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1.
陆长梅  吴国荣 《云南环境科学》2000,19(A08):22-25,39
本文研究了Hg^2+对普通小球藻的致毒效应与银杏叶提取物的保护作用。试验显示:普通小球藻的生理代谢活动对Hg^2+敏感,单Hg^2+浓度提高,普通小球藻生长量降低;可溶性蛋白含量、SOD活性、总抗氛能为等在Hg^2+0~3mg.L^-1范围内应激升高,4~5mg.L^-1时升高幅度下降;而O2^-、MDA、脂质氢过氧化物含量均在供处理Hg^2+浓度 持续上升,表现出Hg^2+促进O2^-、MDA与  相似文献   

2.
利用紫露草微核技术对大气中重要的污染物SO2和NOx进行了室内外试验。结果表明,紫露草对大气中SO2和NOx较敏感,紫露草微核频率MCN%(效应y)与SO2、NOx的浓度(剂量x)的关系在一定的范围内呈正相关。对于SO2当浓度在0.00-3.75mg/m^3之间时,对应的微核频率y=8.38+4.38x,r=0.91;对于NOx当浓度在0.00-1.00mg/m^3之间时,对应的微核频率y=4.8  相似文献   

3.
黄海西部大气湿沉降(降水)的pH与主要酸碱离子的关系   总被引:8,自引:2,他引:8  
对黄海西部的千里岩、青岛的麦岛两个降消要样点1997、1998丙年所收集的113个降 H^+、NH4^+、K^+、Na^+、Ca^2+、Mg^2+、F^-、Cl^-、NO3^-、SO4^2-共10种离子成分的含量,分别用NA^+、Mg^2+、Ca^2++NH4^+)/(NO3+nsaSO4^2-、cmssSO4^2-(nssSO4^2-)的相关分析。结果表明:(1)以Mg^2+作为参考元素计算得到  相似文献   

4.
水中微量铝的间接原子吸收法测定   总被引:2,自引:0,他引:2  
在HAc-NaAc缓冲溶液(pH4.5)体系中,利用(1-(2-萘酚(PAN),Al^3^+与Cu^2^+-EDTA发生定量交换反应,用氯仿萃取出Cu^2^+-PAN,用原子吸收法测定水中的Cu^2^+,以间接测定AL^3^+。方法的最佳线性范围为0.1-1.0mg/L,最低检出浓度为0.1mg/L;测定河水,饮用水,地下水中的Al^3^+,其回收率在85.0%-109%之间,变异系数为1.5%-  相似文献   

5.
利用合成的NIPAAm-AAc温敏性线型共聚研究了其对无机金属离子的吸附性能,以期应用于水污染的治理,结果表明其有明显的浓度效果,在PH=4时,对Y^3+,Er^3+和UO^2+2的浓集率分别达到84%、65%和56%,相应的浓集量分别为11.2mg.g^-1,4.45mg.g^-1和11.3mg.g^-1,并讨论了影响浓集的条件和吸附机理。  相似文献   

6.
报道了一种简便的CC14体外引发自由基反应的模型,以小鼠肝匀浆脂质过氧化产物丙二醛(MDA)的OD532mm值(MDA-OD532mm)作为测定自由基反应的间接指标,研究了Hg^2+、Mn^2+、Ni^2+、Cr^3+、SeO3^2-等离子和Ss2O3水溶液在CC14引发自由基反应体系中的作用。结果表明:Mn^2+能显著抑制自由基的生成,Cr^3+有一定的抑制作用,而HgT^2+对自由基产生有明显促进  相似文献   

7.
选择性螯合滴定法测定钙镁   总被引:1,自引:0,他引:1  
用知量Tartrate、TEA和DL-Cysteine掩蔽Fe^3+、Al^3+、Cu^2+、Ni^2+、Zr^4+、Cd^2+、Pb^2+和Mn^2+等离子,在PH为10左右用EDTA滴定钙镁含量。然后另入Oxine分解Mg-EDTA螯合物,用Ca^2+标准溶液滴定释放出的EDTA。用MTB-XO-CPB为混合指示剂,终点颜色变化敏税,一般常见金属离了均不干扰。可用于测定水和工业废水钙,镁含量。  相似文献   

