Transformation of 3-Chloroallyl Alcohol in Water-Saturated Subsoil Studied with a Column Method     

Wim H. J. Beltman  Minze Leistra  Arriënne M. Matser 《Pest management science》1996,47(4):299-307

The performance of a newly developed column method for pesticide transformation rate measurements in the subsoil was tested using (Z)- and (E)-3-chloroallyl alcohol as model compounds. Sandy anaerobic water-saturated subsoil was collected at between 1·8 and 2·3 m below the surface of a flower-bulb field. Transformation rates were measured using subsoil columns that were filled in situ and were compared with the transformation rates in laboratory incubation systems. In the column experiment the half-life ranged from 0·5 to 5·2 days for (Z)-3-chloroallyl alcohol and from 1·0 to 5·5 days for (E)-3-chloroallyl alcohol. The capacity of the saturated subsoil for transformation of both isomers increased in the course of the column experiment. In the incubation experiment the 3-chloroallyl alcohols were transformed gradually in the first three days, with a half-life of 1·9 days for both isomers. Thereafter the transformation rate accelerated. The general conclusion is that the column method yields results similar to those of the incubation method for these rapidly transforming compounds.  相似文献   

Rate of transformation of atrazine and bentazone in water-saturated sandy subsoils     

Leo J. T. van der Pas  Minze Leistra  Jos J. T. I. Boesten 《Pest management science》1998,53(3):223-232

When pesticides leach through the soil to the upper groundwater zone, it is important to know whether further transformation occurs before the pumping wells for drinking water are reached. Atrazine and bentazone were incubated (at 10°C) in five water-saturated sandy subsoils (collected at depths between 1·5 and 3·5 m), simulating the conditions in the field. In three subsoils with comparatively low pH and intermediate to high redox potential, atrazine was transformed gradually, to leave 1·9%, 6·2% and 17·5% of the dose after about five years. In one of these subsoils, hydroxy-atrazine was detected; the amount corresponded to half of the dose of atrazine. In one anaerobic subsoil with high pH, the transformation of atrazine was comparatively fast (half-life about 0·15 year). Another anaerobic subsoil, with similar pH and a somewhat higher redox potential, however, showed hardly any transformation. Sterilization of the first anaerobic subsoil had no effect on the rate of transformation. In the course of about five years, bentazone in the first three subsoils was transformed gradually to leave <0·25%, 11% and 25% of the dose. Bentazone transformation in the two subsoils with high pH and low redox potential was very slow, but the presence of oxygen in one of these subsoils speeded up the transformation. © 1998 SCI  相似文献   

固化剂对土壤中重金属的稳定作用及其在河岸固化护坡中的应用研究   总被引：1，自引：0，他引：1  

张长波  罗启仕  付融冰  杨洁  章树久  李小平 《农业环境科学学报》2009,28(10)

为评估一种自主开发的固化剂(GSS-02)对土壤中重金属的稳定作用,探讨该固化剂用于河岸固化护坡工程的可行性,在实验室内分别采用普通硅酸盐水泥(OPC)和GSS-02对土壤实施固化处理.用US EPA的TCLP方法测定浸出毒性,评估添加剂对土壤Cu、Zn、Cr和Ni的稳定效果,测定固化体的无侧限抗压强度,初步评估土壤固化体的物理性能.结果表明,加入OPC或GSS-02在一定程度上提高了土壤浸出液的pH值,固化剂添加量与浸出液pH值存在显著的正相关关系;OPC和GSS-02对Cu、Zn和Ni有较好的稳定作用,能使浸出液中重金属浓度降低为对照样品的1/3～1/7,但能够活化Cr;加入OPC或GSS-02能提高固化体的无侧限抗压强度,与OPC相比,低剂量时GSS-02能显著提高无侧限抗压强度,而高剂量时则相反,这有利于土壤生物工程的实施.上海市南汇区某河岸固化工程应用表明,GSS-02能满足土壤重金属稳定和土壤生物生长恢复的需要,与OPC相比是一种良好的生态型同化剂.  相似文献   

自适应差分进化算法在反求含水层参数中的应用     

陈童  常安定  李江杰 《西北农林科技大学学报(自然科学版)》2020,48(2):143-147

【目的】研究自适应差分进化算法在反求含水层参数中的适用性。【方法】以理论计算值与实际观测值的离差平方和的均值作为目标函数,应用自适应差分进化算法优化待估含水层参数;计算相关实例,对比改进直线图解法、混沌序列优化算法、简算法、泰斯配线法、线性回归法与自适应差分进化算法的最终优化结果。【结果】与改进直线图解法、混沌序列优化算法和简算法等计算方法相比,自适应差分进化算法的计算结果更加精确,与实际观测值的差异较小;对于不同的含水层参数取值范围,自适应差分进化算法较传统差分进化算法稳定且寻优率与计算结果精度更高。【结论】自适应差分进化算法是一种有效的反求含水层参数的方法。  相似文献   

