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1.
亚甲基蓝和环丙沙星是水体中2种污染物, 对生态环境有潜在危害. 本文以市政剩余活性污泥为原料, 氯化锌为活化剂热解制备污泥基吸附剂, 研究盐酸酸洗浓度、氯化锌浓度、热解温度、热解时间等对污泥基吸附剂吸附水中亚甲基蓝和环丙沙星性能的影响. 结果表明 (1)污泥基吸附剂对亚甲基蓝的吸附性能随盐酸酸洗浓度的增大而增加, 对环丙沙星的吸附性能则随盐酸酸洗浓度的增大呈先降后增趋势, 两者均在1.500mol·L-1盐酸浓度下取得最优值. (2)污泥基吸附剂对亚甲基蓝和环丙沙星的吸附性能随氯化锌浓度和热解温度的增加呈先升后降趋势, 在氯化锌浓度为4.0mol·L-1、热解温度为500℃时有最优值; 随着热解时间的延长, 污泥基吸附剂对亚甲基蓝和环丙沙星的吸附性能分别在500℃热解70min和80min时有最优值. (3)污泥基吸附剂的最佳制备条件为 氯化锌4.0mol·L-1活化2h、500℃热解70min和80min、1.500mol·L-1盐酸酸洗; 以此制得的污泥基吸附剂对亚甲基蓝和环丙沙星的去除率分别为97.7%和96.4%, 平衡吸附量分别为97.9mg·g-1和3.9mg·g-1, 且污泥基吸附剂对亚甲基蓝和环丙沙星的吸附过程均符合准二级动力学方程. 相似文献
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Srigokul Upadhyayula Vicente Nu?ez Eli M. Espinoza Jillian M. Larsen Duoduo Bao Dewen Shi Jenny T. Mac Bahman Anvari Valentine I. Vullev 《Chemical science》2015,6(4):2237-2251
Cyanine dyes are broadly used for fluorescence imaging and other photonic applications. 3,3′-Diethylthiacyanine (THIA) is a cyanine dye composed of two identical aromatic heterocyclic moieties linked with a single methine, –CH. The torsional degrees of freedom around the methine bonds provide routes for non-radiative decay, responsible for the inherently low fluorescence quantum yields. Using transient absorption spectroscopy, we determined that upon photoexcitation, the excited state relaxes along two parallel pathways producing three excited-state transients that undergo internal conversion to the ground state. The media viscosity impedes the molecular modes of ring rotation and preferentially affects one of the pathways of non-radiative decay, exerting a dominant effect on the emission properties of THIA. Concurrently, the polarity affects the energy of the transients involved in the decay pathways and further modulates the kinetics of non-radiative deactivation. 相似文献
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The chemical equilibrium and reaction kinetic behavior in the synthesis of polyoxymethylene dimethyl ethers(DMMn) were investigated over sulfated titania in order to reveal the decisive factor controlling the reaction. The results showed that the molar ratio of adjacent DMMn products in equilibrium solution had the same value, which depended absolutely on the reaction temperature. Meanwhile, the reactions had the same DMMn products distributions under varied reaction conditions. The equilibrium constants of the related step-wise reactions for DMMn formation were equal, which were calculated based on the bulk compositions of the reaction solution. And thus, the selectivity to DMMn was mainly controlled by the chemical equilibrium, i.e., thermodynamic control. In brief, the present results provide some guidance for future synthesis of DMMn. 相似文献
5.
Sebastian Weske Ramona Schoop Prof. Dr. Konrad Koszinowski 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11310-11316
Trifluoromethylation reactions have recently received increased attention because of the beneficial effect of the trifluoromethyl group on the pharmacological properties of numerous substances. A common method to introduce the trifluoromethyl group employs the Ruppert–Prakash reagent, that is, Si(CH3)3CF3, together with a copper(I) halide. We have applied this method to the trifluoromethylation of aromatic alkynes and used electrospray‐ionization mass spectrometry to investigate the mechanism of these reactions in tetrahydrofuran, dichloromethane, and acetonitrile as well as with and without added 1,10‐phenanthroline. In the absence of the alkyne component, the homoleptic ate complexes [Cu(CF3)2]? and [Cu(CF3)4]? were observed. In the presence of the alkynes RH, the heteroleptic complexes [Cu(CF3)3R]? were detected as well. Upon gas‐phase fragmentation, these key intermediates released the cross‐coupling products R?CF3 with perfect selectivity. Apparently, the [Cu(CF3)3R]? complexes did not originate from homoleptic cuprate anions, but from unobservable neutral precursors. The present results moreover point to the involvement of oxygen as the oxidizing agent. 相似文献
6.
