浅析沧州地区地下咸水环境效应

沧州地区由于地下淡水严重超采,地下水位大幅度下降,形成区域性降落漏斗。结果导致咸水界面下移,咸水入侵,淡水咸化,甚至海水入侵等咸水环境效应。     

苏北盆地地下咸淡水的同位素研究

本文通过苏北盆地地下咸淡水同位索的测试和分析,探讨了地下水化学成分的形成及其演化规律,发现其矿化度的形成主要是由于含水介质矿物成分的淋滤和溶解所致;地下水起源于大气降水,但雨水的下渗速度极为缓慢。此外,还分析了稳定同位素氘在地下水流动方向和垂直方向上的变化,并用同位素组成计算了微咸水中成、淡水的混合比例。     

苏北盆地中层地下水化学成分的起源和演化规律

本文首先指出苏北盆地中层地下水化学成份的一般分布特征。其次根据特征系数、沉积物浸出液主要成份,水中主要成份的稀释曲线以及弱透水层对半咸水、咸水入渗的影响,指出该区中深层微成水水质演化系受石盐的的溶解及少量残留咸水的混合,浅层咸水是同生沉积形成。西部的微咸水为咸水入渗的混合,并受到后期的淡化,北部咸水楔形体是富钙的海水入侵形成,较深的半咸水是咸化的残留海水形成。     

海岸带咸、淡水成因研究的途径与实例

本文从沉积环境、含水介质、水化学成份、同位素组成等途径,探讨海岸带咸、淡水成因。指出海岸带咸水起源通常有如下几种:古代残留海或泻湖的同生沉积水、沉积物堆积后古代海水入渗形成的咸水、深部古卤水或盐丘的淋滤形成的咸水、海相层中盐类的溶解形成的微咸水、现代入侵的海水等,并附以实例作为上述研究的说明。     

深圳滨海地带海水入侵判定界限值的确定

在海水入侵的研究中 ,由于不同地区的地下水特征不同 ,运用统一的海水入侵判定标准 ,对判定研究区的海水入侵会产生很大的误差 ,因此本文根据深圳地区孔隙水和裂隙水的特征 ,分别对其海水入侵的标准进行了分析。为了较准确的确定出该研究区的地下水背景值 ,运用Grubbs统计方法对数据中的干扰数据进行剔除 ,并运用SPSS统计软件 ,在判定各项组分分布类型的基础上 ,确定出不同类型的地下水的环境背景值。同时提出了该研究区的海水入侵的判定标准值。     

充气法解决海水入侵问题的探讨

滨海城市的不断扩大 ,对淡水的需求更加迫切 ,由于大量抽取滨海含水层中的地下淡水 ,出现了海水入侵问题。该文针对过去一些防治方法存在的缺陷 ,提出了利用充气法解决海水入侵问题的设想     

唐山沿海地区海水入侵及防治措施

唐山沿海及近浅海域地处环渤海中枢地带,区位条件优越,有优良的深水港址、丰富的土地资源、油气资源、地热资源、海水资源和海洋生物资源,是环渤海产业经济带,是京津唐经济核心区重点开发建设地区之一。但该区淡水资源缺乏,地质环境脆弱,受自然和人为因素影响,海水入侵越来越严重,侵染面积不断向北推移,该区有咸水区面积已超过3 100 km2,咸水底界埋藏深度有些地区已经超过80m。海水入侵已成为重大环境问题,直接影响沿海地区经济发展。     

测井在水文地质钻探中划分咸淡水分界面的应用

河北平原沿海地区由于常年海水入侵,咸水在浅层水当中普遍存在,给当地人民生活和经济发展造成了严重影响.为了最大程度地降低这些影响,更合理地开发利用咸水,在水文地质钻井当中如何准确测定咸淡水分界面就变得十分重要.物探测井是通过测量钻孔内岩石的各类物理参数和钻孔参数状况来解决地质问题的一种物探方法,其中利用物探测井划分咸淡水...     

