Utilizing UV-LED pulse width modulation on TiO2 advanced oxidation processes to enhance the decomposition efficiency of pharmaceutical micropollutants

The final publication is available at Elsevier via https://doi.org/10.1016/j.cej.2018.12.065. © 2018 This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The presence of pharmaceutical and personal care products (PPCPs) in aquatic systems has been a growing cause for concern. Advanced oxidation processes such as UV/TiO2 (ultraviolet light/titanium dioxide) can break down PPCPs into smaller constituents, reducing the pharmaceutical activity. However, this process is limited by low photonic efficiency under UV systems. Controlled periodic illumination (CPI) is a promising solution to overcome the issues concerning low photonic efficiencies. Using a CPI controlled UV-LED/TiO2 process, a mixture of eighteen PPCP compounds were analyzed for their degradation removal on porous titanium – titanium dioxide (PTT) substrates. The kinetic rate constants of PPCPs may be analyzed using multiple regression analysis with parameters such as net charge at experimental pH, solubility, and molecular weight. Negatively charged PPCP compounds were found to have the highest removal compared to neutral and positively charged compounds due to electrostatic attraction forces. Decreasing the duty cycle under CPI or the UV-LED illumination period did not significantly change the individual and cumulative PPCP compound removal, suggesting that the CPI controlled UV-LED/TiO2 processes using PTT substrates were effective in reducing energy requirements without sacrificing removal performance.Natural Sciences and Engineering Research Council [STPGP430654-12]Schwartz-Resiman FoundationWaterloo-Technion Research Co-operation Progra

Response of broadleaved evergreen Mediterranean forest vegetation to fire disturbance during the Holocene: insights from the peri-Adriatic region

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Probing warm dense lithium by inelastic X-ray scattering

One of the grand challenges of contemporary physics is understanding strongly interacting quantum systems comprising such diverse examples as ultracold atoms in traps, electrons in high-temperature superconductors and nuclear matter(1). Warm dense matter, defined by temperatures of a few electron volts and densities comparable with solids, is a complex state of such interacting matter(2). Moreover, the study of warm dense matter states has practical applications for controlled thermonuclear fusion, where it is encountered during the implosion phase(3), and it also represents laboratory analogues of astrophysical environments found in the core of planets and the crusts of old stars(4,5). Here we demonstrate how warm dense matter states can be diagnosed and structural properties can be obtained by inelastic X-ray scattering measurements on a compressed lithium sample. Combining experiments and ab initio simulations enables us to determine its microscopic state and to evaluate more approximate theoretical models for the ionic structure