西宁市贵德县河滨公园林场第四系含水层弥散试验研究

地下水污染问题日益严重,研究溶质运移的弥散理论开始应用于实际问题。建立地下水溶质运移模型,对地下水中污染物的运移及发展趋势进行准确预测,是对地下水进行保护、对地下水污染进行控制的基础。而弥散参数的确定则是地下水溶质运移模型建立的关键环节之一,直接影响着模型预测结果的精度和准确性。 对西宁市贵德县地下水污染的水质运移规律进行分析,在贵德县河滨公园林场采用径向收敛流水动力弥散理论方法进行了第四系含水层现场弥散试验,计算了试验场地潜水含水层的弥散度,获得纵向弥散度(a_L)为0.843~0.998 cm,横向弥散度(a_T)经验推断值为0.17~0.20 cm,为进一步建立该地区的地下水溶质运移模型、预测地下水污染的发展趋势和评价该地区地下水环境质量提供了数据参考。     

白于山以北潜水含水层野外弥散试验研究

建立地下水溶质运移模型,对地下水中污染因子的运移扩散情况进行预测,是对地下水进行保护和对地下水污染进行控制的关键。地下水溶质运移模型中弥散参数对模型预测结果的精度和准确性有着至关重要的作用。对陕北白于山以北地区潜水含水层污染水体的运移规律进行分析,采用径向收敛流水动力弥散理论方法进行潜水含水层的弥散试验,计算场地潜水含水层的弥散参数。研究结果表明:计算得到的纵向弥散度(a_L)为0.58 cm,横向弥散度(aT)经验推断值为0.116 cm。研究结果可为该地区进一步建立地下水溶质运移模型和制订有效的地下水污染防治措施提供数据参考。     

北京市朝阳区沙子营垃圾污染物在潜水含水层中迁移规律的现场模拟实验

选择北京平原区水文地质、环境地质等方面都比较典型的沙子营垃圾堆放场,建立了其水文地质模型。在充分收集资料、分析得出部分计算所需参数后,采用现场弥散实验、勘查取样测试等方法,求得了该含水层的弥散系数等参数;用二维非稳定流溶质运移方程对污染物在此含水层中的迁移扩散规律、速度和污染范围等进行了模拟计算;采用现场钻探、取样测试分析等方法,评价了该含水层的实际污染状况。实验模拟计算和现场调查结果表明:污染物在潜水含水层中的运移规律遵循二维非稳定流场中的溶质运移方程,污染物在潜水含水层中的运移速度约为86.25m/a,迁移扩散主要发生在地下水流向上,侧向扩散宽度极小,是地下水流向上的1/17。     

岩溶含水层渗漏污染弥散类型分析——以贵州废渣堆场污染为例

在贵州岩溶地区,由于废渣堆场产生渗漏,使强酸强碱性废水污染了岩溶含水层,直接影响了岩溶水资源的开发利用.通过10个工业废渣堆场的岩溶含水层介质特征及污染质运移特征的分析,划分出4种岩溶渗漏污染的水动力弥散类型,为岩溶含水层污染预测评价及渗漏污染治理提供了依据.     

双重介质污染质运移模型研究及其在岩溶区的应用

本文用双重介质理论,在天然裂隙系统中对其裂隙域和孔隙岩块域建立了二维水流和污染质运移模型。讨论了岩块为斜方体、椭园柱体和任意不规则几何形态条件下,耦合项(Γ)的表达式及计算方法。分别对流速、弥散度、孔隙度等因素对污染质运移的控制和影响进行了定量分析。最后,模拟了济南东郊约85km~2岩溶含水层中Cl~-离子的运移情况,取得了比较满意的结果。     

《地下水污染与地下水水质模拟》即将出版发行

由王秉忱研究员等编著的《地下水污染与地下水水质模拟》一书即将公开出版发行。全书共分十六章达九多万字。该书系统论述了环境地质工作中有关地下水污染与地下水水质模拟的基本理论和工作方法。诸如:进行地下水污染研究及其水质预测的基本理论;地下水中溶质运移的基本规律;弥散理论的建立;地下水污染调查及其水质预测的工作方法;弥散参数的实验室和野外测定;地下水运动和地下水污染的基本方程、水动力弥散方程几种典型定解问题的解析解及其应用;水动力弥散方程的有限差分法;水动力弥散方程的有限单元法;解地下水溶质运移方程的边界积分方程法;水动力弥散方     

