重金属污染场地物理化学修复技术研究与工程应用进展

结合我国国情,介绍了国内主要重金属污染场地修复技术,包括客土法、固化/稳定化技术、土壤淋洗法、解吸脱附技术、竖向隔离法和氧化还原技术,并进一步阐述了各个技术最新的科学研究进展和目前的国内工程应用情况,以期为重金属污染场地的修复工作提供借鉴和参考。     

污染土壤的物化修复治理技术

污染土壤的修复治理过程中,物化技术以其快速高效的特点成为国内外研究的热点。本文通过对工程措施、玻璃化技术、热修复、电动力修复、光化学降解、化学淋洗、化学固定/稳定化、化学氧化以及联合修复等常见土壤物化治理技术的分析,探讨了各种工艺技术的性能及优缺点,旨在为我国土壤污染修复治理技术的选择提供参考。     

污染土壤的物化修复治理技术研究

污染土壤的修复治理过程中,物化技术以其快速高效的特点成为国内外研究的热点。本文通过对工程措施、玻璃化技术、热修复、电动力修复、光化学降解、化学淋洗、化学固定/稳定化、化学氧化以及联合修复等常见土壤物化治理技术进行了分析,探讨了各种工艺技术的性能及优缺点,旨在为我国土壤污染修复治理技术的选择提供参考。     

复合固化剂对某钢铁厂污染土壤修复研究

以水泥、生石灰、膨润土、麦饭石和含磷物料为原料,组配了六种固化剂,将其应用于某钢铁厂污染土壤的修复,通过测定固化体无侧限抗压强度和重金属毒性浸出试验对固化/稳定化效果进行分析和评价。结果表明,固化剂的加入使得固化体的pH值升高了2.5~4.4。当固化剂添加量为25%,含水率为30%,养护时间为28 d时,A、B、C和E组能达到US EPA针对填埋场无侧限抗压强度qu(350 kPa)的要求。A~F组固化剂均能很好地固定土壤中的重金属,添加固化剂后各组的Cd、Pb、Cu和Zn的浸出浓度都没有超过《生活垃圾填埋场污染控制标准》的标准限值。     

污染土壤重金属稳定化修复的综合性实验

添加不同种类改良剂对污染农田土壤进行有毒重金属的稳定化修复,内容包括土壤样品制备与培养、pH测定、重金属离子总浓度及有效态浓度测定。首先,学生需要在实验过程中熟练掌握电子天平、pH计、微波消解仪和电感耦合等离子体质谱的操作规程。其次,学生能够在课后利用固化率公式处理数据和评价不同改良剂对重金属的稳定化修复效果,并进行机理解析。本实验不仅可以加强学生对相关专业理论知识的理解和精密化学仪器的使用,还能够培养学生综合运用所学专业知识解决实际应用问题的能力,并进一步激发学生探索化学前沿新知,从而达到拓展创新的培养目标。     

污染土壤修复技术研究现状与趋势

本文综述了国内外污染土壤修复技术的研究现状和发展趋势,并联系我国土壤污染态势探讨了中国土壤修复技术研发的需求.文中指出,包括生物修复、物理修复、化学修复及其联合修复的污染土壤修复技术体系已经基本形成;土壤修复技术正朝着6大方向发展,即向绿色与环境友好的生物修复、联合杂交的综合修复、原位修复、基于环境功能材料的修复、基于设备化的快速场地修复以及土壤修复决策支持系统及修复后评估等技术方向发展.我国土壤环境污染态势严峻,需要发展能广泛应用、安全、低成本的原位农田生物修复技术和物化稳定技术,发展安全、土地能再开发利用、针对性强的工业场地快速物化工程修复技术与设备,发展能控制水土流失与污染物扩散的矿区植物稳定化与生态工程修复技术,建立污染土壤修复技术规范、评价标准和管理政策.     

