淮河流域平原区浅层地下水铁锰分布特征及成因浅析

结合淮河流域平原区水文地质条件,阐述了淮河流域平原区铁锰元素在浅层地下水（埋深0～50 m）中的赋存特征和分布规律.结合前人研究成果并总结现有水质资料,认为淮河流域地下水中铁锰的形成和分布特征除了受含水介质成分、上覆土层性质、酸碱条件等影响外,主要受氧化还原环境控制.建议通过适当除铁锰工艺或改变地下水循环条件等方式来改变研究区浅层水地下水水质状况.     

深部岩体应力瞬态释放激发微地震机制与识别

从能量释放的角度讨论了深部岩体开挖激发微地震的机制. 研究表明, 伴随着爆破破岩新自由面形成而发生的岩体弹性应变能释放属于瞬态过程, 高地应力条件下爆破开挖产生的微地震由爆炸荷载和初始地应力(开挖荷载)瞬态释放耦合作用引起. 地应力瞬态释放激发的微地震可成为周围岩体振动的主要组成部分, 这有赖于岩体自身的蓄能能力、岩体开挖方式及开挖面的大小. 通过瀑布沟地下厂房爆破开挖过程中实测围岩地震信号的时能密度和幅值谱分析, 对地应力瞬态释放激发的微地震进行了识别. 耦合地震信号的低频成分主要由初始地应力瞬态卸荷引起,而高频成分主要由爆炸荷载引起. 应用数字信号处理的FIR滤波方法对耦合振动信号进行了初步分离,数值计算验证了分离结果的可靠性.      

胶东邓格庄金矿黄铁矿成因矿物学特征及其找矿意义

为了在大纵深尺度上揭示石英脉型金矿矿物学标型的变化规律和矿化富集规律,为矿床深部预测提供矿物学标志,对我国最大金矿集区典型石英脉型矿床邓格庄金矿的黄铁矿晶体形态、化学成分和热电性标型特征进行了研究．结果表明：邓格庄金矿黄铁矿的晶体形态以{100},{210}单形晶及其聚形为主;{210}和{100}＋{210}与矿化成正相关关系,而{100}呈负相关关系;f100}＋{210}可作为寻找富矿的依据．黄铁矿的成分亏S富As,特征元素为Mo,As,Pb,Cu,Bi,Zn,Au,Co,Se,Sb,Ag,Ni,Cr和Te;Au和Ag的沉淀主要发生在石英黄铁矿阶段和多金属硫化物阶段．邓格庄金矿P型黄铁矿的出现率为83．52％;与胶东几个典型金矿比较,本矿床黄铁矿热电系数（功值离散性较大;从早到晚不同阶段黄铁矿的热电导型组合变化为P≥N→P〉N→P〉〉N→P〉〉N→P≥N．黄铁矿中As为成矿有利元素,As＋Sb＋Se＋Te和Co＋Ni的相对含量分别与P型和N型均值、出现率呈正相关关系．通过对成矿温度标定、矿化深度和剥蚀程度的判别及矿体延伸规模研究表明：邓格庄金矿成矿温度为150～322℃,为中低温矿床,矿体已剥蚀到中上部,矿体延伸长度〉900m．根据黄铁矿导型及热电系数在垂向上的变化和导型填图结果,邓格庄金矿I2-2矿体94勘探线北东向-425—800m标高可能存在较好的找矿远景．     

湖泊沉积物中微量金属二次迁移过程中微生物作用的实验研究

蓄积在湖泊沉积物中污染物质某些情况下可以成为威胁上覆水体水质安全的二次污染源．根据贵州省阿哈湖季节性缺氧的特性,通过控制氧化还原状况,设计了对该湖沉积物-水柱的原样／抑菌条件的培养实验．实验发现,微生物活动对界面附近氧化还原反应具有控制作用;改变水体的含氧状况可以显著影响上覆水体水质,包括表观性状和水体中污染物含量．聚类分析结果表明,早期成岩过程中Mn,Ga,SO4 2-,Cu,Cr,Pb和Co,Ni,Fe,Sc,V,Rb两大类分别具有相似的地球化学行为．根据实验结果,计算了厌氧培养过程中,微量元素的最大释放量,发现铁、锰在厌氧过程中可以大量向水体释放．     

