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1.
乔俊  张岱琼  费鹏  靳敏  霍金仙 《化学教育》2018,39(22):73-77
为调查A河、B河下游水体的水质现状,于2014年丰水期(8月)和枯水期(12月),选取A、B河下游各8个采样点,对水体的溶解氧、氨氮等6项理化指标,以及Hg、Pb等7项重金属指标进行检测,采用单项参数评价法和综合水质标识指数法对2条河流的水质现状进行分析及评价,并采用对数型幂函数普适指数公式对水体的富营养程度进行评价。结果发现,A、B河下游水质以劣V类为主,水体中各类重金属不超标,主要超标污染物为总氮、总磷、氨氮等。A河水质好于B河,2条河流丰水期水质好于枯水期。A、B河下游水体处于重富和极富营养化状态,应加强整治2条河流流域的农业面污染源,降低河流的富营养化风险。  相似文献   

2.
从地表水来源的整个水流过程对森林净化水质功能和影响贡嘎山自然保护区表水水质的因素进行分析,评价了贡嘎山森林流域水质状况,研究了贡嘎山森林生态系统对水域pH和Ca等营养元素的影响,为森林生态系统水质演化研究提供了例证。  相似文献   

3.
从技术应用原理、方法、应用现状及发展等角度,综合介绍了国内外常见的细胞与分子水平的水质生物识别与安全评价方法,分析了这些技术的优点与不足,指出了水质生物监测技术研究的发展方向。  相似文献   

4.
微量元素与中药的功效和安全性密切相关,也是药材道地性研究的一部分,为探讨党参中重金属元素的安全性、风险性及道地性的相关性。本文采用电感耦合等离子体质谱法(ICP-MS)及原子荧光光谱法(AFS)测定来源于甘肃、山西、湖北、四川等产区的39批党参药材中的20种元素的含量,结果结合化学计量学分析对党参产区进行差异判别。通过单因子污染指数法和内梅罗综合污染指数法对其进行安全性评价,通过健康风险基于暴露量、危害指数法和暴露限值法对其进行风险评估。结果表明,重金属在各自范围内线性关系良好,加样回收率,仪器精密度和重复性良好,其中 Ba、Sr、Mn的含量最高。主成分分析显示39批药材分为三类,同一产区的党参能较好的聚在一起,元素含量差异与产区分布有一定规律,其中Cs、Ga、As、Co、Li、Pb、Hg、Se、V、Mn为关键的差异标志物,为产地元素特征分析鉴别提供依据。安全评价结果为39批党参药材污染等级为安全,但风险评估后DS-31、DS-32、DS-34、DS-36及 DS-37在人体长期蓄积中具有健康风险。结论:本研究方法高效、准确、简便,结合化学计量学可以对党参进行有效的产地判别,评价党参中元素的安全性及风险性,为党参道地性及健康评价提供了科学依据。  相似文献   

5.
在新安江浙皖交界处的村口水断面上,两座水质自动监测站遥相对望。
  20世纪90年代后,千岛湖水质富营养化趋势加剧。浙江省政协一份有关钱塘江的调研报告显示,目前钱塘江流域内上游污染严重,水质以IV类和劣V类为主,饮用水安全存在较大隐患。
  千岛湖是长三角最后一片大型清洁水源,湖水量中有60%以上来自黄山地区,上游来水水质的优劣,对千岛湖水质起着决定性的作用。  相似文献   

6.
为了解雄县地区地下水水化学特征及水质现状,选取43组地下水,采用仪器分析和容量法相结合的方式对雄县地下水典型的环境项目进行测定,运用数理统计和三元相图分析了雄县地下水的主要离子特征,并运用综合评价法对地下水质量予以评价。结果表明,该类指标的方法检出限为0.001~1.30mg/L,相对标准偏差为0.30%~3.7%,pH值和偏硅酸空间变异最低(CV30%),Mg~(2+)、Cl~-、SO_4~(2-)和碘化物的空间变异性最高(CV100%),水化学类型主要以HCO_3-Na型为主,水质评价结果显示研究区域地下水水质总体状况较好,多为Ⅱ类水和Ⅲ类水。研究成果对了解雄县地下水水质现状具有重要意义。  相似文献   

7.
模糊综合评判法在台州市地表水评价中的应用   总被引:1,自引:0,他引:1  
应用模糊综合评判法,以长潭等9个水库为研究对象,对台州地区水质进行厂评价:结果表明,台州地区总体水质较好,除东湖属Ⅳ类水外,其它全为Ⅲ类,适合人们生存及生产需要。根据评价提出了相心的建议  相似文献   

