相转移法环氧氯丙烷装置蒸馏釜燃爆事故分析

针对相转移法环氧氯丙烷装置蒸馏釜燃爆事故,采用故障树分析方法,以蒸馏釜燃爆作为顶上事件进行分析。在进行故障树最小割集分析与基本事件重要度分析的基础上,根据3种不同燃爆事故类型分别提出了相应的蒸馏釜燃爆事故预防措施。     

微波改性高炉瓦斯泥吸附特性研究

以马鞍山钢铁公司高炉瓦斯泥为对象,采用微波改性方法对高炉瓦斯泥的粒度分布、微观形貌及化学变化进行表征分析,揭示了微波作用对瓦斯泥吸附特性的影响.结果表明,高炉瓦斯泥的主要组分为含铁烧结矿和焦炭颗粒,经微波改性的瓦斯泥颗粒,在形貌上显示出粗糙度增大,孔隙结构明显,比表面积增大和活性点增多的特征.通过对亚甲基蓝的吸附测试,...     

催化超临界水氧化技术处理香料废水研究

采用催化超临界水氧化(CSCWO)技术对香料废水进行氧化处理,研究了催化剂浓度、反应温度、压力、停留时间等因素对废水COD、TN去除效果的影响.结果表明:在超临界水中添加cu2+催化剂后有机物的去除效率与无催化剂时相比有显著的提高.香料废水中COD、TN的去除率随催化剂浓度、反应温度和压力的升高,停留时间的延长而提高....     

Characterization of condensed phase nitric acid particles formed in the gas phase

The formation of nitric acid hydrates has been observed in a chamber during the dark reaction of NO2 with O3 in the presence of air. The size of condensed phase nitric acid was measured to be 40–100 nm and 20–65 nm at relative humidity (RH) 6 5% and RH = 67% under our experimental conditions, respectively. The nitric acid particles were collected on the glass fiber membrane and their chemical compositions were analyzed by infrared spectrum. The main components of nitric acid hydrates in particles are HNO3 3H2O and NO3?? xH2O (x> 4) at low RH, whereas at high RH HNO3 H2O, HNO3 2H2O, HNO3 3H2O and NO3?? xH2O (x> 4) all exist in the condensed phase. At high RH HNO3 xH2O (x 6 3) collected on the glass fiber membrane is greatly increased, while NO3?? xH2O (x > 4) decreased, compared with low RH. To the best of our knowledge, this is the first time to report that condensed phase nitric acid can be generated in the gas phase at room temperature.     

中药菊花中12种农药残留量的气相色谱检测方法研究

采用气相色谱仪同时检测中药菊花中12种有机磷和有机氯农药的残留量.用丙酮、石油醚(体积比为6:4)混合溶剂浸泡中药菊花2 h,超声振荡30 min,过滤;滤液经C18柱、石墨碳柱固相萃取、净化.采用电子捕获检测器、程序升温、SPB-5(30 m×0.25 mm×0.25 μm)毛细管柱气相色谱检测技术对菊花中12种农药残留进行分析.结果表明,12种农药残留在22 min内均可很好地得以分离,最低检出浓度为0.01～0.05 mg/L;12种农药的添加回收率为74.7%～100.6%,线性范围为0.1～10.0 mg/L,线性相关系数r2≥0.992 2.本文建立了中药菊花中12种农药残留量的气相色谱分析方法,符合农药多残留分析的要求.     

Application of multiwalled carbon nanotubes treated by potassium permanganate for determination of trace cadmium prior to flame atomic absorption spectrometry

In this study we investigated the enrichment ability of oxidized multiwalled carbon nanotubes (MWCNTs) and established a new method for the determination of trace cadmium in environment with flame atomic absorption spectrometry.The MWCNTs were oxidized by potassium permanganate under appropriate conditions before use as preconcentration packing.Parameters influencing the recoveries of target analytes were optimized.Under optimal conditions,the target analyte exhibited a good linearity (R~2=0.9992) over the concentration range 0.5-50 ng/ml.The detection limit and precision of the proposed method were 0.15 ng/ml and 2.06%, respectively.The proposed method was applied to the determination of cadmium in real-world environmental samples and the recoveries were in the range of 91.3%-108.0%.All these experimental results indicated that this new procedure could be applied to the determination of trace cadmium in environmental waters.     

固相萃取-液相色谱法测定土壤中酚类化合物

建立了索氏提取-固相萃取-液相色谱法测定土壤中环境优先监测的6种酚类污染物监测方法。利用索氏提取和固相萃取法提取净化了土壤中6种酚类化合物,比较5种固相萃取柱萃取的效果,选择PSD固相萃取柱,优化了固相萃取条件,影响固相萃取回收率的4种因子显著性顺序为:水样p H上样速度洗脱液体积溶剂类型。最佳固相萃取条件:上样的水样p H=3,上样速度5 m L/min,洗脱溶剂为乙腈,洗脱溶剂体积是10.0 m L。酚类化合物的检出限为0.01~0.05 mg/kg,加标回收率在85.39%~105.82%之间,相对标准偏差RSD10%(n=7),该法操作方便,灵敏度高,可用于土壤中多种酚类化合物的测定。     

给水厂废弃铁铝泥对湖泊沉积物好氧氨氧化作用的影响

给水厂废弃铁铝泥(Ferric and aluminum residuals,FARs)可用于控制湖泊沉积物磷释放.因此,在实际应用之前对FARs的风险进行评估非常重要.本研究通过室内富集实验,考察FARs对沉积物中氨氧化菌(ammonia-oxidizing bacteria,AOB)活性、丰度和多样性的影响.结果表明:投加FARs后,沉积物对氨氮的去除能力微弱提高.富集后沉积物中AOB丰度增加,投加FARs的沉积物中AOB丰度达到1.32×108copies·g-1,而未投加FARs的沉积物中AOB丰度为1.14×108copies·g-1.此外,amo A基因的系统发育分析表明富集前后沉积物中的AOB均附属于Nitrosospira和Nitrosomonas两个种属,并且投加FARs沉积物中AOB的多样性略高于未投加的.综上结果表明,FARs回用于湖泊富营养化控制的同时,将有益于沉积物中好氧氨氧化作用的进行.     

顶空固相微萃取-气相色谱-质谱法分析土壤中多环芳烃含量

建立了顶空固相微萃取(Head-space Solid phase microextraction,HS-SPME)与气相色谱-质谱(Gas chromatography and mass spectrometer,GC-MS)联用测定土壤中16种多环芳烃的快速分析方法。考察了萃取温度、萃取时间和加水量等因素对萃取效率的影响。结果表明,最佳萃取温度40℃,萃取时间30min,加水量3:5(m L/g)。同时对该方法的检出限、精密度、回收率等进行了评价,结果表明,该方法精密度良好,相对标准偏差小于5.05%,16种组分的回收率在82.8%~101.6%,检出限0.001~0.023μg/kg。该方法前处理步骤简单,灵敏度高,为土壤中的多环芳烃的检测提供了一种简便、快捷、可靠的测定方法。     

全自动固相萃取-高效液相色谱-荧光检测法测定生活饮用水中苯酚

建立全自动固相萃取-高效液相色谱法测定饮用水中苯酚的方法。样品经过全自动固相萃取仪的预处理后,通过XBridger-C18色谱柱分离,以甲醇+0.01mol/L乙酸-乙酸铵缓冲溶液为流动相进行洗脱,于激发波长230nm发射波长320nm荧光检测,测定结果表明,线性范围良好,回收率90%~93%,相对标准偏差1.3%~3.5%。该方法操作简单方便,分析快速、准确,灵敏度高,。