studied samples suggest that these compounds bioconcentrate. The presence of polychlorinated diphenyl ethers and methoxy polychlorinated diphenyl ethers was indicated in a screened seal tissue. Potential environmental sources of the MeO-PBDPEs are discussed.

Polybrominated diphenyl ethers (PBDEs) are widely used as additive flame retardants in, for example, textiles, computers, television sets, and other electrical appliances. PBDEs are ubiquitous environmental contaminants, present also in humans. The environmental levels of the PBDEs are, however, still in general lower than those of polychlorinated biphenyls (PCBs). However, while the levels of PCBs generally are decreasing, those of the PBDEs are increasing in, for example, human milk. In the present study 32 individual PBDE congeners were synthesized and characterized. Physicochemical parameters including melting points and UV, 1H NMR, and mass spectra are reported. Twenty-nine monobrominated to heptabrominated diphenyl ethers were synthesized by the coupling between four diphenyliodonium salts and nine phenolates. One tetrabromodiphenyl ether and two hexabromodiphenyl ethers were synthesized by bromination of two different PBDEs. Twenty-one of the PBDEs and two of the iodonium salts, 2,2‘,4,4‘-tetrabromodiphenyliodonium chloride and 3,3‘,4,4‘-tetrabromodiphenyliodonium chloride, are to the authors' knowledge described for the first time. These synthesized reference compounds will aid in the identification and quantification of PBDEs present in environmental samples and will allow further assessment of PBDE toxicity.

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Reduced graphene oxide-supported nanoscale zero-valent iron (nZVI/rGO) composites were prepared by chemical deposition method and were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, N2-sorption and X-ray photoelectron spectroscopy (XPS). Operating parameters for the removal process of Pb(II) ions, such as temperature (20–40 °C), pH (3–5), initial concentration (400–600 mg/L) and contact time (20–60 min), were optimized using a quadratic model. The coefficient of determination (R2 > 0.99) obtained for the mathematical model indicates a high correlation between the experimental and predicted values. The optimal temperature, pH, initial concentration and contact time for Pb(II) ions removal in the present experiment were 21.30 °C, 5.00, 400.00 mg/L and 60.00 min, respectively. In addition, the Pb(II) removal by nZVI/rGO composites was quantitatively evaluated by using adsorption isotherms, such as Langmuir and Freundlich isotherm models, of which Langmuir isotherm gave a better correlation, and the calculated maximum adsorption capacity was 910 mg/g. The removal process of Pb(II) ions could be completed within 50 min, which was well described by the pseudo-second order kinetic model. Therefore, the nZVI/rGO composites are suitable as efficient materials for the advanced treatment of Pb(II)-containing wastewater.

This paper presents a review on recent progress in quantitative structure-property relationship (QSPR) studies of surfactants and applications of various molecular descriptors. QSPR studies on critical micelle concentration (cmc) and surface tension (γ) of surfactants are introduced. Studies on charge distribution in ionic surfactants by quantum chemical calculations and its effects on the structures and properties of the colloids of surfactants are also reviewed. The trends of QSPR studies on cloud point (for nonionic surfactants), biodegradation potential and some other properties of surfactants are evaluated.

A silica-based monolithic capillary column was prepared via a sol-gel process. The continuous skeleton and large through-pore structure were characterized by scanning electron microscopy (SEM). The native silica monolith has been successfully employed in the electrochromatographic separation of b-blockers and alkaloids extracted from traditional Chinese medicines (TCMs). Column efficiencies greater than 250 000 plates/m for capillary electrochromatography (CEC) separation of basic compounds were obtained. It was observed that retention of basic pharmaceuticals on the silica monolith was mainly contributed by a cation-exchange mechanism. Other retention mechanisms including reversed-phase and normal-phase mechanisms and electrophoresis of basic compounds also played a role in separation. A comparison of the differences between CEC and capillary zone electrophoresis (CZE) separation was also discussed.

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Engineered nanoscale zero-valent metals (NZVMs) representing the forefront of technologies have been considered as promising materials for environmental remediation and antimicrobial effect, due to their high reducibility and strong adsorption capability. This review is focused on the methodology for synthesis of bare NZVMs, supported NZVMs, modified NZVMs, and bimetallic systems with both traditional and green methods. Recent studies have demonstrated that self-assembly methods can play an important role for obtaining ordered, controllable, and tunable NZVMs. In addition to common characterization methods, the state-of-the-art methods have been developed to obtain the properties of NZVMs (e.g., granularity, size distribution, specific surface area, shape, crystal form, and chemical bond) with the resolution down to subnanometer scale. These methods include spherical aberration corrected scanning transmission electron microscopy (Cs-corrected STEM), electron energy-loss spectroscopy (EELS), and near edge X-ray absorption fine structure (NEXAFS). A growing body of experimental data has proven that nanoscale zero-valent iron (NZVI) is highly effective and versatile. This article discusses the applications of NZVMs to treatment of heavy metals, halogenated organic compounds, polycyclic aromatic hydrocarbons, nutrients, radioelements, and microorganisms, using both ex situ and in situ methods. Furthermore, this paper briefly describes the ecotoxicological effects for NZVMs and the research prospects related to their synthesis, modification, characterization, and applications.