地下水中常见有机污染物的原位治理技术现状

随着人类活动的加剧,地下水的污染日益严重,而有机污染的调查与防治也已受到了更多的关注。国外的地下水有机污染治理技术研究和实践已有较长的历史,取得了较多的成果。主要技术方法有曝气法、生物处理法,化学氧化法、植物修复、渗透性反应墙法等。近年来,国内也开始了地下水有机污染治理的研究和试验,但尚处于起步阶段。本文以地下水中常见的有机污染物为线索,总结了它们的来源、危害及国内外治理技术的现状,以期对地下水污染的调查与治理工作有所借鉴。     

地下水中常见无机污染物的原位治理技术现状

随着全球工业化的进展,许多地区地下水的污染问题越来越严重,成为世人共同关注的问题。世界地下水污染的治理技术在飞速发展,欧美地区已有了许多地下水治理工程,我国的地下水治理技术尚处于起步阶段。本文以地下水中常见的无机污染物为线索,总结了它们的来源、危害及国内外治理技术的现状,以期对地下水污染的调查与治理工作有所借鉴。     

甲苯在土壤地下水中迁移规律研究

石油泄漏导致甲苯等有机污染物污染土壤地下水,并且甲苯等石油类有机污染物对土壤地下水污染具有隐蔽性强、难以逆转等特点,污染治理难度大。因此,研究甲苯有机污染物在土壤地下水中运移规律是治理的关键。该文以某污染场地为研究区,以甲苯有机污染物为研究对象,考虑了淋滤、吸附的影响,采用模型计算方法,分析了甲苯在污染场地土壤地下水中迁移规律。结果表明：甲苯在土壤地下水中迁移过程中,淋滤作用对甲苯浓度变化影响显著;吸附影响下扩散作用及地下水位变化对甲苯迁移产生的影响均受到抑制。该文获得的甲苯在土壤地下水中迁移规律可为甲苯有机污染物污染场地修复提供依据。     

地下水农业面源污染研究现状与展望

农业面源污染是造成地下水污染最普遍也是最难治理的主要因素.综述了地下水农业面源污染的危害,主要影响因素,污染物测定方法,数值模拟、RS、GIS技术的应用及其防治对策,并对今后的地下水农业面源污染研究进行了展望.     

某油田地下水污染特征分析

某油田由于开采时间较长,石油的开采活动对地下水产生了影响.为了弄清对地下水的影响程度,对该区地下水进行了分层采样,并检测样品中的常规项目以及石油类,同时对其浓度进行了详细分析.研究以本区外围地下水作为背景值以及地下水的三类标准作为判断标准对地下水进行评价,得出本区地下水2/3受到了污染,其主要的污染物是石油类污染物与NH4 -N、NO2--N.论文对地下水中主要污染物的污染程度及其在地下水中的分布规律进行了分析,并对其来源进行了探讨与分析,最后对研究区地下水的污染防止与治理提出建议和方法.     

地下水中抗生素污染检测分析研究进展

抗生素是一类环境中新型有机污染物,其在地下水系统中的污染状况和环境行为备受关注。本文从污染来源、危害、污染现状、检测技术和迁移转化等方面综述了近年来地下水中抗生素的研究现状。抗生素主要来源于抗生素生产工业、医疗卫生业、畜牧养殖业、水产养殖业等,进入地下水中的微量抗生素不但诱导抗药性细菌的产生,更对原位微生物及人体产生危害。检测技术的进步是抗生素污染研究的重要支撑,目前已有多种抗生素污染的检测技术,其中酶联免疫技术主要用于抗生素污染初步筛查;气相色谱-质谱技术由于需要衍生化等处理过程而较少使用;毛细管电泳技术具有消耗样品量少、分析成本低等优点,但重现性差使其应用受到限制;液相色谱技术是在抗生素检测中应用较普遍的技术,特别是液相色谱-串联质谱技术具有灵敏度高、检出限低、可检测多组分污染物等优点,应用最为广泛。近年来依托于各种检测技术在国内外均有地下水中抗生素检出的报道,其检出浓度范围1~104ng/L不等,检出种类有磺胺类、喹诺酮类、四环素类及大环内酯类抗生素。抗生素在地下水系统中的迁移转化行为包括吸附、水解、光解、生物降解等过程,其基质复杂、含量低和产物难以定性等问题给检测提出了新的挑战。优化检测方法、开发新的预处理技术、开展全面的地下水污染调查、进行代谢产物定性分析、探索抗生素治理技术等,将是今后地下水中抗生素污染研究的主要方向。     

