首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
阿特拉津在土壤中的环境行为研究进展   总被引:1,自引:0,他引:1  
概述了阿特拉津在土壤中的迁移、降解及其对植物的影响等环境行为,阐述了土壤组成、土壤pH值以及温度、湿度等因素对各种环境行为过程的影响,并结合目前国内外的研究现状,提出了阿特拉津环境行为新的研究方向。  相似文献   

2.
阿特拉津在土壤中的环境行为研究进展   总被引:16,自引:0,他引:16  
概述了阿特拉津在土壤中的迁移、降解及其对植物的影响等环境行为,阐述了土壤组成、土壤pH值以及温度、湿度等因素对各种环境行为过程的影响,并结合目前国内外的研究现状,提出了阿特拉津环境行为新的研究方向。  相似文献   

3.
化学改性活性炭对水中阿特拉津的吸附去除   总被引:2,自引:1,他引:2  
以5 mol/L HNO3,40%NaOH及5%H2O2对活性炭进行化学改性,采用序批式实验研究了活性炭改性前后对阿特拉津(AT)的吸附平衡特性,并以Langmuir和Freundlich模型对吸附等温线进行了拟合。结合活性炭改性前后孔结构和表面化学的变化特征,探讨了不同改性方法对AT吸附去除的影响效应。结果表明:活性炭经5 mol/L HNO3改性后对AT的吸附性能显著降低;而5%H2O2和40%NaOH改性炭对AT的吸附能力较原炭明显增强,且40%NaOH改性炭的吸附能力大于5%H2O2改性炭。原炭及改性炭对AT的吸附等温线均符合Langmuir模型。HNO3改性炭对AT吸附的降低主要是由于表面酸性基团的增加引起的;H2O2改性炭对AT吸附能力的提高主要是由于比表面积的增大引起的;而NaOH改性炭对AT吸附能力的提高是由比表面积增大和表面碱性基团增加共同作用的结果。几种改性炭和原炭对AT去除率的大小顺序依次为:NaOH改性炭>H2O2改性炭>原炭>HNO3改性炭。  相似文献   

4.
为改善农药对河岸带土壤污染状况,进而防控农业面源污染,以玉米芯为原料制备生物质炭,利用模拟实验研究其对河岸带土壤中乙草胺和阿特拉津的吸附性能影响,并探讨了其吸附机理。结果表明:河岸带土壤中添加生物炭可使乙草胺和阿特拉津的吸附容量显著增强,其吸附热力学过程与Freundlich和Langmuir模型拟合均有较好的相关性。与对照土壤相比,添加质量分数为1.0%生物炭的土壤对乙草胺的最大吸附量从13.28 μg·g-1升高到769.23 μg·g-1;添加质量分数为0.3%生物炭的土壤对阿特拉津的最大吸附量从70.92 μg·g-1升高到333.33 μg·g-1。伪二级动力学速率方程对河岸带土壤吸附乙草胺和阿特拉津的过程拟合效果较好,优于一级动力学速率模型的拟合结果,吸附量以及吸附速率均与土壤中生物炭投加量成正比。玉米芯生物炭可作为河岸带土壤的修复剂,降低乙草胺和阿特拉津的迁移性。  相似文献   

5.
除草剂阿特拉津(Atrazine)的环境行为综述   总被引:2,自引:0,他引:2  
阿特拉津(2-氯-4-乙胺基-6-异丙氨基-1,3,5,-三氮苯)是目前应用广泛的化学除草剂之一。在世界许多国家和地区的地表水和地下水中已检出了阿特拉津的残留物。阿特拉津对人类的威胁究竟有多大,已成为目前研究的热点。本文从阿特拉津的检测方法、动力学性质、生化性质及风险评估四个方面进行了综述,并提出了自己的观点。  相似文献   