8.
稀土金属离子对梨形四膜虫的24小时生长影响   总被引:1,自引:0,他引:1  
应用4种方法(细胞直计计数法、中性红试验、重蛋白及核酸含量测定)研究不同浓度稀土金属离子La^2+、Sm^3+、Y^3+、Gd^3+处理24h后,对梨形四膜虫的生长影响,结果表明,在低浓度时La^3+、Sm^3+、Y^3+,对四膜虫具有刺激生长的作用。随着浓度的升高,4种稀土金属离子均表现出毒性效应;高浓度时,抑制生长艇特别明显。计算La^3+、Sm^3+、Y^3+、Gd^3+的半数抑制浓度(IC  相似文献   

9.
酸尘降地区酸雨难在短期内单独致使水体和土壤酸化。降尘对土壤--蔬菜中的SO4^2-、NO3^-、Ca^2+和Hg有较大贡献。随着降尘量的增加,对应土壤中的全S、吸附态S和Hg含量也相应增加,表现出高度下相关,但未达显著水平;NO3表现为中度相关,Ca^2+表现为弱相关。降尘土促进酸寸对蔬菜的危害,主要表现多病害,且伴有虫害发生,蔬菜宜种度变窄,对酸沉降敏感的青菜、蕃茄等几乎绝种。钙质土对降尘和酸雨  相似文献   

10.
酸沉降与非金属建筑材料腐蚀机理的探讨   总被引:2,自引:0,他引:2  
将酸雨对非金属建筑材料的整个腐蚀过程分为腐蚀初期,中期和末期3个腐蚀阶段,进而提出腐蚀机理。对整个腐蚀过程探讨表明:酸雨对材料的腐蚀是酸雨中H^+和SO4^2-共同侵蚀作用的结果;H^+将溶解硬化水泥中的Ca(OH)2,SO4^2-将与硬化水泥石作用生成膨胀性的物质CaSO4·2H2O。因此,酸雨对非金属建筑材料的腐蚀,主要是H^+引起溶解腐蚀和SO4^2-引起的膨胀腐蚀 。  相似文献   

11.
运用分形理论修正了颗粒物微界面吸附模型,建立了朗格缪尔(Langmuir)、弗伦德利希(Freundlich)和表面络合模型的分形吸附等温线方程式.其中,朗格缪尔(Langmuir)吸附等温线的分形表达式为:Γ=ΓmCc^1/m/(b^m Cc^1/m),指数m与颗粒物表面分维Ds的关系如下:m∝ac^D/2-1∝ro^Do-2;表面络合模型的分形表达式为:Γ=ΓmCs^(n/x)/(b^(n/x) Cs^(n/x)),而且lgb=lg(ks/kb) pH,指数x/n与颗粒物表面分维Ds的关系如下:x/n∝0^D/2-1∝r0^D-2;相应的弗伦德利希(Freundlich)吸附等温线的分形形式分别为:Γ=(Γm/bm)Cs^1/n,Γ=(Γm/b^(x/n))Cr^(n/x),通过对献中的数据的模拟初步讨论了分形模型的适用性,结果表明,它们具有更接近于实际的描述微界面吸附过程的能力,通过lg(x/n)=lgk’ (Dn-2)lgro计算出土壤颗粒和尾矿砂颗粒的表面分形维数分别为2.42和2.72。  相似文献   

