重金属植物修复

1、Phytoremediation of heavy metals Concepts and applications 重金属的植物修复重金属的植物修复概念和应用概念和应用2Content主要内容主要内容1 1Background 背景背景Brief understanding of phytoremediation 植物修复的简单理解植物修复的简单理解2 23 3 Conclusions 结论结论1. Background 背景背景1.1 Introduction（引言）（引言）Environmental pollution by heavy metals has become a serio

2、us problem in the world. 世界上由重金属引起的环境污染已经成为一个严重的问题。世界上由重金属引起的环境污染已经成为一个严重的问题。concentrations beyond threshold limit浓度超过了阈值浓度超过了阈值have adverse health effects对人体健康产生副作用对人体健康产生副作用extraction from ores and subsequent processing release pollution accumulate（bioaccumulation，biomagnification） risk 矿石中提取，矿石中提

3、取，之后使用过程中释放之后使用过程中释放 污染污染 积累（生物富集，生物放大）积累（生物富集，生物放大） 危险危险interfere with the normal functioning干扰正常代谢干扰正常代谢Essential (Fe, Mn, Cu, Zn, and Ni)Non-essential (Cd, Pb, As, Hg, and Cr)role in biological system 在生物系统中的作用在生物系统中的作用whether needed by physiological and biochemical functions生理生化功能生理生化功能是否需要是否需要

4、YN5 sourcenatural sources: weathering of minerals, erosion and volcanic activityAnthropogenic sources:mining, smelting, electroplating, pesticides , (phosphate) fertilizers , biosolids in agriculture, sludge dumping, industrial discharge, atmospheric deposition cause oxidative stress, enhanced ROS（r

5、eactive oxygen species）overwhelm cells antioxidant defenseslead to cell damage and deathReplace essential metals in pigments or enzymes disrupting their functionMost problematic: Hg Cd Pb As Cu Zn Sn CrHarmful effects1.2 Sources, Harmful effects, Clean up of heavy metals自然来源：自然来源：矿石风化，腐蚀和火山活动矿石风化，腐蚀

6、和火山活动人为来源：人为来源：采矿，冶炼，电镀，农药，（磷）化肥，采矿，冶炼，电镀，农药，（磷）化肥，农业，污泥倾倒，工业排放，大气沉降中农业，污泥倾倒，工业排放，大气沉降中的生物固体的生物固体引起引起氧化应激氧化应激，使，使ROSROS（活性氧）增加（活性氧）增加压倒细胞的抗氧化防御系统压倒细胞的抗氧化防御系统导致细胞损伤和死亡导致细胞损伤和死亡取代取代色素或酶中的必需的金属，干扰它们色素或酶中的必需的金属，干扰它们的代谢功能的代谢功能最有问题的：最有问题的： Hg Cd Pb As Cu Zn Sn Cr6methodConventional methodssuffer from limi

7、tations like high cost, intensive labor, irreversible changes in soil properties and disturbance of native soil microfloraChemical methods can also create secondary pollution problems1.2 Clean upin situ vitrification, soil incineration, excavation and landfill, soil washing, soil flushing, solidific

8、ation, and stabilization (Sheoran et al., 2011; Wuana and Okieimen, 2011)原位玻璃化，土壤焚烧，挖掘和填埋，淋洗，冲洗，固化稳定化原位玻璃化，土壤焚烧，挖掘和填埋，淋洗，冲洗，固化稳定化physical, chemical and biological approaches物理，化学和生物方法物理，化学和生物方法Phytoremediation 植物修复植物修复 cost effective, efficient environment friendlyA green solution？72. Brief understa

9、nding of phytoremediation 植物修复的简单理解植物修复的简单理解 2.1 Concept and Techniques/strategies of phytoremediation 植物修复的定义和技术植物修复的定义和技术 Phytoremediation basically refers to the use of plants and associated soil microbes to reduce the concentrations or toxic effects of contaminants in the environments (Greipsson

