有机酸与表面活性剂联合作用对土壤重金属的浸提效果研究

重金属污染土壤的原位淋洗修复既要实现对重金属的高效去除,还要尽量减少对土壤性质的破坏,这一点在农业污染土壤修复中尤为重要。以张士污灌区农田土壤为研究对象,利用振荡浸提技术筛选有机酸和表面活性剂组合,并确定了两者联合淋洗修复污染土壤的最佳配比。结果表明：有机酸（酒石酸、乙酸、柠檬酸和苹果酸）中的酒石酸浓度为0.5 mol.L-1和表面活性剂（SDBS、鼠李糖和皂素）中的皂素质量分数为0.7%时对土壤Cd、Pb、Zn的浸提效果较好;在酒石酸与皂素体积配比为1∶1时,对重金属Cd、Pb、Zn浸提效果最好,浸提率分别为87.62%、36.30%、20.67%;单一有机酸、表面活性剂或者有机酸与表面活性剂的混合溶液,对土壤重金属的浸提效果均为Cd〉Pb〉Zn。虽然有机酸与表面活性剂联合浸提效果略低于酒石酸浸提,但其弱酸性对土壤性质影响较小,在原位淋洗修复工程中有较好的应用前景。     

污染土壤的修复技术研究进展

分析了当前我国严峻的土壤环境状况，并从重金属和有机污染物两个方面，全面介绍了当前污染土壤的各种修复技术，包括物理化学修复方法、植物修复方法和微生物修复方法等；对各种方法的修复原理、已取得的研究进展、存在的优缺点及其将来的发展趋势进行了较全面的综述和展望。文章认为，污染土壤修复将是一项非常具有挑战性同时又是一项非常有前途的修复技术，将会对人类健康和经济可持续发展发挥重要作用。     

有机肥中重金属特征及其控制技术研究进展

随着工业的快速发展,农药、肥料及地膜等系列农用化学物质的广泛使用,农田土壤重金属污染越来越严重。重金属进入土壤后,其难移动性导致大量积累,造成土壤环境污染,影响植物生长,危及人类的健康。有机肥是我国农业生产中非常重要的肥料,其来源也十分广泛。施用有机肥是提高作物产量的必要措施,同时也是土壤重金属的主要输入途径之一,研究有机肥的重金属特征及其有关控制技术对农产品安全和有机废弃物的再利用具有重要意义。文章就畜禽排泄物堆肥、污泥堆肥、生活垃圾堆肥和沼肥等主要有机肥料的重金属来源、含量以及不同溯源有机肥料对土壤中重金属有效性的影响进行综述,重点介绍了畜禽排泄物堆肥中重金属含量和饲料添加剂之间的关系,为农田土壤重金属污染防治和农产品安全提供科学依据。除从有机肥的源头控制重金属外,文章主要介绍了化学法、生物吸附法、生物淋滤法和电化学法等重金属控制技术,针对各种控制方法,阐述了其原理、应用实例、优缺点及研究进展情况,提出了解决有机肥重金属污染问题的思路和方法,为有机肥料的资源化利用提供了参考。最后指出,为了实现养殖业与种植业的安全链接,除选用重金属含量低的有机肥,通过相关技术有效控制有机肥中的重金属外,还要注重肥料用量、施肥时间、施肥技术的合理选择,从最大程度上避免有机肥料给作物和人类带来的副作用。     

农田重金属污染原位钝化修复研究进展

污染土壤重金属原位钝化修复是通过向土壤中施加一些活性钝化修复材料,通过溶解沉淀、离子交换吸附、氧化还原、有机络合等反应来改变重金属在土壤中的赋存状态,降低土壤中重金属的有效浓度、迁移性和生物有效性。这种方法成本较低、操作简单、见效快且适合大面积推广,在重金属污染土壤修复中有着不可替代的作用。尤其对主要由污水灌溉、大气沉降等造成的农田土壤面源污染,一些具有吸附固定土壤中重金属离子特性的天然物质和工业副产品都可运用在实地的钝化修复中,且不同类型的钝化修复剂对重金属污染土壤的钝化修复效果各不相同。采用实验室评价和实地应用评价,一方面可以评估钝化修复材料对污染土壤中重金属离子的固定效率;另一方面可以评估钝化修复材料对土壤理化性状、养分状况和生物活性的影响。对重金属污染土壤原位钝化修复中不同来源的钝化剂进行了分类,目前广泛使用的钝化修复剂主要包括硅钙物质、含磷材料、有机物料、黏土矿物、金属及金属氧化物、生物碳及新型材料等,概述了它们各自对重金属污染土壤的钝化修复效果。从研究方法、评价指标、环境影响因子、钝化机制以及环境风险评价等方面分析了该领域的研究现状以及存在的主要问题,今后应重点关注钝化修复剂对土壤-作物系统的潜在环境风险以及钝化材料修复效果的田间长期稳定性评价。     

