粉末活性炭吸附水中氯苯的动力学研究

为了解粉末活性炭(PAC)对水中氯苯的吸附性能,研究了4种PAC对水中氯苯的吸附动力学,并对4种PAC的物理特征及孔径分布进行了分析.结果表明:4种PAC均具有较广的孔径分布,其对氯苯的平衡吸附量随比表面积和孔容积的增大而增大.PAC对氯苯吸附速率很快,5 min吸附量可达到平衡时的80%以上,30 min后吸附基本达到平衡.假二级和假三级动力学模型均能较好地描述吸附过程,假二级模型更适合描述2 h以内的吸附过程,假三级模型适合描述吸附时间大于2 h的吸附过程.     

Fe-Mn-CeOx/AC@CNTs催化剂低温协同去除NO和氯苯

以活性炭@碳纳米管（AC@CNTs）为载体，通过浸渍法制备了Mn-CeOx/AC@CNTs催化剂，并考察了铁物种的引入对Mn-CeOx/AC@CNTs催化剂同时去除一氧化氮（NO）和氯苯（CB）活性的影响。利用SEM、XRD、Raman、FTIR、XPS、H2-TPR等方法对催化剂的理化性质进行了表征。结果表明，Mn物种进入CeO2的晶格中形成Mn-Ce固溶体促进氧空位的生成，而催化剂表面存在丰富的C—H基团和含氧基团有利于提高催化剂的低温催化活性。与Mn-CeOx(1:7)/AC@CNTs（n(Mn):n(Ce)=1:7）催化剂相比，Fe-Mn-CeOx(1:7)/AC@CNTs催化剂表面吸附氧的含量和酸位点数量显著增加，使其具有良好的氧化还原性能和表面酸性。Fe-Mn-CeOx(1:7)/AC@CNTs催化剂在整个温度窗口表现出最高的催化活性，其中，在225～300 ℃范围内，NO转化率达到90%以上，300 ℃时，CB转化率>90%。此外，当CB存在时，300 ℃时，Fe-Mn-CeOx(1:7)/AC@CNTs催化剂的NO转化率依然能达到95%。     

Determination of the kinetics of chlorobenzene nitration using a homogeneously continuous microflow

The nitration of chlorobenzene with concentrated mixed acids is a fast and highly exothermic process, which suffers from considerable mass transfer resistance and poor heat transfer rates. The reaction kinetics has not been thoroughly reported before. In this work, a continuous-flow microreactor system and a homogeneous reaction condition were proposed to obtain accurate chlorobenzene nitration kinetics parameters at high mixed acid concentrations. A general model for predicting the observed reaction rate constants was established. With a new method for estimating the equilibria associated with HNO₃ in aqueous sulfuric acid, the rate constants based on nitronium ion and activation energies were obtained. Compared with batch reactors, the continuous-flow microreactor system allows for a sufficient heat transfer efficiency and accurate residence time control, making it possible to study the reaction performance more quickly and sensitively. This work may provide a reliable reference for the kinetic study of similar processes.     

氯苯硝化反应固体酸催化剂的制备及性能

讨论了氯苯硝化反应用催化剂、硫酸溶液浸渍γ-Al_2O_3的制备,考察了硫酸浓度、浸渍时间、焙烧温度对催化剂活性及选择性的影响。     

好氧性活性污泥对氯苯吸附与富集的研究

用氯苯驯化污泥,发现经过短期的驯化,好氧活性污泥难以形成对氯苯的高效降解菌群,对氯苯的去除主要是污泥的物理吸附和生物吸附作用.实验结果表明,污泥吸附氯苯不但与污泥表面的孔隙有关,而且还与氯苯参与细菌菌胶体的形成有关.处于生长繁殖时期的污泥比处于非繁殖期的污泥吸附氯苯的能力更强..     