6.
探讨了天然水体中存在的腐殖酸(HA)可见光降解水中阿特拉津的动力学特征和影响因素。结果表明,pH对HA可见光降解阿特拉津具有明显影响,水中HA质量浓度为5.0mg/L时,pH为3、5、7、9的条件下,受可见光照6.00h后阿特拉津(初始质量浓度5mg/L)的去除率分别为75.5%、77.3%、91.7%、84.9%,中性条件下阿特拉津可见光降解效果最佳;当HA质量浓度分别为1.5、3.0、5.0、10.0mg/L时,HA对水中阿特拉津的可见光降解均表现为促进作用,且降解过程符合一级反应动力学方程,其一级反应动力学常数分别为0.337 0、0.361 4、0.445 4、0.314 6h-1,HA为5.0mg/L时阿特拉津的可见光降解效果最佳。实际应用中,可以通过优化HA与阿特拉津的浓度比值,发挥HA促进阿特拉津可见光降解的最佳效能。  相似文献   

7.
除草剂阿特拉津生物降解研究进展   总被引:4,自引:0,他引:4  
本文综述了近年来国内外在阿特拉津降解菌及降解途径方面的研究进展 ,及在微生物产生的阿特拉津降解酶、其操作基因方面的研究现状 ,并提出了阿特拉津生物降解的研究趋势  相似文献   

8.
除草剂阿特拉津生物降解研究进展   总被引:12,自引:1,他引:12  
本文综述了近年来国内外在阿特拉津降解菌及降解途径方面的研究进展,及在微生物产生的阿拉拉津降解酶,其操作基因方面的研究现状,并提出了阿特拉津生物降解的研究趋势.  相似文献   

9.
阿特拉津在水环境中的残留及其毒理效应研究进展   总被引:5,自引:0,他引:5  
阿特拉津是中国及世界上广泛使用的一种除草剂,目前已存在于某些地区的湖泊和地下水中,并对生态环境和人类饮用水源造成潜在威胁.介绍了阿特拉津的应用概况,综述了阿特拉津在水环境中的残留状况及其对生物的生理生化毒性和遗传毒性研究进展.并在此基础上,提出应加强阿特拉津对生物的"三致"(致癌、致畸、致突变)作用、生殖毒性、蓄积毒性和毒性作用机制的研究,以及阿特拉津与其他污染物对生物的联合毒性作用和毒性作用机制的研究.  相似文献   

10.
饮用水中阿特拉津的气相色谱测定方法   总被引:1,自引:0,他引:1  
采用三氯甲烷液-液萃取技术,萃取液经毛细管柱DB-5(30 m×0.32 mm×0.25μm)分离,用氮磷检测器(NPD)检测饮用水中阿特拉津,得到了良好的分离效果和较高的灵敏度及精密度,能达到GB 3838—2003的要求。  相似文献   

11.
毒死蜱在不同土壤腐殖酸上的吸附/解吸特征   总被引:2,自引:0,他引:2  
通过平衡振荡法研究毒死蜱在不同来源土壤腐殖酸(Has)上的吸附/解吸行为.结果表明,毒死蜱在Has上的等温吸附行为用Freundlich模型描述相对更合理;它们的吸附等温线在实验范围内基本呈直线,且吸附能力很强,顺序为:紫色潮土Has>黄壤Has>中性紫色土Has>酸性紫色土Has>腐殖土Has;但毒死蜱的解吸率较小,其值均小于26.70%,有明显的滞后现象,尤其是腐殖土Has和紫色潮土Has,固定能力顺序为:紫色潮土Has>腐殖土Has>中性紫色土Has>酸性紫色土Has>黄壤Has.由于不同来源土壤中Has的组成结构差异明显,它们对毒死蜱的吸附/解吸规律表现出不同的特征.土壤Has对毒死蜱的吸附/解吸行为的影响是多种因素综合作用的结果,具体作用机理尚待进一步研究.  相似文献   

12.
研究了乐果在颗粒物表面上吸附的动力学特征,观察了颗粒物的性质对吸附行为的影响.结果表明,乐果在3种颗粒物上的吸附过程均符合一级动力学规律,其相关系数在0.986 2~0.990 5,达到极显著水平.颗粒物的性质与吸附量相关分析发现,不同颗粒物对乐果的吸附程度是由颗粒物的有机质、粘粒、阳离子交换容量(CEC)和pH等理化特征综合作用的结果.pH对吸附行为影响的实验结果指出,随着体系的pH逐渐增大,颗粒物对乐果的吸附能力增强.  相似文献   

