土壤,地下水中有机污染物的就地处置

有机化合物对土壤、地下水的污染已引起世界各国的普遍关注。地层介质中的有机物主要以自由态,挥发态、溶解态和固态４种形态存在。有机污染物的自然降解能力较差,如不进行人工清除,在自然环境中它们可能存留长达几埏年之久,对土壤、地下水资源构成长期的威胁。传统的开挖处理技术不仅费用昂贵,而且当贮赃物 地表被利用时则无法进行开挖处理（如有建筑物等）。近扯为,以地下冲洗法,土壤抽水法和地下水曝气法为代表的有机污染     

空气喷射处理饱和土壤和地下水中有机污染物

空气喷射(air sparging)被认为是修复由可挥发性有机物污染的饱和土壤和地下水的一种有效新技术。介绍了空气喷射技术的现场应用与研究现状，讨论了空气喷射技术的原理和各种影响因素，说明了其对于饱和土壤中有氧生物降解的促进作用，分析了空气喷射技术的应用前景。     

土壤、地下水中有机污染物的就地处置

有机化合物对土壤、地下水的污染已引起世界各国的普遍关注.地层介质中的有机物主要以自由态、挥发态、溶解态和固态4种形态存在.有机污染物的自然降解能力较差,如不进行人工清除,在自然环境中它们可能存留长达几十年之久,对土壤、地下水资源构成长期的威胁.传统的开挖处理技术不仅费用昂贵,而且当贮油设施的地表被利用时则无法进行开挖处理(如有建筑物等).近年来,以地下冲洗法、土壤抽水法和地下水曝气法为代表的有机污染物就地处置技术得到了迅速的发展.本文对这3种技术进行概要的介绍,总结指出决定这些技术可能性的主要因素是地层介质的通透能力,有机物的挥发、溶解能力及其可生物降解能力,并列出目前的主要有机污染物挥发、溶解及生物降解能力的相对强弱作为制定具体处置技术的参考指标.     

吉林省某垃圾填埋场地下水有机污染风险评价

以吉林省某垃圾填埋场地下水为研究对象,监测其中的有机污染物,并进行风险评价。结果表明:(1)有机污染物总计检出18种,5种检出率大于50%。其中,三氯甲烷检出率最高,达到85.7%,质量浓度高达0.217mg/L,超过《生活饮用水卫生标准》(GB 5749—2006)限值(0.06mg/L)。(2)地下水污染指数表明,10种有机污染物具有高淋溶迁移性。(3)以三氯甲烷为典型污染物,14个采样点中,非致癌风险指数均未超过1,12个采样点致癌风险指数超过10~(-6),不在可接受范围。主要暴露途径为饮水摄入。     

有机污染物湿地生物降解实验规律研究

本文以苯，甲苯和萘为对象，通过实验研究，测定有机污染物的土壤－水吸附平衡过程，在水溶液中生物降解过程以及在湿地系统（即土壤－水－微生物系统）中生物降解过程，并以质量守恒定律为基础，建立有机污染物湿地生物降解过程综合数学模型，数学模型通过实验验证，利用模型，定量预测了污染物生物降解所需的时间和程度，并提出动力学因子FK，判断污染物湿地生物降解速度的控制因素，定量预测了污染物在土壤固相的浓度分布规律。     

婺江水域有机污染物的定性定量分析

１９９６年对婺江水域地面水和自来水有机污染物进行ＧＣ／ＭＳ定必和定量分析,发现婺江水域已受有机污染物污染,其中含有致癌物和致突变物,各水质检测点均检出有机污染物但数量变化不大,枯水期的有机污染物数量和种类均多丰水期,水持较丰水期差。     

太阳光对湖泊中有机污染物降解的研究进展

论述了太阳光对湖泊水体中有机污染物降解作用的研究，就其降解机理、动力学特征、作用对象及降解产物等作了逐一介绍。阐明了太阳光对生物降解湖泊水体中有机污染物具有协同作用，也概述了光降解作用受pH、溶解性有机物(DOM)、水深与水体运动、地理、水文、水质与气候等因素的影响。并对实验室模拟条件下的降解与自然条件下的降解进行对比，提出今后该领域的发展前景与研究方向。     

