Effects of acid mine drainage on photochemical and biological degradation of dissolved organic matter in karst river water

Dissolved organic matter(DOM)can be removed or transformed by photochemical and biological processes,producing the negative effect of transforming organic carbon into inorganic carbon,which plays a vital role in the karst carbon cycle.However,acid mine drainage(AMD)will affect this process,so the degradation of DOM in karst river water(KRW)needs to be studied in this context.In this study,to reveal the evolution processes of DOM under photochemical and biological conditions in AMD-impacted KRW,AMD and KRW were mixed in different ratios under conditions of visible light irradiation(VL),biodegradation(BD),ultraviolet irradiation(UV)and ultraviolet irradiation+biodegradation(UV+BD).The average DOC concentrations in samples after mixing AMD and KRW in different proportions decreased significantly(by 23%)in UV+BD,which was 1.2–1.4 times higher than under the other conditions and would lead to a significant release of inorganic carbon.Further analysis of the fluorescence parameters via parallel factor analysis(PARAFAC)revealed that the DOM fluorescence components in AMD comprised mainly protein-like substances derived from autochthonous components,while the DOM fluorescence components in KRW were mainly humic-like substances with both autochthonous and allochthonous sources.Therefore,AMD could promote both the photochemical and biological degradation of DOM in karst receiving streams,resulting in the conversion of DOC to inorganic carbon.The results showed that the synergistic effects of UV+BD and AMD accelerated the degradation of DOM and the release of inorganic carbon in KRW,thus affecting the stability of the karst carbon cycle.

The influence of land use change on karst water quality of Shuicheng Basin in Guizhou Province

The influence of land use and land cover on ecological environment is a focus of global change research. The paper chooses an industrial city-Shuicheng in Guizhou Province-as a study area because the karst water quality around the city is deteriorating with land use and land cover change. The natural susceptibility of karst water system is an important factor leading to karst water pollution. But land use and land cover change is also a main factor according to the chemical analysis of karst water quality and land use change. So it is a good way to protect karst water through rational planning and managing of land use and land cover.

Movement characteristics of Karst water in a deep mining area

In order to study the movement characteristics of groundwater in a deep mining area and solve the dispute of the distri- bution rule of hydro-chemical zoning which is contradicted by lixiviation water zoning in a horizontal direction, we directed our attention to the source of deep groundwater, its seepage and hydro-chemical characteristics in a typical mining area. We used a neotectonic water-control theory, chemical and isotope methods, as well as a method for analyzing dynamic groundwater conditions. The results indicate that 1) Karst water in the deep and medium parts of this mining area is recharged by vertical leakage through neotectonic fractures rather than seepage along strata from subcrop parts or surrounding flows; 2) from surface to deep leakage paths, the variation in the types of chemical groundwater agrees with the normal lixiviation water distribution rule and the age of mixed groundwater increases; 3) the water-rich zones along neotectonic fractures correspond with water-diluted zones in a hori-zontal direction; 4) the leakage coefficient and water capacity of aquifers increases during the flow process of Karst water along the antidip direction (from west to east) and 5) Karst water in shallow mining areas forms a strong runoff belt along strikes and quickly dilutes the water from deep and medium mining areas. Overall, chemical and dynamic water characteristics actually agree with in terms of the entire consideration for differences in vertical leakage and abnormalities in the zone of water chemical distribution, along a horizontal runoff direction.

Study on the characteristics and causes of carbon tetrachloride pollution of karst water in eastern suburbs of Jinan

By comparing the testing data of the hydrochemistry components and organic pollution of karst water sample in Jinan with large amount of historical data, the author finds the long-existing problem of carbon tetrachloride pollution and the great change of hydrochemical characteristics of karst water in eastern suburbs of Jinan. Since karst water is the main water-supply source in eastern suburbs of Jinan, these problems have greatly affected the safety of water supply. Based on the analysis of hydrogeological condition in eastern suburbs of Jinan, this thesis discusses the causes of carbon tetrachloride pollution and hydrochemical variation with hydrogeochemical theories so as to protect the precious karst groundwater and Jinan spring water. It is found that through research and analysis that there are mainly two causes of carbon tetrachloride pollution and hydrochemical variation: the vulnerability of karst water in this area; the other being the serious pollution in this area caused by remaining pollution sources of the last century.

Isotope Hydrogeological Study of Karst Water in the Lu' an Mining District and the Xin'ancun Spring Basin, Shanxi

Isotope hydrogeological study has shown that the water supply exploration area in the Lu' an coal mine may be divided into four zones of hydrodynamic conditions and the Xin'ancun Spring Basin where the mine is located may be divided into three Middle Ordovician karst water systems. This paper discusses the features of recharge, runoff and discharge of karst water in various zones, and hydrogeological parameters such as the age, flow rate and natural recharge of karst water have been estimated.

