Potentially toxic metal (PTM) contamination in coal-mining subsidence wetlands poses a significant ecological threat, yet microbial responses at the sediment-water interface (SWI) remain poorly understood. Here, we perform a mechanistic assessment of how PTM gradients shape bacterial and fungal communities and evaluate their utility as ecological indicators. We survey a series of subsidence ponds in Huaibei, China, spanning gradients of Cd, As, Cu, Zn, Pb, Cr, Co, and Ni, and combined 16S rRNA and ITS gene sequencing with geochemical analyses. The results reveal multifaceted but complementary responses: bacterial communities were highly sensitive to PTMs, exhibiting significant declines in α-diversity (e.g., Shannon index, p < 0.01) and pronounced compositional turnover, whereas fungal communities displayed relative resilience, maintaining overall diversity through taxonomic substitution. LEfSe identifies robust biomarkers of high contamination-most notably enrichment of Proteobacteria and depletion of functionally important Nitrospirota. Null-model analyses show that the PTM gradient acts as a strong environmental filter, driving a shift from stochastic to deterministic assembly processes; this pattern is more pronounced in bacterial assemblages, with homogeneous selection increasing from 7.1 % to 46.4 % in sediments, and is corroborated by a reorganization of co-occurrence networks from synergistic to highly competitive, "winner-take-all" architectures dominated by PTM-associated hubs. Collectively, we establish a multi-metric indicator framework integrating diversity metrics, key taxonomic biomarkers and community-assembly mechanisms that offers a mechanistic route for ecological risk assessment and monitoring of PTM-contaminated aquatic ecosystems and to guide remediation efforts.

This study investigates the characteristics and distribution of rare earth elements (REEs) within the multi-aquifer groundwater system of the Panxie mining area in the Huainan coalfield, China. By analyzing groundwater samples from various aquifers, including sandstone, limestone, and shale, the research provides a comprehensive assessment of REE content, fractionation patterns, and anomalies, with a particular focus on Ce and Eu. The results show that, except for the sandstone aquifer, the REE concentrations in other aquifers are generally lower than the global average for river waters, with notable Ce negative anomalies and Eu positive anomalies observed across the samples. Additionally, the study employs Visual MINTEQ software to model the inorganic complexation of REEs, revealing that carbonate complexes, such as Ln(CO3)2-and LnCO3+, dominate in these groundwater systems. Finally, the research constructs a Fisher discriminant model for groundwater source identification, using the concentrations of 14 REEs as variables. The model demonstrates high accuracy, particularly in distinguishing between sandstone and limestone aquifers, offering valuable insights for groundwater management and protection in mining areas. The study not only enhances the understanding of REE geochemical behavior in groundwater but also provides a scientific basis for the development of more effective groundwater resource management strategies in the Panxie mining area and similar environments.

Coal gangue is one of the most accumulated solid wastes in China, its accumulation occupies a large amount of land resources and the potential environmental risks posed by coal gangue continue to rise. In this study, sequential extraction was employed to analyze the fractionation behavior of trace elements (Cd, Cr, Cu, Mn, Ni, Pb, V and Zn), The contamination degree and potential ecological risk of trace elements were comprehensively evaluated by Geo-accumulation Index (Igeo), Potential ecological risk index and the Risk assessment code (RAC) method. The results of XRD shows that there are various minerals in coal gangue, with obvious diffraction peak characteristics, and the minerals with higher levels are quartz, kaolinite, dolomite and potassium feldspar. The trace elements are predominantly found in the residual state. The results of Igeo The potential ecological risk level of Cd belongs to strong risk, while the level of the other elements is slight risk. The result of RAC indicates that the active forms of Mn may cause the greatest harm to the ecological environment, and which deserves further attention. The results can provide scientific basis for the stacking management and comprehensive utilization of coal gangue. reveal that all trace elements are in a pollution -free state.