土壤及地下水有机污染的化学与生物修复

本文综述了土壤及地下水有机污染的化学与生物修复技术研究的最新进展。比较详细地介绍了土壤及地下水有机污染的化学修复、生物修复、化学与生物相结合修复的具体方法、治理效率及其影响因素。     

电化学法去除有机污染物机理研究进展

电化学方法因其所具有的多功能性，操作简单，易于自动化并且具有环境兼容性等特点而倍受人们重视。近年来，国内外研究者对该方法在水处理中的应用进行了广泛的研究。并对有机污染物电化学降解机理提出了不同观点，本文对这些观点进行了分类，并对其中的主要观点进行论述。     

表层土壤中有机污染物的光化学行为

本文首先简要介绍了光化学反应的基本原理。然后 ,重点介绍了研究表层土壤中有机污染物光化学行为的实验方法 ,影响光化学行为的因素及影响机理 ,光化学反应与吸附、迁移等的互相作用。最后阐述了这方面存在的问题 ,并且提出了一些建议     

Multiphase flow and transport caused by spontaneous gas phase growth in the presence of dense non-aqueous phase liquid

Disconnected bubbles or ganglia of trapped gas may occur below the top of the capillary fringe through a number of mechanisms. In the presence of dense non-aqueous phase liquid (DNAPL), the disconnected gas phase experiences mass transfer of dissolved gases, including volatile components from the DNAPL. The properties of the gas phase interface can also change. This work shows for the first time that when seed gas bubbles exist spontaneous gas phase growth can be expected to occur and can significantly affect water-gas-DNAPL distributions, fluid flow, and mass transfer. Source zone behaviour was observed in three different experiments performed in a 2-dimensional flow cell. In each case, a DNAPL pool was created in a zone of larger glass beads over smaller glass beads, which served as a capillary barrier. In one experiment effluent water samples were analyzed to determine the vertical concentration profile of the plume above the pool. The experiments effectively demonstrated a) a cycle of spontaneous gas phase expansion and vertical advective mobilization of gas bubbles and ganglia above the DNAPL source zone, b) DNAPL redistribution caused by gas phase growth and mobilization, and c) that these processes can significantly affect mass transport from a NAPL source zone.     

Three-dimensional visualization and quantification of non-aqueous phase liquid volumes in natural porous media using a medical X-ray Computed Tomography scanner

This study demonstrates the capabilities of a typical medical X-ray Computed Tomography (CT) scanner to non-destructively quantify non-aqueous phase liquid (NAPL) volumes, saturation levels, and three-dimensional spatial distributions in packed soil columns. Columns packed with homogeneous sand, heterogeneous sand, or natural soil, were saturated with water and injected with known quantities of gasoline or tetrachloroethene and scanned. A methodology based on image subtraction was implemented for computing soil porosity and NAPL volumes in each 0.35 mm x 0.35 mm x 1 mm voxel of the columns. Elimination of sample positioning errors and instrument drift artifacts was essential for obtaining reliable estimates of above parameters. The CT data-derived total NAPL volume was in agreement with the measured NAPL volumes injected into the columns. CT data-derived NAPL volume is subject to a 2.6% error for PCE and a 15.5% error for gasoline, at average NAPL saturations as low as 5%, and is mainly due to instrument noise. Non-uniform distributions of NAPL due to preferential flow, and accumulation of NAPL above finer-grained layers could be observed from the data on 3-D distributions of NAPL volume fractions.     

