浅层地下水氟的溶解／沉积作用的定量研究

以河北邢台山前平原浅层高氟地下水为例，根据氟的化学热力学分析，确定了控制浅层地下水中氟迁移和富集的固相沉淀物，以及不同化学类型的浅层地下水中含氟固相沉淀物的溶解／沉淀条件，利用浅层地下水化学平衡反应模型和ＰＨＲＥＥＱＥ软件，确定了氟化钙的稳定区域，计算了氟化钙的饱和指数，研究结果表明，在浅层高氟地下水的整个形成过程中，都表现为氟由固相转入水相的趋势，有利于氟的迁移和富集。     

非饱和带土体-浅层地下水系统氟的地球化学——以河北邢台山前平原为例

邢台山前平原浅层高氟地下水分布区，浅层地下水与非饱和带土体构成了一个完整的水文地球化学系统。在该系统中，非饱和带土体的氟源强度及浅层地下水体聚集和保存氟的条件是影响非饱和带土体浅层地下水之间氟迁移和富集的两个关键因素。其中前者直接受控于土体的矿物成分、化学成分和粒度组成，而后者主要取决于浅层地下水的化学成分特征。大气降水入渗条件下，非饱和带土体浅层地下水系统氟迁移和富集动态模拟实验结果表明，非饱和带土体是浅层地下水重要的供氟源，非饱和带水土系统氟的地球化学反应主要为水相络合反应、溶解／沉淀反应和吸附／解吸     

浅层地下水氟的质量平衡反应模型及其化学演变

以邢台山前平原浅层地下水系统为例，本文运用地下水质量平衡反应模型的理论和方法，建立了浅层地下水氟的质量平衡反应模型。确定了从氟的淋溶一移带至氟的富集带，沿水流路径在水－岩相互作用过程中含氟和其它（矿）物相的质量转移数量。在此基础上探讨了浅层地下水氟的化学演变过程和形成机制，使氟的水文地政治协商会议化学分带建立在量化的基础上，深化了对浅层地下水中氟的化学行为的认识。     

寿光市高氟地下水的分布规律和成因

寿光市曾经是山东省地氟病防治的重点地区,通过在病区开展野外调查和岩土、水样测试等工作,总结了该区地氟病分布及地球化学环境特征,探讨了地氟病与地层岩性、土壤、地形地貌、浅层地下水、生活用水等的关系。在系统环境地球化学调查的基础上,研究了当地高氟地下水的成因,认为岩石、土壤、海水是高氟浅层地下水的主要来源,高氟浅层地下水形成可能有海侵富集型和蒸发浓缩型。分析了地下水中氟富集的因素与过程,提出了地氟病的防治措施。     

鲁西南浅层高氟地下水成因的水文地球化学研究

鲁西南京杭运河以西的大部分地区浅层地下水氟含量普遍偏高,最高达6.0 7mg/L,是地方性氟中毒症高发区。根据巨野煤田勘探期间在巨野、郓城、嘉祥等地进行的浅层地下水(埋深<2 0m)水文地球化学调查资料,结合本区地形、地貌、气候、岩性等因素,对浅层地下水的水文地球化学特征及高氟地下水的成因机理进行了研究,指出本区地下水氟的富集主要与pH值、矿化度、HCO₃-、Ca2+、Mg2+含量有关,计算了F、Ca、Mg 3种元素的组分浓度以及几种固相沉积物的饱和指数,并提出了相应的预防和治理措施。      

黔中岩溶地区岩土水系统中氟的环境地球化学研究

通过对研究区碳酸盐岩— 土— 水系统中氟的系统测定和吸附实验,结合矿物表面化学和土壤化学研究,揭示了岩溶地区岩— 土— 水系统中氟的地球化学特征和迁移富集机理。黔中岩溶地区深层地下水( 100m 以下)和土层具有高氟异常特征,而浅层地下水和地表水含氟较低(大多在0. 5mg /l以下)。以含石膏碳酸盐岩为主的三叠纪海相地层是该区土水中氟的主要来源。土层中针铁矿表面对氟的专性吸附及其解吸作用是岩溶地区土水系统中氟迁移和富集的重要机理。      