邢台市岩溶水污染现状与演化趋势预测

由于地表水的污染和固体废物的乱堆放,导致邢台市岩溶水多处出现污染现象,且污染范围不断扩大,严重威胁下游水源地的供水安全。本文依据大量水质监测数据,评价了岩溶水的污染现状,采用数值方法预测了污染源继续存在和污染源得到治理两种情况下地下水污染的演化趋势,并分析了其对水源地的影响。预测结果表明:污染源存在时,地下水污染物Cr6+超标浓度等值线将以0.769m/d的速度扩散;在污染源得到有效治理和控制后,地下水污染物超标浓度等值线扩散速度将减少至0.402m/d,可见污染源治理对减缓地下水污染的扩散有重要作用。预测结果可作为选择地下水保护方案和污染治理措施的依据。      

地下水硝酸盐污染与治理研究进展综述

地下水的硝酸盐污染是全球所面临的一个日益严重的问题,对硝酸盐污染的地下水修复技术的研究也自然成为近年来国内外学者研究的热点。就地下水硝酸盐污染的机理和途径、对人体及其它生物的危害以及修复技术等方面作了详细介绍,另外,就地下水硝酸盐污染的治理引用了工程实际加以说明。最后指出了未来地下水硝酸盐污染治理研究的方向。     

地下水污染场地风险管理与修复技术筛选

国际上对于地下水污染场地的控制与修复研究已经取得了许多成果,已有成功的修复实例。我国虽然起步晚,但非常重视地下水污染的防治,开展了全国范围的地下水污染调查,并进行了地下水污染的防治规划。地下水污染的控制与修复已经逐渐进入示范性研究阶段。面对地下水污染场地风险管理的不同方法,以及众多的污染修复技术,如何制定风险管理策略,如何在各种各样的修复技术中筛选合适的技术或技术组合,对于地下水污染场地的防治具有非常重要的意义。笔者分析了发达国家地下水污染风险管理策略,结合在地下水污染场地研究方面的经验,对一些主要的地下水污染修复技术进行了分析论述,提出了考虑污染物特征、场地水文地质条件的地下水污染修复技术的筛选过程和方法。     

欧美地下水有机污染调查评价进展

1999年中国地质调查局启动了第一个地下水有机污染调查项目,当时检测指标只有20个(包括11个挥发性有机污染物、8种有机氯农药和1种多环芳烃)。"十一五"的地下水有机污染调查必测项目包含了38项(挥发性指标28项、有机氯农药9项和1种多环芳烃),取得了地下水有机污染的基本资料。但从对国外文献的调研来看,地下水中有机污染的种类远远超过38种。为了更全面地掌握中国地下水的质量,有必要对不同地区或不同类型的地下水中典型的有机污染物的种类进行研究,为后续地下水有机污染调查的增项做准备。通过检索美国环保局(USEPA)、美国地质调查局(USGS)和欧盟(EU)近年来的地下水质量年度报告和相关文献,调研了地下水中典型有机污染物的类型,选出最常检出的有机污染物,形成最常检出的有机污染物的检出率排序表,列出了检出率高的前50个污染物的名单。     

Groundwater quality Management in China

Groundwater quality is of vital importance in groundwater safety especially for the purpose of water supply, its management becomes more and more necessary as groundwater contamination has threaten its safe use in China. The article analyzed the contamination sources of groundwater and impact of contamination on human health and water supply, the knowledge gaps were pointed and recommendations were made for groundwater quality management in China.     

