Temperature dependence of the absolute rate constant for the reaction of ozone with dimethyl sulfide

Absolute rate constants for the reaction of ozone with dimethyl sulfide (DMS) were measured in a 200-L Teflon chamber over the temperature range of 283-353 K. Measurements were carried out using DMS in large excess over ozone of 10 to 1 or greater. Over the indicated temperature range,the data could be fit to the simple Arrhenius expression as KDMS = (9.96±3.61)×10-11exp(-(7309.7±1098.2)/T)cm3/(molecule·s). A compared investigation of the reaction between ozone and ethene had a kc2H4 value of(1.35±0.11)×10-18 cm3/(molecule·s) at room temperature.     

Determination of alcohol compounds using corona discharge ion mobility spectrometry

Ion mobility spectrometry （IMS） is a very fast, highly sensitive, and inexpensive technique, it permits efficient monitoring of volatile organic compounds like alcohols. In this article, positive ion mobility spectra for six alcohol organic compounds have been systematically studied for the first time using a high-resolution IMS apparatus equipped with a discharge ionization source. Utilizing protonated water cluster ions （H2O）nH^＋ as the reactant ions and clean air as the drift gas, alcohol organic compounds, ethanol, 1- propanol, 2-propanol, 1-butanol, 1-pentanol and 2-octanol, all exhibit product ion characteristic peaks in their respective ion mobility spectrometry, that is a result of proton transfer reactions between the alcohols and reaction ions （H2O）nH^＋. The mixture of these alcohols, including two isomers, has been detected, and the results showed that they could be distinguished effectively in the ion mobility spectrum. The reduced mobility values have been determined, which are in very well agreement with the traditional ^63Ni-IMS experimental values. The exponential dilution method was used to calibrate the alcohol concentrations, and a detection limit available for the alcohols is in order of magnitude of a few ng/L.     

Amplification of plasmid DNA bound on soil colloidal particles and clay minerals by the polymerase chain reaction

Polymerase chain reaction(PCR)was used to amplify a 600-base pair(bp)sequence of plasmid pGEX-2T DNA bound on soil colloidal particles from Brown soil(Alfisol)and Red soil(Ultisol),and three different minerals(goethite,kaolinite,montmorillonite). DNA bound on soil colloids,kaolinite,and montmorillonite was not amplified when the complexes were used directly but amplification occurred when the soil colloid or kaolinite-DNA complex was diluted,10- and 20-fold.The montmorillonite-DNA complex required at least 100-fold dilution before amplification could be detected.DNA bound on goethile was amplified irrespective of whether the complex was used directly,or diluted 10- and 20-fold.The amplification of mineral-bound plasmid DNA by PCR is,therefore,markedly influenced by the type and concentration of minerals used.This information is of fundamental importance to soil molecular microbial ecology with particular reference to monitoring the fate of genetically engineered microorganisms and their recombinant DNA in soil environments.     

两性木质素接枝共聚物的聚合反应与离子化改性

研究碱木质素与复合单体在水相中接枝共聚,以Mannich反应进一步对接枝产物进行阳离子化改性.结果表明:在70℃±5℃下进行木质素与复合单体接枝共聚反应,当pH值为7.0-8.0、反应时间为2h-2.5h,获得较理想的接枝效果,过硫酸盐引发效果优于过氧化氢,引发剂适宜的反应浓度约为10mmol·l-1.共聚物阳离子化改性的适宜条件为:醛、胺与木质素的质量比为0.5∶1.2∶1,反应温度60℃-70℃,反应时间2h,反应产物为一种具有阴、阳离子两性基团的木质素聚合物. 以丙酮分离产物,当体积比为0.75时,获得产物与水较好的分离效果. 红外光谱分析表明,木质素与复合单体实现了有效的接枝共聚和离子化改性.     

