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51.
建立了高效液相色谱法测定水中六种邻苯二甲酸酯(邻苯二甲酸二甲酯、邻笨二甲酸二乙酯、邻苯二甲酸二丁酯、邻苯二甲酸二(2-乙基己基)酯、邻苯二甲酸二辛酯、邻苯二甲酸丁基苄酯)的检测方法.对水样中邻苯二甲酸酯的萃取条件和高效液相色谱分析条件进行优化,采用正己烷二次萃取,浓缩定容后分析,以乙腈-水为流动相梯度洗脱,紫外检测波长226 nm,16 min可将六种邻苯二甲酸酯分离出.方法的检出限为0.13μg/L ~0.37 μg/L,加标回收率为78.6%~118.5%,相对标准偏差为0.82%~2.17%,是一种理想的测定水中六种邻苯二甲酸酯的方法.  相似文献   
52.
海水中二甲基硫测定方法的研究   总被引:10,自引:0,他引:10  
胡敏  李金龙 《环境化学》1995,14(2):157-163
二甲基硫(DMS)是雨水天然酸性的贡献者和影响气候变化的重要痕量气体,本文海水中DMS测定方法,即采用冷却预浓缩技术处理海水样品,用带有火焰光度检测器气相色谱仪分析,此方法的精密度为12%,准确度为10%,对100ml海水样品最小检测量为0.054ng(DMS)。同时对色谱柱的选取,实验材料的选择,浓缩柱填充材料的选择,鼓气效率,干燥管,样品解析,样品保存等有关实验步骤进行了讨论。  相似文献   
53.
A series of experiments were carried out to determine the effect of surfactants at low concentrations on the sorption of atrazine by natural sediments. With surfactant concentrations ranging from 0 to 20 mg/ L, anionic and cationic surfactants appreciably reduce the adsorption of atrazine, while nonionic surfactant decreases the adsorption of atrazine at concentrations equal to or less than 1 mg/L and increases adsorption at higher concentrations. Desorption of atrazine in the presence of different sodium dodecylbenzene sulfonate (SDBS) concentrations shows that a portion of the bound pesticide resists desorption in the SDBS free system. However, the addition of SDBS accelerates the desorption of atrazine. Furthermore, the nature of sediment and the contacting sequence of SDBS, at 10 mg/L, with the sediment, also influence the adsorption of atrazine. The conclusions in this study could be explained partially by the effect of the type and concentration of surfactants and the characteristics of sediments.  相似文献   
54.
交联壳聚糖冠醚的合成及其对金属离子的吸附性能   总被引:21,自引:1,他引:21  
汪玉庭  栾兆坤 《环境化学》1998,17(4):349-354
本文合成了交联壳聚糖苯并-15-冠-5醚和交联壳聚糖苯并-18-冠-6醚,研究了它们对Ag(Ⅰ)Pd(Ⅱ),Pb(Ⅱ),Cd(Ⅱ),Cr(Ⅲ)等金属离子的吸附性能和选择性,实验结果表明:无论是在单一金属离子体系还是在二元或三元金属离子体系中,CCTS-BX和CCTS-BY对Ag(Ⅰ)和Pd(Ⅱ)者有较高的吸附选择性。  相似文献   
55.
通过融合污泥粘度与污泥浓度关系式、污泥粘度与温度关系式,得到一个新的关系式:污泥粘度与污泥浓度、温度的关系式,并通过实验数据拟合出各项参数,拟合效果比较理想.得出的污泥粘度与污泥浓度、温度的关系式对了解污泥的粘度变化非常有帮助,同时,该关系式也将为污泥处理、处置方案的制定提供参考依据.  相似文献   
56.