12.
The present study was undertaken to determine the persistence and mobility of 2,4-dichlorophenoxy acetic acid (2,4-D) in unsaturated soil zone under real field conditions for the wheat crop in Roorkee, India. Three experimental plots were chosen in the agricultural field itself to represent the real field conditions in the study area and the potential movement and persistence of herbicide 2,4-D was investigated under three different irrigation treatments. The presence of herbicide along with soil water content was determined in soil at different depths at a temporal scale. The movement of the herbicide was also simulated numerically by solving the coupled soil water content movement and mass transport equations using HYDRUS-1D. The measured soil water content trends and the 2,4-D concentration profiles showed a good agreement with the numerically simulated results. The maximum effect of the herbicide was primarily retained up to 15 cm of the soil profile. The current existing dosage of 0.5 kg ha−1 of pesticide was found to be safe to avoid soil contamination as no residue of 2,4-D was traced at the end of the wheat crop season in any of the plots. Higher concentrations of 2,4-D were also simulated numerically and the simulated results showed that the safe dosage of pesticide application would depend on irrigation treatments.  相似文献   

13.
纳米四氧化三铁对2,4-D的脱氯降解   总被引:8,自引:4,他引:4  
方国东  司友斌 《环境科学》2010,31(6):1499-1505
采用纳米四氧化三铁(Fe3O4)降解水溶液中的2,4-二氯苯氧乙酸(2,4-D),考察了2,4-D初始浓度、纳米Fe3O4投加量、溶液pH和温度等因素对2,4-D降解率的影响.结果表明,纳米Fe3O4对2,4-D有显著的降解效果,初始浓度为10 mg/L的2,4-D, 48 h内降解率可达48%.纳米Fe3O4对2,4-D的降解是一个还原脱氯过程,反应体系中氯离子浓度随2,4-D浓度降低而升高.LC/MS分析表明,2,4-D降解的主要产物是苯酚,其他中间产物是2,4-二氯苯酚(2,4-DCP)、4-氯苯酚(4-CP)和2-氯苯酚(2-CP).溶液中2,4-D的降解符合准一级反应动力学,产物4-CP、2,4-DCP和苯酚的反应速率常数K分别为0.0043、0.0026和0.0032 h -1.环境条件对降解效率有显著影响,2,4-D初始浓度在0~10 mg/L、纳米Fe3O4投加量0~300 mg/L的范围内,2,4-D降解率随初始浓度和纳米Fe3O4投加量的增加而增大;pH对2,4-D的脱氯降解有显著影响,在pH为3.0时,纳米Fe3O4对2,4-D的还原脱氯效果最好;温度升高,可以提高脱氯反应速率.  相似文献   

14.
Pesticide pollution of surface waters represents a considerable hazard for the aquatic environment. However, the mean amount of pesticides reaching the water resources varies considerably between regions and depends highly upon application rates, chemical characteristics of pesticides and natural conditions during application. In this study a model was developed which estimates loss of 42 active ingredients applied to 11 field crops, vineyards and orchards along each non-point source path of entry (subsurface drains, runoff and spray drift). A spatially and temporally differentiated data set of application rates and periods was compiled for each active ingredient and target culture to enable the modeling of pesticide transport. The model results are provided in digital raster format (100 m×100 m) within a geographic information system (GIS). The calculated pesticide loads in surface waters were compared with measured loads from different catchments in Germany. Both data sets agreed as to the order of magnitude, nevertheless due to the scale of the study the estimated loads cannot be interpreted as absolute values and only differences between active ingredients, regions and application periods should be assessed.  相似文献   

15.
16.
To elucidate the effect of nitrite ion (NO2^-) on the photodegradation of organic pollutants, a 300 W mercury lamp and Pyrex tubes restricting the transmission of wavelengths below 290nm were used to simulate sunlight, and the photodegradation processes of 2,4-dichlorophenoxyacetic acid (2,4-D) with different concentrations of NO2^- in freshwater and seawater were studied. The effect of reactive oxygen species (ROS) on the photolysis of 2,4-D was also demonstrated using electron paramagnetic resonance (EPR). The results indicated that the 2,4-D photolysis reaction followed the first-order kinetics in freshwater and seawater under different concentrations of NO2^-. Meanwhile, the photochemical reaction rate of 2,4-D increased with increasing concentration of NO2^-. When the concentration of NO2^- was lower than 23 mg/L, the photodegradation rate of 2,4-D in seawater was higher than that in freshwater. However, when the concentration of NO2^- was reached 230 mg/L, 2,4-D degradation slowed down in seawater. It was important to note that EPR spectra showed NO2 radical was generated in the NO5 solution under simulated sunlight irradiation, indicating that 2,4-D photodegradation could be induced by NO2. These results show the key role of NO2^- in photochemistry and are helpful for better understanding of the phototransformation of environmental contaminants in natural aquatic systems.  相似文献   