识别地下水超采区井水位异常性质的理论与方法

长期过量开采地下水,使地下水位持续下降、水质发生变化,动水位观测井断流;地面沉降造成井管上窜,观测管路系统被损坏等,这些现象对地震地下流体观测地震前兆异常的正确判断带来很大困难。应用水文地质理论与方法,分析含水层的水均衡状态、应力-应变状态及其与水位动态的关系,初步探讨了超采区井水位异常性质的理论与方法。结果表明,根据井孔所在区水位下降漏斗的扩散特征,结合以上所提到的理论和方法,依据资料多年变化特征,可以较准确地判断异常的性质。研究结果有助于区分单一集中抽水与长期地下水超采对水位观测的影响,有助于正确识别超采区水位前兆异常,有助于地震分析预报水平的提高     

底泥就地稳定化中零价铁(Fe0)对有机污染物的作用及其对上覆水体水质的影响

在实验室模拟静态湖泊体系条件下,通过向实际底泥中投加零价铁(Fe~0),考察反应前后底泥中有机物数量、种类、总有机质含量以及上覆水体溶解氧(DO)浓度、氧化还原电位(Eh)、pH和化学需氧量(CODCr)浓度等指标的变化,探讨Fe~0对底泥有机物的降解效果以及对上覆水体水质的影响.结果表明,投加Fe~0处理80 d后,(1)经GC-MS检测出底泥中易被降解的小分子有机物(分子量小于200)数量明显增多,底泥总有机去除率为44%.(2)上覆水体的DO浓度、Eh和pH都有不同程度的变化.DO浓度从6.6 mg/L迅速下降至0.2 mg/L,Eh从150 mV左右下降至74 mV,pH升高至8.4,此体系易形成厌氧环境;且上覆水体中CODCr低于纯底泥-水体系,上覆水中DO浓度、Eh及pH与CODCr浓度具有一定相关性.综上,底泥中投加Fe~0可有效降解有机物,且不会对上覆水体产生持久、较大的影响.     

氧化还原条件对红枫湖沉积物磷释放影响的微尺度分析

选取贵州红枫湖为研究对象,在实验室条件下模拟了自然、好氧和厌氧条件下沉积物内源磷的释放过程,联合应用微电极技术和沉积物磷形态分析对沉积物—水界面开展了微尺度观测与研究.结果表明,厌氧条件下红枫湖沉积物总磷含量显著降低,且主要是NaOH提取态磷(NaOH-P)和残渣态磷(rest-P)含量降低所致,厌氧条件下沉积物孔隙水中磷酸盐浓度明显升高,而好氧条件下沉积物孔隙水磷酸盐浓度显著降低,反映厌氧条件显著促进了红枫湖沉积物磷释放.厌氧条件下沉积物内部溶解氧浓度下降、硫还原活动增强可能是导致NaOH-P释放的主要原因.O_2浓度的降低加速了沉积物还原作用并产生大量H2S,进而与二价铁离子形成硫化亚铁沉淀,最终导致NaOH-P(Fe-P)释放到孔隙水中.好氧条件向厌氧条件的转换可通过改变沉积物内部pH值分布和微生物活动促使rest-P释放:厌氧条件下,厌氧微生物不仅可以消耗硫酸根产生H_2S,导致pH值降低,还可消耗有机质,将有机磷转变为无机磷.上述研究结果表明,沉积物—水界面氧化还原环境可影响沉积物氧渗透深度、pH值分布、微生物活动、硫循环以及有机质降解过程,进而控制沉积物磷的形态转化与释放.联合应用微电极技术和沉积物磷形态分析对湖泊沉积物—水界面开展微尺度观测研究是揭示沉积物内源磷释放机制与控制因素的有效途径.     

观测室环境对水汞观测结果的影响

对观测室环境和观测时间改变对水汞观测数据产生的影响进行了实验研究和分析,详细介绍了一次水汞测值异常的核实过程,得出以下结论:(1)观测环境及观测时间的改变不会对水汞观测结果产生明显影响;(2)由于观测室内会残存汞蒸汽,应将观测室随时保持通风状态以降低观测室残存汞蒸气对水汞测值的影响;(3)要加强对试剂、观测室空气中汞含量的监测,避免外界条件变化对水汞观测结果带来的影响。     