8.
吴淑琰 《化学教育》2017,38(6):47-49
采用“任务式”教学法实施综合设计性水分析化学实验教学。通过师生讨论完善实验方案、学生自主实践方案、自主编制水质监测报告、教学评价等4个教学环节的展开,巩固了学生的专业基础知识和技能,培养了学生知识综合运用能力,激发了学生对于科学探究的兴趣和创新意识。  相似文献   

9.
<正>在新安江浙皖交界处的村口水断面上,两座水质自动监测站遥相对望。20世纪90年代后,千岛湖水质富营养化趋势加剧。浙江省政协一份有关钱塘江的调研报告显示,目前钱塘江流域内上游污染严重,水质以IV类和劣V类为主,饮用水安全存在较大隐患。千岛湖是长三角最后一片大型清洁水源,湖水量中有  相似文献   

10.
简要评述了化学品安全性的传统评价方法。详细介绍了一种快速评价化学品安全性的重要方法——诱变性测试法。该方法选用几种标准(或特定)的鼠伤寒沙门氏菌(Salmonella typhimurium)作为观察对象来研究待测化学品对菌株的诱变情况,以菌株回复突变的数目表征待测化学品的诱变性。当回复突变数目为零剂量(化学品)的2倍以上时,所测定化学品具有诱变性。具有诱变性的化学品为不安全化学品。  相似文献   

11.
The study presents the application of selected chemometric techniques: cluster analysis, principal component analysis, factor analysis and discriminant analysis, to classify a river water quality and evaluation of the pollution data. Seventeen stations, monitored for 16 physical and chemical parameters in 4 seasons during the period 1999-2003, located at the Bagmati river basin in Kathmandu Valley, Nepal were selected for the purpose of this study. The results allowed, determining natural clusters of monitoring stations with similar pollution characteristics and identifying main discriminant variables that are important for regional water quality variation and possible pollution sources affecting the river water quality. The analysis enabled to group 17 monitoring sites into 3 regions with 5 major discriminating variables: EC, DO, CL, NO2N and BOD. Results revealed that some locations were under the high influence of municipal contamination and some others under the influence of minerals. This study demonstrated that chemometric method is effective for river water classification, and for rapid assessment of water qualities, using the representative sites; it could serve to optimize cost and time without losing any significance of the outcome.  相似文献   

12.
Understanding the mobility of radiocesium and radiostrontium within geological environment is important from ‘deep geological repository system’—safety assessment point of view. Cs and Sr radionuclide sorption studies have been carried out with a stalagmite sample collected from Lesser—Himalayas. Detailed microstructural studies, backed up by micro-Raman and LIBS analyses, identified three different domains within the sample; constituted of microcrystalline calcite, botryoidal aragonite and palisadic calcite respectively. Experimental studies showed that both the radionuclides exhibit moderate to low sorption coefficients within all the different domains of stalagmite under acidic environment.  相似文献   

13.
14.
《Comptes Rendus Chimie》2016,19(6):754-765
Rosemary (Rosmarinus officinalis L.) is a perennial herb with an intensive aromatic flavor. Its most important chemical constituents are essential oils (e.g., 1,8-cineole and camphor) and antioxidants (e.g., carnosic acid and rosmarinic acid). The common methods to extract the essential oil of rosemary are steam or hydro distillation. The aim of this work is to investigate the residual antioxidants after hydro distillation, especially rosmarinic acid and carnosic acid. For this purpose, the hydro distillation water residues were analyzed by HPLC-UV. Moreover, the influence of the extraction duration on the concentration of the antioxidants was investigated. Also, the residual amount of these compounds in the leaves was examined. The total antioxidant activity of the extracts and of the pure compounds was determined by DPPH assays. It is shown that after 2.5 h of hydro distillation the amount of rosmarinic acid and the antioxidant activity in the water residue reaches a maximum value. In addition, the yield and the quality of the essential oil were investigated to draw a comparison between steam and hydro distillations of Moroccan rosemary leaves.  相似文献   

15.
Alga as Achnanthes minutissima among diatoms is a widely adaptable taxon on the state of an aquatic environment. In this study, it was found that diatom had a specific tolerance to heavy metals (Cu, Zn, Pb, and Cd etc.) in river water samples, because the diatom assemblage consisted of almost only Achnanthes minutissima in Kakehashi river and Godani river, which were polluted with waste water from Ogoya copper mine. The relationship between the concentrations of heavy metals (Cu, Zn, Pb and Cd) in river water and the attached substances (algae and silt etc.) and the relative abundances of diatom taxa were investigated in detail. The results indicated that the higher is the concentration of heavy metals in the river environment, the higher is only the relative abundances of Achnanthes minutissima. Thus, the taxon can be used as a bioindicator of heavy metal pollution. The relative rates of toxic chemical forms of copper in algae were 61 - 92% in the attached substances and 49-70% in the sediment on the river bed, respectively. Therefore, it was found that diatom as Achnanthes minutissima had a tolerance to heavy metals in river water, being able to live in such an environment. Since the water treated with calcium hydroxide from the deposition reservoir of Ogoya mine enters in Godani river, the river is polluted by heavy metals (Cu, Zn, Pb and Cd etc.). From the viewpoint of both biological and chemical analyses, Godani river is still polluted with heavy metals, because their concentrations in the river samples were very high. On the other hand, in Kakehashi river, the concentrations of heavy metals were very low and the distributions of some diatoms appeared in an unpolluted Nishimata river were observed. Therefore, Kakehashi river seems to be considerably recovered from heavy-metal pollution after closing the Ogoya mine.  相似文献   