地表灌溉对沉积含水层中碘迁移释放过程的影响

灌溉等人为活动会造成外源物质的输入,如硝酸盐、有机质等,从而引起浅层地下水环境发生周期性波动。为研究农业灌溉对沉积含水层中碘迁移富集过程的影响,选取代表性富碘沉积物,通过室内实验模拟了灌溉活动外源物质输入条件下,盆地地下水系统中碘迁移释放的（生物）地球化学过程。实验结果表明：厌氧条件下,外源有机质输入可促使微生物利用有机质作为电子供体,还原固相铁矿物相,进而造成搭载于铁氧化物/氢氧化物表面的碘释放,以碘离子形式在地下水中富集;而在NO₃^-输入情况下,微生物会优先利用NO₃^-为电子受体,至硝酸盐被全部消耗后,Fe（Ⅲ）可进一步被还原为Fe（Ⅱ）。研究结果表明,人为活动造成浅表环境外源物质的输入可直接影响浅层地下水中碘的迁移释放过程。伊利石黏土矿物吸附的铁氧化物矿物相可能为浅层环境中碘的主要搭载介质,微生物作用下,铁氧化物/氢氧化物的还原溶解是高碘地下水形成的主控因素。     

塔里木盆地南缘绿洲带地下水砷氟碘分布及共富集成因

由于地表水资源稀缺,地下水是塔里木盆地南缘绿洲带重要用水水源,因此,系统查明该区地下水砷氟碘的分布及成因至关重要。基于塔里木盆地南缘绿洲带233组地下水水样检测结果,分析不同含水层中高砷、高氟和高碘地下水的空间分布及水化学特征,结合研究区地质、水文地质条件和地下水赋存环境进一步揭示影响地下水砷氟碘的来源、迁移与富集的水文地球化学过程。结果表明:地下水砷、氟、碘浓度变化范围分别为1.091.2 μg/L、0.0128.31 mg/L、10.02 637.0 μg/L。地下水高砷、高氟和高碘水样分别占总水样的7.3%、47.2%和11.6%,砷氟碘共富集占比为3.0%。砷氟碘共富集地下水主要分布于研究区中部的民丰县,水化学类型主要为Cl·SO₄-Na型。自补给区至过渡区再至蒸发区,地下水氟、碘浓度明显增大,砷浓度在过渡区和蒸发区均较大;砷氟碘共富集地下水取样点主要分布于36.060.0 m深度的浅层承压含水层中。浅层地下水受蒸发作用和矿物溶解沉淀作用的影响,随砷氟碘富集项的增多而增大。第四纪成因类型中风积物对氟浓度的影响较大,洪积-湖积物对砷和碘浓度的影响较大。细粒岩性、平缓的地形、地下水浅埋条件、偏碱性的地下水环境、微生物降解作用下有机质介导的矿物溶解是利于砷氟碘共富集的主要机制。     

华北平原原生富碘地下水系统中碘的迁移富集规律:以石家庄-衡水-沧州剖面为例

高碘地下水是继高砷、高氟地下水之后的又一全球性饮水安全问题,但对地下水系统中碘的赋存形态及迁移富集机理研究尚显不足.为了解华北平原地下水系统中碘的空间分布特征及迁移富集规律,选取石家庄-衡水-沧州典型水文地质剖面,完成地下水样品采集,分析其水化学组成、总碘含量及碘形态组成特征,同时运用phreeqc完成水文地质剖面地球化学反向模拟及相关矿物饱和指数计算,定性定量表征水流场内所发生的水文地球化学过程,进而深入探讨上述过程对地下水系统碘迁移富集的影响.结果表明,区域内地下水中碘含量变化范围为3.35~1 106.00 μg/L,其中,41.86%样品碘含量超过《水源性高碘地区和地方性高碘甲状腺肿病区的规定（GB/T19380-2003）》所界定的150 μg/L国家标准;空间上,高碘地下水主要分布于渤海湾区;地下水中碘的主要赋存形态为碘离子及碘酸根离子,其分布受氧化还原环境控制,碘酸根离子主要出现于氧化环境中;沿地下水流向,地下水环境朝利于液相碘迁移富集的方向演变;渤海湾区,海水入侵影响下形成的偏碱性、（弱）还原环境,利于碘从沉积物中迁移释放至地下水中;碘在不同铁矿物相上的搭载能力及氧化还原环境演化导致的铁矿物相转化,是造成华北平原地下水系统中碘迁移富集的主要水文地球化学过程.      

吉林省松嫩平原氟中毒病区水文地质特征及防氟改水对策

阐述了吉林省西部松嫩平原氟中毒病区的分布、地下水中氟的来源及其迁移富集规律,从水文地质角度论述了区域地下水径流-汇水和富集形成高氟水的全过程.结合氟中毒区水文地质特征并通过多年的改水实践工作,确定了该地区的防氟改水对策.     