长江中下游湖泊沉积物氮磷形态与释放风险关系

运用聚类分析、主成分分析和相关矩阵的统计分析手段,对长江中下游湖群共18个湖泊的沉积物氮磷释放风险以及湖泊沉积物、间隙水和上覆水中氮磷形态以及其他相关地球化学参数进行分析。草型和藻型湖泊的环境差异是造成氮磷释放风险的主要原因。氮磷释放风险与铁磷、藻类可利用磷、总氮、总磷、上覆水氮磷含量、间隙水氮含量、孔隙度和有机质含量间的关系最为密切。决定磷酸盐释放风险的主要形态磷是藻类可利用磷和铁磷,其他形态磷或者含量较低或者不易被转化释放,对磷酸盐释放风险影响较小。有机磷含量对磷的释放风险没有直接决定作用,但它与有机质含量间呈显著正相关。     

龙门山灌县—安县断裂带断层泥低磁化率的矿物、化学响应和蠕滑作用环境

断层带内的流体不仅可以通过水岩反应改变断裂岩的矿物组成和化学成分,从而导致化学性质和物理性质的变化,而且可以影响或控制断裂带的变形行为.断裂带中岩石磁学特征是由特定化学环境下磁性矿物的种类和含量所决定的,因此,从矿物学和地球化学角度探讨断裂岩的磁性变化,对揭示断层的变形行为和环境具有一定的指示作用.本文以汶川科钻WFSD-3P钻孔中龙门山灌县—安县断裂带断裂岩为研究对象,运用高分辨率磁化率测试、XRD矿物成分半定量分析、XRF元素扫描以及不同价态Fe元素含量分析等多种方法开展断层磁学变化和变形环境的研究.磁化率测试结果表明灌县—安县断裂带断层泥的磁化率值普遍低于对应的围岩磁化率平均值.结合前人研究成果表明造成该断层泥低磁化率异常的原因是在间震期的长期流体作用下,铁磁性矿物（例如磁铁矿）转变成顺磁性矿物（铁硫化物、菱铁矿或含铁的黏土矿物）.新生铁硫化物和含铁黏土矿物是在间震期缓慢形成的,而黏土矿物含量的增加弱化了断层强度,促进断层蠕滑,这说明断层泥低磁化率异常可能指示了该断裂在间震期长期缓慢活动,即为蠕滑变形.断层泥中黄铁矿的发育和高Fe²⁺和S元素、低Fe³⁺的特征显示灌县—安县断裂作用环境通常是在低温、还原环境中进行的.这些结果与低磁化率值的相关性暗示断层泥低磁化率异常可能对活动断层的低温还原环境具有指示意义.     

Arsenic Control During Aquifer Storage Recovery Cycle Tests in the Floridan Aquifer

Implementation of aquifer storage recovery (ASR) for water resource management in Florida is impeded by arsenic mobilization. Arsenic, released by pyrite oxidation during the recharge phase, sometimes results in groundwater concentrations that exceed the 10 µg/L criterion defined in the Safe Drinking Water Act. ASR was proposed as a major storage component for the Comprehensive Everglades Restoration Plan (CERP), in which excess surface water is stored during the wet season, and then distributed during the dry season for ecosystem restoration. To evaluate ASR system performance for CERP goals, three cycle tests were conducted, with extensive water‐quality monitoring in the Upper Floridan Aquifer (UFA) at the Kissimmee River ASR (KRASR) pilot system. During each cycle test, redox evolution from sub‐oxic to sulfate‐reducing conditions occurs in the UFA storage zone, as indicated by decreasing Fe²⁺/H₂S mass ratios. Arsenic, released by pyrite oxidation during recharge, is sequestered during storage and recovery by co‐precipitation with iron sulfide. Mineral saturation indices indicate that amorphous iron oxide (a sorption surface for arsenic) is stable only during oxic and sub‐oxic conditions of the recharge phase, but iron sulfide (which co‐precipitates arsenic) is stable during the sulfate‐reducing conditions of the storage and recovery phases. Resultant arsenic concentrations in recovered water are below the 10 µg/L regulatory criterion during cycle tests 2 and 3. The arsenic sequestration process is appropriate for other ASR systems that recharge treated surface water into a sulfate‐reducing aquifer.     

Abandoned Underground Storage Tank Location Using Fluxgate Magnetic Surveying: A Case Study

In 1993, during the removal of a diesel and a gasoline underground storage tank at the municipal garage of the Village of Kohler, Sheboygan County, Wisconsin, soil testing revealed environmental contamination at the site. A site investigation revealed the possibility of a second on-site source of petroleum contamination. Limited historical data and the present usage of structures within the suspected source area precluded the use of most invasive sampling methods and most geophysical techniques. A fluxgate magnetometer survey, followed by confirmatory excavation, was conducted at the site. The fluxgate magnetometer survey identified nine possible magnetic anomalies within the 18 × 25 m area. The subsequent excavation near the anomalies revealed the presence of five paired and two individual 2000 L underground storage tanks. The fluxgate magnetometer survey, although affected by the proximity of buildings, was able to detect the buried tanks within 3 m of the brick structures, using a 1.5 × 1.5 m sampling array.     