Ameliorants to immobilize Cd in rice paddy soils contaminated by abandoned metal mines in Korea

The cadmium (Cd) content of rice grain grown in metal-contaminated paddy soils near abandoned metal mines in South Korea was found to exceed safety guidelines (0.2 mg Cd kg?1) set by the Korea Food and Drug Administration (KFDA). However, current remediation technologies for heavy metal-contaminated soils have limited application with respect to rice paddy soils. Laboratory and greenhouse experiments were conducted to assess the effects of amending contaminated rice paddy soils with zerovalent iron (ZVI), lime, humus, compost, and combinations of these compounds to immobilize Cd and inhibit Cd translocation to rice grain. Sequential extraction analysis revealed that treatment with the ameliorants induced a 50-90% decrease in the bioavailable Cd fractions when compared to the untreated control soil. When compared to the control, Cd uptake by rice was decreased in response to treatment with ZVI + humus (69%), lime (65%), ZVI + compost (61%), compost (46%), ZVI (42%), and humus (14%). In addition, ameliorants did not influence rice yield when compared to that of the control. Overall, the results of this study indicated that remediation technologies using ameliorants effectively reduce Cd bioavailability and uptake in contaminated rice paddy soils.     

土壤石油污染物生物通风修复的研究进展

生物通风是一种去污效果好、操作费用低的土壤原位修复技术。文章概述了生物通风系统的结构、设计目的、适用范围和优缺点，详细论述了生物通风的国内外研究现状，包括现场应用、影响因素和强化技术及理论研究，并展望了生物通风在我国的应用前景。     

Redox processes in water remediation

Groundwater is the main source of drinking water and water for agricultural and industrial usage. Therefore, groundwater contamination is prevented and contaminated groundwater is remediated to protect public health and the environment. Methods to remediate groundwater contamination have been recently developed. The use of redox processes in water remediation technologies has not been properly reviewed. Numerous water remediation technologies, such as ultrasonication, bioremediation, electrokinetics and nanotechnology, are closely related to redox processes. Redox processes control the chemical speciation, bioavailability, toxicity, mobility and adsorption of water pollutants in environment. Here, we review (1) general introduction of redox processes, (2) applicability of redox processes in water remediation, and (3) catalytic enhancement of redox potentials to explore its wide applicability in environmental remediation.     

A review of combinations of electrokinetic applications

Anthropogenic activities contaminate many lands and underground waters with dangerous materials. Although polluted soils occupy small parts of the land, the risk they pose to plants, animals, humans, and groundwater is too high. Remediation technologies have been used for many years in order to mitigate pollution or remove pollutants from soils. However, there are some deficiencies in the remediation in complex site conditions such as low permeability and complex composition of some clays or heterogeneous subsurface conditions. Electrokinetic is an effective method in which electrodes are embedded in polluted soil, usually vertically but in some cases horizontally, and a low direct current voltage gradient is applied between the electrodes. The electric gradient initiates movement of contaminants by electromigration (charged chemical movement), electro-osmosis (movement of fluid), electrolysis (chemical reactions due to the electric field), and diffusion. However, sites that are contaminated with heavy metals or mixed contaminants (e.g. a combination of organic compounds with heavy metals and/or radionuclides) are difficult to remediate. There is no technology that can achieve the best results, but combining electrokinetic with other remediation methods, such as bioremediation and geosynthetics, promises to be the most effective method so far. This review focuses on the factors that affect electrokinetic remediation and the state-of-the-art methods that can be combined with electrokinetic.     