10、, 2011） 植物修复是指利用植物和相关的微生物减少环境中污染物的浓度或毒性植物修复是指利用植物和相关的微生物减少环境中污染物的浓度或毒性 The purpose of phytoremediation can be threefold:risk containment (phytostabilization);(2) phytoextraction of metals with market value such as Ni, Tl and Au;(3) durable land management where phytoextraction gradually improves soi

11、l quality for subsequent cultivation of crops with higher market value (Vangronsveld et al., 2009)植物修复的目的分为三部分：植物修复的目的分为三部分：遏制风险（植物稳定）遏制风险（植物稳定）提取具有市场价值的金属，比如镍提取具有市场价值的金属，比如镍Ni，铊，铊Tl，金，金Au持久的土地管理，植物提取提高土质，用于之后的作物种植持久的土地管理，植物提取提高土质，用于之后的作物种植9 techniquesTechniques of phytoremediation include phytoextr

12、action /phytoaccumulation, phytofiltration, phytostabilization, phytovolatilization, and phytodegradation (Alkorta et al., 2004)植物提取植物提取/植物富集，植物过滤，植物固定，植物挥发，植物降解植物富集，植物过滤，植物固定，植物挥发，植物降解2022-5-7 Phytoextraction-植物提取植物提取 also known as phytoaccumulation, phytoabsorption or phytosequestration 又称植物富集，植物吸

13、收或植物隔离又称植物富集，植物吸收或植物隔离 uptake of contaminants from soil or water by plant roots and their translocation to and accumulation in aboveground biomass i.e., shoots (Sekara et al., 2005; Yoon et al., 2006; Rafati et al., 2011). 通过植物根系将从土壤或水中吸收污染物并转移到地上部分积累通过植物根系将从土壤或水中吸收污染物并转移到地上部分积累 techniques Phytofilt

14、ration -植物过滤植物过滤 The removal of pollutants from contaminated surface waters or waste waters by plants (Mukhopadhyay and Maiti, 2010) 通过植物将污染物从地表水或废水中去除通过植物将污染物从地表水或废水中去除 May be rhizofiltration (use of plant roots) or blastofiltration (use of seedlings) or caulofiltration (use of excised plant shoots

15、）用植物的根，幼苗或离体的植物的地上部分用植物的根，幼苗或离体的植物的地上部分the contaminants are absorbed or adsorbed and thus their movement to underground waters is minimized污染物被吸收或吸附，使迁移到地下水的污染物最小化污染物被吸收或吸附，使迁移到地下水的污染物最小化2022-5-7 Phytostabilization-植物稳定化植物稳定化 The use of certain plants for stabilization of contaminants in contaminate

16、d soils (Singh, 2012) 利用某些植物固定受污染的土壤中的污染物利用某些植物固定受污染的土壤中的污染物 Aimreduce the mobility and bioavailability of pollutants in the environment，preventing their migration to groundwater or their entry into the food chain (Erakhrumen, 2007 ) 目的目的减少环境中污染物的移动性和生物可利用性，阻止污染物迁移到地下水减少环境中污染物的移动性和生物可利用性，阻止污染物迁移到地下水

17、 或进入食物链或进入食物链 Methodsorption by roots, precipitation, complexation in rhizosphere 方法方法根系吸收，化学沉淀，络合根系吸收，化学沉淀，络合 Limitationnot a permanent solution，the heavy metals remain in the soil; only their movement is limited 缺陷缺陷不是长久的方法，重金属仍然在土壤中，只是被固定了不是长久的方法，重金属仍然在土壤中，只是被固定了 techniques2022-5-7Phytovolatiliza

18、tion-植物挥发植物挥发 the uptake of pollutants from soil by plants, their conversion to volatile form and subsequent release into the atmosphere 植物从土壤中吸收污染物植物从土壤中吸收污染物, 转换为气态，随即释放到大气中转换为气态，随即释放到大气中 This technique can be used for organic pollutants and some heavy metals like Hg and Se 适用于有机污染物以及汞适用于有机污染物以及汞H

