土壤中有机污染物的植物修复研究进展

植物修复是土壤有机污染物修复的有效途径之一，主要包括植物吸收、根际土壤酶促进降解和微生物对其的一系列降解。本文简述了植物修复的含义，系统综述了植物修复有机污染物的机理，并阐述了利用植物对农药、氯代化合物、多环芳烃和其它有机污染物进行修复的研究成果与应用，展望了今后进一步研究的重点。     

植物修复技术及其在环境保护中的应用

阐述了植物修复技术的含义,即利用植物去修复和消除有机毒物和无机毒物引起的土壤环境污染,介绍了对有机污染物修复的方法：（１）根收获,（２）叶表挥发,（３）植物降解;对无机污染物修复的方法;（１）收获生物量或将污染物进行生物挥发从而将污染物将出土体,（２）将污染物转变成为无生物活性的形态收获生物量对于回收某些贵重金属是很有价值的。基因工程技术以及农业技术的综合运用可以更好地促进植物修复的效果。     

有机污染物根际胁迫及根际修复研究进展

根际环境及根际微生物是植物降解有毒有害有机污染物的基础。污染土壤植物修复的纵深研究产生了根际修复新技术。通过总结近20年来有机污染物胁迫的根际效应的研究,探讨了有机物污染士壤根际修复的可能性,为加强有机污染物在环境中的迁移、调控研究及土壤有机物污染的原位修复提供有利信息。     

植物清除环境污染物的策略及应用

综述了无机污染物和有机污染物的植物修复策略及应用。指出植物具有许多内在的遗传和生化生理特性，利用植物抽提、隔离、解除污染物毒 性来清除土壤和水体环境污染物已取得明显进展，相对于机械去污法，植物修复已被广泛地认为是一种生态可靠的替代方法。     

持久性有机污染物的根际修复及其研究方法

根际是具有特殊性质的土壤微生态环境,对土壤中持久性有机污染物的行为及生物修复具有重要作用。本文从微生物降解、植物过程、非生物降解、土壤吸附、挥发、淋溶等方面归纳了有机污染物根际修复的研究进展,并从细胞培养、添加根系分泌物或根系残留物、挥发污染物收集和残留态污染物测定等方面综述了有机污染物根际行为的研究方法及其优缺点。     

农田土壤-植物系统持久性有机污染物的界面过程与自修复——以多氯联苯为例

土壤-植物系统是地球陆地表层生态系统中非常重要的亚系统,对保障粮食安全与人体健康发挥着关键作用。持久性有机污染物是土壤环境中难降解、长残留的毒害污染物。这类有机污染物在土壤组分、土壤微生物和植物的共同作用下,发生着一系列的物理化学与生物学的界面过程,导致其或者生物有效性的降低和毒性的下降,或者快速降解,进而减少在食物链中传递的风险,达到自然条件下土壤污染净化,实现自修复。以多氯联苯为例,综述了农田土壤-植物系统中持久性有机污染物的土壤组分界面过程、根际界面过程和植物体微界面过程研究进展,提出了发挥土壤-植物系统降解净化作用,实现持久性有机污染物自修复的新思路。参30。     

污染土壤植物修复技术研究进展

综述了国内外污染土壤植物修复技术研究进展 ,植物修复是利用某些植物对土壤重金属的超量吸收挥发以及对土壤中有机污染物降解等特殊功能 ,并与根际微生物协同作用 ,原位修复污染土壤的方法 ,费用低 ,效果显著 ,环境友好 ,是极具发展潜力的“绿色产业”。     

菌根真菌对土壤有机污染物的生物降解

利用土壤真菌和植物的结合体菌根真菌修复土壤，尤其是修复有机污染的根际土壤，正作为一个新的研究方向开始受到广泛关注。菌根真菌作为土壤真菌的一种，与放线菌和细菌等微生物相比，对土壤中有更大的忍耐能力，并且能将许多持久性有机污染物（POPs）做为碳源来获取能量。文章通过总结近20年菌根真菌与土壤有机污染物关系的研究。列出了43种能分解POPs的菌根真菌，并探讨了菌根真菌通过直接分解和共代谢的方式降解土壤有机污染物的可能性，为进一步研究菌根真菌生物降解土壤中持久性有机污染物，利用菌根植物生物修复有机污染土壤提供信息。     

菌根真菌影响土壤有机污染物降解机理的研究进展

菌根是植物根系与菌根真菌形成的共生体,它能增强植物的逆境抗胁迫能力,有促进有机污染物降解和转化的作用。近年来很多学者对其进行了研究,然而有关其降解和转化的机理目前仍不是很明确。介绍了国内外涉及菌根真菌对土壤中有机污染物的降解机理的研究成果,为促进菌根真菌在土壤有机污染生物修复中的应用提供了基础信息。     

