TY - JOUR A1 - Zietzschmann, F. A1 - Dittmar, S. A1 - Splettstößer, L. A1 - Hunsicker, J. A1 - Dittmann, Daniel A1 - Meinel, F. A1 - Rößler, A. A1 - Metzger, S. A1 - Jekel, M. A1 - Ruhl, A. S. T1 - Fast empirical lab method for performance projections of large-scale powdered activated carbon re-circulation plants JF - Chemosphere N2 - Powdered activated carbon (PAC) for organic micro-pollutant (OMP) removal can be applied effectively on wastewater treatment plant (WWTP) effluents by using re-circulation schemes, accumulating the PAC in the system. This technique is complex because several factors are unknown: (i) the PAC concentration in the system, (ii) specific and average contact times of PAC particles, and (iii) PAC particle loadings with target compounds/competing water constituents. Thus, performance projections (e.g. in the lab) are very challenging. We sampled large-scale PAC plants with PAC sludge re-circulation on eight different WWTPs. The PAC plant-induced OMP removals were notably different, even when considering PAC concentrations in proportion to background organic sum parameters. The variability is likely caused by differing PAC products, varying water composition, differently effective plant/re-circulation operation, and variable biodegradation. Plant PAC samples and parts of the PAC plant influent samples were used in laboratory tests, applying multiples (0.5, 1, 2, 4) of the respective large-scale “fresh” PAC doses, and several fixed contact times (0.5, 1, 2, 4, 48 h). The aimwas to empirically identify suitable combinations of lab PAC dose (as multiples of the plant PAC dose) and contact time, which represent the PAC plant performances in removing OMPs (for specific OMPs at single locations, and for averages of different OMPs at all locations). E.g., for five well adsorbing, little biodegradable OMPs, plant performances can be projected by using a lab PAC dose of twice the respective full-scale PAC dose and 4 h lab contact time (standard deviation of 13 %-points). KW - Adsorption KW - Powdered activated carbon KW - Organic micro-pollutant KW - Trace organic contaminant PY - 2019 DO - https://doi.org/10.1016/j.chemosphere.2018.10.055 VL - 215 SP - 563 EP - 573 PB - Elsevier Ltd. AN - OPUS4-46957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gnutzmann, Tanja A1 - Kahlau, R. A1 - Scheifler, S. A1 - Friedrichs, Ferdinand A1 - Rössler, A. A1 - Rademann, Klaus A1 - Emmerling, Franziska T1 - Crystal growth rates and molecular dynamics of nifedipine JF - CrystEngComm N2 - The unusually fast crystallization of the organic compound nifedipine has been investigated in detail using different solutions as precursors for the formation of the initial glassy nifedipine films. Starting from these amorphous films the crystallization process was investigated by time-resolved light microscopy at different temperatures around Tg of nifedipine. In all studied cases (acetone, acetonitrile, ethyl acetate, dichloromethane, tetrahydrofuran) the measured mean crystallization rates are, on average, 10000 times higher than rates reported in previous studies. Such high rates cannot be explained by a classical diffusional crystal growth mechanism of nifedipine. Instead, nifedipine shows a strong propensity for diffusionless growth. Solvent assisted or solvent induced preordering of the glassy modification is suggested to be the most probable driving force behind these fast crystallization processes. The nifedipine crystallization rates can be controlled not only by specific solvent–molecule interactions but also by temperature. Below 40 °C, the temperature dependence of the rates is generally small. Above 40 °C, a slowing down of the crystallization rates with increasing temperatures indicates a kinetic competition between different polymorphs. The