The Hg released from coal mining activities can endanger soil ecosystems and pose a risk to human health. Understanding the accumulation characteristics of mercury (Hg) in coal mining soil is important for effectively controlling Hg emissions and developing measures for the prevention and control of Hg contamination. To identify the potential sources of Hg in soils, the Hg concentration and isotopic composition characteristics of raw coal and different topsoil types from the areas surrounding a coal mine were determined in this study. The results showed that Hg in coal mainly exists mainly in the form of inorganic Hg, and Hg has experienced Hg2+ photoreduction prior to incorporating into coal. In addition, the composition of Hg isotopes differed significantly among different topsoil types, and the δ202Hg value of the farmland soil exhibited large negative excursions compared to the coal mining soil. The ternary mixed model further revealed the presence of substantial differences in potential Hg sources among the two regions, with the coal mining soil being greatly disturbed by anthropogenic activity, and the relative contributions of Hg from raw coal, coal gangue, and background soil to coal mining soil being 33.42%, 34.4%, and 32.19%, respectively. However, Hg from raw coal, coal gangue and background soil contributed 17.04%, 21.46%, and 61.51% of the Hg in the farmland soil, indicating that the accumulation of Hg in farmland soil was derived primarily from the background soil. Our study demonstrated that secondary pollution in soil caused by immense accumulation of solid waste (gangue) by mining activities offers a significant challenge to ecological security. These findings provide new insights into controlling soil Hg in mining areas and further highlight the urgency of strict protective measures for contaminated sites.

The rapid increase in urbanization and intensive coal mining activities have accelerated the deterioration of surface water quality. Environmental problems caused by the accumulation of nitrate and sulfate from natural, urban, and agricultural sources have attracted extensive attention. Information on nitrate and sulfate sources and their transformations is crucial for understanding the nitrogen and sulfur cycles in surface water. In this study, we monitored nitrate and sulfate in three representative rivers in mining cities in northern China. The main pollution sources and biogeochemical processes were identified by using stable isotopes (δD, δ18OH2O, δ15N, δ18ONO3, δ34S and δ18OSO4) and hydrochemistry. The contribution of natural and anthropogenic sources was quantitatively estimated based on a Bayesian mixed model. The results indicated a large variation in sulfate and nitrate sources between the different rivers. Nitrate in the Tuohe River mainly derived from manure/sewage (57.9%) and soil N (26.9%), while sulfate mainly derived from manure/sewage (41.7%) and evaporite dissolution (26.8%). For the Suihe River, nitrate was primarily sourced from chemical fertilizer (37.9%) and soil nitrogen (34.8%), while sulfate was mainly sourced from manure/sewage (33.1%) and chemical fertilizer (21.4%). For the Huihe River, nitrate mainly derived from mine drainage (56.6%) and manure/sewage (30.6%), while sulfate predominantly originated from mine drainage (58.3%) and evaporite dissolution (12.9%). Microbial nitrification was the major pathway for the migration and transformation of nitrate in the surface water. However, denitrification and bacterial sulfate reduction (BSR) did not play a significant role as aerobic conditions prevailed. In this study, we elucidated the sources and transformation mechanisms of nitrate and sulfate. Additionally, we provided a reference for formulating a comprehensive strategy for effective management and remediation of surface water contaminated with nitrate and sulfate in mining cities.

