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Novel quaternary ammonium/magnetic graphene oxide composites (M-PAS-GO) that efficiently remove Cr(VI) ions were fabricated through the introduction of the (3-aminopropyl) triethoxysilane and Fe3O4 nanoparticles on the surface of GO, and then modified with n-butyl bromide. The fabricated M-PAS-GO was comprehensively characterized by SEM, TEM, EDX, XRD, Raman spectroscopy and FTIR, and the results manifest that the quaternary ammonium group was introduced onto the surface of GO. Under the reaction conditions of pH 3.20, temperature of 25 °C and M-PAS-GO dosage of 0.01 g/50 mL, 90% of 10 mg/L Cr(VI) ions were removed from the solution within 20 min. The kinetics study indicates that the adsorption process followed the pseudo-second-order model and was surface reaction-controlled. The thermodynamic parameters calculated from temperature-dependent adsorption isotherms suggest that the adsorption process was an exothermic and spontaneous process. The maximum adsorption capacities of Cr(VI) ions on M-PAS-GO composites calculated by the Langmuir model were 46.48 mg/g. Moreover, the reusability and stability of M-PAS-GO demonstrates its economic sustainability. This study suggests that M-PAS-GO is a potential candidate adsorbent for the separation of Cr(VI) from wastewater. [ABSTRACT FROM AUTHOR]

This paper presents recent development and applications of thermal lens microscopy (TLM) and beam deflection spectrometry (BDS) for the analysis of water samples and sea ice. Coupling of TLM detection to a microfluidic system for flow injection analysis (μFIA) enables the detection of microcystin-LR in waters with a four samples/min throughput (in triplicate injections) and provides an LOD of 0.08 µg/L which is 12-times lower than the MCL for microcystin-LR in water. μFIA-TLM was also applied for the determination of total Fe and Fe(II) in 3 µL samples of synthetic cloudwater. The LODs were found to be 100 nM for Fe(II) and 70 nM for total Fe. The application of µFIA-TLM for the determination of ammonium in water resulted in an LOD of 2.3 µM for injection of a 5 µL sample and TLM detection in a 100 µm deep microfluidic channel. For the determination of iron species in sea ice, the BDS was coupled to a diffusive gradient in the thin film technique (DGT). The 2D distribution of Fe(II) and total Fe on DGT gels provided by the BDS (LOD of 50 nM) reflected the distribution of Fe species in sea ice put in contact with DGT gels. [ABSTRACT FROM AUTHOR]

Carbon source precursors for high-grade, clean, and low-carbon refractories were obtained by in situ exfoliation of flake graphite (FG) and phenol–formaldehyde resin (PF) composites with three-roll milling (TRM) for the fabrication of graphite nanoplatelets. In addition, by using Ni(NO3)2·6H2O as a catalyst in the pyrolysis process, multidimensional carbon nanostructures were obtained with coexisting graphite nanoplatelets (GNPs), glassy carbon (GC), and carbon nanotubes (CNTs). The resulting GNPs (exfoliated 16 times) had sizes of 10–30 μm, thicknesses of 30–50 nm, and could be uniformly dispersed in GC from the PF pyrolysis. Moreover, Ni(NO3)2·6H2O played a key role in the formation and growth of CNTs from a catalytic pyrolysis of partial PF with the V–S/tip growth mechanisms. The resulting multidimensional carbon nanostructures with GNPs/GC/CNTs are attributed to the shear force of the TRM process, pyrolysis, and catalytic action of nitrates. This method reduced the production costs of carbon source precursors for low-carbon refractories, and the precursors exhibited excellent performances when fabricated on large scales. [ABSTRACT FROM AUTHOR]

Emerging construction practices such as building information modelling (BIM), prefabrication construction, green building, and integrated project delivery methods are gaining momentum in China, with great potential due to the size of its construction market. Through this, the sustainability level of China's construction industry is expected to be enhanced from the economic, social and environmental perspectives. So far, there has been limited understanding of how BIM, as a digital technology, would affect other contemporary sustainable construction practices from the industry professionals' point of view. Limited studies have been carried out to study the regional differences of these contemporary sustainable practices in China. This study adopted a questionnaire-based approach targeting industry professionals from three different metropolitan cities (Shanghai, Guangzhou, and Wenzhou).The follow-up comprehensive statistical analysis revealed that with regards to these contemporary sustainable construction practices, survey participants held much varied views on the growth of renovation projects, traditional Design–Bid–Build delivery, and conventional on-site construction methods. These three types were also generally perceived to have weak correlation with BIM application. Regional comparison further conveyed information on differences in perceptions among survey respondents from these three cities. For example, respondents from Wenzhou perceived more positive effects of BIM use in conventional construction projects. This research addressed the inter-correlation among these emerging sustainable construction practices, as well as the regional differences in China's construction market. The findings provide insights and the big picture for both governmental authorities and industry practitioners on the latest sustainable practices of China's construction industry. Recommendations are also offered towards improved economic, social and environmental sustainability performance for construction projects in the country. [ABSTRACT FROM AUTHOR]