The behavior of chlorobenzenes in Ise bay, estimated from their concentrations in various environmental media

Field survey of pollutants in various environmental media is indispensable for modeling the behavior of organic compounds discharged into the coastal environment. In this study, the concentrations of chlorobenzenes were measured in Ise Bay where industrial wastewater enters. Some chlorobenzene congeners, 1, 3-dichlorobenzene and 1, 2, 4-trichlorobenzene, were detected in seawater, suspended particulate and bottom sediment samples and their behavior was analyzed.The horizontal distributions showed that these chlorobenzene concentrations in the surface water and sediments were higher in the area near the shore of the industrial area than in the offshore area. The soluble chlorobenzene concentrations in the bottom water were low at all stations. The vertical distribution survey at each sampling site showed that the soluble concentrations were high in the surface water and low in the bottom water, but that those in the suspended particulates and the bottom sediments (dry solid base) had relatively similar concentrations. This indicated that chlorobenzenes in the bottom suspended particulates and in the bottom sediments were not equilibrated with chlorobenzenes in the bottom seawater. This could be explained by the following chlorobenzene behavior: the chlorobenzenes were adsorbed by suspended particulates in the surface water and settled to the bottom swiftly through less polluted seawater in the lower water layer with little desorption. This caused the chlorobenzene concentration gradient in the bottom sediment which reflected the chlorobenzene concentration absorbed by suspended particulates in the surface water.The behavior of chlorobenzenes suggested in this study showed that the use of chemical fate models based on the assumption that the soluble fraction and the fraction adsorbed by suspended particulates are always in equilibrium may yield misleading results.     

Solubilities of propene,butane, isobutane and isobutene gases in n-Octane,Chlorobenzene and n-Butanol solvents

Solubilities are reported for atmospheric pressure and temperatures of 298.15, 323.15 and 343.15 K for the gases propene, butane, isobutane and isobutene in the solvents n-octane, chlorobenzene and n-butanol. The solvents were chosen to investigate the effect of the nature of the solvent on gas solubility. The solvents range from the non-polar (octane) to slightly polar (chlorobenzene) and to polar and associating (butanol). The order of gas solubilities in the slightly polar chlorobenzene is found to be closely related to the normal boiling points of the dissolving gases. A method for relating solubilities at various temperatures in similar polar and associating solvents is examined.     

Pd/C催化剂催化氯苯加氢脱氯性能

以氯苯为模型反应原料,采用Pd/C为催化剂催化加氢氯苯脱氯,考察溶剂种类、反应温度、反应压力和反应时间对Pd/C催化剂催化氯苯加氢脱氯性能的影响。结果表明,采用Pd/C为催化剂,以甲醇与水质量比1∶1为溶剂,在反应温度70℃和反应压力0.8 MPa条件下反应100 min,Pd/C催化剂上氯苯转化率超过50%。以甲醇与水质量比1∶1为溶剂,在减少废水和降低成本方面有较大优势。     

对氯氯苄合成方法改进

改进了以氯苯为原料合成对氯氯苄的方法,采用浓硫酸与氯化钠作用产生氯化氢,氯化氢与解聚的甲醛作用生成二氯甲基醚,不用分离即可用它与氯苯在浓硫酸催化作用下制得对氯氯苄.将二步反应"一锅化",简化了操作.     

氯苯和腐殖酸的活性炭竞争吸附模型曲面拟合

研究了氯苯和腐殖酸在活性炭上的竞争吸附。采用1stOpt和MATLAB数据拟合软件解决了氯苯和腐殖酸在活性炭上竞争吸附的多元非线性模型拟合问题,拟合得到的参数方程可以模拟氯苯和腐殖酸在活性炭上的竞争吸附行为。按照拟合方程绘制的三维图形表明,腐殖酸浓度越高,氯苯浓度越低,氯苯被活性炭吸附时受腐殖酸的影响越大,其影响程度可由方程计算得出,可为活性炭滤柱的设计提供基础参数。