Mercury in coals might emit into the environment from coal combination, and finally cause environmental pollution. In this paper, 26 coal samples were selected from No. 1 which is coal in the Shanxi Formation of Zhangji and Xinjier mines in the Huainan coalfield. The mineralogical and geochemical components of coal samples were determined by DMA-80 mercury-measuring instrument, XRF, XRD, ICP-MS, and the relationship between the depositional environment of the coal seam and mercury enrichment was analyzed. The results show that the mercury content of coal in the study area ranged from 0.03 to 0.93 μg/g, with an arithmetic means of 0.21 μg/g, higher than the background values of coal in China and the world. The mercury content of Shanxi Formation coal varied among different mines, the arithmetic mean value of mercury in Zhangji coal mine and Xinjier mine coal is 0.35 μg/g and 0.12 μg/g respectively. Due to the complex depositional environment and depositional facies, the distribution of mercury content in the coal seam is quite different. XRD, Microscopic observation and the ratio of (CaO + MgO + Fe2O3)/(SiO2+ Al2O3) and Al2O3/TiO2 show that the main mineral in the depositional environment of this study area is kaolinite, quartz and pyrite, and the depositional facies are intercontinental and sea-land, so the parent rock type belongs to acid bedrock. The Ni/Co, Sr/Ba, and Sr/Cu ratios were used to indicate a weak oxidation-reduction, Marine salt water, and an arid and hot environment. The vertical distribution of mercury in coal and the characteristics of the depositional environment are combined to show that mercury in coal is easily affected by redox conditions, paleosalinity and paleoclimate in the depositional environment. At the same time, mercury accumulation is more easily in the depositional environment dominated by seawater intrusion than in the terrigenous input.

Coal mining has produced a large amount of coal gangue. It makes the soil around the mining area seriously polluted by heavy metals, affects the growth of crops, and endangers human health. Therefore, there is an urgent need to develop new materials for remediation of Cd in soil. In this study, mercaptosilane-modified sepiolite (Q-Sep) was used as a basic passivator, and it was pretreated with acid (H-Q-Sep) and high temperature (R-Q-Sep) respectively. By analyzing the forms of Cd and pH values in soil after adding modified sepiolite, we compared the remediation effects of two modified methods on Cd in soil. The enrichment of spinach (Spinacia oleracea L) to Cd and changes in physiological and biochemical indexes of spinach were determined, and the effect of modified sepiolite on the growth of spinach was judged. The experimental results showed that the addition of modified sepiolite could significantly increase the soil pH values (p < 0.05); the content of exchangeable Cd in soil decreased by 60.4%; and the maximum increase of residual state was 32.9%. The absorption of Cd in soil by spinach decreased, and root length, plant height, and biomass of spinach all increased. It was proved that the addition of modified sepiolite can improve the productivity of soil, reduce toxicity of heavy metals in soil, and promote growth of plants. As a result, the addition of H-Q-Sep and R-Q-Sep can effectively repair Cd in gangue filled soil, which provides a certain theoretical basis for the passivation remediation of Cd in soil.

Coal, being one of the major energy sources for power generation, contains several critical trace elements. There is a growing scarcity and expense of these critical elements as a result of the increased demand and limitation of mining sources. To explore the geochemical characteristics of the rare-metal, rare-dispersed (scattered), and rare-earth elements (TREs) in coal, 25 coal seam samples of the Shanxi Formation in the Huainan coalfield were collected. The major element oxides, minerals, and TREs were analyzed by X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), and inductively coupled plasma-mass spectrometry (ICP-MS). The results revealed that the coal of the Shanxi Formation had ultra-low moisture and low ash yield and was medium–high-volatility with low sulfur content and high calorific value. Concerning minerals, the coal was mainly composed of kaolinite, illite, quartz, calcite, dolomite, and pyrite. Compared with Chinese coal and world hard coal, rare-metal element Li and rare-dispersed element Se were enriched, whereas Ga and Ta were only slightly enriched. The average content of REYs was 51.34 μg/g, which is lower than the average content of REYs in Chinese coal. It has the enrichment characteristics of light REYs. In the vertical direction, the content of most TREs was higher in the roof and floor of the coal seam and the parting, indicating that the sedimentary microenvironment plays an important role in controlling the migration and enrichment of elements. The experimental results of sequential chemical extraction and correlation analysis showed that the TREs in the Shanxi Formation coal mainly exist in a residual and carbonate bound state, and occur in clay minerals and carbonate minerals. The enrichment of Se may be due to its high organic form ratio. The C-value, B content, w(Sr)/w(Ba), and REY geochemical parameters indicated that the Shanxi Formation Coal seam was developed in a transitional, semi-saline, deltaic sedimentary environment. With their development affected by seawater, REYs in coal are greatly supplied by terrigenous clastics. The complex sedimentary environment is an important reason for the varying occurrence states of TREs in the Shanxi Formation coals.