Detection of Mixing Dynamics During Pumping of a Flooded Coal Mine

In complex hydrogeological environments the effective management of groundwater quality problems by pump‐and‐treat operations can be most confidently achieved if the mixing dynamics induced within the aquifer by pumping are well understood. The utility of isotopic environmental tracers (C‐, H‐, O‐, S‐stable isotopic analyses and age indicators—¹⁴C, ³H) for this purpose is illustrated by the analysis of a pumping test in an abstraction borehole drilled into flooded, abandoned coal mineworkings at Deerplay (Lancashire, UK). Interpretation of the isotope data was undertaken conjunctively with that of major ion hydrochemistry, and interpreted in the context of the particular hydraulic setting of flooded mineworkings to identify the sources and mixing of water qualities in the groundwater system. Initial pumping showed breakdown of initial water quality stratification in the borehole, and gave evidence for distinctive isotopic signatures (δ³⁴S(SO4) ? ?1.6‰, δ¹⁸O(SO₄) ? +15‰) associated with primary oxidation of pyrite in the zone of water table fluctuation—the first time this phenomenon has been successfully characterized by these isotopes in a flooded mine system. The overall aim of the test pumping—to replace an uncontrolled outflow from a mine entrance in an inconvenient location with a pumped discharge on a site where treatment could be provided—was swiftly achieved. Environmental tracing data illustrated the benefits of pumping as little as possible to attain this aim, as higher rates of pumping induced in‐mixing of poorer quality waters from more distant old workings, and/or renewed pyrite oxidation in the shallow subsurface.     

Surface water and groundwater interactions in an extensively mined watershed,upper Schuylkill River,Pennsylvania, USA

Streams crossing underground coal mines may lose flow, whereas abandoned mine drainage (AMD) restores flow downstream. During 2005–2012, discharge from the Pine Knot Mine Tunnel, the largest AMD source in the upper Schuylkill River Basin, had near‐neutral pH and elevated concentrations of iron, manganese and sulphate. Discharge from the tunnel responded rapidly to recharge but exhibited a prolonged recession compared with nearby streams, consistent with rapid infiltration of surface water and slow release of groundwater from the mine complex. Dissolved iron was attenuated downstream by oxidation and precipitation, whereas dissolved CO₂ degassed and pH increased. During high flow conditions, the AMD and downstream waters exhibited decreased pH, iron and sulphate with increased acidity that were modelled by mixing net‐alkaline AMD with recharge or run‐off having low ionic strength and low pH. Attenuation of dissolved iron within the river was least effective during high flow conditions because of decreased transport time coupled with inhibitory effects of low pH on oxidation kinetics. A numerical model of groundwater flow was calibrated by using groundwater levels in the Pine Knot Mine and discharge data for the Pine Knot Mine Tunnel and West Branch Schuylkill River during a snowmelt event in January 2012. Although the calibrated model indicated substantial recharge to the mine complex took place away from streams, simulation of rapid changes in mine pool level and tunnel discharge during a high flow event in May 2012 required a source of direct recharge to the Pine Knot Mine. Such recharge produced small changes in mine pool level and rapid changes in tunnel flow rate because of extensive unsaturated storage capacity and high transmissivity within the mine complex. Thus, elimination of stream leakage could have a small effect on the annual discharge from the tunnel, but a large effect on peak discharge and associated water quality downstream. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.     

