垃圾渗滤液污染物在土壤中迁移规律试验及模拟

为全面系统地研究垃圾渗滤液迁移规律,科学地分析污染物运移规律和预测污染物浓度分布情况,通过垃圾渗滤液的动态淋溶试验,研究了垃圾渗滤液主要污染物包括有机物(CODcr,)、Cl-、SO42-、总硬度等在土壤水环境中的运移机理,试验结果表明迁移速度最快和最慢的分别为Cl-与有机物(CODCr);并对建立的一维数学模型求解表明·模型曲线与COD试验曲线较好的吻合,说明所建数学模型模拟有机污染物的有效性.     

考虑组分活度的多组分污染物扩散模型

在处置固体废弃物时多采用具有隔离和屏障作用的压实黏土衬垫体系,其渗透性极低,渗滤液溶质在其中的主要运移方式为扩散。针对各类堆场渗滤液中多组分污染物并存的实际工程现象,研究了多组分污染物在防渗黏土垫层中的扩散规律。基于混合物组分线性动量平衡,引入可考虑组分有效浓度的活度系数,建立了多组分污染物在黏土垫层中的一维扩散模型。使用有限元软件COMSOL Multiphysics对所建扩散模型进行求解,揭示了多组分污染物在黏土垫层中的扩散规律。结果表明:与单组分污染物扩散相比,多组分污染物共存时组分活度的引入对独立组分的扩散起到了阻滞作用。研究结果能够为各类堆场设计合理经济的防渗隔污屏障提供理论依据。     

垃圾焚烧发电厂渗滤液处理站除臭系统设计方案

介绍了垃圾焚烧发电厂渗滤液处理站的臭气来源及各种除臭技术及除臭系统方案设计。运行结果表明,臭气经焚烧处理后,渗滤液处理站恶臭污染物厂界浓度限值达到《恶臭污染物排放标准》(GB 14554—93)中二级标准,符合环评批复要求,且此法经济、实用、运营管理方便,适合焚烧电厂渗滤液处理站的恶臭气体的处理。     

垃圾填埋场渗滤液水质影响因素的研究

渗滤液是垃圾填埋场的主要污染源之一，而水质的确定是渗滤液处理的关键。作者在实验室建立了模拟填埋场的反应器，研究了加水和回灌对渗滤液水质的影响。结果表明：加水和回灌加快了填埋场和渗滤液的稳定化，使渗滤液水质得到均化；加水增加了污染物的溶出负荷，加快了污染物的溶出，而回灌则相反。     

南方地区垃圾渗滤液、粪便污水与城市污水合并处理初步研究

对南方地区垃圾渗滤液、粪便污水和城市污水水质特点进行调查分析,结果表明,混合污水主要高浓度污染物为氨氮和有机物。采用倒置A2/O工艺对混合污水进行处理,试验结果表明:采用倒置A2/O工艺,控制垃圾渗滤液、粪便污水与城市污水混合比,污染物去除效果较好,出水CODCr、NH3—N和TN可以达到《城镇污水处理厂污染物排放标准》(GB18918—2002)一级排放标准。     

垃圾填埋场渗滤液特征及其治理

介绍了垃圾渗滤液对水体产生污染的实例，通过讨论和总结揭示了垃圾填埋场渗滤液特征，即垃圾渗滤液污染物浓度高、持续时间长、流量极不均匀、水质变化大。根据垃圾渗滤液特征提出了治理垃圾渗滤液的有效措施。     

光催化氧化技术在水处理中的研究进展

介绍了二氧化钛(TiO2)光催化氧化的机理,阐述了TiO2光催化氧化技术在降解水中有机污染物、无机污染物及饮用水净化和垃圾渗滤液处理中的研究进展,并对TiO2光催化氧化技术的研究前景进行了展望.二氧化钛(Ti02)化学性质稳定、难溶、无毒、成本低、催化效率高,因此光催化氧化技术在难降解有机物、微污染水等处理中相对于其他传统水处理工艺具有一定的优势,是一种很有发展前途的水处理技术,对太阳能的利用和环境保护有重要的意义,可以预见光催化氧化将成为新型有效的水处理手段.     

基于流固耦合的垃圾污染物运移模型及模拟

基于流固耦合和溶质运移理论,建立了垃圾渗滤液有机污染物运移耦合模型,用SOM法对所建的模型进行数值求解,利用该数值模型对垃圾渗滤液在地下水中迁移行为进行模拟,预测了污染物浓度的时空分布特征,对耦合、非耦合模拟结果结合实际监测数据进行对比,并对污染晕的大小、分布范围进行了数值模拟分析.结果表明,耦合模型模拟的污染物浓度变化趋势与监测值基本吻合,从而验证了耦合模型的可靠性和实用性.     

