城市污泥重金属形态及其生物有效性的研究的英文文献的翻译Word格式.docx

城市污泥重金属形态及其生物有效性的研究的英文文献的翻译Word格式.docx

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LIShu􀀁

geng1,2,ZHANGKe􀀁

fang3,ZHOUShao􀀁

qi1,CHENQiu􀀁

li3,ZHANGLi􀀁

qiu3

（1.SchoolofEnvironmentalScienceandEngineering,SCUT,Guangzhou􀀂

510006,China;

2.SchoolofEnvi􀀁

ronmentalScienceandEngineering,GuangzhouUniversity,Guangzhou􀀂

3.SchoolofCivil

Engineering,GuangzhouUniversity,Guangzhou􀀂

510006,China）

Abstract:

Thetotalcontentsandchemicalfractionsofheavymetals（Zn,Cu,Cd,Cr,Pb

andNi）insewagesludgewereanalyzedinthepresentstudywithTessier!

sprocedure.The

bioavailabilityoftheseheavymetalswasalsostudiedbypottingplantingofDockleafKnot􀀁

weed.TheresultsshowedthatthetotalcontentsofZn,Cu,Cd,Cr,PbandNiwereallless

thantheChinesesewagesludgecriteriaforagriculturaluse（soilpH∀6.5）.AsforZn,Cd,

CrandPb,residualfractionwasthepredominantfraction,whileforCuandNi,organicfrac􀀁

tionwasthepredominantfraction.TheproportionsofunbioavailableformsofZn,Cd,Cr

andPbweremorethan50%,whichwasfavorableforusingsludgeinagriculture.Theroots

ofDockleafKnotweedcouldaccumulatemoreheavymetalsthanshoots.Theheavymetals

absorbedbypottedplantincludednotonlyexchangeableandcarbonateforms,butalsoiron􀀁

manganeseoxidesandorganicformswhichwerereleasedundercertainconditions.

Keywords:

sewagesludge;

heavymetals;

chemicalfraction;

bioavailability;

DockleafKnot􀀁

weed

CLCNumber:

X705􀀂

DocumentCode:

A

0􀀂

Introduction

Sludgeisoneoftheprincipalbyproductsofwastewatertreatmentplants（WWTP）.Therearesev􀀁

eralwaystohandlethesludge,suchasincineration,landfillinganduseasfertilizerforenergycropsor

inagriculturalfoodproduction.Theuseofsewagesludgeincropproductionisideallyfavorableinasus􀀁

tainablesociety,asthiswouldrecycleasubstantialcontentofnutrientsandorganicmatter[1].Howev􀀁

er,itsuseforfoodproductionishighlyquestionedduetohealthconcerns.Theoftenhighmetalcon􀀁

tentsinsludgewereformerlyseenasprimarilyaproblemofaccumulationinsoilwhenusedforagricul􀀁

turalpurposes.Manystudiesshowedthatthetoxicityofheavymetalswasnotonlyrelatingtothetotal

contentsbutalsodependentonthechemicalfractionofheavymetals.Theenvironmentalbehaviorsand

bio􀀁

toxicityofheavymetalsvaryindifferentchemicalfractionsofheavymetals.

Bioavailabilityofheavymetalsreferstothedegreetowhichthesemetalsareadsorbedoraccumula􀀁

tedinorganisms.Totalmetalconcentrationisnotaveryusefulpredictorofbioavailabilityorsoluble

concentrationofthemetal[2,3].Asfaraselementwhichcouldbeadsorbedbyplantinsoilisconcerned,

*收稿日期:

2008-03-17

作者简介:

李淑更（1978-）,女,河北省广宗县人,讲师,在读博士生,研究方向:

环境生物技术

基金项目:

广东省科技计划项目（2005B3303008）,建设部科技计划项目（2004（149））

陕西科技大学学报第26卷

thecommonmethodforjudgingthebioavailabilityofitistodocorrelationalanalysisbetweenelement

contentinsoilandinplant.Ourobjectiveinthepresentstudywasto:

（1）determinethechemicalfrac􀀁

tiondistributionofheavymetals（Zn,Cu,Cd,Cr,PbandNi）insewagesludge;

（2）findtherelation􀀁

shipsbetweenthemetalsconcentrationsinthesludgeandmetalcontentinatestplant,DockleafKnot􀀁

weed;

（3）evaluatethebioavailabilityofthesludge.

1􀀂

MaterialsandMethods

1.1􀀂

Characteristicsofthesludge

ThesludgeusedintheexperimentswasobtainedfromtheDatanshawastewatertreatmentplantof

Guangzhoucity（Guangdongprovince,China）inSeptember2006.Thesludgewasair􀀁

driedtoconstant

weightpriortosievingthrougha2mmsievebeforeuse.Thephysicalandchemicalpropertiesofthe

sludgearepresentedinTab.1.