煤矸石的露天堆放,不仅侵占大量的土地资源,还会带来严重的环境污染问题.为研究煤矸石中放射性核素对周边土壤环境的影响,采集煤矸石及矸石堆周边土壤样品,测试样品中放射性核素238U、232Th的活度浓度,分析煤肝石及周边土壤中放射性核素238U、232Th的分布特征,采用地累积指数法对土壤污染状况进行综合评价.结果表明,矿区煤矸石主要以粘土矿物为主,而粘土矿物是吸附铀、钍的关键性矿物;土壤中放射性元素238U、232Th活度范围分别为31.51-58.81、53.33-94.48 Bq·kg-1,远低于煤肝石,其活度浓度呈现出与肝石堆距离增加而减小的分布趋势;煤肝石中238U、232Th主要以残渣态为主,土壤样品中238U赋存形态以有机结合态和碳酸盐结合态最为突出,而232Th总体上以残渣态为主;地累积指数法评价结果表明,S1-S9号采样点处Igeo(238U)在不同深度段均小于0,表明周边土壤并未受到238U这种元素的污染,而靠近肝石堆的表层土壤(0-20 cm)受到232Th轻微污染,其污染范围限定在距肝石堆30 m以内.

稀土元素由于其独特的化学特征被广泛应用于环境地球化学分析过程研究.以淮南采煤沉陷区表层沉积物中稀土元素(REEs)为研究对象,采集研究区潘一、顾桥、谢桥沉陷区的表层沉积物样品共12个,采用ICP-MS对样品的稀土元素含量进行测试分析,探讨了表层沉积物中稀土元素的含量分布特征、控制因素及其物质来源.结果表明:研究区表层沉积物中稀土元素含量为54.63～130.45μg/g,平均102.60μg/g;LREE/HREE比值为11.89～20.55,平均14.29,轻稀土呈现明显富集现象;相关性分析结果显示,REEs趋向于黏土组分中富集;研究区养殖和捕捞活动导致表层沉积物中稀土元素含量的降低;球粒陨石标准化结果表明,研究区稀土元素呈现不同程度的La和Gd正异常,其中,Gd正异常主要是受到燃煤的影响,而La正异常主要与燃煤和化肥有关.结合Pearson相关性、球粒陨石标准化和(La/Yb)N-(La/Sm)N-(Gd/Yb)N三元图判别,认为研究区水体表层沉积物中稀土元素与人类活动(燃煤和化肥)有关,研究认识为污染物的源头控制和煤矿区环境的生态治理提供参考依据.

Severe environmental issues are caused by long-term coal mining activities; however, the process of mercury (Hg) response in mining subsidence area sediments (MSAS) is still unclear, and direct evidence showing the relationship between Hg accumulation mechanism in sediments and mining activities is lacking. In this study, the characteristics of total mercury (THg) content in MSAS were investigated. Moreover, Hg isotopes were obtained to determine the main sources and environmental process of mercury in MSAS, and a MixSIAR mixing model was first used to estimate the potential Hg sources. The THg content ranged from 27.5 to 113.9 ng/g, with a mean of 65.8 +/- 29.4 ng/g, exceeding the local soil background value (19.7 ng/g). The Hg in MSAS was affected by clay and organic matter. The delta Hg-199 and delta Hg-201 in the sediments varied from -0.05-0.05 parts per thousand & nbsp; (mean:-0.01 +/- 0.03%o) and -0.07-0.01 parts per thousand & nbsp; (mean:-0.02 +/- 0.03 parts per thousand & nbsp;), respectively, with the fitting results suggesting that a photochemical reaction occurred in some of the Hg in the sediments prior to deposition. The results of the MixSIAR mixing model revealed that the Hg in MSAS was mainly derived from gangue, soil erosion, coal, fly ash, and feed, and their corresponding percentage contribution was 51.5 +/- 9.6%, 23.8 +/- 13.1%, 13.9 +/- 7.9%, 8.1 +/- 5.4%, and 3.1 +/- 1.4%, respectively. Hg isotopes can be used to trace the transport and transformation of environmental pollutants, and this may provide an important reference for the assessment and prevention of Hg pollution in typical areas such as coal mining and coal-fired.