Numerical Modelling of Geochemical Behaviour of Fluoride in the Shallow Groundwater Systems

The Xingtai piedmont plain in Hebei Province is a representative area in northern China where endemic fluorosis is serious and shallow high-F ground water is distributed. In this paper, the area is selected as a typical study area, and on the basis of large amounts of field work and the experiments, through groundwater geochemical modelling and by applying the theory and method of the coupled model of hydrodynamic transport and chemical reactions in a multicomponent system, the author performed numerical modelling of the geochemical behaviour of fluoride in a shallow groundwater system, quantitatively studied the hydrodynamic transport and chemical reaction of fluorine migration, transformation and concentration in a water-heterogeneous unsaturated soil system under the conditions of meteoric water infiltration and quantitatively determined the speciation of fluorine and the saturation state and dissolution/precipitation trend of various solid precipitates in shallow high-F groundwater, thus deepening t     

大同盆地高氟地下水水化学特征及其成因

为查明控制大同盆地高氟地下水形成的主要地球化学过程,对大同盆地地下水高氟区31个水样进行了水化学特征及因子分析研究.结果表明,研究区浅层和深层地下水中均检测出氟,且氟含量高,最大ρ(F)达10.37 mg/L.该区高氟地下水以Na-HCO3型水为主,具有典型的富Na特征.PHREEQC饱和指数计算结果表明,地下水中萤石为不饱和状态,地下水中ρ(F)主要受到萤石溶解影响.因子分析研究表明,水一岩相互作用、碳酸盐矿物溶解沉淀及Na- Ca离子交换作用是控制大同盆地地下水氟富集的主要水化学过程.     

Research on quality changes and influencing factors of groundwater in the Guanzhong Basin

This paper studies the distribution features, the chemical elements beyond standards and the influencing factors of shallow groundwater quality in the Guanzhong Basin through the data monitored in the last twenty years. The final purpose is to comprehensively evaluate the divisions of groundwater quality in the Guanzhong Basin. Results show that , the groundwater quality is in good shape, and suitable for drinking. Drinking accounts for 16.02% of the total, most of which are distributed in the lubotan of Weibei. Some come from loess plateau of Qian-Liquan County and some are generated by the industrial pollution of Xingping City. Materials exceeding standards include chloride, sulfate, three nitrogen, fluoride, manganese, iron, hexavalent chromium and so on. The main factors influencing the quality of shallow groundwater include groundwater exploitation, natural background value of special components and precipitation, among which the groundwater exploitation poses the greatest impact. The depth of water is positively correlated with the concentration of sulfate, nitrate and total hardness.     

北京大兴区第四系高氟地下水分布规律研究

北京市大兴区供水以地下水为主,研究该区高氟地下水的分布规律及其成因,对指导区域地下水的开发利用和保障居民饮水安全是必要的。在野外调查和以往研究成果的基础上,测试了北京大兴区地下水氟离子浓度。结果表明,高氟水分布区地层岩性以粘性土为主;浅层高氟水主要分布在大兴区的南部及东南部,超标区面积为258.57 km2;深层高氟水主要分布在中部,超标区面积为20.91 km2。建议对浅层高氟地下水加大止水深度,统一并严格设计饮用水井结构;对深层氟超标水,避免饮用或采取降氟措施后再饮用。     

Hydrochemical status of groundwater in district Ajmer (NW India) with reference to fluoride distribution

High fluoride in groundwater has been reported from many parts of India. However, a systematic study is required to understand the behaviour of fluoride in natural water in terms of local hydrogeological setting, climatic conditions and agricultural practices. Present study is an attempt to assess hydrogeochemistry of groundwater in Ajmer district in Rajasthan to understand the fluoride abundance in groundwater and to deduce the chemical parameters responsible for the dissolution activity of fluoride. Ajmer district falls in the semi-arid tract of central Rajasthan and is geologically occupied by Precambrian rocks (granites, pegmatites, gneisses, schists etc) where groundwater occurs under unconfined condition. A total of 153 well-water samples, representing an area of 8481 km² (further subdivided into eight blocks), were collected and chemically analyzed. The results of chemical analyses (pre-monsoon 2004) show fluoride abundance in the range of 0.12 to 16.9 mg/l with 66% of the samples in excess of permissible limit of 1.5 mg/l. Presence of fluoride bearing minerals in the host rock, the chemical properties like decomposition, dissociation and dissolution and their interaction with water is considered to be the main cause for fluoride in groundwater. Chemical weathering under arid to semi-arid conditions with relatively high alkalinity favours high concentration of fluoride in groundwater. Dental and skeletal fluorosis are prevalent in the study area which can be related to the usage of high fluoride groundwater for drinking. The suggested remedial measures to reduce fluoride pollution in groundwater include dilution by blending, artificial recharge, efficient irrigation practices and well construction.     