基于高密度电阻率成像法的低渗黏土中轻非水相液体运移规律探索

为了实时掌握轻非水相液体 (LNAPL) 泄漏后在黏土中的动态分布及入渗时的运移规律,进行了室内模型箱实验,由上至下设置均一含水土层及含毛细水土层,采用高密度电阻率成像法对土体的电阻率变化进行监测,获得了加注过程中及加注结束后LNAPL的运移规律。实验结果表明：LNAPL渗入黏土提高了黏土的电阻率,质量含水率为10%的黏土可提高50 Ω·m左右,随黏土含水率的增加,该提高数值逐渐减小;0~9 h加注阶段,在质量含水率10%的土层中LNAPL水平扩散速度的峰值将近90 cm²·h⁻¹,运移至非饱和毛细带时,随土体含水率的增加,其水平扩散速度的峰值逐渐降低;停止加注后,LNAPL在黏土中的高浓度污染区位置逐渐下移,局部区域的污染羽锋面出现回缩,回缩速度可达0.15 cm²·h⁻¹。该研究可为探索沿海、沿江等低渗黏土污染区中LNAPL的运移规律及分布特征提供参考。     

低浓度硫化氢废气的液相催化氧化法净化实验研究

针对H2S浓度为750~1500mg/m3的气体的液相催化氧化技术进行了动力学实验研究。配制了以铁基离子作为主催化剂的复合吸收净化溶液,同时加入稳定剂和表面活性剂提高催化剂在碱性吸收溶液的活性。分别考察了原料气中H2S、O2含量以及吸收液中催化剂离子浓度、温度等因素对吸收速率的影响;确定了较为理想的吸收操作条件并获得了较好的吸收净化效果;饱和吸收液易于再生,净化性能恢复良好,可重复使用。     

The effect of surface-active solutes on water flow and contaminant transport in variably saturated porous media with capillary fringe effects

Organic contaminants that decrease the surface tension of water (surfactants) can have an effect on unsaturated flow through porous media due to the dependence of capillary pressure on surface tension. We used an intermediate-scale 2D flow cell (2.44 x 1.53 x 0.108 m) packed with a fine silica sand to investigate surfactant-induced flow perturbations. Surfactant solution (7% 1-butanol and dye tracer) was applied at a constant rate at a point source located on the soil surface above an unconfined synthetic aquifer with ambient groundwater flow and a capillary fringe of approximately 55 cm. A glass plate allowed for visual flow and transport observations. Thirty instrumentation stations consist of time domain reflectometry probes and tensiometers measured in-situ moisture content and pressure head, respectively. As surfactant solution was applied at the point source, a transient flow perturbation associated with the advance of the surfactant solution was observed. Above the top of the capillary fringe the advance of the surfactant solution caused a visible drainage front that radiated from the point source. Upon reaching the capillary fringe, the drainage front caused a localized depression of the capillary fringe below the point source because the air-entry pressure decreased in proportion to the decrease in surface tension caused by the surfactant. Eventually, a new capillary fringe height was established. The height of the depressed capillary fringe was proportional to height of the initial capillary fringe multiplied by the relative surface tension of the surfactant solution. The horizontal transport of surfactant in the depressed capillary fringe, driven primarily by the ambient groundwater flow, caused the propagation of a wedge-shaped drying front in the downgradient direction. Comparison of dye transport during the surfactant experiment to dye transport in an experiment without surfactant indicated that because surfactant-induced drainage decreased the storage capacity of the vadose zone, the dye breakthrough time to the water table was more than twice as fast when the contaminant solution contained surfactant. The extensive propagation of the drying front and the effect of vadose zone drainage on contaminant breakthrough time suggest the importance of considering surface tension effects on unsaturated flow and transport in systems containing surface-active organic contaminants or systems, where surfactants are used for remediation of the vadose zone or unconfined aquifers.     