16.
Ion exchange of the sodium hydro sodalites [Na3(H2O)4]2-[Al3Si3O12]2 [Na4(H3O2)]2[Al3Si3O12]2 and [Na4(OH)]2[Al3Si3O12]2 with aqueous Pb(NO3)2 solutions yielded, whichever reactant sodalite phase was used, the same lead hydro sodalite, [Pb2(OH)-(H2O)3]2[Al3Si3O12]2. Thus, in the case of the non-basic reactant [Na3(H2O)4]2-[Al3Si3O12]2 an overexchange occurs with respect to the number of nonframework cationic charges. Rietveld structure refinement of the lead hydro sodalite based on powder X-ray diffraction data (cubic, a = 9.070 A, room temperature, space group P43n) revealed that the two lead cations within each polyhedral sodalite cage form an orientationally disordered dinuclear [Pb2(micro-OH)(micro-H2O)(H2O)2]3+ complex. Due to additional lead framework oxygen bonds the coordination environment of each metal cation (CN 3+3) is approximately spherical, and clearly the lead 6s electron lone pair is stereochemically inactive. This is also suggested by the absence of a small peak at 13.025 keV, attributed in other Pb2+-O compounds to an electronic 2p-6s transition, in the PbL3 edge XANES spectrum. 1H MAS NMR and FTIR spectra show that the hydrogen atoms of the aqua hydroxo complex (which could not be determined in the Rietveld analysis) are involved in hydrogen bonds of various strengths.  相似文献   

17.
The occurrence of antibiotics in the aquatic environment is an important emerging issue due to potential adverse effect of these compounds on ecosystem and human health. For a correct environmental risk assessment there is a need for appropriate analytical methods for monitoring antibiotic residues in a variety of water matrices. This paper describes a method for the determination of eleven sulphonamide compounds in surface and drinking waters using solid-phase extraction and liquid chromatography-tandem mass spectrometry. Recoveries of the analytes in both surface and drinking water matrices at different fortification levels, always exceed 87%; the limits of quantification in surface water samples are between 0.005 and 0.021 μg L−1 depending on the compound, and the interday method precision is less than 12%. Matrix effects were evaluated in drinking and surface water samples. The method has been applied to a small scale reconnaissance of river, lake, mineral and municipal water samples; results indicate the occurrence of sulphonamides in some surface and mineral waters analyzed.  相似文献   

18.
Summary Radioactivity of water and sediments from the Danube river in its course through Serbia during 2001-2003 years has been tested by alpha- and gamma-ray spectrometry. Except for cesium originating from Chernobyl, the radioactivity level of water and sediment coincide with the content of natural radionuclides in the environment of rivers basin. No increase in the radioactivity of sediments, due to slowing down of the water flow, was observed. The obtained results were analyzed in accordance with the model which considers only naturally occurring radionuclides originating in river sediment. The distribution coefficients for natural radionuclides are determined.  相似文献   

19.
Summary The radioactivity of water and sediments from the Sava river in the course through Serbia during 2001-2003 has been examined by alpha- and gamma-ray spectrometry. Except for cesium originating from Chernobyl, the radioactivity level of water and sediment coincide with the content of natural radionuclides in the environment of the river basin. Distribution coefficients as well as the runoff coefficient were determined for 137Cs.  相似文献   

20.
A global population increase and an improved standard of living are generally expected. To meet these demands, an increased production of chemicals will be necessary while protecting human health and the environment. However, most current methods of chemical production are unsustainable. New designs must result in plants that assure process and operator safety, the sustained health of workers and the community, and the protection of the environment. Traditional safety precautions and process controls minimize risk but cannot guarantee the prevention of accidents followed by serious consequences. Therefore, the general approach to environmental and safety problems must be changed from reactive to proactive. One way is to further develop the concept of inherent safety. In this paper some methods for inherent safety evaluations are reviewed. The aim of the study is to analyze the different tools available for inherent safety evaluation and identify the most important criteria in determining the inherent safety of a process plant. A model is proposed to show the interactions of different factors on the inherent safety level of a process and the model is illustrated by a case study.  相似文献   

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