molecular dynamics of nifedipine molecules in the amorphous phase as well as the relaxation times are studied by dielectric measurements. The dielectric data corroborate the inherently strong propensity of nifedipine to crystallize diffusionlessly under all conditions. KW - Fast crystallization KW - Diffusionless growth KW - Polymorphism KW - Nifedipine KW - Preordering KW - Raman spectroscopy KW - Dielectric spectroscopy PY - 2013 DO - https://doi.org/10.1039/c2ce26911b SN - 1466-8033 VL - 15 IS - 20 SP - 4017 EP - 4202 CY - London, UK AN - OPUS4-28307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Westendarp, A. A1 - Reschke, T. A1 - Kühne, Hans-Carsten A1 - Maultzsch, Matthias A1 - Dauberschmidt, C. A1 - Rößler, G. T1 - Instandsetzung von Wasserbauwerken aus Beton; Teil 2 JF - Beton KW - Instandsetzung KW - Beton KW - Wasserbau KW - Spritzmörtel KW - Geringer fester Beton KW - ZTV-LB 219 PY - 2006 SN - 0005-9846 VL - 55 IS - 3 SP - 94 EP - 100 PB - Verlag Bau + Technik CY - Erkrath AN - OPUS4-12347 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Westendarp, A. A1 - Reschke, T. A1 - Kühne, Hans-Carsten A1 - Maultzsch, Matthias A1 - Dauberschmidt, C. A1 - Rößler, G. T1 - Instandsetzung von Wasserbauwerken aus Beton; Teil 1 JF - Beton KW - Instandsetzung KW - Beton KW - Wasserbau KW - Spritzmörtel KW - Geringer fester Beton KW - ZTV-LB 219 PY - 2006 SN - 0005-9846 VL - 56 IS - 1+2 SP - 22 EP - 29 PB - Verlag Bau + Technik CY - Erkrath AN - OPUS4-12348 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Schießl, P. A1 - Meng, Birgit A1 - Rößler, G. A1 - Schröder, P. A1 - Schwamborn, B. A1 - Spengler, A. A1 - Wallner, B. ED - Zilch, K. ED - Diederichs, C.J. ED - Katzenbach, R. ED - Beckmann, K. J. T1 - Konstruktiver Ingenieurbau und Hochbau T2 - Handbuch für Bauingenieure - Technik, Organisation und Wirtschaftlichkeit KW - Baustoffe KW - Beton KW - Bindemittel KW - Zement PY - 2012 SN - 978-3-642-14449-3 IS - Kap. 3.1 SP - 966 EP - 1038 PB - Springer ET - 2. Aufl. AN - OPUS4-25844 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kahlau, R. A1 - Gnutzmann, Tanja A1 - Emmerling, Franziska A1 - Rademann, K. A1 - Rössler, E.A. T1 - Quinaldine: Accessing two crystalline polymorphs via the supercooled liquid JF - The journal of chemical physics N2 - Quinaldine (2-methyl quinoline) is a liquid at room temperature, which can be supercooled to reach finally the glassy state. By heating the glass above the glass transition temperature Tg = 180 K the sample performs two subsequent transitions into, likewise, dielectrically active phases. Thus, the reorientational relaxations of these phases as well as the kinetics of the phase transitions can be tracked in a highly resolved way by dielectric spectroscopy. X-ray diffraction analysis clearly shows two structurally different crystalline phases in addition to the supercooled liquid. Calorimetric measurements support the notion of first order phase transitions, occurring irreversibly in the supercooled regime, and suggest that the intermediate crystalline phase is metastable, too. Analyzing the quite distinct dielectric relaxation strengths, we discuss the possible nature of the two crystalline phases. Additionally, a very similar behavior to quinaldine is observed for 3-methyl quinoline, indicating a broad field of polymorphism among the quinoline derivatives. KW - Calorimetry KW - Dielectric liquids KW - Dielectric relaxation KW - Glass transition KW - Liquid structure KW - Organic compounds KW - Polymorphism KW - Supercooling KW - X-ray diffraction PY - 2012 DO - https://doi.org/10.1063/1.4738583 SN - 0021-9606 SN - 1089-7690 VL - 137 IS - 5 SP - 054505-1 - 054505-10 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-26347 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -