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1.
我国化肥和农药非点源污染状况综述   总被引:3,自引:0,他引:3  
从农田排水与径流对地表水体的污染,渗漏对地下水体的污染和生态系统内部结构破坏加剧污染物流失等3个方面综述了我国近年来在化肥、农药非点源污染调查与研究方面取得的成果。  相似文献   

2.
Specific anthropogenic substances derived from seepage and leakage water from a waste deposit landfill were analysed in groundwater and drainage effluents using gas chromatography-mass spectrometry (GC/MS). Here, we demonstrate the application of an organic marker approach to study lateral and vertical distribution of contamination as well as the long-term emission behaviour. Source-specific and environmentally-stable pesticides, plasticisers and pharmaceuticals, such as N,N-diethyl toluamide, N-butyl benzene sulfonamide, clofibric acid, mecoprop and bisphenol A, were quantitatively analysed. A distinct lateral expansion was detected. Although temporal variations were high, no significant trend was observed.  相似文献   

3.
Small air-breathing terrestrial arthropods (e.g. beetles, ants, crabs) living within the intertidal zone of mud and sand flats construct burrows with a narrow opening to the substrate surface. Despite frequently remaining open, these burrows are not flooded by the incoming tide. We examine, from a theoretical standpoint, the rôle of burrow-opening diameter in preventing burrow flooding. We determine a critical burrow diameter of 3 mm above which burrows are likely to flood unless the entrance is plugged by the burrow's inhabitant(s) prior to tidal inundation. We examine water penetration via the burrow entrance and seepage through the burrow walls. A practical mathematical solution is provided which can be used to examine the extent to which water may penetrate a given animal burrow in the field.  相似文献   

4.
本文探讨了有机磷、有机氯和氨基甲酸酯等杀虫剂、杀菌剂和除草剂的各种不同类型以及所研究的全体农药在正辛醇与水中的分配系数与其水溶解度的相关关系,建立了相关经验方程。回归结果表明,除杀菌剂外两者间具有很好的线性关系。所有农药的回归方程中,分配系数和水溶解度均覆盖了10个数量级,两者间可很好地进行互算。  相似文献   

5.
新烟碱类农药的污染现状及转化行为研究进展   总被引:1,自引:0,他引:1  
新烟碱类(neonicotinoids)农药自在20世纪80年代中期引入以来,便发展成为世界上使用最广泛的一类杀虫剂。近年来,该类化合物在环境中被不断检出,并通过饮用水和食物等方式进入食物链,给人类健康带来极大的安全隐患。文章综述了新烟碱类杀虫剂在空气、土壤、水相、生物体和人体中的暴露浓度,以及这类农药在环境中的转化行为。目前针对新烟碱类杀虫剂的环境暴露研究仍十分有限,需要更全面调查其在多环境介质中的暴露状况以综合评价其生态风险。关于新烟碱类化合物的毒理学研究主要集中在急性毒性试验,而对于其他形式的毒性效应有待进一步研究。最后对新烟碱农药未来的研究重点和方向提出了展望。  相似文献   

6.
Loss of two pesticides with different mobility characteristics, bentazone (Koc approximately 34) and propiconazole (Koc approximately 1800), were studied at three agricultural fields (Askim, Bj?rnebekk and Syverud) in SE Norway. A conservative tracer (Br) was used to follow the flow of water. The loss of pesticides varied among the fields, depending on hydrological characteristics and soil properties. The loss of pesticides was higher from two artificially levelled silty clay loam soils with poor aggregate stability (Askim and Bj?rnebekk) compared to a loam/silt loam soil with increased content of organic carbon and better aggregate stability (Syverud). The total accumulated loss was <0.5% from all fields. The highest pesticide concentrations were measured at the first runoff episode after application for both the mobile (bentazone) and less mobile pesticide (propiconazole) in the surface runoff. In the drainage water, the peak for the less mobile pesticide coincided with the Br tracer, while the peak for mobile pesticide appeared earlier than the Br tracer. Rapid movement of water, particles and pesticides through soils indicate flow through macropores. Larger proportions (in percent of total applied) of both the mobile and the strongly sorbed pesticides were lost through the drainage as compared to the loss through surface runoff at Askim. Here, it is suggested that macropore flow contribute to the increased loss of pesticides through the drainage. At Syverud, high infiltration capacity reduces the amount of water available for surface runoff, and somewhat higher loss of the mobile pesticide was registered in the drainage compared to the surface runoff. For the strongly sorbed pesticide, however, propiconazole was neither detected in surface nor in drainage water at Syverud. Generally, there was a higher percentage loss of the mobile compared to the strongly sorbed pesticide in both surface and drainage water, which is in agreement with the pesticides mobility characteristics in soil. An exception was, however, the erodible soil Bj?rnebekk, where a higher fraction of propiconazole was lost in the surface runoff compared to bentazone. Large amounts of sediment transport from the Bj?rnebekk field probably contributed to enhanced transport of the strongly sorbed pesticide.  相似文献   