国内外垃圾渗滤液中有害有机污染物筛查综述

垃圾渗滤液中物质的种类和浓度与垃圾填埋场地条件、填埋物种类和垃圾处理方法有密切关系。国内外对于垃圾渗滤液中有害有机物有多种分类法,按物质结构可以分为脂肪烃类、单环芳烃类、酚类、多环芳烃类、邻苯二甲酸酯类;按污染物源的用途可分为农用类、医用类、电子元件类等。许多污染物对人类有致癌、致畸、致突变作用,或为内分泌干扰物,影响人类健康安全。目前国内对这些在地下水中含量甚微但危害巨大的有机污染物的限制规定很少。为此,探讨了一些危害严重污染物的限制标准。建议今后在地下水有机污染调查研究中,应有针对性地着重研究此类污染物,相关部门应加强管理,防止地下水受到此类物质污染。     

基于流固耦合的垃圾污染物运移模型及模拟

基于流固耦合和溶质运移理论，建立了垃圾渗滤液有机污染物运移耦合模型，用SOM法对所建的模型进行数值求解，利用该数值模型对垃圾渗滤液在地下水中迁移行为进行模拟，预测了污染物浓度的时空分布特征，对耦合、非耦合模拟结果结合实际监测数据进行对比，并对污染晕的大小、分布范围进行了数值模拟分析。结果表明，耦合模型模拟的污染物浓度变化趋势与监测值基本吻合，从而验证了耦合模型的可靠性和实用性。     

煤矸石淋溶液地下迁移规律的模拟研究

煤矸石淋溶液的地下迁移严重影响了地下水水质,对人类的生命构成了威胁.本文研究了煤矸石在降水淋溶和地下水迁移条件下,污染物在地下土层和岩层内的迁移规律.通过对阜新新邱南露天矿矸石山淋溶液中主要污染物离子(Ca~(2+)和Mg~(2+))迁移规律的数值模拟,得到特征截面的污染物浓度变化曲线和地下水迁移的水头压力曲线,其结果对水污染治理有一定的指导意义.     

城市垃圾渗滤液对地下水的污染及防治对策

文中主要阐述了城市垃圾渗滤液对地下水的污染情况，分析了垃圾渗液的主要成分，提出了环境监测方法，并针对垃圾渗滤液的特征以及我国目前的情况提出了其污染防治对策。     

Experimental investigation on diffusive contaminant release from permeable sediment layer under unidirectional unsteady flow

The interfacial diffusive contaminant（phosphorus） release from permeable sediment layer into overlying water column under a unidirectional unsteady（periodic） flow condition was experimentally measured and analyzed. The experimental results indicate that the gross diffusive contaminant release rate is substantially enhanced as compared to that under a steady flow condition, and this enhancement trend is much more pronounced in an immediate release stage. The interfacial diffusive contaminant release rate tends to increase with the increasing flow velocity, decreasing period and augmenting amplitude for the case of the unsteady flow. The additional interfacial diffusive contaminant release under the unsteady flow condition may be related to the hydrodynamic response of the diffusive boundary layer to the flow unsteadiness of the overlying water, depending upon not only the periodic thickness variation of the diffusive boundary layer immediately above the sediment-water interface modulated by the temporal flow velocity of the overlying water column but also the intensified turbulent mixing between the overlying water and the pore-water within the superficial sediment layer induced by an alternate acceleration/deceleration fluctuation during each period.     

修复渗滤液污染物的新型PRB模型构建及可行性分析

针对垃圾填埋场渗滤液渗漏造成土壤及地下水等环境污染及其修复技术等问题,提出由环境友好型材料雾化钢渣(PS球)和废旧轮胎橡胶构建双层生物可渗透活性反应墙系统(DBPRBs),通过可行性分析表明该系统具有生物-非生物强化协同去污能力,该新型系统的构建和研究成果将进一步揭示污染地下水的PRB修复机理,对我国地下水污染的PRB修复产业发展具有重要的理论意义和实用价值。     

Numerical research on the mechanism of contaminant release through the porous sediment-overlying water interface

After the pollutant discharged into the river or lake has been reduced, the release of the contaminant from the sediment to the overlying water may cause the river and lake be contaminated again. On the condition that the overlying water flow does not lead to sediment suspension, numerical researches are carried out for the mechanism of contaminant release through the sedimentoverlying water interface. The overlying water flow is calculated as turbulence. The sediment is regarded as isotropic homogeneous porous medium, therefore the seepage field in the porous sediment layer is obtained by solving Darcy＇s equations. Coupled two dimensional steady flows of the overlying water and the pore water in the sediment are calculated. Based on the flow fields obtained, the unsteady contaminant solute transportation process in the pore water in the sediment and the overlying water is numerically simulated, as the shapes of the sediment-overlying water interface are flat or periodic triangular respectively. Numerical results show that the exchange of the pore water and the overlying water is an important factor which decides the release flux of the contaminant from the sediment to the overlying water. The pressure distribution produced by the overlying water flow along the sedimentoverlying water interface, as it is not flat, may induce the seepage of the pore water in the sediment and through the sedimentoverlying water interface, which may increase the release flux of the contaminant from the sediment to the overlying water.     

