固相萃取-气相色谱法测定水样中马拉硫磷残留

采用C-18小柱萃取、毛细管柱分离、气相色谱氢火焰离子化检测器（FID）测定水样中的马拉硫磷,检测限为0．12μg／L。试验了样品流量和洗脱剂对回收率的影响,结果表明样品流量为6mL／min、二氯甲烷作洗脱剂时,回收率较好。测定蒸馏水、地下水和河水样品,相对标准偏差〈2．2％。加标回收率在79．0％-109％之间。     

固相萃取-气相色谱法测定饮用水中甲基汞

根据巯基棉在一定酸性条件下能定量吸附甲基汞的原理,利用多通道并联的固相萃取装置,采用气相色谱(ECD)方法测定饮用水中痕量甲基汞,考察了水样pH值对回收率的影响.方法在0.050 mg/L～1.00 mg/L范围内线性良好,当采样体积为1.0 L时,检出限为0.03 ng/L,标准样品与实际水样平行测定的相对标准偏差均...     

Zr掺杂TiO_2介孔材料光催化降解头孢氨苄

采用固相合成法制备了Zr掺杂TiO_2(Zr-TiO_2),运用XRD技术对其进行了表征,并将其用于水中头孢氨苄的光催化降解,通过单因素实验及正交实验优化了光催化反应条件。结果表明:制备的Zr-TiO_2为锐钛矿型介孔材料,孔径约为8.12 nm;各因素对头孢氨苄去除率的影响由大到小依次为光照时间、Zr-TiO_2投加量、初始头孢氨苄质量浓度;在Zr-TiO_2投加量为1.5 g/L、初始头孢氨苄质量浓度为10 mg/L、溶液pH为7.0、光照(300 W UV)时间为1.5 h的优化条件下,头孢氨苄去除率高达99.46%;Zr-TiO_2光催化剂的重复使用性能良好。     

土壤中钙、镁的形态分析及提取序列的研究

本文采用改进的BCR三步连续提取法对河北某食道癌高发地土壤中钙、镁进行了形态分析及提取序列的研究。实验表明：该地区土壤中镁主要以残渣态形式存在（占总量的83.66％-88.36％）,钙则受提取序列的影响很大,在第一提取序列中,以酸溶态为主（74.11％-83.38％）;第二提取序列中,以有机物结合态为主（78.12％-97.17％）;第三、四提取序列中,以氧化物结合态为主（87.49％-103％）。提取剂的加入顺序明显影响到钙的各个形态的真实含量。     

辽河油田稠油泥砂综合处理工艺的研究*

稠油污泥作为含油污泥的典型代表,其成分极为复杂、处理难度极大,由于目前国内外尚无成熟工艺可完全实现其"减量化、资源化、无害化处理",给油田生产和环境保护带来了严重影响。文章分析了稠油污泥的组成及性质,根据稠油污泥来源不同实施分类预处理,利用热风干化技术将其减量,经热解气化焚烧和热能利用,为实现含油污泥无害化处理进行了有益探索。     

垃圾焚烧飞灰处理处置研究进展

针对作为危险废物的垃圾焚烧飞灰,介绍了近年来国内外对其进行处理处置的研究情况.飞灰的固化/稳定化处理主要从水泥(沥青)固化、熔融固化及化学药剂固化几方面进行论述,飞灰中重金属的提取主要从酸碱浸提、生物浸提、螯合剂浸提及电渗析法提取几方面进行论述.     

不同市场结构组合下稀土最优开采路径研究

本文从价格视角将我国稀土市场结构的变化历程划分为不同阶段,分别从理论和现实视角上探讨了在国际、国内都是完全竞争市场,国际市场垄断、国内市场完全竞争,国际市场完全竞争、国内市场垄断,国际、国内都是垄断市场条件下稀土最优开采路径及最优耗竭时间,并通过设定参数判断其相对大小关系。发现在一定的假设条件下,开采前期当国内和国际市场都是完全竞争时,稀土最优开采量是最大的;当国内和国际市场都是垄断时,稀土最优开采量是最小的;其他两种市场情况下稀土最优开采量居于中间,当国际市场是稀土的主要消费地时,国际竞争-国内垄断市场情况下稀土最优开采量大于国际垄断-国内竞争市场情况下稀土最优开采量,反之,国际垄断-国内竞争市场情况下稀土最优开采量大于国际竞争-国内垄断市场情况下稀土最优开采量。     

Determination of Au(III) and Pd(II) ions by flame atomic absorption spectrometry in some environmental samples after solid phase extraction

A simple and sensitive solid phase extraction method was developed for simultaneous separation and preconcentration of gold and palladium ions with N-(4-methylphenyl)-2-{[(4-phenyl-5-pyridine-4-yl-4H-1,2,4-triazol-3-yl)thio]acetyl}hydrazine carbo thioamide complex on Amberlite XAD-1180 resin before their determination by flame atomic absorption spectrometry. Some analytical parameters such as HNO₃ concentration of the sample solution, amount of complexing agent, sample volume, eluent type and volume, effects of foreign ions and adsorption capacity of the resin were investigated for quantitative recovery of gold and palladium ions. The effects of some anions and cations were also examined. Under optimum conditions, the detection limits for gold and palladium ions were found to be 0.29 and 0.19 μg L^?1, respectively. The preconcentration factor for gold and palladium was 250. After being validated by standard addition and analysis of standard reference material, the procedure was successfully applied to the analysis of sea and stream water, anodic slime, gold ore, soil and electronic waste.     

Supercritical Fluid Extraction for Forensic Analysis of Hydrocarbons in Soil

Supercritical fluid extraction (SFE) was investigated to evaluate its potential for obtaining high quality chromatographic fingerprints from soils encountered in environmental investigations. While the volatile and semivolatile fractions of light nonaqueous phase liquid (LNAPL) samples can be “fingerprinted” in a single chromatographic run, it is commonly not possible to obtain samples of LNAPL in the locations of interest. For this and other reasons, it was desirable to develop this method (SFE) of soil extraction, which allows chromatographic fingerprinting of the same quality routinely obtained with LNAPL so that environmental forensic investigations could be extended to areas beyond those containing LNAPL in monitoring wells. In this study, SFE was compared to conventional dichloromethane extraction. Both artificially spiked soil and soil from petroleum release sites were tested. Since water can be a problem when using the SFE method, particular attention was given to handling soils with high moisture contents. The SFE extracts showed excellent retention of low molecular components, including pentanes. Gas chromatography of SFE extracts yielded molecular distributions that showed no significant bias toward either low or high molecular weight components. These results show that SFE can be used to obtain an unbiased, single-run chromatographic “fingerprint” of both volatile and semivolatile hydrocarbons in contaminated soil samples.     

萃取净化电镀含镉废水

研究了二壬基萘磺酸(DNNSA)形成的微乳液从模拟含镉废水中萃取镉离子的工艺条件。分别考察了相体积比(O/A)、萃取时间、温度及萃取剂浓度对废水中镉离子萃取的影响。结果表明,萃取平衡时间为10 mim,降低温度及增加萃取剂浓度均有利于萃取。紫外光谱证实当DNNSA萃取镉时,所形成萃合物对萘环的结构无影响,且不会破坏微乳相的结构;分子荧光光谱表明镉离子对配体DNNSA有荧光猝灭作用。