17.
取代芳烃对酵母菌毒性的定量结构-活性相关研究   总被引:2,自引:0,他引:2  
定量测定了苯胺类、苯甲酸类、卤代苯类、苯腈类、硝基苯类、苯酚类等6类化合物对酵母菌的生长抑制毒性,结果表明化合物的最小产生清晰抑菌圈浓度Cmiz与辛醇-水分配系数及一阶分子连接性价指数有如下关系:log(1/Cmiz)=0.38logKow+0.33^1X^v-0.38 r=0.92 s=0.22 n=77。在上述6类取代苯类化合物中,它们与酵母菌的反应性大小有如下顺序:卤代苯类≈苯甲酸类〈苯胺类  相似文献   

18.
两种微藻胞外分泌物与NO2-、NO3-对2,4-D光解的影响   总被引:1,自引:1,他引:0  
在模拟太阳光照射下,利用旋转式光化学反应装置,研究了海水小球藻(Chlorella vulgaris)和新月菱形藻(Nitzschia closterium)的胞外分泌物(EOM),以及分别在NO-2或(和)NO-3共存条件下对2,4-二氯苯氧乙酸(2,4-D)光解的影响.实验结果表明,2,4-D在海水小球藻和新月菱形藻EOM及分别在NO-2、NO-3共存下的光解过程均符合准一级动力学反应.研究发现,2,4-D的光解速率随海水小球藻和新月菱形藻EOM浓度的增加而减小,表明这两种微藻EOM可抑制海水中2,4-D的光解.当在微藻EOM溶液中分别加入不同浓度的NO-2或NO-3后,微藻EOM对2,4-D光解的抑制作用减弱,且随着NO-2和NO-3浓度的增加,2,4-D光解速率明显增加.特别是当微藻EOM与NO-2或NO-3三者共存时,可进一步促进2,4-D的光解.  相似文献   

19.
株洲市工业区大气中SO2转化速率的研究   总被引:2,自引:0,他引:2  
在湖南省株洲市工业区的下风向布点,同时测定大气中SO2的浓度、TSP和<0.25μm细粒子中SO2-4的浓度.结果表明,大气中SO2浓度随着离污染源距离的增加迅速下降,和SO2相比,颗粒物中SO2-4浓度随距离的增加而降低的程度要慢得多.同步测定的SO2浓度和细粒子SO2-4浓度有显著的相关关系.根据风向、风速和新产生的细粒子中的SO2-4浓度及大气中SO2的浓度计算了株洲教育学院处SO2的转化速率,春季湿度大,SO2转化速率也大,为4.8%/h,秋季湿度小,SO2的转化速率变低,为1.5%/h.春季中路铺SO2转化速率为3.1%/h.  相似文献   

20.
张剑波 《环境科学》1999,20(6):87-90
利用合成的PNIPAAm/AAc交联共聚温敏性水凝胶分别对水溶液中微量的Y^2+,CU2^2+离子进行浓集分离研究。实验结果表明,凝胶能有效浓集Y^2+,UO2^2+离子,在PH=1~4范围内,凝胶的溶胀比及对Y^3+,UO2^2+的浓集率均随PH的增大而增大,浓集率分别达到80%和90%,凝胶溶胀比的增大浓集量分别为5.293mg.g^-1、36.16mg.g^-1凝胶的表面积也对浓集率有限大影  相似文献   

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