深层灰岩水在长时间水岩耦合作用下各含水层的水化学成分有所不同,但随着地壳运动、采动影响等因素导致不同含水层产生水力联系.重大的突水事故都是深层高压灰岩水以浅层灰岩水为通道突入矿井发生的.依据对淮南煤田潘谢矿区9对矿井2015—2018年182个地面水文观测孔的水位数据及潘二矿突水后各水文观测孔水位变化的时空规律,得出水文观测孔的水位变化数据比水位高程数据更灵敏,潘谢矿区深层灰岩水由下向上对浅层灰岩水进行补给,通过聚类分析算法识别出矿井与深层灰岩水存在补给关系的浅层灰岩含水层区域;另一方面基于改进的随机森林算法对收集的7000多条矿井水质化验资料进行分析,基于错分数据识别出与深层灰岩水水力联系紧密的各矿含水层信息.综合分析水位变化数据聚类分析结果,得出各矿井的突水风险区域.基于含水层分类显著因子、水化学空间分布特征,结合温度、流量、水位、水质等参数的高精度传感器,构建快速准确突水预警系统,对矿井出水点进行智能监测,为实施防治水措施提供快速、可靠的依据,可以极大地避免矿井发生突水事故和减少突水事故产生的损失.

The deep Carboniferous Taiyuan Formation and Ordovician limestone water are not only valuable groundwater resources in North China but also the main source of water hazards for Carboniferous-Permian coal mining. Currently, there are still insufficient studies on the recharge, circulation, and water–rock interactions of deep limestone water. Taking the Panxie mining area of Huainan, Anhui Province, as the research area, this study investigated the water–rock interaction and water cycle of deep limestone groundwater by combining hydrochemistry and stable isotopes of hydrogen and oxygen. The results show that (1) the average total dissolved solids (TDS) values of the Taiyuan Formation limestone and Ordovician limestone water were 852.72 mg/L and 2785.52 mg/L, respectively, and the Ordovician limestone water was high-salinity water. The main hydrochemical type of the Taiyuan Formation limestone water is Cl·HCO3-Na, and the main type of Ordovician limestone water is Cl-Na. Evaporite dissolution and cation alternate adsorption jointly control the source and composition of limestone water chemical ions. The dissolution effect of evaporite in Ordovician limestone water is stronger, while cation alternate adsorption in Taiyuan Formation limestone water is stronger. (2) The hydrogen and oxygen stable isotope values of limestone water are distributed at the lower right of the atmospheric precipitation line and close to the precipitation line, indicating that the groundwater is primarily derived from atmospheric precipitation. Some water sample points deviate far from the atmospheric precipitation line, mainly due to the isotope exchange equilibrium reaction between groundwater and surrounding rock in long-term full contact, showing a certain degree of the “oxygen (deuterium) drift” phenomenon. (3) Most of the Taiyuan Formation limestone water isotopic values are greater than the average annual precipitation, while those of the Ordovician limestone water are the opposite, which indicates that the Taiyuan Formation limestone water produces varying degrees of evaporation and infiltration in the replenishment path, and Ordovician limestone water is unevenly recharged by precipitation in different seasons.