常州浅层地下水污染预测方法的初步研究

在文献[1][2]中,就常州浅层地下水污染水质水平运移作了初步探讨。由于常州地下水污染主要是污水垂直入浸浅层水而引起的,因此,考虑污水垂直如何运移是很重要的。由于污质垂直运移比水平运移速度慢得多,同时测试也遇到很大的困难,本文对垂直水质弥散提出一个简化的数学模型,并利用这个模型对污水坑污质运移作了预报,同时对[1][2]作了     

长春西部串湖含水介质弥散试验及污染质运移研究

水动力弥散系数是建立地下水水质模型,进行地下水溶质运移研究的重要参数。在野外调查的基础上,设计并开展了室内二维水动力弥散试验,应用直线图解法确定了研究区含水介质的纵向、横向弥散系数。建立了该区地下水溶质运移模型,并对其进行了预测分析。     

具有弱透水层的多层介质含水系统中污染质运移数值模拟研究——以大庆市纳污湖泡区为例

选取大庆市贴不贴泡区具有普遍意义的饱和-非饱和多层介质含水系统中石油类污染为研究对象.在分析水文地质条件的基础上, 利用实验研究获得含水系统中连接上下含水层的弱透水层的渗透规律, 然后运用数值模拟技术建立起此类含水系统中石油类污染质运移数值模拟模型.应用所建模型对污染质的污染趋势进行了预测, 并提出污染控制措施.      

用同位素示踪测定地下水水质弥散系数的探讨

地下水弥散系数是表征地下水污染质传布的重要参数,为建立地下水水质数学模型所不可缺少。作者近年来对第四系孔隙水与奥陶系基岩裂隙岩溶水,用同位素示踪剂~(131)I进行了多次地下水弥散系数的就地测量工作。文中对野外弥散系数测定工作中发现的问题,进行一些讨论,并例举了二个孔隙水与岩溶水含水层的弥散试验。     

溶解气运移特征砂槽模型实验研究

借助于砂槽承压含水层模型 ,以氩溶解气为研究对象 ,模拟气体聚集或稀释的异常源产生后 ,其在含水层中的运移过程。实验包括三组 ,分别模拟在不同的气源气体流量、水头压力和承压荷载条件下氩溶解气的运移过程。在实验的基础上 ,分析研究氩溶解气的运移特征 (主要包括运移模式、运移速率和溶解气峰值含量 )与气源气体流量、水位和承压荷载压力的关系。结果表明氩溶解气在低流量的范围内呈现出与离子类似的弥散特征 ,与离子不同的是氩溶解气的运移明显地受到气源气体流量的影响。     

Mathematical model for hydraulically aided electrokinetic remediation of aquifer and removal of nonanionic copper

One of the most cost-effective in situ technologies for soil and groundwater (i.e., aquifer) remediation is electrokinetic remediation. In electrokinetic remediation, electromigration due to electric field is combined with hydromigration due to hydraulic flow by purge water to remove pollutants from aquifers through the pore water. This study aims at investigating theoretically the role of electromigration (as active movement) of pollutants and the role of hydromigration (as passive movement) of pollutants in electrokinetic remediation, and making it clear that the control variables for electrokinetic remediation are the applied voltage and the hydraulic flow rate. These aims are pursued by construction of a mathematical model based on physico-chemical considerations and by model simulations of the electrokinetic remediation applied to the virtual aquifer polluted by heavy metals of copper sulfate. According to numerical simulations with the model: (1) heavy metal (nonanionic copper) is removed from the upstream anode region and accumulated in the downstream cathode region; (2) to carry away the heavy metal outside the aquifer (global removal), hydromigration by purge water flow is essential; and (3) electromigration contributes mainly to the redistribution of heavy metals within the aquifer (local removal and local accumulation).     