7.
太湖水体中5种有机磷农药混合物生态风险评价   总被引:2,自引:0,他引:2  
有机磷农药是一类广泛分布于我国水环境中的污染物,即使在水体中的污染水平处于规定“安全标准”之下,其联合暴露产生的风险仍有可能威胁水生生态安全。采用基于浓度加和模型与生物敏感度分布曲线的混合物风险商法,评价了太湖水体中敌敌畏、对硫磷、甲基对硫磷、马拉硫磷和乐果5种有机磷农药混合物产生的生态风险。结果表明:2003~2004年期间3个不同时期太湖水体中5种有机磷农药的混合物生态风险商(RQm )均大于1,有机磷农药混合物在2003~2004年期间对太湖水生生物构成了一定威胁。  相似文献   

8.
消落带土壤水分是制约植物生长发育的关键因素,对库区消落带生态修复意义重大.本文系统分析了乌东德库区消落带修复试验区土壤含水量分布,探索了土壤水分空间变化和影响因素.结果表明:研究区5月水分含量低于5%,不同试验分区和高程区域土壤水分分布受到微地形、土壤特征、植被类型和植被覆盖度等影响.土壤水分随深度变化的主控因素包括地...  相似文献   

9.
《Ecological modelling》2007,209(1):53-64
In this paper, a state-of-the-art is given of the current knowledge related to the occurrence and sources of pesticides in surface waters. An emphasis is put on sources and transport routes that contribute most to the pesticide loads found in river systems. Possible mitigation measures are described. Once pesticides have entered a river system, they are exposed to different physical, chemical and microbial processes which determine their fate. As mathematical models can describe the fate of pesticides in river systems and can be used for the control of environmental pollution and management of resources, an overview is given of available watershed and in-river water quality models able to predict pesticide concentrations in surface waters. Advantages and disadvantages of simple screening tools and complex watershed models are discussed. Finally, some recommendations are made concerning monitoring, modeling and their combined use in order to achieve the water quality goals set by the EU Water Framework Directive.  相似文献   

10.
为明确蔬菜常用农药在地下水中的环境风险,运用China-Pearl和SCI-GROW模型开展地下水环境暴露评估,并根据我国成人和儿童暴露参数推导25种农药预测无效应浓度(PNEC)。研究发现,25种农药PECgw为0~18.340μg·L-1,成年人PNECgw为0.003~19.654 mg·L-1,儿童PNECgw为0.001~23.253 mg·L-1。成年人和儿童的RQgw值均小于1,表明25种农药按照登记用量使用,我国成人和各年龄阶段儿童直接饮用施用农药区域地下水的环境风险可接受。  相似文献   

11.
The drawback of some organic pesticides is their low water solubility. Cyclodextrins are used as agents for improving pesticides water solubility. However, the stabilization of the crystalline lattice can reduces to a large extent the solubility of cyclodextrins, especially β-cyclodextrin. Here, searching for the water soluble β-cyclodextrin derivatives, a set of new “host” compounds were prepared by the reaction of β-cyclodextrin with methyl epoxycinnamate. The reactants ratio was varied in to study the substitution degree of the obtained derivatives. The structure was determined by the 1H-NMR and FT IR spectra. The average degree of substitution was determined by integration of the corresponding NMR signals and by elemental analysis. The solubility of four selected pesticides: dimethoate, simazine, linuron and thiram, in water with and without addition of the new modified β-cyclodextrin was measured by ultraviolet spectrophotometry. Our results showed that the modified β-cyclodextrins significantly improve solubility of pesticides.  相似文献   

12.
快速测定水中有机磷农药方法的研究   总被引:25,自引:0,他引:25  
研制出一种能快速测定水中有机磷农药的植物酯酶片和底物片。这种酶片和底物片具有价格低,易获取、稳定性好等优点,适用于野外无仪器设备条件下快速检测有机磷农药危险水平,对常用几种有机磷农药来说,其检出限在0.04-10.0mg.l^-1范围。  相似文献   