Review of Study on Groundwater Contamination Risk Assessment in Vadose Zone-Aquifer

The vadose zone-aquifer is an important media for water circulation and solute transport in soil, surface water and groundwater. It is a research hotspot in the field of earth science. In this paper, we took the groundwater contamination risk assessment for the vadose zone-aquifers as the review object. The groundwater contamination status of vadose zone-aquifers was pointed out. The characterization of vadose zone-aquifers, the flow and solute transport as well as the key effect parameters were systematically analyzed and the research progresses were reviewed. Finally, the existing problems in the groundwater contaminant risk assessment under the condition of different scales of vadose zone-aquifers and future research direction were pointed out from the perspective of groundwater contaminant risk assessment. In particular, more attention should be paid to the groundwater contamination risk assessment based on percolation threshold.     

Identification of groundwater contamination sources in Dindugal district of Tamil Nadu,India using GIS and multivariate statistical analyses

The purpose of this research is to evaluate the groundwater quality in Dindugal district of Tamil Nadu based on the water quality index by geographic information system (GIS) and statistical analysis. This area consists of 80 functional tanneries around Dindigul town with a capacity to process about 200 Mt of hides and skins as leather. In 13 villages, as many as 1090 houses were damaged by tannery contamination. A total of 66 groundwater samples were collected to identify the geochemical sources and contamination. The order of major cations is Na > Ca > Mg > K, while that of anions is Cl > SO₄ > HCO₃ > F > PO₄. CaCl₂, MgCl₂, and (CaHCO₃)₂ types suggested that the mixing of high-salinity water was caused by irrigation return flow, domestic wastewater, and septic tank effluents, with existing water followed by ion exchange reactions. Moreover, Gibbs plots indicated that groundwater contamination was derived from the weathering of granitic gneisses as well as the leaching of evaporated and crystallized ions from agricultural and industrial effluents. The water quality index (WQI) exhibited 8 % of the groundwater samples were not suitable for drinking purpose. The GIS maps showed that the poor water quality decreased toward the southern part of the study area. WQI of TDS, fluoride, sodium, potassium, and bicarbonate were high in groundwater. Multivariate statistical analyses (principal component analysis (PCA), factor analysis (FA)) suggested that the groundwater chemistry was changed by the weathering of source rocks ion exchange and leaching of inorganic components and addition from anthropogenic effluents. Finally, it is thought that the monitoring and assessment works are very useful to understand the degree and sources of groundwater contamination.     

Nitrate contamination in a shallow urban aquifer in East Ukraine: evidence from hydrochemical,stable isotopes of nitrate and land use analysis

A combined hydrochemical and stable isotope approach was used to investigate the origin of nitrate in the shallow unconfined groundwater of Kharkiv city, Eastern Ukraine. The contamination was investigated in the context of land use within the catchment area. The observed enrichment of sulfate, chloride and nitrate suggests significant groundwater contamination in the shallow urban aquifer, which is widely used as drinking water source for the urban population. Characteristic nitrate/chloride ratios as well as stable isotope ratios (N and O) of nitrate in the most contaminated springs confirmed that septic waste from leaky sewer systems was the main source of nitrate contamination in the groundwater. Nitrate contamination is linked to the type of land use and sewage treatment regime in the catchment area. It is also modulated by the regional hydrogeology, which determines the susceptibility of a given aquifer toward groundwater pollution. A more quantitative assessment of nitrate sources based on the nitrate isotope analysis alone is rather difficult. However, our study confirms that the combination of hydrochemical tracers, robust land-use analysis and nitrate stable isotope measurements represents a valuable approach to identify the origin of the nitrate contamination.     

Overview of groundwater sources and water-supply systems,and associated microbial pollution,in Finland,Norway and Iceland

The characteristics of groundwater systems and groundwater contamination in Finland, Norway and Iceland are presented, as they relate to outbreaks of disease. Disparities among the Nordic countries in the approach to providing safe drinking water from groundwater are discussed, and recommendations are given for the future. Groundwater recharge is typically high in autumn or winter months or after snowmelt in the coldest regions. Most inland aquifers are unconfined and therefore vulnerable to pollution, but they are often without much anthropogenic influence and the water quality is good. In coastal zones, previously emplaced marine sediments may confine and protect aquifers to some extent. However, the water quality in these aquifers is highly variable, as the coastal regions are also most influenced by agriculture, sea-water intrusion and urban settlements resulting in challenging conditions for water abstraction and supply. Groundwater is typically extracted from Quaternary deposits for small and medium municipalities, from bedrock for single households, and from surface water for the largest cities, except for Iceland, which relies almost entirely on groundwater for public supply. Managed aquifer recharge, with or without prior water treatment, is widely used in Finland to extend present groundwater resources. Especially at small utilities, groundwater is often supplied without treatment. Despite generally good water quality, microbial contamination has occurred, principally by norovirus and Campylobacter, with larger outbreaks resulting from sewage contamination, cross-connections into drinking water supplies, heavy rainfall events, and ingress of polluted surface water to groundwater.     

