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1.
Soil pollution is a major environmental problem and many contaminated sites are tainted with a mixture of organic and heavy metal contaminants. Compared to other remedial strategies, phytoremediation is a low cost, environmentally-friendly, sustainable means of remediating the contamination. This review first provides an overview of phytoremediation studies where the soil is contaminated with just one type of pollutant (heavy metals or organics) and then critically evaluates the applicability of phytotechnologies for the remediation of contaminated sites where the soil is polluted by a mixture of organic and heavy metal contaminants. In most of the earlier research studies, mixed contamination was held to be detrimental to plant growth, yet there were instances where plant growth was more successful in soil with mixed contamination than in the soil with only individual contaminants. New effective phytoremediation strategies can be designed for remediation of co-contaminated sites using: (a) plants species especially adapted to grow in the contaminated site (hyperacumulators, local plants, transgenic plants); (b) endophytic bacteria to enhance the degradation in the rizhosphere; (c) soil amendments to increase the contaminants bioavailability [chelating agents and (bio)surfactants]; (d) soil fertilization to enhance the plant growth and microbial activity in the soil; and (e) coupling phytoremediation with other remediation technologies such as electrokinetic remediation or enhanced biodegradation in the rhizosphere.  相似文献   

2.
Phytoremediation of toxic aromatic pollutants from soil   总被引:9,自引:0,他引:9  
The enormous growth of industrialization, and the use of numerous aromatic compounds in dyestuffs, explosives, pesticides and pharmaceuticals has resulted in serious environmental pollution and has attracted considerable attention continuously over the last two decades. Many aromatic hydrocarbons, nitroaromatic compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, diauxins and their derivatives are highly toxic, mutagenic and/or carcinogenic to natural microflora as well as to higher systems including humans. The increasing costs and limited efficiency of traditional physicochemical treatments of soil have spurred the development of new remediation technologies. Phytoremediation is emerging as an efficient treatment technology that uses plants to bioremediate pollutants from soil environments. Various modern tools and analytical devices have provided insight into the selection and optimization of remediation processes by various plant species. Sites heavily polluted with organic contaminants require hyperaccumulators, which could be developed by genetic engineering approaches. However, efficient hyperaccumulation by naturally occurring plants is also feasible and can be made practical by improving their nutritional and environmental requirements. Thus, phytoremediation of organics appears a very promising technology for the removal of contaminants from polluted soil. In this review, certain aspects of plant metabolism associated with phytoremediation of organic contaminants and their relevant phytoremediation efforts are discussed.IMTECH Communication No. 013/2002  相似文献   

3.
The redevelopment of contaminated land is becoming increasingly necessary under sustainable- development legislation; however, many of the contaminated sites are "orphan" sites and therefore require a low-cost remediation technology. These sites often contain a cocktail of pollutants including organics and inorganics. Phytoremediation provides a possible solution, but there is little information available on the tolerance of plant species to multiple pollutants and their ability to remediate in mixed-contaminant soils. The effect of a polycyclic aromatic hydrocarbon (pyrene) in soil upon the remediation of zinc by Brassica juncea and Festuca arundinacea was investigated under normal climatic conditions in the United Kingdom. Zinc was effectively removed from mixed-contaminant soils in the presence of both species, in comparison to a control treatment. Both species accumulated zinc in plant tissues in the presence of pyrene, but the growth of B. juncea was significantly reduced when zinc and pyrene were supplied in combination. Zinc was predominantly associated with root tissues for F. arundinacea, whereas B. juncea contained higher concentrations in shoot tissues. F. arundinacea provides a possible species to be used for the phytoremediation of brownfield sites, but further research is required to determine a range of species that may be used and their applicability to different contaminants.  相似文献   

4.
This paper presents a numerical analysis of the migration and transformation mechanism of petroleum hydrocarbons (PHs) pollutants in soil. The mathematical model of the solute migration and plant–microbial remediation for PH polluted soil was established. The model was verified by field experimental data. Then, the software Hydrus-1D was employed to simulate the processes of diffusion, adsorption, desorption, microbial degradation, and plant adsorption of PHs in the soil–water system. The process of plant–microbial remediation for PH-contaminated soil was also simulated. The space-time change of PHs in soil was obtained, and the fate and remediation efficiency of PHs in soil were revealed in different remediation conditions. The results indicated that the Hydrus-1D model can adequately simulate the process of plant–microbial remediation. Plant–microbial remediation appears to be more efficient than the application of bacteria or Suaeda salsa. The majority of PH pollutants are degraded in the upper soil levels. For long-chain petro-alkane-contaminated soil, plant–microbial remediation is a more efficient method. A suitable moisture level in soil is important for improving the bioremediation effect of plant–microbial remediation technology.  相似文献   