Effect of soil moisture dynamics on dense nonaqueous phase liquid (DNAPL) spill zone architecture in heterogeneous porous media

The amount, location, and form of NAPL in contaminated vadose zones are controlled by the spatial distribution of water saturation and soil permeability, the NAPL spill scenario, water infiltration events, and vapor transport. To evaluate the effects of these processes, we used the three-phase flow simulator STOMP, which includes a new permeability-liquid saturation-capillary pressure (k-S-P) constitutive model. This new constitutive model considers three NAPL forms: free, residual, and trapped. A 2-D vertical cross-section with five stratigraphic layers was assumed, and simulations were performed for seven cases. The conceptual model of the soil heterogeneity was based upon the stratigraphy at the Hanford carbon tetrachloride (CT) spill site. Some cases considered co-disposal of NAPL with large volumes of wastewater, as also occurred at the Hanford CT site. In these cases, the form and location of NAPL were most strongly influenced by high water discharge rates and NAPL evaporation to the atmosphere. In order to investigate the impact of heterogeneity, the hydraulic conductivity within the lower permeability layer was modeled as a realization of a random field having three different classes. For six extreme cases of 100 realizations, the CT mass that reached the water table varied by a factor of two, and was primarily controlled by the degree of lateral connectivity of the low conductivity class within the lowest permeability layer. The grid size at the top boundary had a dramatic impact on NAPL diffusive flux just after the spill event when the NAPL was present near the ground surface. NAPL evaporation with a fine grid spacing at the top boundary decreased CT mass that reached the water table by 74%, compared to the case with a coarse grid spacing, while barometric pumping had a marginal effect for the case of a continuous NAPL spill scenario considered in this work. For low water infiltration rate scenarios, the distribution of water content prior to a NAPL spill event decreased CT mass that reached the water table by 98% and had a significant impact on the formation of trapped NAPL. For all cases simulated, use of the new constitutive model that allows the formation of residual NAPL increased the amount of NAPL retained in the vadose zone. Density-driven advective gas flow from the ground surface controlled vapor migration in strongly anisotropic layers, causing NAPL mass flux to the lower layer to be reduced. These simulations indicate that consideration of the formation of residual and trapped NAPLs and dynamic boundary conditions (e.g., areas, rates, and periods of different NAPL and water discharge and fluctuations of atmospheric pressure) in the context of full three-phase flow are needed, especially for NAPL spill events at the ground surface. In addition, NAPL evaporation, density-driven gas advection, and NAPL vertical movement enhanced by water flow must be considered in order to predict NAPL distribution and migration in the vadose zone.     

江苏省太湖流域水功能区纳污能力及限制排污总量研究

水功能区纳污能力及限制排污总量研究是制定区域水污染控制规划的基础。依据《江苏省地表水(环境)功能区划》,结合江苏省太湖流域现状水质和污染概况,针对河网区和湖库区分别采用一维、二维非稳态模型,计算江苏省太湖流域水功能区纳污能力,在此基础上,引入最大污染物入河量,核定50%、75%和90%水文保证率下的最大污染物入河量分别为2015年、2020年和2030年限排总量。结果表明:(1)CODMn和氨氮纳污能力分别为284 803 t/a和22 448 t/a;(2)2015年CODMn和氨氮限排总量分别为221 867 t/a和20 520 t/a,2020年和2030年限排总量递减,均小于纳污能力;(3)CODMn和氨氮入河量削减率分别为21.8%和46.3%,与水质超标率相差均在25%以内,基本相符。江苏省太湖流域纳污能力、限排总量、污染物入河量削减率和水质超标率之间关系合理,计算结果合理。研究成果为太湖流域水环境控制规划提供决策依据。     

柴油机排放多环芳香烃气/颗粒相分配研究

为了对柴油机排放PAHs在气相和颗粒相中的分配进行研究,采用了滤膜串联＂PUF/XAD-2/PUF＂吸附柱的方法采集柴油机排气中的气相和颗粒相PAHs,使用程序升温挥发（PTV）技术结合气相色谱-质谱联用（GC-MS）方法对PAHs进行了定性和定量分析。所用分析方法重复性的相对标准偏差（RSD）低于6.1%,检出限范围...     

Study on the dissipation pattern and risk assessment of metalaxyl-M in rice grains and paddy soil and water by liquid chromatography-tandem mass spectrometry

Environmental Science and Pollution Research - Herein, field experiment trials were conducted at two different sites (Heilongjiang and Hubei Province) in China to determine the residual levels and...