活化过硫酸盐原位化学氧化修复有机污染土壤和地下水

原位化学氧化 （ISCO）是近些年来国内外较为推崇的一种土壤和地下水修复技术。过硫酸盐（PS,S₂O₈^2-）具有易运输、较稳定、易溶于水和易传质等性质,能很好地适应ISCO的发展要求。它在光、热、过渡金属离子、强氧化剂和强碱性环境等活化条件下,能产生强氧化性的硫酸根自由基SO₄^·-,适用于氧化降解各种有机污染物。本文在分析活化过硫酸盐（activated persulfate,APS）氧化机理的基础上,综述了不同方式活化过硫酸盐原位修复有机污染土壤和地下水及APS协同、联用技术的应用,并就值得深入研究的问题和热点趋势进行了展望。     

铅污染土壤的修复技术

综述了铅对土壤的污染及其修复技术。目前应用于污染土壤的修复技术可分为物理化学修复技术和生物修复技术。物理化学修复技术又可分为隔离包埋技术,固化稳定技术,Pyrometalluryical separation,化学稳定技术,电动修复技术等;生物修复技术可分为微生物修复技术和植物修复技术等。以期进一步推动铅污染土壤的治理和修复工作。     

污染土壤电动修复技术研究进展

电动修复是一种新兴的原位土壤修复技术,主要用于有机及重金属污染土壤/场地的修复.本文作者介绍了电动修复污染土壤的技术原理;探讨了电动技术与Fenton技术、表面活性剂/助溶剂、超声波技术、微生物技术及渗透性反应屏障技术的联合应用;总结了土壤电动修复中,土壤pH不均衡及有机污染修复效率较低的问题.确定了电动技术与多种技术的联用为土壤修复的研究和应用趋向.     

氯化铵焙烧结合二苯硫脲泡塑富集-电感耦合等离子体-原子发射光谱法测定锑金矿中的金

建立氯化铵焙烧结合二苯硫脲泡塑富集-电感耦合等离子体-原子发射光谱法测定锑金矿中金的方法。使用泡塑分离富集锑金矿中的金,对影响测定结果准确度的因素进行了系统的分析,采取分两次加氯化铵焙烧试样、二苯硫脲泡塑分离富集金的方法处理样品,然后用电感耦合等离子体-原子发射光谱法测定金的含量。方法检出限为0.015μg/g,测定结果的相对标准偏差为1.44%~2.65%(n=5),该法测定值与火法测定值基本吻合。该方法可用于各种含量的锑金矿石中金的测定,能够满足地质样品中金含量测定的技术要求。     

有机杂化锑基主族异金属硫属化物的研究进展

本文综述了有机杂化锑基主族异金属硫属化物的研究进展,对它们的结构和异金属次级结构基元进行了描述、归类和总结;探讨了有机组分分别作为结构导向剂和配体两种角色所起到的不同作用;介绍了这类化合物在离子交换、光催化性能方面的研究;展望了该体系的发展趋势。     

有机杂化锑基主族异金属硫属化物的研究进展

本文综述了有机杂化锑基主族异金属硫属化物的研究进展, 对它们的结构和异金属次级结构基元进行了描述、归类和总结;探讨了有机组分分别作为结构导向剂和配体两种角色所起到的不同作用;介绍了这类化合物在离子交换、光催化性能方面的研究;展望了该体系的发展趋势。     

电动修复土壤中重金属污染的改良方法

介绍了治理土壤重金属污染的电动修复技术的一些进展,包括:通过控制电解过程中的极化、土壤pH值、控制土壤温度来对电动修复技术方法进行改良。     

The preparation and utilization of performance evaluation soils for evaluating radioassay laboratories engaged in site remediation work

Site remediation projects dealing with uranium, thorium or radium require the services of a radioassay laboratory during the site characterization, remediation and final site survey/verification phases. In the U.S., regulatory agencies and industry guidelines recommend that the remediation contractor conduct an external laboratory QC program to ensure the quality of the analytical results. The commercial availability of certified natural soil matrices is extremely limited not only by nuclide and nuclide concentration but also by soil type. In most cases, the applicability of these materials for an external QC program is questionable since the chemical constituents of the certified soil may not be representative of the remediation soil type. Also, such materials are typically only suitable as single blind performance evaluation (PE) samples. The Yankee Atomic Environmental Laboratory (YAEL) has characterized soil materials from several uranium mining and milling sites for use in two laboratory PE programs. The site specific PE materials were prepared in accordance with their intended use and quality performance requirements. One PE material was dried, pulverized to a particle size of approximately 10 microns and homogeneously blended. The second PE material (total of 1,024 kg) was methodically field blended and aliquoted to produce 1,000 separate homogeneous 1 kg samples. Both PE materials were characterized for radionuclide concentration and heterogeneity or sample distribution. A summary of the characterization studies of the different PE materials as well as the quality performance criteria developed for evaluating the laboratory's performance and the advantages and disadvantages of using each PE material will be discussed and summarized.     