南亚热带富营养化抽水型水库轮虫的组成与动态

大镜山水库位于广东省珠海市,是一座供应珠海市和澳门特别行政区饮水的抽水型中型水库.抽水改变了水体的水动力过程以及水体生态系统的动态过程.为了解这一动态过程中轮虫的群落结构及环境冈子对轮虫的影响,于2005年1-12月,每月一次对该水库敞水区进行了采样调查.共采集到轮虫32种,其中,臂尾轮科12种,异尾轮科、腔轮科各有4种,它们主要是热带、亚热带地区的常见种和优势种类.热带龟甲轮虫(Keratella tropica)、对棘异尾轮虫(Trichocerea stylata)、螺形龟甲轮虫(Keratella cochlearis)、迈氏三肢轮虫(Filinia maior)、裂痕龟纹轮虫(Anuraeopsis fissa)、角突臂尾轮虫(Brachionus angularis)、剪形臂尾轮虫(Brachionus forficula)、卵形无柄轮虫(Ascomorpha ovalis)、敞水胶鞘轮虫(Collotheea pelagiea)和卜氏品囊轮虫(Asplanchna brightwelli)为优势种,这些优势种个体小、具有硬被甲.轮虫的多样性指数在0.29-0.81之间变动,与相同营养水平的湖泊相比,大镜山水库轮虫的种类数和多样性指数均较低,轮虫丰度和生物量的分布范围分别为21-1094ind./L和4.04-1127μg/L,高峰期均出现在2月和5月,二者具有相似的动态特征.轮虫个体的大小范围在50-620μm之间,轮虫种类和丰度的组成均以200μm以下的小型个体为主,如裂痕龟纹轮虫、角突臂尾轮虫等,轮虫生物量组成主要是以200-400μm的中型个体为主,如卜氏晶囊轮虫、萼花臂尾轮虫(Brachionus Calyeiflorus)等,温度、透明度、浮游植物生物量和蓝藻生物量是影响水库轮虫群落结构特征和动态的主要环境因子.     

Spatial–temporal variability in water quality and macro-invertebrate assemblages in the Upper Mara River basin,Kenya

Tropical rivers display profound temporal and spatial heterogeneity in terms of environmental conditions. This aspect needs to be considered when designing a monitoring program for water quality in rivers. Therefore, the physico-chemical composition and the nutrient loading of the Upper Mara River and its two main tributaries, the Amala and Nyangores were monitored. Initial daily, and later a weekly monitoring schedule for 4 months spanning through the wet and dry seasons was adopted. Benthic macro-invertebrates were also collected during the initial sampling to be used as indicators of water quality. The aim of the current study was to investigate the physico-chemical status and biological integrity of the Upper Mara River basin. This was achieved by examining trends in nutrient concentrations and analyzing the structure, diversity and abundance of benthic macro-invertebrates in relation to varying land use patterns. Sampling sites were selected based on catchment land use and the level of human disturbance, and using historical records of previous water quality studies. River water pH, dissolved oxygen, electrical conductivity (EC), temperature, and turbidity were determined in situ. All investigated parameters except iron and manganese had concentration values within allowable limits according to Kenyan and international standards for drinking water. The Amala tributary is more mineralized and also shows higher levels of pH and EC than water from the Nyangores tributary. The latter, however, has a higher variability in both the total phosphorus (TP) and total nitrogen (TN) concentrations. The variability in TP and TN concentrations increases downstream for both tributaries and is more pronounced for TN than for TP. Macro-invertebrate assemblages responded to the changes in land use and water quality in terms of community composition and diversity. The study recommends detailed continuous monitoring of the water quality at shorter time intervals and to identify key macro-invertebrate taxa that can be used to monitor changes of the water quality in rivers of the Mara basin as a result of anthropogenic changes.     

氯化钡直接法测定地下水中硫酸根含量的研究

氯化钡直接法以茜素红－Ｓ为指示剂，用氯化钡标准溶液滴定，直接测定地下水中硫酸根的含量。与ＥＤＴＡ容量法等方法进行比较，氯化钡直接简便，快速，其准确度，精密度，相关性等均获得满意结果，适合地震监测水质分析中运用。     

新疆博斯腾湖水盐变化及其影响因素探讨

在博斯腾湖水文和水化学实测资料的基础上,研究了博斯腾湖水盐的年际和年内变化。近40年来,水质年际变化经历了好→中→差→中的过程;年内变化与区内最大补给源开都河不同季节河流来水量变化以及湖周农田排盐水等因素直接相关,而湖水的矿化度与水位变化呈负相关。对湖水主要离子含量变化特点和湖区矿化度变化规律的研究表明,湖水补给源及湖水循环状况是影响湖水水质变化的主要因素。     

延庆台地电阻率铁质干扰的有限元模拟

近年来延庆台地电阻率观测多次出现因环境干扰而引起的较为显著的异常变化,尤其是观测环境中铁质干扰源对地电阻率观测的幅度和形态的影响.本文依据台站测区地下高密度电性结构剖面和电测深结果建立了三维数值模型,分析了几种铁质对延庆台地电阻率观测的影响幅度和形态,结果表明,在扣除地电阻率基准值后,干扰幅度和形态与实际观测值的异常变化较吻合,从而从数值分析的角度确定了地下铁质对延庆地电阻率观测的干扰.