湿地沉积物污染风险评价及生物修复技术研究进展

在简要介绍湿地沉积物的主要污染物和来源之后,依据国内外近年来有关污染沉积物研究的相关成果,阐述了潜在生态风险指数法、SEM/AVS法和沉积物质量基准法等对沉积物中重金属/有机污染物进行的主要生态风险评价方法。回顾了污染沉积物的物理、化学和生物3大主要修复措施,重点总结了生物修复技术中微生物修复、植物修复及植物-微生物联合修复方面的研究进展。最后提出了研究展望和思考,旨在为河流湖库沉积物及水体环境的污染风险评价及污染修复提供科学依据。     

Assessing the effects of environmental pollutants on soil organisms,communities, processes and ecosystems

A wide range of pollutants reach the soils of natural and managed ecosystems in concentrations that can affect their function. These chemicals, which include pesticides, heavy metals, acid deposition and a range of industrial chemicals, can reach soils in many different ways and by various routes. The ecological impacts of these chemicals on agricultural systems can involve effects at the: (i) organism population level, in terms of individual life histories (birth rate, numbers, growth, mortality); (ii) at the community level in terms of effects on plant/plant, plant/microbial, or plant/faunal interactions, species diversity and on soil food webs; (iii) at the ecosystem level, effects on primary and secondary productivity, organic matter breakdown and nutrient cycling; (iv) at the landscape level, changes in spatial heterogeneity of plants and soil organisms, material transfer of soil and nutrients, and hydrologic transfers of nutrients. Currently available methods of assessing the effect of pollutants include single species laboratory tests, a few multi-species assays, and integrated soil microcosms and terrestrial model ecosystems. The latter two methods produce data on the effects of pollutants on populations, communities and ecosystems as well as the fate of pollutants.     

逆境胁迫下的农业管理中土壤-植物-微生物相互作用研究进展

The expected rise in temperature and decreased precipitation owing to climate change and unabated anthropogenic activities add complexity and uncertainty to agro-industry.The impact of soil nutrient imbalance,mismanaged use of chemicals,high temperature,flood or drought,soil salinity,and heavy metal pollutions,with regard to food security,is increasingly being explored worldwide.This review describes the role of soil-plant-microbe interactions along with organic manure in solving stressed agriculture problems.Beneficial microbes associated with plants are known to stimulate plant growth and enhance plant resistance to biotic (diseases) and abiotic (salinity,drought,pollutions,etc.) stresses.The plant growth-promoting rhizobacteria (PGPR) and mycorrhizae,a key component of soil microbiota,could play vital roles in the maintenance of plant fitness and soil health under stressed environments.The application of organic manure as a soil conditioner to stressed soils along with suitable microbial strains could further enhance the plant-microbe associations and increase the crop yield.A combination of plant,stress-tolerant microbe,and organic amendment represents the tripartite association to offer a favourable environment to the proliferation of beneficial rhizosphere microbes that in turn enhance the plant growth performance in disturbed agro-ecosystem.Agriculture land use patterns with the proper exploitation of plant-microbe associations,with compatible beneficial microbial agents,could be one of the most effective strategies in the management of the concerned agriculture lands owing to climate change resilience.However,the association of such microbes with plants for stressed agriculture management still needs to be explored in greater depth.     

土壤中有机化学品降解动力学的某些模型与机理建模中的相似观

如果不同事物的机理可被函数形式严格相同的数学模型所描述。我们就认为在这些事物之间存在机理相似性。机量相似性可以帮助我们在机理建模方法的科学探索。降解有机化学品的微生物在机理上相似于相互用种群的Ｖｏｌｔｅｒｒａ模型中的捕食者种群；但有机化学品浓度的变化在数理上不同于Ｖｏｌｔｅｒｒａ模型中被捕食者种群密度的变化。     

Mineralization of organic contaminants under aerobic and anaerobic conditions in sludge-soil mixtures

Background and Main Features  The mineralization of eight organic chemicals (surfactants, substituted aromatic compounds, di(2-ethylhexyl)phthalate and phenanthrene) was examined in sludge-soil mixtures under aerobic, denitrifying and methanogenic conditions. Results and Discussion  Most of the chemicals were extensively or partially mineralized under aerobic conditions with mineralization half-lives between 1.5 and 12.5 days. Linear tridecyl tetra ethoxylate, di(2-ethylhexyl)phthalate and 2,4-dinitrophenol were also mineralized partially under denitrifying conditions. No mineralization of the chemicals was observed under methanogenic conditions, with the exception of a minor mineralization of linear tridecyl tetraethoxylate. Conclusion  This study indicates that the examined organic chemicals may be rapidly degraded in sludge-amended fields under aerobic conditions, and that some of the chemicals may also be degraded during denitrification. Recommendations and Outlook  When investigating the degradation of sludge-bound chemicals in soil, it is relevant to consider both aerobic and anaerobic soil regimes due to spatial and temporal variations in the redox conditions within sludge and soil. The approach presented in this article may be used for evaluation of the long-term fate of sludge-bound chemicals in soil.     