13.
Atrazine transport through packed 10 cm soil columns representative of the 0-10 cm soil horizon was observed by measuring the atrazine recovery in the total leachate volume, and upper and lower soil layers following infiltration of 7.5 cm water using a mechanical vacuum extractor (MVE). Measured recoveries were analyzed to understand the influence of infiltration rate and delay time on atrazine transport and distribution in the column. Four time periods (0.28, 0.8, 1.8, and 5.5 h) representing very high to moderate infiltration rates (26.8, 9.4, 4.2, and 1.4 cm/h) were used. Replicate soil columns were tested immediately and following a 2-d delay after atrazine application. Results indicate atrazine recovery in leachate was independent of infiltration rate, but significantly lower for infiltration following a 2-d delay. Atrazine distribution in the 0-1 and 9-10 cm soil layers was affected by both infiltration rate and delay. These results are in contrast with previous field and laboratory studies that suggest that atrazine recovery in the leachate increases with increasing infiltration rate. It appears that the difference in atrazine recovery measured using the MVE and other leaching experiments using intact soil cores from this field site and the rain simulation equipment probably illustrates the effect of infiltrating water interacting with the atrazine present on the soil surface. This work suggests that atrazine mobilization from the soil surface is also dependent on interactions of the infiltrating water with the soil surface, in addition to the rate of infiltration through the surface soil.  相似文献   

14.
The behavior of chlorantraniliprole (CAP) and dinotefuran (DNF) insecticides was investigated in clay loam soil, a common type of the Egyptian soil. Effect of temperature, pH and particle size of the soil on the adsorption process was studied. Adsorption isotherm by bulk soil and its constituents; humic acid (HA), clay, silt and sand fractions was measured using batch equilibration technique. The results showed that the adsorption of the insecticides tested was significantly affected by the temperature and was a spontaneous interfacial process in the soil. Freundlich model accurately predicted the adsorption behavior of both insecticides. The interaction between soil and insecticides was endothermic and the highest adsorption for CAP and DNF was obtained at pH 9. However, the effect of pH on the adsorption of DNF was lower than that of CAP. Sorption of CAP and DNF on HA fraction was significantly greater than on clay fraction and bulk soil. In addition, the adsorption was significantly increased with particle size decrease. It could be inferred that the adsorption of CAP and DNF on clay loam soil was physical in nature and greatly influenced by the soil components, pH and temperature.  相似文献   

15.
Abstract

The adsorption, desorption, and mobility of permethrin in six tropical soils was determined under laboratory and greenhouse conditions. The six soils were selected from vegetable growing areas in Malaysia. Soil organic matter (OM) was positively correlated (r 2 = 0.97) with the adsorption of permethrin. The two soils, namely, Teringkap 1 and Lating series with the highest OM (3.2 and 2.9%) released 32.5 and 30.8% of the adsorbed permethrin after four consecutive repetitions of the desorption process, respectively, compared to approximately 75.4% of the Gunung Berinchang soil with the lowest OM (1.0%) under the same conditions. The mobility of permethrin down the soil column was inversely correlated to the organic matter content of the soil. Permethrin residue penetrated only to the 10–15 cm zone in the Teringkap 1 soil with 3.2% OM but penetrated to a depth of more than 20 cm in the other soils. The Berinchang series soil with the lowest OM (1.0%) yielded leachate with 14.8% permethrin, the highest level in leachates from all the soils tested. Therefore, the possibility for permethrin to contaminate underground water may be greater in the presence of low organic matter content, which subsequently allows a higher percentage of permethrin to move downwards through the soil column.  相似文献   

16.
Studies were carried out on the adsorption and desorption of added copper (from 100 to 600 microg g(-1)) to whole soils with contrasting properties: a Podzol (Godech A and Godech B) and a Chernozem (Gramada). Adsorption resulted in high Cu concentrations for the Podzol. The adsorbed copper, especially that in the B-horizon, is also potentially mobile, as judged by its ease of desorption on treatment with 0.01 m CaCl(2). A higher proportion of the added adsorbed copper is retained in Godech A soil (4% clay), than in Godech B soil (41% clay). Clay minerals are the principal adsorbent in the Podzol (Godech B), because of the high desorption observed at a low site coverage (7% CEC). The Godech B clay fraction (<0.001 mm) simulates the behaviour of the whole soil. The clay fraction from the Chernozem (Gramada) shows contrasting behaviour, as compared to the whole soil. Copper in the Chernozem is specifically (non-exchangeably) adsorbed, even at pH 2.7. A Langmuir model is appropriate for describing Cu-adsorption for the systems investigated at the acid pH values.  相似文献   