基于GIS的孔隙含水层系统三维空间离散方法研究

分析了目前孔隙地下水流三维有限差分数值模拟中对含水层系统三维空间离散存在的问题，针对自然界孔隙含水层与隔水层空间分布的不连续性与厚度的不均匀性，研究了基于GIS的孔隙含水层系统三维空间离散实现的技术路线，提出了基于GIS与不规则六面体元的孔隙含水层系统的三维空间离散方法，最大限度地保证了离散体元中含水层类型的单一性，提高了孔隙地下水流模拟模型三维空间离散的精度。     

Transformations and hydraulic captures of petrochemical contaminants in a karst-fractured aquifer

 The development of a petrochemical industry may be responsible for petrochemical contamination of karst-fractured aquifers in an urban water supply system. In the Dawu Well Field, a karst-fractured aquifer in Zibo City, in the east of China, has been seriously polluted by petrochemicals from the operation of petrochemical plants. More than 60 species of organic contaminants have been detected in the water supply wells of the Liuhang-Hougao zone, in the west part of Dawu Well Field. Investigations indicate that contaminants are transported from the petrochemical plants to the karst-fractured aquifer along karst fractures and the Jinling Fault. In the groundwater, concentrations of pollutants vary with depth. Concentrations are greater with depth because of the transmissibility of the Jinling fault. The local convective flow field has a significant influence on transportation of contaminants. Hydraulic barriers can prevent the transportation of contaminants and they can be removed by extraction. Received: 22 October 1999 · Accepted: 14 February 2000     

A simplified model for computing pollutants release from granular pavement base to local aquifer

A simplified model is proposed to estimate the leaching constituents from waste granular pavement base to adjacent groundwater. The model considers pollutants leaching from a longitudinally infinite waste granular base. The leaching of the base is deemed to obey the diffusion model. After leaving the pavement layers, the leachate is subjected to retardation and dilution during its transport to the nearby aquifer. The retardation is estimated from the breakthrough curve of steady-water flow through a homogeneous soil profile. The model is available for any waste granular base that contains any type of leachable pollutants. But parameterization of the model is different substantially for different pollutants; therefore how to parameterize the mode is discussed. Recycled glass is exemplified as the granular base materials, and the transport of Cadmium to the local aquifer is demonstrated. A sensitivity study is conducted to demonstrate the influences of field conditions and waste-leaching characteristics on the pore concentration of the pollutants in the target well.     

Analytical solution of advection–diffusion equation in heterogeneous infinite medium using Green’s function method

Some analytical solutions of one-dimensional advection–diffusion equation (ADE) with variable dispersion coefficient and velocity are obtained using Green’s function method (GFM). The variability attributes to the heterogeneity of hydro-geological media like river bed or aquifer in more general ways than that in the previous works. Dispersion coefficient is considered temporally dependent, while velocity is considered spatially and temporally dependent. The spatial dependence is considered to be linear and temporal dependence is considered to be of linear, exponential and asymptotic. The spatio-temporal dependence of velocity is considered in three ways. Results of previous works are also derived validating the results of the present work. To use GFM, a moving coordinate transformation is developed through which this ADE is reduced into a form, whose analytical solution is already known. Analytical solutions are obtained for the pollutant’s mass dispersion from an instantaneous point source as well as from a continuous point source in a heterogeneous medium. The effect of such dependence on the mass transport is explained through the illustrations of the analytical solutions.     

Factors of bacteria and virus transport in groundwater

The underground transport of pathogenic bacteria and viruses may be described by the general transport equation considering dispersion, adsorption, and biological elimination. The survival time of bacteria and viruses in groundwater is different for the specific species and for the specific groundwater environment. Dispersion causes a distribution of pollutants in time and space, thus their concentration decreases over time and with transport distance. Microorganisms are reversibly adsorbed on underground particles, which causes a retardation of their transport velocity with respect to groundwater flow velocity. An additional approach is provided by the filter theory. Presented at the International Symposium, International Association of Hydrogeologists, “Impact of Agricultural Activities on Ground Water Quality and Quantity,” Prague, Czechoslovakia, September, 1982.     

碳酸盐溶解、沉淀控制下的反应－迁移模型研究

以碳酸盐岩中方解石、白云石和石膏的溶解和沉淀化学反应为基础，阐述了反应模型和水流模型，建立了化学动力学方程－水流方程的关系，并且采用解析法－数值法混合解法求解济南岩溶区的反应－迁移模型，计算该区的化学反应速率常数和水动力参数