5.
Novel roles for genetically modified plants in environmental protection   总被引:2,自引:0,他引:2  
Transgenic plants of environmental benefit typically consist of plants that either reduce the input of agrochemicals into the environment or make the biological remediation of contaminated areas more efficient. Examples include the construction of species that result in reduced pesticide use and of species that contain genes for either the degradation of organics or the increased accumulation of inorganics. Cutting-edge approaches, illustrated by our own work, focus on the applicability of genetically modified (GM) plants that produce insect pheromones or that are specifically tailored to the phytoremediation of cadmium or PCBs. This paper discusses the role that the next generation of GM plants might play in preventing and reducing chemical contamination and in converting contaminated sites into safe agricultural or recreational land.  相似文献   

6.
Despite many studies on phytoremediation of soils contaminated with either heavy metals or organics, little information is available on the effectiveness of phytoremediation of co-occurring metal and organic pollutants especially by using wetland species. Phragmites australis is a common wetland plant and its potential for phytoremediation of cadmium pentachlorophenol (Cd-PCP) co-contaminated soil was investigated. A greenhouse study was executed to elucidate the effects of Cd (0, 10, and 20 mg kg?1) without or with PCP (0, 50, and 250 mg kg?1) on the growth of the wetland plant P. australis and its uptake, accumulation and removal of pollutant from soils. After 75 days, plant biomass was significantly influenced by interaction of Cd and PCP and the effect of Cd on plant growth being stronger than that of PCP. Coexistence of PCP at low level lessened Cd toxicity to plants, resulting in improved plant growth and increased Cd accumulation in plant tissues. The dissipation of PCP in soils was significantly influenced by interactions of Cd, PCP and plant presence or absence. As an evaluation of soil biological activities after remediation soil enzyme was measured.  相似文献   

7.
江苏长江岸线生态修复评价指标体系研究   总被引:4,自引:1,他引:3  
廖迎娣  张欢  侯利军  陈达 《生态学报》2021,41(10):3910-3916
通过分析江苏长江岸线生态修复的现状及存在的问题,明确了构建生态修复评价指标体系的必要性。基于江苏长江岸线生态修复的实际情况,借鉴前人相关研究成果及湿地、水生态等领域有关生态评价的规范,提出植物覆盖度、水土保持度、原生植物恢复度、植物物种多样性、护岸型式多样性和岸线曲折度6项关键指标,以及各项指标的定量化确定方法。在此基础上,构建了以前4项为主要指标,其它为附加指标的评价体系,明确了赋分等级和对应分值。分析研究结果表明,6项指标全面系统考虑了长江岸线生态修复对植物生长状态、动物生存条件和岸坡稳定等方面要求;修复评价指标体系通过主要指标和附加指标相结合的方式,既实现了对生态修复效果的定量化评价,又体现了对生态修复工程设计理念的引导,为长江岸线生态修复的有序推进奠定了基础。  相似文献   

8.
9.
植物根系分泌物对土壤污染修复的作用及影响机理   总被引:4,自引:0,他引:4  
王亚  冯发运  葛静  李勇  余向阳 《生态学报》2022,42(3):829-842
生物修复是一种经济环保的土壤修复技术。根系分泌物是利用生物修复污染土壤过程中的关键物质,也是植物与土壤微生物进行物质交换和信息传递的重要载体,在植物响应污染物胁迫中扮演重要角色。研究植物根系分泌物对土壤污染修复的作用和影响机理,是深入理解植物和微生物环境适应机制的重要途径,对促进生物修复污染土壤有重要指导意义。从污染物胁迫对根系分泌物的影响、根系分泌物对土壤污染物环境行为的影响、根系分泌物在调控污染土壤中根际微生物群落结构和多样性中发挥的作用等几个方面综述了根系分泌物对土壤污染修复的影响及内在机制。研究结果表明,根系分泌物在降低重金属对植物的毒性、加速有机污染物降解等方面有非常重要的作用。根系分泌物对土壤微生物的丰度和多样性均有显著影响,其与根际微生物互作在土壤污染物的消减中发挥了重要的调控作用。在此基础上,提出了以往研究中的不足,并对污染物胁迫下根系分泌物未来研究的方向和趋势进行了展望。  相似文献   

10.
The remediation of solvent contaminated low permeable soils poses a significant problem for many facilities. A consortium of industrial partners (Monsanto, DuPont and General Electric), the USEPA and the DOE jointly developed a technology that integrates electrokinetics with in-situ treatment of chlorinated organics to address this problem. The process, called LasagnaTM, utilizes a DC electric field to move pore water and contaminants uniformly through the soil mass to treatment zones emplaced within the contaminated area. The emplacement is performed using common piling technologies and results in little or no wastes. The treatment materials emplaced are typically iron, coke and kaolin. After two in-field demonstrations, a full-scale Lasagna remediation system was implemented at the DOE facility in Paducah, KY for the remediation of TCE contaminated clay soils. The system was installed and operated over a two-year period. The process was shut down in December 2001 after meeting the cleanup target of 5.6 mg/kg specified by the Record of Decision (ROD) for the site. The final results show an average TCE concentration of 0.38 mg/kg.  相似文献   

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