农田土壤重金属污染状况及修复技术研究

重金属污染因具有毒性、易通过食物链在植物,动物和人体内累积,对生态环境和人体健康构成严重威胁。随着工业快速发展、农药及化肥的广泛使用,农田土壤重金属污染越来越严重,研究农田土壤重金属污染现状及修复技术对农产品安全具有重要意义。综合国内外农田土壤重金属污染状况,农田土壤重金属污染主要来源于固体废弃物堆放及处置、工业废物大气沉降、污水农灌和农用物质的不合理施用。该文综述了国内外有关农田重金属污染土壤修复技术（物理修复、化学修复、生物修复、农业生态和联合修复）的研究进展,并针对各种修复方法,阐述了其原理、修复条件、应用实例及其优缺点,重点论述了植物修复的机理和应用,提出了草本与木本联合修复可有效提高农田土壤重金属复合污染的修复效率,为农田土壤土壤重金属复合污染修复提出了新的途径。最后在对已有研究分析的基础上,提出了联合修复技术（如生物联合技术、物理化学联合技术和物理化学-生物联合技术）可以在一定程度上克服使用单一修复手段存在的缺点,可提高复合污染的修复效率、降低修复成本,未来应深入探索联合修复技术间的相互作用机理,以期为农田土壤重金属综合治理与污染修复提供科学依据。     

有机酸与表面活性剂联合作用对土壤重金属的浸提效果研究

重金属污染土壤的原位淋洗修复既要实现对重金属的高效去除,还要尽量减少对土壤性质的破坏,这一点在农业污染土壤修复中尤为重要。以张士污灌区农田土壤为研究对象,利用振荡浸提技术筛选有机酸和表面活性剂组合,并确定了两者联合淋洗修复污染土壤的最佳配比。结果表明:有机酸(酒石酸、乙酸、柠檬酸和苹果酸)中的酒石酸浓度为0.5 mol.L-1和表面活性剂(SDBS、鼠李糖和皂素)中的皂素质量分数为0.7%时对土壤Cd、Pb、Zn的浸提效果较好;在酒石酸与皂素体积配比为1∶1时,对重金属Cd、Pb、Zn浸提效果最好,浸提率分别为87.62%、36.30%、20.67%;单一有机酸、表面活性剂或者有机酸与表面活性剂的混合溶液,对土壤重金属的浸提效果均为Cd>Pb>Zn。虽然有机酸与表面活性剂联合浸提效果略低于酒石酸浸提,但其弱酸性对土壤性质影响较小,在原位淋洗修复工程中有较好的应用前景。     

Remediation of soil and groundwater contaminated with organic chemicals using stabilized nanoparticles: Lessons from the past two decades

▪ Overviewed evolution and environmental applications of stabilized nanoparticles. ▪ Reviewed theories on particle stabilization for enhanced reactivity/deliverability. ▪ Examined various in situ remediation technologies based on stabilized nanoparticles. ▪ Summarized knowledge on transport of stabilized nanoparticles in porous media. ▪ Identified key knowledge gaps and future research needs on stabilized nanoparticles. Due to improved soil deliverability and high reactivity, stabilized nanoparticles have been studied for nearly two decades for in situ remediation of soil and groundwater contaminated with organic pollutants. While large amounts of bench- and field-scale experimental data have demonstrated the potential of the innovative technology, extensive research results have also unveiled various merits and constraints associated different soil characteristics, types of nanoparticles and particle stabilization techniques. Overall, this work aims to critically overview the fundamental principles on particle stabilization, and the evolution and some recent developments of stabilized nanoparticles for degradation of organic contaminants in soil and groundwater. The specific objectives are to: 1) overview fundamental mechanisms in nanoparticle stabilization; 2) summarize key applications of stabilized nanoparticles for in situ remediation of soil and groundwater contaminated by legacy and emerging organic chemicals; 3) update the latest knowledge on the transport and fate of stabilized nanoparticles; 4) examine the merits and constraints of stabilized nanoparticles in environmental remediation applications; and 5) identify the knowledge gaps and future research needs pertaining to stabilized nanoparticles for remediation of contaminated soil and groundwater. Per instructions of this invited special issue, this review is focused on contributions from our group (one of the pioneers in the subject field), which, however, is supplemented by important relevant works by others. The knowledge gained is expected to further advance the science and technology in the environmental applications of stabilized nanoparticles.     

Ökotoxikologische und humantoxikologische Risikobewertung PAK-belasteter Böden vor und nach biologischer Behandlung