砷镉复合污染稻田修复研究进展

我国农田土壤重金属污染严重,其中稻田土壤砷镉(As/Cd)复合污染形势严峻。相较于其他粮食作物,水稻具有更强的积累As/Cd能力,稻米中As/Cd通过食物链进入人体会对人类健康带来危害。因此,修复As/Cd复合污染稻田土壤,降低稻米As/Cd含量,对保障我国粮食安全生产意义重大。本文综述农田As/Cd复合污染现状及危害,讨论了As/Cd有效性影响因素及水稻中As/Cd吸收转运机制,详细探讨了稻田中As/Cd污染的修复方法。最后针对目前修复技术提出存在的不足和展望,以期为As/Cd复合污染稻田土壤修复提供一定的指导。     

Green Synthesis of Superparamagnetic Iron Oxide Nanoparticles with Eucalyptus globulus Extract and Their Application in the Removal of Heavy Metals from Agricultural Soil

The green synthesis of metal oxide nanoparticles is presented as an excellent sustainable alternative for achieving nanostructures, with potential applications. This research provides important information regarding the influence of the type of solvent used in extracting organic reducing agents from E. globulus on the FeO NPs green synthesis protocol. A broad approach to characterization is presented, where UV-vis spectrophotometry suggests the presence of this type of nanoparticulate material. Likewise, the reduction mechanism was evaluated by FT-IR and the magnetic properties were evaluated by PPSM. In addition, characterizations were linked via elemental analysis (EDX), crystallographic characterization (XRD), electron microscopy (SEM/STEM), and Z potential to evaluate colloidal stability. The results show the influence of the type of solvent used for the extraction of organic reducing agents from E. globulus, and the effect on the synthesis of FeO NPs. In addition, the nanostructure material obtained showed excellent efficiency in the remediation of agricultural soil, eliminating metals such as Cr-VI, Cd, and, to a lesser extent, Pb.     

Polychlorinated Biphenyls-contaminated Soil Washing with Mixed Surfactants Enhanced by Electrokinetics

On the basis of comparing the adsorption loss of different surfactants[single nonionic surfactant sorbitanmonooleatepolyoxyethylene ether(Tween 80), anionic surfactant sodium dodecyl benzene sulfonate(SDBS), and mixed surfactants Tween 80/SDBS(3:2), Tween 80/SDBS(4:1)] and their performance in the enhancement of polychlorinated biphenyls(PCBs) desorption from soil, the impact of electric field intensity on the desorption of PCBs and the transport of surfactants in washing resulted solution were investigated in this study. With regard to the remediation cost, 1000 mg/L mixed Tween 80/SDBS(3:2) was recognized as an optimum concentration in the remediation of PCBs-contaminated soil, because Tween 80/SDBS(3:2) had the highest washing capacity and relatively low adsorption loss onto soil. Electrokinetics can enhance the washing efficiency of PCBs-contaminated soil by Tween 80/SDBS(3:2) effectively and safely at an electric field intensity of 1.5 V/cm for 10 d, for the desorption of PCBs was 1.57 times more than that without electrokinetics, and the most of organic residue in washing resulted solution was removed in an electrical field to avoid the possible secondary contamination risk.     

COMMUNICATION. OBSERVATIONS ON THE 121-Sb MÖSSBAUER PARAMETERS OF ANTIMONY (III) COMPOUNDS FEATURING A PYRAMIDAL SbS3 SKELETAL UNIT

Abstract

A linear correlation between the chemical isomer shift and the quadrupole coupling constant for a number of antimony tris-thiolates has been evidenced. This behaviour can be rationalized on considering a modulation of the s/p character of the lone pair of electrons from the influence of secondary bonds.     

Piezocatalytic Techniques in Environmental Remediation

As a consequence of rapid industrialization throughout the world, various environmental pollutants have begun to accumulate in water, air, and soil. This endangers the ecological environment of the earth, and environmental remediation has become an immediate priority. Among various environmental remediation techniques, piezocatalytic techniques, which uniquely take advantage of the piezoelectric effect, have attracted much attention. Piezoelectric effects allow pollutant degradation directly, while also enhancing photocatalysis by reducing the recombination of photogenerated carriers. In this Review, we provide a comprehensive summary of recent developments in piezocatalytic techniques for environmental remediation. The origin of the piezoelectric effect as well as classification of piezoelectric materials and their application in environmental remediation are systematically summarized. We also analyze the potential underlying mechanisms. Finally, urgent problems and the future development of piezocatalytic techniques are discussed.