矿区土壤重金属植物修复技术研究进展(英文)_

Research Progress of Phytoremediation

Technology on Soils Polluted by Heavy Metals in Mining Areas

Ying WANG,Zhun XIANG,Hongzao HE,Chunguang REN,Chao SUN *

Institute of Biology,Guizhou Science Academy,Guiyang 550009,China

*Corresponding author.E -mail:chao_sun2000@ Received:September 25,2012Accepted:October 8,2012

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Agricultural Science &Technology,2012,13(10):2133-2136

Copyright 訫2012,Information Institute of HAAS.All rights reserved

Soil and Fertilizer

Abstract Phytoremediation is an efficient and economic ecological technology.It in -cludes phytostabilization,phytovolatilization,and plant absorption.In the research,status quo and progress of Phytostabilization and plant absorption in soils polluted with heavy metals in metal mines were summarized,including the characteristics and status quo of phytoremediation and selection method of hyperaccumulator.In addition,further research was proposed as well.

Key words Heavy metals;Polluted soils;Phytoremediation;Hyperaccumulator

R

ecently,soil pollution with heavy metals is increasingly serious in mining areas and

neighboring regions,threatening eco -environment,food security and peo -ples ’health.It is urgent to develop economic and high efficient soil restoration technology for environment improvement,which is a research hots -pot in environmental sciences,geological sciences and agricultural sciences [1-6].Heavy metals in soils in -clude Chromium (Cr),Lead (Pb),Mer -cury (Hg),Znic (Zn),Stannum (Sn),Cadmium (Cd)and Arsenic (As).Some of the heavy metals would have a direct effect on environment,such as Cd,Pb,Hg and As and some,as necessary microelements,would pol -lute environment if the contents ex -ceed a certain value,such as Zn and Cu.Presently,Cd,Pb,As,Pb and Hg are most studied [7].

The restoration methods of soils contaminated by heavy metals are physical method,chemical method and biological method,among which the first two,expensive and complicat -ed,usually destroy soil structure or biodiversity and are not suitable for soils polluted in large area [8-10].Biore -mediation technique,especially for

phytoremediation,enjoys many ad -vantages,such as safeness and low cost,eco -balance and environment -friendliness.However,some condi -tions should be satisfied,as follows:Plants tolerant to heavy metals or hy -peraccumulator should be selected;the theories and operation technolo -gies for optimal restoration effect should be obtained [11-12].Phytoremedi -ation on soils polluted by heavy metals can be observed from phytostabiliza -tion,phytovolatilization and plant ab -sorption.The researches available concentrate on the plants which would remove heavy metals efficiently (hy -peraccumulator)and plants which would prevent heavy metals being ab -sorbed (hyper -tolerant plants).

Characteristics of Phytore -mediation

Exploitation of metal mine is characterized with pollution by heavy metals.Hence,pollution reduction of heavy metal should be considered in treatment of soil erosion in mining ar -eas.Although the methods of heavy metal treatments are multiple,at home and abroad,phytoremediation proves optimal,which is economic,high -effi -

cient and safe.It has been an emerg -ing technology in restoration of soils polluted by heavy metals.

Phytoremediation refers to the natural ability of certain plants called hyperaccumulators to bioaccumulate,degrade,or render heavy metals in soils and can be classified into phy -toextraction,phytovolatilization,rizofil -tration,and phytostabilization.The first three are usually called removing pro -cess and the last one is called stabi -lization period.Phytoextraction is quite popular in research field.For restora -tion of heavy metals in metal mines,the plants with ability of hyper -collec -tion are mainly made use of.There -fore,soil erosion would be reduced and heavy metals in soils would be transferred into plants which would be processed together to be raw materi -als of industry production.

Status quo of Phytoreme -diation Research

Hyper -tolerant plants can make use of root absorption and collection a -bility to fix heavy metals in plant roots and rhizosphere soils,further reducing transferring ability of heavy metals in soils.Hence,bioavailability and bio -toxicity of heavy metals would drop ac -cordingly [13-14].With this kind of plants,vegetation coverage in mining area can be enhanced and erosion condi -tions would be improved.It is of practi -cal significance for ecological restora -tion and soil pollution restoration to grow the plants in metal mines.

Agrostis tenuis and Festuca rubra ,discovered by Smith and Brad -shaw [15],have been applied in heavy metal stabilization,such as Pb,Zn and