The goal of the present work is to assess the adverse effects of soil bound polycyclic aromatic hydrocarbons (PAH) which remain in soils after biological remediation. We focus on risk assessment for mammalian species with respect to the oral uptake of contaminated soil particles and compare the results of a biomarker test with those of an ecotoxicological assay, the bioluminescence inhibition test withVibrio fischeri. As a biomarker effect in mammals, we determined the liver microsomal cytochrome P450 enzyme CYP1A1 which is induced by PAH in exposed rats. After biological soil treatment, different amounts of PAH remain in the soil depending on the soil properties and initial pollutant composition. Particularly, higher condensated PAH resists biological treatment due to its hydrophobicity. In addition, high amounts of organic carbon in the soils affect remediation efficiency. In the bioluminescence inhibition test, eluates of all biologically treated soils studied do not reveal any or only low inhibitory effects. In contrast, the oral uptake of biologically treated contaminated soils leads to induction levels for CYP1A1 similar to those in the untreated samples. A good correlation is obtained between CYP1A1 levels and the amount of 5 and 6-ring PAH in the soil samples. The main result is that the remediation efficiency determined by the luminescence test is not reflected by the biomarker test, a finding which indicates the high bioavailability of residual PAH in soils. Consequently, new criteria for human risk assessment can be delineated.     

Stabilization treatment of contaminated soil: a field-scale application in Shanghai,China

Stabilization is one of the best demonstrated available technologies for treating toxic pollutants in soils and has been used worldwide but is rarely used for treatment of contaminated sites in China despite many bench-scale studies. Here, a field-scale application of stabilization treatment in Shanghai, China was summarized to demonstrate the whole engineering process and the key technical issues regarding stabilization of contaminated soil. A site contaminated with arsenic (As) and polycyclic aromatic hydrocarbons (PAHs), formerly used as a lighting plant in Shanghai, was chosen as the demonstration site. Stabilizing measures were taken to treat the contaminated soil to reuse the site for residential purposes. The whole engineering remediation process consisted of phase I environmental site assessment (ESA) and phase II ESA, quantitative human health risk assessment, remediation alternatives evaluation, bench-scale testing, remedial design, engineering implementation, and post-remediation assessment. A third party conducted evaluation monitoring indicated desirable results were achieved via the stabilization treatment. In addition, some technical obstacles related to soil stabilization treatment were discussed, including soil quality evaluation, stabilization effectiveness validation, and soil reuse assessment.     

重金属污染土壤的电动原位修复技术研究

电动力学修复技术作为一种新型的修复技术,由于其处理土壤污染的高效性,近几年来受到了越来越多的关注。综述了电动力学修复技术原理及近几年来其在重金属修复中的最新研究进展,阐述了电动力学修复技术相对于其它修复技术的优势,并指出了电动修复技术中需要克服的技术障碍,探讨了其大规模商业应用的可行性。电动技术能够强化土壤物质的传质过程,能够高效、快速定向迁移土壤中重金属离子达到去除的目的;同时电动技术可以与其它修复技术结合发展出系列组合修复技术,具有广泛的应用前景。从单一电动到复合电动是今后电动力学技术发展的重要方向。目前对污染物质复合电动力学效应下的迁移机理及模型、不同土壤性质(组分、酸碱性等)对于污染物质去除效率及其调控措施的研究仍需进一步深入。     

植物-微生物修复石油烃污染土壤与根际微生态环境变化

石油烃作为一类持久性难降解有机污染物对土壤环境质量产生严重的危害。以天津大港油田原油污染土壤中筛选出的耐低温高效石油烃降解菌为靶细胞,以小麦、紫花苜蓿作为供试植物,利用盆栽试验,对植物-外源菌协同修复体系中的脱氢酶活性和土壤微生物多样性进行研究,分析其变化及其与石油烃降解率的关系。结果表明植物-微生物协同修复对石油烃具有较好的降解能力,其中小麦-固定化外源菌组具有最高的降解率,石油烃含量从最初的30 600 mg獉kg-1下降为24 300 mg獉kg-1,降解率为20.6%,并且其试验后期石油烃的降解率最大,远远高于其他时期,表现出良好的修复潜力。外源菌投加的初始阶段会迅速提高脱氢酶活性,然而这种影响随着降解时间延长而逐渐减弱。初期脱氢酶活性与总石油烃的降解存在较好的相关性,脱氢酶活性可以在一定程度上表征土壤石油烃的降解情况。微生物多样性与总石油烃降解也存在一定的相关性。     

两种土壤中对硝基氯苯被Fe~0还原的对比研究

利用零价铁(Fe~0)还原技术修复受对氯硝基苯(p-CNB)污染的土壤,研究常温常压下松砂土和中壤土两种不同土壤的理化性质对还原反应的影响.结果表明:Fe0能有效还原松砂土和中壤土中的p-CNB,生成对应的苯胺化合物,降低毒性;当土壤中p-CNB的含量约为2.5×10~(-6)mol·g~(-1),Fe~0用量为25 mg·g~(-1),反应体系中水分含量为0.75 mL·g~(-1)时,于25℃反应2 h后,松砂土和中壤土中p-CNB的还原率均超过93%;还原反应在中壤土中进行得较快.污染物在土壤中的老化时间对Fe~0还原降解效果影响很小,而土壤粒径、土壤是否灭菌以及土壤有机质含量等因素则对还原有较明显影响;还原降解反应在没有灭菌、有机质含量较高且粒径偏小的壤土中进行得最彻底.     