Rapid,Wet Oxidation Procedure for the Estimation of Silicon in Plant Tissue

Abstract

The quantification of silicon (Si) in plant samples is being requested more frequently, especially in agricultural laboratories associated with the determination of nutritional requirements of sugarcane (Saccharum officinarum L.) and rice (Oryza sativa L.). The analysis of plant material for Si can be protracted, especially if laboratories do not have access to X‐ray flourescence (XRF) instrumentation and large numbers of samples are involved. A simplified procedure using equipment considered standard in most agricultural laboratories is reported. Dry, ground plant material is subjected to nitric acid/peroxide oxidation in a low‐pressure laboratory microwave digestion system. The hydrated silica liberated from the organic matrix is dissolved in a small volume of sodium hydroxide solution also using the microwave digestion system. Silicon is measured by inductively coupled plasma atomic emission spectrometry (ICP‐AES). This method gives results that are linearly correlated with the much slower conventional techniques and avoids using hazardous chemicals (hydrofluoric acid) sometimes employed in other microwave methods.     

Bioavailability of hydrophobic organic contaminants in soils: fundamental concepts and techniques for analysis

Soils represent a major sink for organic xenobiotic contaminants in the environment. The degree to which organic chemicals are retained within the soil is controlled by soil properties, such as organic matter, and the physico‐chemical properties of the contaminant. Chemicals which display hydrophobic and lipophilic characteristics, as well as a recalcitrant chemical structure, will be retained within the soil, and depending on the ‘strength’ of the association may persist for long periods of time. This review describes the behaviour of hydrophobic organic contaminants in soils, focusing on the mechanisms controlling interactions between soil and contaminants. The bioavailability of contaminants in soil is also discussed, particularly in relation to contact time with the soil. It considers the degradation of organic contaminants in soil and the mechanisms microbes use to access contaminants. Finally, the review discusses the ‘pros’ and ‘cons’ of chemical and biological techniques available for assessing bioavailability of hydrophobic organic chemicals in soils, highlighting the need to quantify bioavailability by chemical techniques. It concludes by highlighting the need for understanding the interactions between the soil, contaminants and biota which is crucial to understanding the bioavailability of contaminants in soils.     

估算有机化合物土壤吸着系数Koc的片段常数法

根据５９２种有机化合物实测Ｋｏｃ数据,研究了用片段常数法估算有机化合物土壤吸着系数的可能性。将５９２种化合物随机划分为建模组和验证组。前者用于模型建立,后者用于模型检验。计算结果证明,包括７４种结构片段和２４个结构校正因子的回归模型能够很好的预测有机化合物的吸着系数。对所有５９２种化合物而言,模型原可决系数高达０．９６９６,估算结果的平均绝对误差仅为０．３７个对数单位。     

Effects of DD,EDB and PCP upon microorganisms and their activities in soil part I effects on microflora

The extensive use of various insecticides or herbicides makes it desirable to know what influences, if any, such chemicals may exert upon soil microorganisms. The effect of chemicals should be considered not only upon plant pathogenes, but also upon general soil micro-organisms.     

有机化工废弃物的土地处理研究

本文对三种供试工业废弃物，经土地处理后表明，发光细菌毒性明显降低，有的废渣处理物毒性已消除；Ａｍｅｓ试验和发光细菌自发暗变种的遗传毒减弱，由阳性下降为阴性，或阳性程度明显减弱。     

Evaluation of soil health in organic vs. conventional farming of basmati rice in North India

Conventional agricultural practices that use excessive chemical fertilizers and pesticides come at a great price with respect to soil health, a key component to achieve agricultural sustainability. Organic farming could serve as an alternative agricultural system and solve the problems associated with the usage of agro‐chemicals by sustainable use of soil resources. A study was carried out to evaluate the impact of organic vs . conventional cultivations of basmati rice on soil health during Kharif (rainy) season of 2011 at Kaithal district of Haryana, India, under farmers' participatory mode. Long‐term application of organic residues in certified organic farms was found to improve physical, chemical, and biological indicators of soil health. Greater organic matter buildup as indicated by higher soil organic carbon content in organic fields was critical to increase soil aggregate stability by increasing water holding capacity and reducing bulk density. Proper supplementation of nutrients (both major and micro nutrients) through organic residue addition favored biologically available nutrients in organic systems. Further, the prevalence of organic substrates stimulated soil microorganisms to produce enzymes responsible for the conversion of unavailable nutrients to plant available forms. Most importantly, a closer look at the relationship between physicochemical and biological indicators of soil health evidenced the significance of organic matter to enzyme activities suggesting enhanced nutrient cycling in systems receiving organic amendments. Enzyme activities were very sensitive to short‐term (one growing season) effects of organic vs . conventional nutrient management. Soil chemical indicators (organic matter and nutrient contents) were also changed in the short‐term, but the response was secondary to the biochemical indicators. Taken together, this study indicates that organic farming practices foster biotic and abiotic interactions in the soil which may facilitate in moving towards a sustainable food future.