厦门岛地下水中营养盐含量及氯含量指标的确定

该文以厦门岛地下水为研究对象 ,研究了地下水中营养盐含量的空间分布和变化。结果表明 2 0 0 1年DIN(无机氮总 -N)含量的变化范围是 2 0 1 2～ 136 8 1μg dm3,PO4 -P含量的变化范围是 9 2～ 1190 0 μg dm3。从 1999年至 2 0 0 0年 ,DIN含量的变化范围是 74～ 2 0 6 8μg dm3,PO4 -P含量的变化范围是 70 9～ 182 5 μg dm3。同时该文将地下水中氯离子作为海水入侵指标 ,根据氯离子背景值确定出海水入侵氯含量指标值。     

深圳南山后海海水入侵及侵蚀性研究

沿海地区的海水入侵使地下水类型和环境发生了改变，对地下建(构)筑物的混凝土以及钢筋混凝土结构中的钢筋产生侵蚀，影响地下建筑物的安全。深圳市南山区后海为填海区，存在海水入侵情况。该文通过对地下水水质试验数据进行统计分析，按水化学环境指标对海水入侵进行评价，从水平和竖直两个方向分析海水入侵的特征，同时按照环境类别和地层渗透性对混凝土以及按环境类型对钢筋混凝土中的钢筋进行腐蚀性评级，分析腐蚀的区域性特征，为工程的侵蚀性评价以及钢筋混凝土防腐作参考。     

Hydrochemical Analysis of Groundwater in Coastal Coal Mining Areas—A Case Study of the Liangjia Coal Mine,North China

To understand the hydrochemical characteristics and circulation pattern of groundwater in coastal coal mining areas, we analyzed 81 water samples from different water bodies in the Liangjia coal mine (LCM) area using multivariate statistical analysis and hydrochemical methods. The Quaternary groundwater (QW), accumulated water (AW) in the subsidence area, and mine water (MW) in the LCM all exhibit weakly alkaline to slightly saline water chemistry. The dominant cations and anions in the water are sodium (Na⁺) and chloride (Cl^?), reflecting the influence of seawater intrusion. Some ions in QW, AW, and MW exhibited significant annual variations, but Na⁺ and Cl^? concentrations increased with time. The water samples were divided into four categories through cluster analysis: C1 and C2 (bedrock water samples), C3 (water samples prominently affected by seawater intrusion), and C4 (QW and AW in the surface subsidence area). According to the Piper diagram, QW and AW in the surface subsidence area mainly correspond to the Na?Cl type, whereas the MW mainly consists of Na?Cl and Na?HCO₃ types. Factor analysis revealed four main factors: seawater recharge, HCO₃-rich bedrock water, alkaline water, and Quaternary groundwater (QW) with eigenvalues of 4.18, 2.44, 1.22, and 1.19 respectively, which explained 81.98% of the original data information. The comprehensive results of hydrochemical analysis and mathematical statistics indicated that the recharge sources of MW in LCM include seawater, QW, AW, HCO₃-rich bedrock water, and mixed water. Based on regional hydrogeological conditions, a preliminary groundwater circulation model of the coastal coal mining area was constructed. Groundwater generally flows into the Bohai Sea from southeast to northwest, and coal mining has changed the original local groundwater runoff patterns and intensified seawater intrusion.

     

地下水环境背景值的确定

以研究深圳市滨海地带海水入侵为例根据研究区的水文地质奈件将其划分为两个单元进行研究。运用Grubbs统计方法对数据中的异常值进行剔除。并运用SPSS统计软件，在判定各项组分符合何种分布的基础上，对不同类型的地下水的环境背景值进行了确定，为研究海水入侵是否发生入侵提供了判定依据。     

北海市滨海含水层海水入侵的水化学判别

北海市滨海含水层地下水具有矿化度和pH值低，水化学类型复杂等特点。钻井地下水化学成分变化可大体上分为稳定型、波动型和恶化型．在北侧海岸带西部，由于海水入侵，地下水中Cl-和Na （＋K＋）含量明显升高，以Cl－Na型水为主．海岸带以Cl-含量大于50mg/L作为判别海水入侵的标准，最大海水入侵范围已超过3km2。     

Assessment of Water Sources and Mixing of Groundwater in a Coastal Mine: The Sanshandao Gold Mine,China

Water inrush is a potential disaster in the Sanshandao Gold Mine, which is located on the coast of the BoHai Sea. A conceptual model based on the water chemistry and hydrogeological setting was established to identify potential water sources. Then, a mixing pattern was developed based on the δ¹⁸O and Cl^? values. Finally, a linear mixing model was used to estimate the mixing ratios of water sources at each site. Four sources were identified: freshwater: (F), quaternary water (Q), seawater (S), and brine (B), and four mixing patterns were developed: B-F-Q, F-Q-S, B-Q-S, and B-S. The mixing ratios showed that brine was the main water type when mining began. However, seawater (mean?=?48.3%) and quaternary water (mean?=?36.04%) came to dominate the groundwater composition over a short period of time. The field investigations and hydrochemical analysis indicated that the main flow paths of these waters were along NW-oriented fractures and the F3 fault. Freshwater mainly recharged the shallow fractures (above ?285 m) and represented a small proportion of the groundwater (mean?=?11.2%). The main freshwater flow paths were bare rock fractures in the mountains.     