13.
Groundwater is the only source of water in the Gaza Strip. The results of a 10-year monitoring program revealed that more than 90% of the available water is not suitable for drinking purposes as a result of elevated chemical contaminants as well as microbiological organisms. The archives of the local hospitals showed catastrophic records on diseases caused by water directly and indirectly. Methemoglobinemia and dental fluorosis are well-known diseases caused by elevated nitrate and fluoride, respectively. Water-borne diseases are currently high and will increase if water, sanitation, and food-control services are not restored, or are allowed to deteriorate further. Heavy use and misuse of banned and prohibited pesticides may show other hard diseases in the near future. Geography, politics, and war combine to make the Gaza Strip a worst-case scenario for water-resource planners. Urgent alternative water resources should be secured and the human health should be given the highest priority.  相似文献   

14.
Loss of two pesticides with different mobility characteristics, bentazone (Koc 34) and propiconazole (Koc 1800), were studied at three agricultural fields (Askim, Bjørnebekk and Syverud) in SE Norway. A conservative tracer (Br) was used to follow the flow of water. The loss of pesticides varied among the fields, depending on hydrological characteristics and soil properties. The loss of pesticides was higher from two artificially levelled silty clay loam soils with poor aggregate stability (Askim and Bjørnebekk) compared to a loam/silt loam soil with increased content of organic carbon and better aggregate stability (Syverud). The total accumulated loss was <0.5% from all fields. The highest pesticide concentrations were measured at the first runoff episode after application for both the mobile (bentazone) and less mobile pesticide (propiconazole) in the surface runoff. In the drainage water, the peak for the less mobile pesticide coincided with the Br tracer, while the peak for mobile pesticide appeared earlier than the Br tracer. Rapid movement of water, particles and pesticides through soils indicate flow through macropores. Larger proportions (in percent of total applied) of both the mobile and the strongly sorbed pesticides were lost through the drainage as compared to the loss through surface runoff at Askim. Here, it is suggested that macropore flow contribute to the increased loss of pesticides through the drainage. At Syverud, high infiltration capacity reduces the amount of water available for surface runoff, and somewhat higher loss of the mobile pesticide was registered in the drainage compared to the surface runoff. For the strongly sorbed pesticide, however, propiconazole was neither detected in surface nor in drainage water at Syverud. Generally, there was a higher percentage loss of the mobile compared to the strongly sorbed pesticide in both surface and drainage water, which is in agreement with the pesticides mobility characteristics in soil. An exception was, however, the erodible soil Bjørnebekk, where a higher fraction of propiconazole was lost in the surface runoff compared to bentazone. Large amounts of sediment transport from the Bjørnebekk field probably contributed to enhanced transport of the strongly sorbed pesticide.  相似文献   

15.
A high performance liquid chromatographic method has been developed to determine pesticides in river water as both dissolved phase and suspended phase. The target pesticides were eight herbicides, asulam, diuron, flazasulfuron, linuron, MCPB, mecoprop, pyrazosulfuron‐ethyl and siduron, and two fungicides, oxine‐copper and thiram. The pesticides in filtered river water were extracted with styrene‐divinylbenzene copolymer and were eluted with acetonitrile. The pesticides on suspended solids were extracted ultrasonically with acetonitrile. Each eluate was concentrated and analyzed by HPLC with multiwavelength detector. Recoveries of the pesticides in the overall procedure of this method were 78–114% for filtered river water and 75–107% for suspended solids. The limits of detection in water and suspended solids ranged from 0.1 to 0.9 μg/L and 1 to 7 μg/g, respectively. Pesticide distribution between soluble phase and suspended phase in river water was measured by this method.  相似文献   

16.
构建了东苕溪流域水稻地表水暴露场景,对国外已广泛应用的稻田-地表水暴露评价模型(RICEWQ—EX—AMS)进行二次开发,并应用构建的场景和开发的模型对东苕溪流域稻田常用农药品种进行水生生态风险评价和健康风险评价。结果表明,在所评价的10种东苕溪流域常用农药品种中,除草剂氟乐灵对藻具有急性高风险,杀虫剂硫丹对鱼既具有急性高风险,又具有慢性风险,阿维菌素对泾具有急性高风险,氟铃脲对涵既具有急性高风险,又具有慢性风险,其余品种对鱼、溢和藻的急慢性风险均较低。运用传统评价法和风险评价模型计算法得出了相一致的结论,即所评价的10个农药品种对人体健康均无风险,该评价结果与所评价农药的实际风险表现较吻合。认为所构建的场景、模型能较好地用于东苕溪流域稻田农药品种的风险评价。  相似文献   