集成电路产业含氟废水处理工程

介绍采用三级反应一级沉淀为主体工艺,处理集成电路产业含氟废水的实际应用情况和工程治理效果。实践表明,采用本处理技术,能确保出水水质氟离子浓度达到上海市《污水综合排放标准》(DB31/199-1997)的二级标准,即F-浓度≤10mg/L。     

壬基酚聚氧乙烯醚在水溶液中的光降解行为研究

采用模拟日光灯和长波紫外灯（UVA-365nm）2种光源,对水溶液中壬基酚聚氧乙烯醚（NPEOs）的光降解动力学、降解过程中NPEO同系物成分的变化、以及氧化剂过氧化氢的加入对光降解的影响进行了研究,并采用LC-MS对光降解的产物进行了分析.研究表明,实验周期内NPEOs在模拟日光和长波紫外光下均发生不同程度的光降解,降解速率常数分别为6.20×10^-3　μmol/(L·h)和1.18×10^-2　μmol/(L·h).在模拟日光下,在NPEOs降解过程中观察到短链的NPEO_1,3分布比例的增加,而在长波紫外光下的降解过程中并没有发现NPEO成分分布的变化.过氧化氢的加入对NPEOs的光降解具有明显的促进作用,特别是在模拟日光下,0.01 mmol/L和1.00 mmol/L H₂O₂的加入使NPEOs的96h降解率由20.9%分别提高至44.4%和91.5%.通过LC-MS分析,初步认为壬基酚三乙氧基乙酸的烷基氧化产物(CA_3～9PEC₃)是溶液中NPEOs光降解的主要产物,并据此推断了可能的反应历程.     

浅议高纯铜锌合金滤材处理水中重金属的应用

介绍高纯铜锌合金滤材的特性和先进性,以及讨论了去除水中铅、砷、汞的机理,可应用的范围,应用现状及前景。介绍高纯铜锌合金滤材的特性和先进性,以及讨论了去除水中铅、砷、汞的机理,可应用的范围,应用现状及前景。     

西藏盐井地区盐泉同位素特征示踪研究

对西藏盐井地区盐泉、曲孜卡泉、地表水及重要地层进行了同位素测定和分析,结合区域地质构造条件、辅以水化学证据确定泉水的补径排模式。δD~δ18O规律指示出盐泉和温泉的补给类型的差异;用δ18O对泉水的补给区海拔高程进行恢复;泉水、岩样的δ13C~δ18O规律指示出盐泉流经的主要相关层位为上三叠统地层T3b~T3d;其排泄主要受到芒康-盐井复式向斜次级背斜核部的张性裂隙所控制。     

六氯苯碱催化分解脱氯效果及影响因素研究

采用自主设计开发的碱催化设备研究了碱催化分解技术(BCD)对六氯苯(HCB)脱氯的效果.考察了反应温度、氢氧化钠投加比例以及不同催化剂对六氯苯去除效率、脱氯效率以及中间代谢产物的影响.提高反应温度和氢氧化钠投加比例能够有效提高六氯苯的脱氯解毒效率,当六氯苯与氢氧化钠投加质量比为1:5时,在360℃下反应4h后,六氯苯的去除率为99.97%,脱氯效率达到91.08%.还原铁粉作为催化剂时,在330℃反应1h后,能够将六氯苯的脱氯效率由38.99%提高至77.51%.     

不同金属离子对Vc引发的小鼠肝匀浆自由基反应的影响

以小鼠肝匀浆脂质过氧化产物丙二醛(MDA)的OD_532nm值(MDA-OD_532nm)作为测定自由基反应的间接指标,研究了Hg²⁺、Mn²⁺、Ni²⁺、Cd²⁺、Cr³⁺、SeO^2-₃等离子和As₂O₃水溶液在Vc引发自由基反应体系中的作用.结果表明:Cr³⁺与Mn²⁺具有显著的抑制作用;Hg²⁺、Cd²⁺与As₂O₃对自由基反应有促进作用;Ni²⁺、SeO^2-₃对Vc引发小鼠肝匀浆的自由基反应作用不明显.