17.
This investigation was performed to determine the effect of physicochemical soil properties on penoxsulam, molinate, bentazon, and MCPA adsorption–desorption processes. Four soils from Melozal (35° 43′ S; 71° 41′ W), Parral (36° 08′ S; 71° 52′ W), San Carlos (36° 24′ S; 71° 57′ W), and Panimavida (35° 44′ S; 71° 24′ W) were utilized. Herbicide adsorption reached equilibrium after 4 h in all soils. The Freundlich L-type isotherm described the adsorption process, which showed a high affinity between herbicides and sorption sites mainly because of hydrophobic and H-bonds interaction. Penoxsulam showed the highest adsorption coefficients (4.23 ± 0.72 to 10.69 ± 1.58 mL g?1) and were related to soil pH. Molinate showed Kd values between 1.72 ± 0.01 and 2.3 ± 0.01 mL g?1and were related to soil pH and organic matter, specifically to the amount of humic substances. Bentazon had a high relationship with pH and humic substances and its Kd values were the lowest, ranging from 0.11 ± 0.01 to 0.42 ± 0.01 mL g?1. MCPA Kd ranged from 0.14 ± 0.02 to 2.72 ± 0.01 mL g?1, however its adsorption was related to humic acids and clay content. According to these results, the soil factors that could explain the sorption process of the studied herbicides under paddy rice soil conditions, were principally humic substances and soil pH. Considering the sorption variability observed in this study and the potential risk for groundwater contamination, it is necessary to develop weed rice management strategies that limit use of herbicides that exhibit low soil adsorption in areas with predisposing conditions to soil leaching.  相似文献   

18.
聚丙烯酰胺在土壤上的吸附研究   总被引:3,自引:0,他引:3  
采用静态吸附法研究了聚丙烯酰胺(PAM)在黄土、盐碱土上的吸附行为,考查了不同液固比、吸附时间对土壤吸附量的影响,得出了PAM在土壤上的吸附等温线.结果表明,PAM在土壤上有很强的吸附亲合力,在盐碱土、黄土上的吸附等温线都符合Langmuir吸附模式,在相同实验条件下,盐碱土饱和吸附量比黄土饱和吸附量大.  相似文献   

19.
活性炭纤维对染料的吸附性能研究   总被引:7,自引:0,他引:7  
研究了聚丙烯腈活性炭纤维(P-ACF)、粘胶活性炭纤维(R-ACF)和颗粒活性炭(GAC)对5种红色染料的吸附能力,通过简单的模型,算出5种染料在两种活性炭纤维上的吸附速率常数。结果表明,尽管吸附能力随染料种类不同而有一定的差别,但总体上,聚丙烯腈活性炭纤维的吸附能力略低于颗粒活性炭,而粘胶活性炭纤维的吸附能力则远远优于前两种,对染料有着较大的吸附容量和较快的吸附速率。  相似文献   

20.
新型树脂对氯酚类物质的吸附研究   总被引:4,自引:0,他引:4  
合成了乙酰氯修饰树脂NDA-O,与Purolite公司的MN-200相比,合成的树脂比表面积较小,但酸性官能团较多.用两种树脂吸附2-氯酚、4-氯酚和2,4-二氯酚发现,吸附结果可以用Langmuir和Freundlich等温吸附方程很好地模拟,合成的NDA-O对3种氯酚类物质的吸附能力优于MN-200.两种树脂对氯酚类物质的吸附量随着温度的升高而减少,表明吸附是放热过程,同时对氯酚类物质的吸附焓变随着吸附量的增大而减小.对同一种树脂来说,吸附量随着氯代程度的增加而增加,取代氯数相同的时候,吸附量与吸附质的K..成正相关.进一步研究了pH对吸附的影响,在pH大于9时,3种氯酚类物质的吸附量均急剧减少.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号