17.
ABSTRACT

The main objective of this study was to investigate the effects of combining subsoil and incorporation of corn stover on soil profile, soil physicochemical properties, and corn yield. A five-year field trial was conducted that consisted of two treatments arranged in a completely random design and replicated three times. Two soil management operations were tested: subsoil + corn stover incorporation (plow construction [PC] treatment) and conventional rotary tillage (control check [CK] treatment). Compared with rotary tillage, it was found that combining subsoil and corn stover incorporation significantly affected corn grain yield in all seasons. Further, combining subsoil and corn stover incorporation significantly increased the thickness of the plow layer, quantity of plow layer soil, thickness of the plow pan and soil bulk density, as well as soil organic matter, available nitrogen, available phosphorus, and available potassium. Evidence indicates that reconstructing the soil plow layer through combination of subsoil and corn stover incorporation improved soil structure, nutrient content, and corn yield. It is of interest that farmers are now applying subsoil and returning crop straw instead of solely relying on rotary tillage.  相似文献   

18.
调研已开发的包括吡虫啉、噻虫嗪、噻虫胺、啶虫脒、噻虫啉、呋虫胺、烯啶虫胺、环氧虫啶、氯噻啉、哌虫啶和氟啶虫胺腈在内的11种新烟碱类农药在我国的登记现状。根据已登记的新烟碱农药的使用方法,开展了不同暴露场景下蜜蜂的初级风险评估。结果表明,喷施场景下,吡虫啉、噻虫嗪、噻虫胺、烯啶虫胺、呋虫胺、氟啶虫胺腈和氯噻啉这7种新烟碱类农药在不同作物上使用对蜜蜂的风险商值均大于1,风险均不可接受;啶虫脒、哌虫啶和噻虫啉在所有登记作物上使用对蜜蜂的风险商值均小于1,风险可接受。土壤或种子处理场景下,除噻虫啉外,其余4种新烟碱类农药包括吡虫啉、噻虫胺、噻虫嗪和呋虫胺对蜜蜂的风险商值均大于1,风险均不可接受。评估结果可为新烟碱类农药在我国的登记管理提供科学参考。  相似文献   

19.
Results of a field experiment (please refer to Warrelmann et al. 2000a) document TNT-degradation and regeneration after the establishment of a phytoremediation. Various approaches are included in a complex monitoring system, which are conducted in the field (nitroaromatics in soil, seepage water, and plants; soil fauna; soil fungi; decomposition) as well as in the lab (a battery of 6 biotests). The data document a high heterogeneity of the TNT-contamination, a rapid initial decrease and a mediocre displacement of nitroaromatics in plants and seepage water. The initial rapid transformation of TNT to aminodinitrotoluenes ceases significantly after 3 months. Results of the biotest battery allow a sophisticated assessment of soil toxicity; the results from the soil ecological field investigations make the long-term effects of TNT-contamination likely. In a third part of the series of articles, a synopsis and judgement of the project will be delivered.  相似文献   

20.
A study was performed in a Protected Area (Natural Reserve of Sado Estuary) in 1996, to evaluate the acute toxicity for aquatic life of surface water from rice fields treated with pesticides, particularly with molinate and quinclorac. As a preliminary assessment, the following rapid toxicity tests were used: “Rotoxkit F”;, “Thamnotoxkit F”; and the recently introduced “Daphtoxkit F magna”; and “Algaltoxkit F”;. Water samples were collected from: a water source for irrigating the rice fields, two rice plots, a drainage channel and from Sado river in which the water is discharged. The results showed that samples from the rice plot treated with molinate were more toxic than those obtained from rice plot treated with quinclorac. Water samples from the river were the most toxic, causing 100% of immobility in all organisms and a substantial inhibition in the algal growth. Water collected from the drainage channel in late July, was also found to be quite toxic. The results obtained until now indicate that some characteristics of these microbiotests, like their rapidity, simplicity and relatively low cost, make them a practical tool to evaluate acute effects of pesticides in freshwater ecosystems. They may also contribute to suggest some changes in pesticides use to promote agricultural practices with lower impact to aquatic life.  相似文献   

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