Exploration of Water Resource and Multiple Model for Water Resource Development in Karst Areas with the Preferred Plane Theory

According to the theory of preferred plane, preferred planes (faults) alwayscontrol the distribution of bedrock fissure water and hold abundant groundwater. Thus, theexploration of fissure or karst water can be converted into searching for the watery preferred plane(WPP). In the paper, the characteristic of watery preferred planes is analyzed and a series ofsuperior indices has been set up. It is introduced that WPPs are determined by the methods ofgeological analysis, superior index and complex geophysical analysis. Meanwhile, new multiple modelfor water resource development in the water-scarce areas of karst mountainous regions are advanced.

Numerical modeling of water yield of mine in Yangzhuang Iron Mine, Anhui Province of China

This study develops a three-dimensional heterogeneous numerical model to simulate the water inrush process and predict the water yield for mineral exploration in Yangzhuang Iron Mine in Anhui Province. To identify the hydrogeological parameters of the aquifer in the study area, the model was calibrated and validated using the observed heads through the integrated trial-and-error and automated techniques. Also, the sensitivity analysis of the model was performed to evaluate the uncertainty associated with the calibrated model. According to the mine construction plan at different mining levels of-500 m,-600 m, and-700 m, the calibrated model was then applied to predict the water yields dependent on the different mining levels. As indicated by the prediction results, the numerical simulation model can systematically describe the groundwater system in the mining area and determine the source of water inrush in this iron mine. In conclusion, numerical analyses carried out in this study can provide guidance to decision-makers in balancing the iron ore mining and mine dewatering in the future.

广邻快速公路华蓥山特长隧道方案的地质条件比选研究

广邻快速公路为连接广安市与邻水县的重要高等级公路,其控制性工程华蓥山特长隧道工程地质条件和水文地质条件极其复杂,施工及运营风险极高。为了降低隧道工程施工及运营风险,分析了隧址区的工程地质条件,重点论证了岩溶及岩溶水与煤矿采空区2类重大工程地质问题,并通过对比不同方案的地质条件,确定了岩溶发育路段短、岩溶水危害较小、对环境影响较小、煤矿采空区长度短的隧道方案。

平顶山八矿深部寒灰热水的疏放与地面利用结合研究

平顶山八矿开采二水平二1煤受底板高温高压寒灰岩溶水的突水威胁,水温50~52℃,水质属于富含偏硅酸和锶,属于适合饮用的天然矿泉水。因突水系数超过临界值,所以需要疏水降压。八矿将疏放寒灰水与地面工业广场的生活用水结合起来,建成了地热水综合利用工程,既消除了岩溶水对井下采煤的水害影响,每年也为矿井节省数百万元的燃煤、排水等费用。

水文地质条件极复杂矿井底板岩溶水害强化注浆加固应用与效果分析

为保障矿井安全生产、延长矿井使用寿命、减少生产成本和保护环境。针对水文地质条件极复杂矿井底板岩溶水害治理难题,研究强化注浆加固技术的应用效果。结合121103工作面实际工程,通过对矿井地质构造和水文地质条件的详细分析,制定科学的注浆加固设计方案,采用注浆钻孔布置和井下钻孔探查方法,根据设计要求对奥灰顶部和徐灰进行强化注浆综合治理。并在实施注浆加固工程后,监测注浆终压、钻孔注浆覆盖率、块段吨水注干料数等指标,并通过检查孔和井下物探方法评价改造效果。结果表明,奥灰顶部和徐灰的强化注浆改造均取得显著成效,注浆终压达到预期标准,钻孔注浆覆盖率和块段吨水注干料数达到设计要求,检查孔分析和井下物探结果显示,水害问题得到有效控制,矿井安全生产条件显著改善。

基于瞬变电磁的岩溶发育及富水分区特征研究

针对川南煤田观文煤矿的岩溶水害问题,采用瞬变电磁技术探测了矿区地层视电阻率,结合矿井地质资料确定了地层物性特征,分析了矿区岩溶发育情况和富水性特征,并对富水性进行了分区,判定了矿井充水水源。结果表明:观文煤矿水文地质条件复杂,岩溶发育分布广泛;共有富水异常体37个,其中岩溶溶洞异常数共20个,占54.1%;矿区岩溶富水性在平面和剖面上都具有显著分区特征,基本表现为下部强上部弱,北部强南部弱,西部强东部弱;西北端发育一条暗河,且与断层造成的破碎带相连,形成大面积的强富水区;长兴组灰岩岩溶—裂隙弱含水层和茅口组灰岩岩溶—裂隙含水层分别是未来矿井顶板和底板充水的主要水源。研究成果可以为矿井防治水工作提供依据。