The contents of eight trace elements(Mn, Cr, Pb, As, Se, Zn, Cd, Hg) in raw coal, bottom ash and fly ash were measured in a 220 t/h pulverized coal boiler. Factors affecting distribution of trace elements were investigated, including fly ash diameter, furnace temperature, oxygen content and trace elements‘ characters. One coefficient of Meij was also improved to more directly show element enrichment in combustion products. These elements may be classified into three groups according to their distribution: Group 1. Hg, which is very volatile. Group 2: Pb, Zn, Cd, which are partially volatile. Group 3: Mn, which is hardly volatile. Se may be located between groups 1 and 2. Cr has properties of both group ! and 3. In addition, the smaller diameter of fly ash, the more relative enrichment of trace elements (except Mn). The fly ash showed different adsorption mechanisms of trace elements and the volatilization of trace elements rises with furnace temperature. Relative enrichments of trace elements(except Mn and Cr) in fly ash are larger than that in bottom ash. Low oxygen content can not always improve the volatilization of trace elements. Pb is easier to form chloride than Cd during coal combustion. Trace elements should be classified in accordance with factors.  相似文献   
57.
IntroductionThesorptionofhydrophobicorganiccontaminants(HOCs)onnaturalgeosorbentsplaysasignificantroleintheirtransport,degradationandultimatefateintheaquaticenvironment (Alexander,1995 ;Luthy ,1997;Weber,2 0 0 1) .Sincethelate 1970s,theorganicmatter(OM)ha…  相似文献   
58.
Atmospheric oxidizing capacity (AOC) is an essential driving force of troposphere chemistry and self-cleaning, but the definition of AOC and its quantitative representation remain uncertain. Driven by national demand for air pollution control in recent years, Chinese scholars have carried out studies on theories of atmospheric chemistry and have made considerable progress in AOC research. This paper will give a brief review of these developments. First, AOC indexes were established that represent apparent atmospheric oxidizing ability (AOIe) and potential atmospheric oxidizing ability (AOIp) based on aspects of macrothermodynamics and microdynamics, respectively. A closed study refined the quantitative contributions of heterogeneous chemistry to AOC in Beijing, and these AOC methods were further applied in Beijing-Tianjin-Hebei and key areas across the country. In addition, the detection of ground or vertical profiles for atmospheric OH·, HO2·, NO3· radicals and reservoir molecules can now be obtained with domestic instruments in diverse environments. Moreover, laboratory smoke chamber simulations revealed heterogeneous processes involving reactions of O3 and NO2, which are typical oxidants in the surface/interface atmosphere, and the evolutionary and budgetary implications of atmospheric oxidants reacting under multispecies, multiphase and multi-interface conditions were obtained. Finally, based on the GRAPES-CUACE adjoint model improved by Chinese scholars, simulations of key substances affecting atmospheric oxidation and secondary organic and inorganic aerosol formation have been optimized. Normalized numerical simulations of AOIe and AOIp were performed, and regional coordination of AOC was adjusted. An optimized plan for controlling O3 and PM2.5 was analyzed by scenario simulation.  相似文献   
59.
报道了久效磷对3种海洋微藻细胞内2种清除活性氧的关键性酶--超氧化物歧化酶和过氧化物酶活性的影响.结果显示:1.在久效磷的胁迫下,扁藻和三角褐指藻细胞的超氧化物歧化酶(SOD)活性均表现出下降的总变化趋势,而叉鞭金藻细胞的SOD活性时而上升,时而下降,在整个胁迫过程中呈现出无规律性的变化.2.随着久效磷胁迫时间的延长,3种微藻细胞的过氧化物酶活性均逐渐下降,表现出相同的变化规律性.这说明不同的藻种,久效磷对其细胞内酶活性的影响不尽相同.推测超氧化物歧化酶和过氧化物酶(POD)活性的降低是微藻细胞内过量产生活性氧,进而引起藻细胞膜脂过氧化伤害的主要原因之一.  相似文献   
60.
2,4,6—三硝基甲苯废水治理技术的研究进展   总被引:19,自引:0,他引:19  
论述了2,4,6-三硝基甲苯废水中化学耗氧量和色度的研究进展情况,指出生化法中白腐菌综合治理2,4,6-三硝基甲苯废水的处理方法是目前极有前途的有效的技术。  相似文献   
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