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1、农业环境科学学报2011,30(4):677-683JournalofAgro-EnvironmentScience红薯对Pb、Cd的吸收累积特征及根际土壤Pb、Cd形态分布研究*寇士伟,吴锦标,谢素,蔡素英,亦如瀚(暨南大学环境工程系;广东省高校水土环境毒害性污染物防治与生物修复重点实验室,广州510632)摘要:为了解土壤在Pb、Cd单一以及复合污染条件下红薯对Pb、Cd的吸收和积累规律,通过盆栽试验对红薯地上部和地下部的生物量和重金属含量进行测定,分析了单一及复合污染土壤中重金属Pb、Cd形态分布特点。结果表明,相对于对照,较低浓度的Pb、Cd能显著促进红薯
2、的生长(P<0.05),Pb超过50mg·kg-1、Cd超过3mg·kg-1时,红薯生长受到显著抑制(P<0.05),Cd是影响红薯生长的主要因素;随着试验处理浓度的升高,红薯体内重金属含量也随之升高,二者之间存在极显著的相关性(P<0.01),Pb、Cd共存对红薯吸收累积Pb、Cd具有明显的交互作用,Pb促进Cd向地上部转移,Cd促进Pb在地下部积累。根际土壤中Pb、Cd以可交换态与碳酸盐结合态为主,二者均占总量的55%以上,在复合污染条件下,Pb浓度为50mg·kg-1时其活性系数显著高于其他Pb处理(P<0.05),并在很大程度上促进有效态Cd含量的增加。关
3、键词:红薯;生物量;吸收累积特点;重金属形态分布中图分类号:X503.231文献标志码:A文章编号:1672-2043(2011)04-0677-07AbsorptionandAccumulationofPbandCdinSweetPotatoandSpeciesDistributionofPbandCdinRhizo-sphereSoilKOUShi-wei,WUJin-biao,XIESu,CAISu-ying,YIRu-han*(DepartmentofEnvironmentalEngineering,JinanUniversity,KeyLaborator
4、yofWater/SoilToxicPollutantsControlandBioremediation,De-partmentofEducationofGuangdongProvince,Guangzhou510632,China)Abstract:Inpresentstudy,effectsofsingleandcombinedpollutantsPb,CdandCd-Pbonthegrowth,accumulatingpotentialitiesandPb,Cdformdistributioninsweetpotato-rizospheresoilsyste
5、mwerestudiedwitha60-daypotexperiment.Astheresultsofsinglepollutantstreatments,thesuitableconcentrationsofCd(1mg·L-1),Pb(10mg·L-1)werefoundtoimprove,andthethresholdconcentrationsofCd(>3mg·L-1),Pb(>50mg·L-1)werefoundtoinhibitthegrowthofsweetpotato(P<0.05).Themajoraffectingfactorforsweet
6、potatoaccumulationwasconcentrationofCd,andtherewasverypositivesignificantcorrelationbetweenthem(P<0.01).IntreatmentsofcombinedpollutantsCd-Pb,therewasmarkedinteractionsbetweenconcentrationsofCd-Pbandsweetpotatoaccumulation,namelyPbstimulatedCdtotransferfromsweetpotatoroottoitstop,whil
7、eCdstimulatedPbtoaccumulateinsweetpotatoroot.TheavailableCdandPbcontentsaccountedformorethan55%ofthetotalPb,Cd,andtheactivityindexofPbintheconcentrationof50mg·kg-1wassignificantly(P<0.05)higherthanthatintheotherconcentrationsofPbundercombinedpollutantsCd-Pb,moreoveritmarkedlyimprovedt
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