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Precisely measuring the adsorption capability of materials towards toxic heavy metal ions in aqueous solution is essential for the synthesis of effective novel adsorbents. Nonetheless, no such technology is available that can accurately measure the adsorption capability at arbitrary adsorption sites. In the present study, we employed an artificial intelligence route to predict the adsorption capability of two-dimensional niobium carbide (Nb2CTx) at arbitrary adsorption sites for lead (Pb(II)) and cadmium (Cd(II)) ions. A crystal graph convolution neural network (CGCNN) model was applied to predict the adsorption capability of Nb2CTx with the results indicating that Pb(II) ions had a higher adsorption energy than Cd(II) ions with a mean absolute error and root-mean-squared error less than 0.09 eV and 0.16 eV, respectively. The proposed CGCNN model has a similar prediction to the ab initio DFT calculations, yet significantly fast and economical. Finally, the adsorption capability of Nb2CTx synthesized using a fluorine-free route was also experimentally verified, and the results were consistent with DFT calculations and CGCNN predictions. In addition, the synthesized Nb2CTx exhibited a higher recycling potential over five successive runs. Collectively, these findings indicated that the proposed technique is highly efficient in investigating the adsorption performance of materials and can be further extended for use in the removal of other hazardous pollutants from aqueous environments. [ABSTRACT FROM AUTHOR]

The technical papers published in 2019 regarding wastewater treatment and microbial films were classified into two categories: biofilm and biofilm reactors. The biofilm category includes biofilm formation, biofilm consortia, bacterial signals, biofouling, extracellular polymeric substances, and biofilm membrane bioreactors. The biofilm reactors category provides recent information on rotating biological contactors, fluidized‐bed biofilm reactors, integrated fixed‐film activated sludge, moving‐bed biofilm reactors, packed‐bed biofilm reactors, sequencing biofilm batch reactors, and trickling filters. [ABSTRACT FROM AUTHOR]

The influence of the cationic sites on the luminescent properties of Eu3+ in Gd2BaZnO5 has been investigated by the site-selective laser excitation and emission spectroscopy along with luminescence decays. It has been revealed that the Eu3+ ions occupy two cationic sites. The Stark energy levels of Eu3+ at two different sites in Gd2BaZnO5 were assigned from selectively excited emission spectra at 10 K. The energy transfer between two crystallographic Eu3+ centers in Gd2BaZnO5 is detected and discussed. Excitation spectrum in the UV region and UV-excited emission spectrum were also performed, which indicate that an efficient energy transfers from the host and directly Gd3+ to Eu3+ ions in Gd2BaZnO5. [ABSTRACT FROM AUTHOR]

Dysprosium-doped oxyfluoride glasses and nanocrystalline glass ceramics have been synthesized and studied by x-ray diffraction, absorption, and visible and near-infrared emission spectra. The samples emit intense white light when populating the 4F9/2 level with a 451 nm laser light and, from the visible emission spectra, yellow to blue intensity ratios and chromaticity color coordinates have been calculated and their relative variation have been discussed based on the concentration of Dy3+ ions and the heat treatment conditions used to prepare the glass ceramics. Infrared emission has also been observed in glasses and glass ceramics after laser excitation at 800 nm, showing bands at 1.33 and 1.67 μm, useful for optical amplification in fiber amplifiers. [ABSTRACT FROM AUTHOR]