根据淮北临涣采煤沉陷区水生态调查数据,基于方差赋权的生态系统综合指数法,采用主成分分析与相关性分析方法进行指标筛选,建立了沉陷区生态系统健康评价指标体系.结果表明:(1)功能区周边环境大致相同,沉陷区西部废水排放区环境最差,东部近矸石山区状况最好,其综合健康指数值分别为0.422、0.566;(2)临涣采煤沉陷区生态系统处于亚健康状态,栖息地环境和水生生物指标分别为0.337 5和0.256 6,是影响临涣采煤沉陷水域生态系统最大的两个指标类型.矿业生产活动、露天矿业废弃物堆放、农业生产和居民生活污水是导致临涣采煤沉陷区生态系统亚健康的主要原因.

以淮南煤田深部山西组煤为研究对象,分别采集研究区张集煤矿和新集二矿二叠系山西组1煤层的煤样品,测试了样品中总汞的含量,分析汞的空间分布特征,采用浮沉实验、逐级化学提取实验以及相关性分析研究了煤中汞的赋存状态,并结合沉积环境探讨了深部山西组煤中汞的富集成因.结果 表明:(1)研究区煤样中汞含量介于0.03～0.93 μg/g之间,算术平均值为0.21 μg/g,均高于中国和世界煤中汞的背景值,与地壳中汞含量相比,富集系数高达2.6,表现出明显富集;(2)淮南煤田不同煤矿山西组煤中汞含量不同,张集煤矿煤中汞算术平均值为0.35 μg/g,新集二矿煤中汞算术平均值为0.12 μg/g;受复杂沉积环境和沉积相作用,同一煤层中,汞含量分布差异性较大;(3)相关性分析、浮沉实验和逐级化学提取实验结果表明,煤中的汞主要以硫化物结合态存在;矿物分析结果显示,黄铁矿是煤中汞的主要载体,张集煤矿煤中的汞主要以固溶态赋存于原生黄铁矿中,新集二矿山西组煤中的汞主要赋存于裂隙充填的后生黄铁矿中.

通过采集淮南潘一矿采煤沉陷复垦区不同深度覆土样品,检测土壤中有机质、总氮、速效磷、速效钾等指标,分析采煤沉陷复垦区土壤肥力时空变化特征.结果表明:复垦9年,0 cm～20 cm、20 cm～40 cm、40 cm～60 cm覆土厚度土壤中有机质增长率分别为61.68％、69.44％、55.68％,总氮增长率分别为71.60％、67.86％、57.95％,速效磷增长率分别为72.56％、75.32％、52.09％,速效钾增长率分别为72.96％、68.77％、47.51％.复垦区土壤肥力有机质处于Ⅳ级较缺乏水平,总氮处于Ⅱ级和Ⅰ级,较丰富水平及以上,速效磷处于Ⅲ级,中等水平,速效钾处于Ⅱ级,较丰富水平.

以安徽淮南煤田深部山西组煤样为研究对象,通过设计不同燃烧温度条件,测定各温度下燃煤产物中有害元素含量,拟合得到As、Se、Sb的释放曲线与释放强度曲线,并对原煤及不同温度条件下燃煤产物中各元素的赋存状态进行分析.结果表明,燃烧温度由500℃升至1 000℃过程中,As、Se、Sb的释放比例逐渐增大,三种有害元素挥发性难易程度顺序表现为Se＞As＞Sb;不同温度下有害元素释放强度不同,As在700～815℃的区间内出现一个释放强度峰,而Se与Sb的释放强度峰出现在600～700℃阶段;随燃煤温度不断升高,As、Se、Sb的各赋存形态均发生不同程度的迁移及转化,温度升高至1 000℃,As、Se、Sb的固相形态明显降低.