A NEW NUMERICAL METHOD FOR GROUNDWATER FlOW AND SOLUTE TRANSPORT USING VELOCITY FIELD

A new numerical method for groundwater flow analysis was introduced to estimate simultaneously velocity vectors and water pressure head. The method could be employed to handle the vertical flow under variably saturated conditions and for horizontal flow as well. The method allows for better estimation of velocities at the element nodes which can be used as direct input to transport models. The advection-dispersion process was treated by the Eulerian-Lagrangian approach with particle tracking technique using the velocities at FEM nodes. The method was verified with the classical one dimensional model and applied to simulate contaminant transport process through a slurry wall as a barrier to prevent leachate pollution from a sanitary landfill.     

A NEW NUMERICAL METHOD FOR GROUNDWATER FIOW AND SOLUTE TRANSPORT USING VELOCITY FIELD

A new numerical method for groundwater flow analysis was introduced to estimate simultaneously velocity vectors and water pressure head. The method could be employed to handle the vertical flow under variably saturated conditions and for horizontal flow as well. The method allows for better estimation of velocities at the element nodes which can be used as direct input to transport models. The advection-dispersion process was treated by the Eulerian-Lagrangian approach with particle tracking technique using the velocities at FEM nodes. The method was verified with the classical one dimensional model and applied to simulate contaminant transport process through a slurry wall as a barrier to prevent leachate pollution from a sanitary landfill.     

东北寒区黑土稻田土壤水分剖面二维运动规律研究

为揭示东北寒区黑土稻田分层土壤水分二维运动规律,选择黑龙江省庆安灌溉试验站稻田土壤开展控制灌溉水层及地下水位条件下分层土壤与均质土壤室内入渗试验。设计装置分层收集侧渗水量,定量识别分层土壤垂直渗漏与侧向渗漏,并基于HYDRUS-2D软件建立水分二维运动模型。结果表明土壤水力特性参数反演效果较好,模型模拟值与实测值吻合;土壤的分层结构抑制了水分入渗,降低了水平侧渗速率及垂直渗漏速率,分层土柱犁底层基本无侧渗输出,耕作层与底土层稳定后的侧渗速率分别为0.007和0.023 cm/h。进行水量平衡分析,分层土柱入渗稳定后侧向渗漏占总渗漏的72.45%,主要通过底土层输出(63.42%);引入"单宽侧渗量"表示不同控制条件下土壤的侧渗输出,灌溉水层的增加显著增大了耕作层与底土层土壤的单宽侧渗量,控制灌溉水层有利于减少侧渗,提高用水效率;犁底层厚度增加主要贡献底土层的单宽侧渗量,反之,地下水位埋深增大则降低了底土层的单宽侧渗量,因此维持稻田适宜的犁底层厚度及地下水位埋深有利于减少深层渗漏损失。     

填海工程背景下半岛地下水流场及污染物运移的数值模拟分析

以古雷半岛为例,基于GMS地下水数值模型探索海砂填海(情景一)、海砂+黏土填海(情景二)、黏土填海(情景三)这三种填海情景对研究区地下水流场及污染物运移的影响。结果表明:(1)研究区在填海背景下地下水水位整体抬升,水位上升幅度由小到大依次为情景一、情景二、情景三,最高升幅达4.78m。(2)不同填海情景下的地下水流场差异在填海区的黏土区域最为明显,情景二、情景三与情景一的地下水水位差最大值分别为4.44 m和8.20m。(3)在仅考虑物理作用的情况下,三种填海情景下污染物运移均呈现以水平运移为主、垂向运移为辅的特点。(4)相较于污染物运移基本相同的情景一与情景二,预测时间30a时,水平方向上情景三污染物迁移面积、迁移速率分别下降23.07%、18.89%;垂向上污染物主要积聚于第一层含水层,情景三观测井在第一层含水层的污染物浓度为情景一(或情景二)的5.87倍。说明采用低渗透性黏土填海对于污染物运移具有一定的阻滞作用。