黄土新含水层饱水机理的试验研究     

刘俊民  陈艳霞  杨平 《灌溉排水学报》2006,25(4):16-19

以黄土原状土为研究对象,进行室内饱水试验,利用Diviner2000含水量测定仪,取得第一手资料。根据实验所得数据资料,首先对黄土饱水过程是否完成进行了判断,然后对黄土层不同深度体积含水量、累积饱水量、饱水速率、不同深度处的水力梯度等随时间的变化规律进行分析。经判断,黄土试样达到基本饱和,其饱和含水量为12.3%,小于国内同类研究结果,究其原因在于试样顶部裸露,饱水过程存在蒸发。最后,揭示出黄土层的饱水机理。  相似文献   

承压含水层水压力传递滞流效应的定量分析     

卢玉东  李佩成 《灌溉排水学报》2006,25(4):48-51

针对承压含水层抽水试验中水压力传递滞流效应,应用连续介质力学理论,推导了包括惯性项的运动方程。含有加速度项的地下水运动方程,是一衰减的波动方程,它包含有kρ/μn这一时间单位项。水压力传递速度C主要是贮水率Ss的函数,水和骨架介质的压缩性越大,水压力传递的速度便越小。实际承压含水层井水位的变化与观测井的响应有一滞后时间。这一滞后时间与含水介质的性质及2个点的间距有关。  相似文献   

岩溶含水层四氯化碳人体健康风险评价   总被引：2，自引：0，他引：2  

项玮  韩宝平  朱雪强 《农业环境科学学报》2007,26(5):1702-1706

四氯化碳是地下水中常见的有机污染物,主要通过食入和皮肤接触两种途径进入人体,健康风险评价是定量描述污染对人体健康产生危害的重要方法,针对某市南区地下水遭受四氯化碳污染对当地居民进行健康风险评价。结果显示,不同时期X-49井的风险指数最高,其中致癌指数为1.79×10-4,非致癌指数为3.44,均超过规定标准,并且饮水带来的风险远大于皮肤接触带来的风险,约占总风险的99.6%。但饮用开水在很大程度上能降低风险,建议当地居民不饮用生水。  相似文献   

含水层储气库注采效应的数值模拟     

赵斌  李云鹏  田静  王芝银 《油气储运》2012,31(3):211-214,218,247

以适于建造地下含水层储气库的某区地质资料为背景,采用气水二相渗流理论及数值模拟方法,对含水层储气库在注采气过程中储层平均压力和气泡体积的变化特征,以及储层构造特征、储层非均质性、注采方案对注气效果的影响等问题进行了研究。结果表明:在含水层储气库注采过程中存在压力相移现象;对于储层岩性特征为层状分布的含水层,应分层注采和分层管理;用泡沫作为气驱前缘可提高严重非均质性单一储层气体的波及效率;在注气过程中应注意利用重力排驱机理,采用合理的注气工作制度有利于储气量的提高;储集层在断层或断层与断层交接的部位是发生气体泄漏的危险区域。  相似文献   

Application of the Irrigation Land Environmental Evaluation Tool for flood irrigation management and evaluation of water use     

I. García-Garizábal  J. Causapé  R. Abrahao 《CATENA》2011

Irrigated zones worldwide suffer from water deficits, making it necessary to analyze irrigation management and to study alternatives to maximize adequate partitioning and distribution of irrigation water. The objective of this study is to compare the water use efficiency before (2001) and after (2002–2008) implementation of a new irrigation management plan in an area operating with traditional methods.  相似文献   

大恒煤矿开采对地下水疏干的影响     

邓强伟  张永波 《水土保持通报》2014,(6):123-125

应用Visual Modflow建立了水文地质概念模型和数学模型,以山西省朔州市平鲁区大恒煤矿开采为例探讨了其对地下水水位和水量的影响。在对矿界周边50 km²的范围内水井水位进行调查的基础上,依据划分的各采区开采时间,结合区域地下水埋藏深度与地层走向和调查范围内各个时期水井水位埋深的监测,对大恒煤矿的开采进行建模并验证了模型的准确性。研究结果显示,大恒煤矿开采28.8 a之后会形成面积9.5 km²,深度55 m的降落漏斗,表明煤矿开采会使上覆含水层水位下降并形成降落漏斗,对地下水资源造成严重破坏。  相似文献