为揭示煤矿区地下水稀土元素地球化学特征,采集潘谢矿区松散层、太原组灰岩(太灰)和奥陶系灰岩(奥灰)3个含水层共65个水样,进行稀土元素测试,探讨不同含水层稀土元素的含量特征及控制因素.结果 表明:研究区地下水整体呈弱碱性,水质类型整体为Cl-Na,Cl· HCO3-Na型.地下水稀土元素含量总体较低,轻稀土元素亏损,中重稀土元素富集.奥灰水中稀土总量最低,可能与金属氧化物(如铁、锰)吸附或与碳酸岩(如方解石)发生共沉淀有关.3个含水层地下水均表现为明显的Eu正异常,可能与含水介质中富Eu矿物(如长石)的优先化学风化溶解有关.太灰水和奥灰水Ce负异常明显,松散层水Ce负异常较弱,研究区地下水Ce负异常与其继承母岩密切相关.pH对水体中的稀土元素总量的控制与碱度有关,碱度较低时控制作用显著.碳酸根的络合反应、铁的胶体或氧化物与稀土元素的吸附/络合反应是稀土元素分异的重要控制因素.

This study investigated the environmental geochemical characteristics of rare-earth elements (REEs) in surface waters in the Huainan mining area, Anhui Province, China. The REEs concentrations were determined by ICP-MS, and the inorganic species of dissolved REEs in the river and coal mining subsidence area water samples were calculated by using the Visual MINTEQ (version 3.1) code. On this basis, the distribution and geochemical characteristics of REEs in the surface waters were systematically analyzed, and the main inorganic species of REEs were investigated. The results showed the following: (1) The REEs concentrations in the surface waters were relatively low, ranging from 0.1361 to 0.3536 μg/L, and the average ∑REEs concentration was 0.2062 μg/L. Compared with light rare-earth elements (LREEs), heavy rare-earth elements (HREEs) were significantly enriched, with an average enrichment factor of 1.4642. Due to the interaction of high pH values and high cation concentrations, the ∑REEs content in the subsidence area water was significantly lower than that in the river water. (2) The distribution pattern of REEs in the surface waters normalized against the North American Shale Composite (NASC) showed that the REEs in the study area had different degrees of cerium (Ce) and europium (Eu) anomalies. The negative Ce anomalies were probably closely related to the pH conditions, whereas the positive Eu anomalies were mainly attributed to preferential chemical weathering and the dissolution of feldspar minerals. (3) The simulation results obtained by using Visual MINTEQ code showed that the dominant and typically inorganic complex form of REEs in the surface waters was carbonate complexes, and this form was one of the reasons for the enrichment of HREEs in the surface water.

为研究粉煤灰掺入量对煤矸石水力学性质和导气率的影响,设计9种矸灰比的粉煤灰-煤矸石混合物,运用室内一维定水头法和压力膜仪(DIK-3423)以及一维瞬态法测试了混合物饱和含水量、饱和导水率、水分特征曲线和导气率等指标,并与土壤、粉煤灰和煤矸石进行对比分析.结果表明:1)粉煤灰的掺入可以提高煤矸石的饱和含水量,矸灰比3:7～2:8的混合物的饱和含水量为36.9％～41.4％,数值上最接近土壤;2)混合物的饱和导水率受粉煤灰掺入量和容重影响,相同粉煤灰掺入量下提高容重会降低饱和导水率,而饱和导水率变化的整体趋势随粉煤灰掺入量的增大而减小;3)混合物的持水性能随粉煤灰掺入量的增大而增大;4)混合物的导气率随粉煤灰掺入量的增大而减小,粉煤灰掺入量<40％的混合物导气率对含水量的敏感度呈先减小后增大的趋势,其余比例混合物导气率变化较均匀;5)矸灰比(煤矸石与粉煤灰体积比)在3:7～2:8混合物的植物有效水含量为17.3％～17.6％,数值上最接近土壤,选用粉煤灰-煤矸石混合物充填塌陷土地时可控制矸灰比在3:7,此时渗透性小,且可以保证有良好的土壤有效水供给.研究结果可为塌陷区土地复垦质量的改良提供数据参考.