湖南省界牌岭矿区矿坑充水途径研究

湖南省界牌岭矿区在深部多金属矿探采结合施工时,出现了矿坑涌水量大和西南部塔下村余家组发生了大量岩溶地面塌陷等问题。尽管以往开展过矿区水文地质勘查工作,但对水文地质条件尤其是威胁矿山安全生产及对周边地质环境造成破坏的矿坑潜在充水水源和充水通道了解得不够清楚。文章系统整理分析了矿区前期各阶段水文地质资料,结合地面调查、物探、钻探、抽水试验等常规方法,对界牌岭矿区水文地质条件进行了研究,并重点分析了矿坑充水途径。结果显示:(1)研究区西南部新发现NE向断层F_(303)。(2)矿坑主要充水途径有2条:①矿区西部F_(201)至F_(32)段隔水层测水组缺失,壶天群、梓门桥组与石蹬子组直接接触,同时受F_(201)、F_(303)、F_(32)的影响,构成矿坑最主要的充水途径;②矿区西北部沿花岗斑岩岩体与围岩接触带富水性较好,围岩接触带构成矿坑充水途径;主要充水水源为西部壶天群地下水和田尾溪水。建议在F_(1)的西侧梓门桥组、壶天群范围内利用下部隔水层测水组对梓门桥组、壶天群内的充水途径进行帷幕注浆,阻隔矿区与河水、壶天群的地下水水力联系。研究结果可为矿山下一步防治水工作的实施提供参考依据。

深部开采底板奥灰突水水害防治的实践

针对虎龙沟煤业煤矿开采时底板奥灰水突水危害,提出了钻探揭露、注浆改造的治理方案。根据奥灰水突水特点,以及空洞和裂隙受注介质的特点,设计奥灰含水层为注浆目标层,注浆时首先用比重1.5的稠浆低压充填,再用比重1.2的稀浆高压补充。通过工程应用,发现工作面奥灰平均单位吸水率由0.003L/min.m.m降至0.0009L/min.m.m,突水区域出水量减少74%。

典型岩溶矿区突水成因研究——以龙宝煤矿为例

为研究岩溶地区煤矿采面突水成因,以贵州黔北地区龙宝煤矿为试验地点,采用可控源音频大地电磁法确定水源及导水通道,并结合COMSOL建立突水模型,分析突水过程裂隙水压和突水量变化.采用可控源音频大地电磁法探明突水点附近T_(1)y^(2)地层形成2条导水通道,P_(3)c地层形成5条导水通道,P_(3)l地层形成4条导水通道,煤层采动导致应力场和地下水的天然流场发生变化,在上部地层形成岩体裂隙并贯穿T_(1)y^(1)和T_(1)y^(3)隔水层.通过模拟不同裂隙与工作面导通后的突水量,并结合现场实测突水量综合分析可知,突水前,采空区的冒落带已经导通了Ⅰ号导水通道,使涌水量一直保持在20 m^(3)/h左右;推采过程中,顶板受到采动影响冒落,使采面与Ⅱ号导水通道贯通,导致含水层T_(1)y^(2)中的承压水通过Ⅱ号导水通道瞬间涌入工作面,使涌水量突然增大至100 m^(3)/h.

采煤作用下岩溶水水化学时空演化特征及控制因素分析——以山东济南潘西煤矿为例

为揭示采煤作用下岩溶水水化学的时空演化规律,以潘西煤矿岩溶水为研究对象,运用Piper三线图、相关性分析、离子比例关系及矿物饱和指数等方法分析了岩溶水水化学特征及演化规律,探讨了物质来源及煤矿开采对主要离子的影响。研究结果表明:岩溶水中优势阳离子为Ca^(2+),优势阴离子为HCO_(3)^(-);岩溶水中常规离子含量均有上升,SO_(4)^(2-)、Na^(+)及Cl^(-)含量上升幅度较大,伴随着煤矿的开采地下水化学类型由单一向复杂化发展;岩溶水化学组分主要来源于碳酸岩、硫酸盐及蒸发岩盐等溶解。采煤作用使岩溶水系统由还原环境转变为氧化环境,导致SO_(4)^(2-)、Na^(+)含量持续上升。

闭坑矿井水影响下喀斯特河流污染特征演化及水质评价

闭坑矿井水汇入河流会对河流的水生态环境产生较为严重的影响。以贵阳市受闭坑矿井水污染的喀斯特地貌河流为研究对象,分析河流的污染特征并评价其水质。结果表明:闭坑矿井水汇入喀斯特地貌地表河流后,水体SO_(4)^(2-)、Fe等酸性闭坑矿井水特征污染物含量升高;研究区河流除了受闭坑矿井水污染外,还有其他污染水体汇入,主要为当地居民生活污水、农业灌溉排水。研究区水质指数(WQI)、重金属污染指数(HPI)、重金属污染评价指数整体变化趋势相同;河流源头处水质级别为优,闭坑矿井水汇入后,水质变为差、较差,经地表水、地下水汇入补给以及河流自净,水质级别变为好。