Source partitioning of anthropogenic groundwater nitrogen in a mixed-use landscape,Tutuila, American Samoa

This study presents a modeling framework for quantifying human impacts and for partitioning the sources of contamination related to water quality in the mixed-use landscape of a small tropical volcanic island. On Tutuila, the main island of American Samoa, production wells in the most populated region (the Tafuna-Leone Plain) produce most of the island’s drinking water. However, much of this water has been deemed unsafe to drink since 2009. Tutuila has three predominant anthropogenic non-point-groundwater-pollution sources of concern: on-site disposal systems (OSDS), agricultural chemicals, and pig manure. These sources are broadly distributed throughout the landscape and are located near many drinking-water wells. Water quality analyses show a link between elevated levels of total dissolved groundwater nitrogen (TN) and areas with high non-point-source pollution density, suggesting that TN can be used as a tracer of groundwater contamination from these sources. The modeling framework used in this study integrates land-use information, hydrological data, and water quality analyses with nitrogen loading and transport models. The approach utilizes a numerical groundwater flow model, a nitrogen-loading model, and a multi-species contaminant transport model. Nitrogen from each source is modeled as an independent component in order to trace the impact from individual land-use activities. Model results are calibrated and validated with dissolved groundwater TN concentrations and inorganic δ¹⁵N values, respectively. Results indicate that OSDS contribute significantly more TN to Tutuila’s aquifers than other sources, and thus should be prioritized in future water-quality management efforts.     

太湖流域某地区浅层地下水有机污染特征

对太湖流域某地区浅层地下水有机污染特征进行了总结，并就污染来源、污染途径和典型污染源附近浅层地下水有机污染特征等问题进行了研究。研究结果表明，该地区浅层地下水中各组分的检出率较高，但检出浓度较低，除苯在个别采样点处超出美国环保局（EPA）饮用水标准外，其余卤代烃和单环芳烃组分均没有超标；平面分布上，卤代烃和单环芳烃各组分的浓度高值点大都集中于该地区东南部的工业区内，这种空间分布特征与工业区的分布具有明显的一致性；垂向上有浅部地下水的污染程度相对较重、深部地下水较轻的特点；典型污染源周边浅层地下水的污染程度较重，但随着采样点远离污染源，地下水中各有机污染组分的浓度迅速衰减。     

Nitrate contamination in irrigation groundwater,Isfahan, Iran

Groundwater is one of the major sources of water in Isfahan. Efficient management of these resources requires a good understanding of its status. This paper focuses on the hydrochemistry and also it wants to assess the nitrate concentration in irrigation groundwater of Isfahan suburb. All the groundwater samples are grouped into three categories, including Na-Cl + Ca-Cl (63 %), Na-SO₄ + Ca-SO₄ (23 %) and Ca-HCO₃ (14 %). According to the EC and SAR, the most dominant classes are C3S1, C4S2 and C4S3. 55 % of samples indicate very high salinity and medium to very high alkalinity that is not suitable for irrigation. 84 % of the groundwater samples show nitrate contents higher than HAV (13 mg l^?), while more than 25 % exceeded the maximum contamination level (44.27 mg l^?) according to EPA regulations. The horizontal and vertical distribution patterns of nitrate in groundwater samples show a surficial origin for nitrate contamination. The high nitrate content can be attributed to the agricultural activities along with domestic sewage and industrial wastewaters in populated area. Based on results, using high nitrate groundwater for irrigation can minimize the requirement for inorganic fertilizers and reduce the cost of cultivation and nitrate contamination.