19、g 和和 硒硒Se等重金属等重金属 it does not remove the pollutant completely; only it is transferred from one segment (soil) to another (atmosphere) from where it can be redeposited 并没有完全去除污染物并没有完全去除污染物;只是转移从一个介质只是转移从一个介质(土壤土壤)转移到另一个介质，仍然可转移到另一个介质，仍然可以再沉积以再沉积 the most controversial of phytoremediation technologies

20、(Padmavathiamma and Li, 2007). 最有争议的植物修复技术最有争议的植物修复技术 techniques2022-5-7Phytodegradation-植物降解植物降解 the degradation of organic pollutants by plants with the help of enzymes， such as dehalogenase and oxygenase 在酶的作用下用植物降解有机污染物，比如脱卤素酶和加氧酶在酶的作用下用植物降解有机污染物，比如脱卤素酶和加氧酶 not dependent on rhizospheric microorg

21、anisms (Vishnoi and Srivastava, 2008) 不是依靠根际微生物的作用不是依靠根际微生物的作用 limited to the removal of organic pollutants only because heavy metals are nonbiodegradable 重金属不可生物降解，只能去除有机污染物重金属不可生物降解，只能去除有机污染物 techniques14Rhizodegradation-根际降解根际降解the breakdown of organic pollutants in the soil by microorganisms in

22、the rhizosphere (Mukhopadhyay and Maiti, 2010)通过通过根际根际微生物降解土壤中的有机污染物微生物降解土壤中的有机污染物 techniquesPhytodesalination-植物脱盐化植物脱盐化It is a recently reported and emerging technique (Zorrig et al.,2012)the use of halophytic plants for removal of salts from salt-affected soils in order to enable them for support

23、ing normal plant growth (Manousaki and Kalogerakis, 2011; Sakai et al., 2012)在盐生土壤中种植嗜盐性植物使土壤适合于正常植物生长在盐生土壤中种植嗜盐性植物使土壤适合于正常植物生长 Constructed wetlands are used for clean-up of effluents and drainage waters (Vangronsveld et al., 2009) 用于出水和排水的清理用于出水和排水的清理cost-effective , technically feasible ,effective

24、 and successful (Williams, 2002; Olguin and SanchezGalvan, 2010; Rai, 2012) 经济有效，技术可行，高效成功经济有效，技术可行，高效成功Aquatic macrophytes are more suitable for wastewater treatment than terrestrial plants (Sood et al., 2012)大型水生植物比陆生植物更适用大型水生植物比陆生植物更适用于污水处理于污水处理 faster growth 长得快长得快 production of more biomass 产生更

25、多的生物质产生更多的生物质 relative higher ability of pollutant uptake对污染物吸收能力相对高对污染物吸收能力相对高 direct contact with contaminated water 直接和污染水体接触直接和污染水体接触2.2 Use of constructed wetlands for phytoremediationFloating, emerged and submerged aquatic species 浮水，挺水，沉水水生植物浮水，挺水，沉水水生植物Water hyacinth(水葫芦水葫芦) (Liao and Chang,

26、 2004)、 water lettuce（水浮莲）（水浮莲） (Hua et al., 2012)、 Azolla （满江红）（满江红）(Sood et al., 2012)local, endemic wetland species(Adams et al., in press) 地方性特有物种地方性特有物种Although a promising approach, it also suffers from some limitations (Clemens, 2001; Tong et al., 2004; LeDuc and Terry, 2005; Karami and Shams

27、uddin, 2010; Mukhopadhyay and Maiti, 2010; Naees et al., 2011; Ramamurthy and Memarian, 2012) 尽管是一种好方法，但是也有局限性尽管是一种好方法，但是也有局限性 Long time required for clean-up 清理需要的时间长清理需要的时间长 Phytoremediation efficiency of most metal hyperaccumulators is usually limited by their slow growth rate and low biomass 大多数金属超富集植物的修复效率通常由缓慢生长和低生物质限制大多数金属超富集植物的修复效率通常由缓慢生长和低生物质限制2.3 Limitations of phytoremediation Difficulty in mobilization of more tightly bound fraction of metal ions from soil i.e., l