Delineating the Origin of Groundwater in the Golgohar Mine Area of Iran Using Stable Isotopes of <Superscript>2</Superscript>H and <Superscript>18</Superscript>O and Hydrochemistry

The Golgohar iron ore mine in southern Iran is a large open pit that uses dewatering (≈4000–5000 m³/day) to prevent flooding. A vast cone of depression has formed, and water from a large area flows into the pit. A study of the different sources of this water was necessary to plan a proper dewatering project. Moreover, the discharged water is saline and contains high levels of contaminants. Based on hydrochemical and isotope (¹⁸O and ²H) analysis, it was concluded that the area’s deep saline groundwater is coming from the Sirjan (Kheirabad) salt playa (north of the mine) by saltwater intrusion while the chemistry of more distant groundwater was due to dissolved minerals.     

海南省洋浦港滨海水源地最大开采量确定方法的研究

本文将研究区含水系统概化为五层结构的不稳定准三维流模型,根据海岸带地下水水头随海潮波动的信息,用数值方法确定了承压含水层海底边界的位置及相应的水文地质参数.在此基础上用迦辽金有限元方法反求了研究区有关的水文地质参数,并预测了未来地下水开采动态特征及不发生海水入侵前提下地下水的最大可开采量和开采井的布局.     

Temporal Variations in Water Chemistry at Abandoned Underground Mines Hosted in a Carbonate Environment

Abstract  Closure of Pb-Zn mines in the Iglesias district (SW Sardinia, Italy) caused the cessation of pumping in 1997, and the consequent flooding of underground workings. Deep saline water mixed with the shallow groundwater as the water table rose, increasing salinity. Stratification caused the saline water at depth to settle over a period of three years. At the beginning of rebound, an increase in dissolved Zn, Cd, Pb, and Hg was observed under near-neutral pH conditions. Following peak concentrations, a marked decrease of Zn, Cd, and Hg, and to a lesser extend Pb, occurred. After 7 years of rebound, the concentrations of these metals are relatively low at most mine sites, although the levels are generally still higher than in unmined areas. Nowadays, the highest release of metals to the aquatic system occurs from the weathering of tailings and mine wastes.     

Effect of water quality on the leaching of a low-grade copper sulfide ore

Copper extractions from a low-grade, ground copper sulfide ore (0.7% Cu) leached in three media were freshwater < seawater > double-strength seawater and pH 1.5 ⩾ pH 2; 84% extraction was achieved in pH 1.5 seawater in 28 days at 23 °C. Cu-oxide and carbonate dissolved completely and chalcocite was altered to secondary covellite, some of which persisted in all media for the duration of the 28-day experiment. Chalcopyrite and bornite were both oxidised more readily in saline water. Iron, sodium, potassium and sulfur (sulphate) concentrations in leach solutions diminished and the amounts of insoluble iron(III) reaction products increased with increased salinity and increased solution pH. While, overall, silicate dissolution was small, the amounts of poorly crystalline phases (both iron(III) and silica-rich phases) increased with increased salinity and were greater in pH 1.5 media. In the context of heap leaching, the increased amounts of secondary precipitates formed if saline water was used could result in lower extraction efficiency and the increased total dissolved solids, density and viscosity could result in increased energy costs for solution management at operations.The software package Geochemist’s Workbench was evaluated by modelling the synthetic seawater – pH 2 test. It was possible to predict the evolution of the solution composition, the main species and phase boundaries at the start and end of leaching, and the formation of three reaction products in accord with experimental data by applying the React sliding function.The tests were conducted using a pulverised ore sample to increase dissolution reaction kinetics, particularly for chalcopyrite. Future tests should be conducted using ore particle sizes appropriate to heap leaching. The copper distribution within particles indicated that the test ore may not be suited to heap leaching because the surface exposure of copper sulfide grains is limited. Therefore reactor designs better suited to smaller sized particles with/without pre-treatment should be considered.     

数值法在西北某铜冶炼项目地下水环境影响评价中的应用

应用数值法预测西北某铜冶炼厂废水泄漏对地下水的环境影响。结果表明,项目运行不会对冶炼厂区周围及下游地下水环境产生较大影响。评价结果可为类似冶炼项目地下水环境影响评价提供参考。