Association and Dissociation of Grignard Reagents RMgCl and Their Turbo Variant RMgCl⋅LiCl 下载免费PDF全文
Christoph Schnegelsberg Sebastian Bachmann Marlene Kolter Thomas Auth Dr. Michael John Prof. Dr. Dietmar Stalke Prof. Dr. Konrad Koszinowski 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(23):7752-7762
Grignard reagents RMgCl and their so‐called turbo variant, the highly reactive RMgCl?LiCl, are of exceptional synthetic utility. Nevertheless, it is still not fully understood which species these compounds form in solution and, in particular, in which way LiCl exerts its reactivity‐enhancing effect. A combination of electrospray‐ionization mass spectrometry, electrical conductivity measurements, NMR spectroscopy (including diffusion‐ordered spectroscopy), and quantum chemical calculations is used to analyze solutions of RMgCl (R=Me, Et, Bu, Hex, Oct, Dec, iPr, tBu, Ph) in tetrahydrofuran and other ethereal solvents in the absence and presence of stoichiometric amounts of LiCl. In tetrahydrofuran, RMgCl forms mononuclear species, which are converted into trinuclear anions as a result of the concentration increase experienced during the electrospray process. These trinuclear anions are theoretically predicted to adopt open cubic geometries, which remarkably resemble structural motifs previously found in the solid state. The molecular constituents of RMgCl and RMgCl?LiCl are interrelated via Schlenk equilibria and fast intermolecular exchange processes. A small portion of the Grignard reagent also forms anionic ate complexes in solution. The abundance of these more electron‐rich and hence supposedly more nucleophilic ate complexes strongly increases upon the addition of LiCl, thus rationalizing its beneficial effect on the reactivity of Grignard reagents. 相似文献
7.
Gated Channels and Selectivity Tuning of CO2 over N2 Sorption by Post‐Synthetic Modification of a UiO‐66‐Type Metal–Organic Framework 下载免费PDF全文
Alexander Kronast Sebastian Eckstein Dr. Peter T. Altenbuchner Dr. Konrad Hindelang Dr. Sergei I. Vagin Prof. Dr. Bernhard Rieger 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(36):12800-12807
The highly porous and stable metal–organic framework (MOF) UiO‐66 was altered using post‐synthetic modifications (PSMs). Prefunctionalization allowed the introduction of carbon double bonds into the framework through a four‐step synthesis from 2‐bromo‐1,4‐benzenedicarboxylic acid; the organic linker 2‐allyl‐1,4‐benzenedicarboxylic acid was obtained. The corresponding functionalized MOF (UiO‐66‐allyl) served as a platform for further PSMs. From UiO‐66‐allyl, epoxy, dibromide, thioether, diamine, and amino alcohol functionalities were synthesized. The abilities of these compounds to adsorb CO2 and N2 were compared, which revealed the structure–selectivity correlations. All synthesized MOFs showed profound thermal stability together with an increased ability for selective CO2 uptake and molecular gate functionalities at low temperatures. 相似文献
8.
Mark Brouar Helen Chadwick Sean D. S. Gordon Cornelia G. Hei Balazs Hornung Bethan Nichols Jacek K?os Pablo G. Jambrin F. Javier Aoiz 《化学物理学报》2020,33(2):217-233
本文对NO(X)-Xe碰撞系统在碰撞能量为519 cm-1,测量了完全?-双峰分解的微分截面和碰撞引起的旋转准直力矩. 同时结合初始量子态选择,使用六极杆的非均质电场,借助量子态分辨的测量,利用(1+1'')共振增强的多光子电离和速度离子成像. 结果显示,微分截面以及偏振相关的微分截面均显示与从头算势能面上进行的量子力学散射计算[J. K?os etal. J. Chem. Phys. 137, 014312 (2012)]一致. 通过与准经典轨迹、硬壳势能的量子力学散射以及运动近端模型的比较,评估了势能对所测微分截面和碰撞引起的旋转准直力矩的影响. 相似文献
9.
Mnich Konrad Lazarek Mateusz Stefanski Andrzej Perlikowski Przemyslaw 《Meccanica》2022,57(8):1955-1973
Meccanica - This paper presents the experimental identification of the friction force in the inerter with constant and variable inertance. The change of intertance is possible due to the... 相似文献
10.