固定化毛霉对工业和农田污染土壤中多环芳烃的降解和生物有效性评价

为了探讨微生物修复不同类型多环芳烃污染土壤的可行性,应用固定化毛霉对多环芳烃污染工业土壤及农田土壤进行微生物修复,用羟丙基-β-环糊精(HPCD)提取模拟评价多环芳烃的微生物可利用性,并分析多环芳烃微生物降解和生物可利用性的相关关系.焦化厂污染土壤中多环芳烃的30 d降解率为77.6%,沈抚灌区污染土壤中多环芳烃的30 d降解率为54.2%,焦化厂土壤和污灌区农田土壤中多环芳烃降解差异明显.焦化厂土壤和污灌区土壤中多环芳烃的30 d降解量和多环芳烃的环糊精可提取量具有相关性,各环数多环芳烃的环糊精可提取量变化解释了焦化厂和污灌区土壤中多环芳烃降解的差异机制,说明可用环糊精提取量预测微生物降解土壤多环芳烃的情况.     

High-energy milling to decontaminate soils polluted by polychlorobiphenyls and atrazine

Mechanical energy has been used so far for running chemical reactions and for preparing new materials in absence of solvents. Very recently, the technology has been applied to solve environmental problems. In this paper, we describe the application of high-energy milling (HEM) for the remediation of soils contaminated by chlorinated organic compounds such as polychlorobiphenyls (PCBs) and agrochemicals like atrazine. NaBH₄ and LiAlH₄ have been successfully used for the total dehydrohalogenation of both classes of compounds, leaving a residue lower than 2 ppmw of the starting compound in the treated soil. LiAlH₄ was found to be more active than NaBH₄.     

Engineering practice of mechanical soil aeration for the remediation of volatile organic compound-contaminated sites in China: Advantages and challenges

In recent years, many industrial enterprises located in the urban centers of China have been relocated owing to the rapid increase in urban development. At the sites abandoned by these enterprises, volatile organic compounds have frequently been detected, sometimes at high concentrations, particularly at sites abandoned by chemical manufacturing enterprises. With the redevelopment of sites and changes in land-use type associated with these sites, substantial amounts of contaminated soils now require remediation. Since China is a developing country, soil remediation warrants the usage of techniques that are suitable for addressing the unique challenges faced in this country. Land shortage is a common problem in China; the large numbers of contaminated sites, tight development schedules, and limited financial resources necessitate the development of cost-effective methods for land reclamation. Mechanical soil aeration is a simple, effective, and low-cost soil remediation technique that is particularly suitable for the remediation of large volatile organic compound-contaminated sites. Its effectiveness has been confirmed by conducting laboratory studies, pilot tests, and full-scale projects. This study reviews current engineering practice and developmental trends of mechanical soil aeration and analyzes the advantages and disadvantages of this technology for application in China as an emerging soil remediation market. The findings of this study might aid technology development in China, as well as assist other developing countries in the assessment and implementation of costeffective hazardous waste site soil remediation programs.

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Sol-gel immobilisation of methyl parathion degrading bacteria isolated from agricultural areas of Pakistan

The following areas are discussed in this paper: immobilisation of bacterial consortium in sol-gel; methyl parathion degradation and bioremediation applications; evaluation of indigenous bacterial isolates of contaminated soils. Bacterial strains were isolated from agricultural areas of Pakistan which were contaminated with methyl parathion. A bacterial consortium of seven (out of 64) Enterobacteriaceae isolates including Citrobacter, Enterobacter and Proteus vulgaris capable of degrading methyl parathion (enzyme activity ranging 410–675 mU mL^?1 for individual isolates and 982 mU/mL for consortium) was selected and subsequently immobilised in tetraethyl orthosilicate (TEOS) and sodium-silicate-based sol-gel matrices. Cell viability of suspended and immobilised bacterial consortium was monitored using a minimal salt medium supplemented with methyl parathion. The results indicate that sol-gel immobilisation can be helpful to increase the shelf life of methyl parathion degrading bacterial strains along with preservation of biological activity for bioremediation applications in field.