罗山自然保护区地下水化学特征研究

罗山自然保护区是宁夏中部的水源涵养林区。通过对罗山地下水进行取样分析、综合运用描述性分析、因子分析的方法,对地下水化学成分的统计特征及其在空间上的变化规律进行了分析研究。结果表明:①罗山浅层地下水中HCO3-和SO42-绝对含量较高,为地下水中的主要离子。以罗山为中心,向四周辐射,地下水化学类型特征及演变规律;地下水中的Mg2+、Na+、Cl-、SO42-、NO3-和TDS的相关程度很高,主要是来自沉积砂岩、板岩中的长石、石英和绢云母;区内硫酸根离子、氯离子和水的总硬度普遍超标,咸水区对人体有害的氟化物含量超标,部分微咸水区的氟化物含量超标,淡水区未出现超标现象。     

Initial observations of water quality indicators in the unconfined shallow aquifer in Dili City,Timor-Leste: suggestions for its management

The management of groundwater quality is a critical issue in developing nations where sanitation and drinking water targets are commonly addressed by facilitating access to groundwater, which is then managed as a common-pool resource. We investigate the quality of the shallow unconfined groundwater in Dili’s alluvial fan system, which 50% of Dili’s rapidly growing population use for all their water requirements. Using the basic chemical and microbiological analyses that are locally available (sulfate, total hardness, fluoride, manganese, iron, ammonia, nitrite, nitrate, total coliform and E. coli) we show that the shallow wells commonly contain enhanced concentrations of dissolved solids and microbiological contaminants (total coliform and E. coli), relative to deeper wells. Cool, shallow wells are worse than warm equivalents. Elevated nitrate and nitrite pollution in the embassy district are tentatively attributed to affluence factors, such as lawn cultivation and water filtration equipment. Microbiological contamination, and associated manganese contamination of groundwater, mimic population patterns, but are concentrated in the finer grained sediments of the small fans and low-slope interdistributary areas. We suggest that rapid development and successful implementation of appropriate sanitation policy in Dili (and elsewhere) is required to address the problematic features of the shallow groundwater system. Success will be predicated on (1) the establishment of baseline data, and (2) development of a systems-thinking approach to holistic water resource management.     

内蒙古杭锦旗气田区地下水化学特征及其形成机制

对内蒙古杭锦旗气田区浅层地下水运用Piper三线图、Gibbs图、氯碱指数图等方法进行水化学特征及其形成作用分析研究,结果表明：杭锦旗气田区浅层地下水具有较高的矿化度,偏碱性,硬度较大,枯水期TDS浓度和总硬度高于丰水期;研究区浅层地下水化学组分在小范围内具有一定的空间变异性,地下水阳离子以Na+、Ca2+为主,阴离子以HCO3-为主,水化学类型主要有HCO3 Ca型、HCO3 Na型和SO4·Cl Na型;研究区浅层地下水化学组分来源于碳酸盐矿物、硅铝酸盐矿物和蒸发岩的风化溶解,且丰水期和枯水期水化学组分有微弱变化,地下水化学特征的形成以岩石风化溶解作用为主。     

Regional appraisal of the fluoride occurrence in groundwaters of Andhra Pradesh

Fluoride (F^?) is essential for normal bone growth, but higher concentration in the drinking water causes health problems which are reported in many states of India. Andhra Pradesh is one of the states which suffer from excess fluoride in groundwater particularly in the hard rock terrain. In this context, a study was conducted in Andhra Pradesh based on chemical analysis of water samples from hydrograph net work stations (dug wells) and exploratory bore wells. The concentration of fluoride in groundwaters ranges from traces to 9.75 mg/l. The occurrence of fluoride is mostly sporadic, uneven and varies with depth. The highly affected districts include Nalgonda and Warangal in Telangana region, Prakasam in coastal region, Anantapur and Kurnool in Rayalaseema region. In certain areas of Nalgonda district, 85% of wells have fluoride more than permissible limit (> 1.5 mg/l) for drinking water. High F^? is present in all the geological formations, predominantly in granitic aquifers, compared to the other formations. The average value of fluoride is high in the deeper zone (1.10 mg/L), compared to the shallow zone (0.69 mg/L). The fluoride-rich minerals present are the main sources for fluoride concentrations in groundwater. Residence time, evapotranspiration and weathering processes are some of the other supplementary factors for high fluoride concentrations in groundwater. Long-term data of hydrograph net work stations (dug wells) reveal that fluoride concentrations do not show any marked change of trend with respect to time. The concentration of fluoride is found to increase with increase of Na⁺and HCO ₃ ^? , and decrease with increase of Ca²⁺. Sodium bicarbonate waters are more effective in releasing fluoride from minerals into groundwater. High fluoride waters are of Na⁺ type. The paper presents a brief account of the study and its results.