1.2􀀂

Plantgrowthexperiments

Tab.1􀀂

Physicalandchemicalpropertiesofsewagesludge

watercontent/%pHorganicmatter/%totalnitrogen/%totalphosphorus/%

76.00#1.985.8#0.2440.57#1.741.66#0.051.71#0.08

􀀂

Notes:

Allvaluesareexpressedinmean#standarddeviationofthreereplicates.

Theplantsweregrown

inpotslocatedinrooms

withsufficientsunlight.

Theplasticspotswerecho􀀁

sen,ofwhichdiametersandheightswere11cmand12cm,respectively.Onekgsludgewasputinto

eachpotforplanting,withfivereplications.

TheDockleafKnotweedusedintheexperimentwasthesamekindastheonegrowninthecampus

landscapingareas.Weselectedtheyoungplantsastheexperimentalplantsandgrewoneplantineach

pot.Thepotswerewateredtofieldcapacityat4pmeveryday.Wegrewtheplantfor60days,approxi􀀁

mately2months（betweenSeptemberandNovember,2006）,undernormaltemperature.Duringthis

period,noadditionalsludgeorsoilwasapplied,noranypesticides.

Atharvesting,plantswereremovedcarefullywithnorootsdamaged.Wewashedtheleavesand

rootswithdeionizedwatertoremoveanyattachedparticles,andthendriedthemat80∃toconstant

weighting.Driedplantssampleswerecrumbledpriortosievingthrougha1mmsievebeforedigestion.

1.3􀀂

Sampleanalysis

Ouranalysisofthesludgesamplesfollowedthechemicalanalyticalmethodsforsoil[4].Sludgesam􀀁

plesweredigestedwithaquaregiaandHClO4first,andthenthetotalheavymetal（Zn,Cu,Cd,Cr,Pb

andNi）contentwasmeasuredwithanatomicabsorptionspectrophotometer（SHIMADZU,AA6800,

Japan）.

Tab.2􀀂

DetailsofTessier!

ssequentialfractionationprocedure（0.5gsludge）

fraction􀀂

solutionequilibriumconditions

exchangeable8mL1MMgCl2（pH7.0）1h,roomtemperature

carbonates8mL1MNaOAc（pH5.0）6h,roomtemperature

feandMnoxides8mL0.04MNH2OH/HClin25%（v/v）HOAc6h,96∃

organicmatter3mL0.02MHNO3+5mL30%H2O2（pH2.0）4h,85∃

2mL3.2MNH4OAcin20%（v/v）HNO330min,roomtemperature

residualHNO3digestion

DriedplantsamplesweredigestedinHNO3andHClO4withelectrothermalplate（Guangming,ML􀀁

3􀀁

4,China）andheavymetal（Zn,Cu,Cd,Cr,PbandNi）contentsweredeterminedwithanatomicab􀀁

sorptionspectrophotometer（SHIMADZU,AA6800,Japan）.

Thechemicalfractionsofheavymetals（Zn,Cu,Cd,Cr,PbandNi）insewagesludgewereana􀀁

126

第3期李淑更等:

城市污泥重金属形态及其生物有效性的研究

lyzedwithTessier!

sprocedure[5].DetailsofthisprocedurearepresentedinTab.2.

Sampleanalysiswascarriedoutintriplicateandtheresultwasshownwithmeanofthreevalues.

2􀀂

ResultsandDiscussion

2.1􀀂

Chemicalfractionsofheavymetalsinsludge

Thechemicalfractionsofheavymetalsinsludgeweremeasuredandtheresultsarepresentedin

Tab.3.Therecovery（in%）wascalculatedastheratiobetweenthesumcontentofallthefractionsand

thetotalcontent.

Tab.3􀀂

thecontentsofCu、Zn、Pb、Cd、Cr、Niindifferentfractions

ZnCuCdCrPbNi

exchangeablenda23.63#3.760.8#0.30nda25.5#1.536.89#3.47

carbonates75.42#4.5410.95#0.760.14#0.09nda2.71#0.123.75#1.29

feandMnoxides98.58#9.317.75#0.410.25#0.13nda0.15#0.075.38#0.24

organicmatter144.12#2.44152.32#5.980.15#0.0233.51#3.721.17#0.6647.38#0.63

residual371.1#4.6785.38#4.951.86#0.1251.92#6.78109.59#1.5914.78#0.63

sumup689.22280.033.2085.43139.1278.18

totalcontents723.62#8.42289.43#4.953.48#0.30105.54#0.84145.75#0.3486.92#6.16

recovery/%95.2596.7591.9580.9595.4689.94

Chinesequalitystandards1000b500b20b1000b1000b200b

Allmetalconcentrationsareexpressedinmg/kg#standarddeviationofthreereplicates;

and=notdetected;

b

Chinesesewagesludgecriteriaforagriculturaluse（GB4282􀀁

84）,SoilpH∀6.5.

AsseeninTab.3,thetotalcontentofZnwasthehighest（723.62mg/kg）amongthesesixmetals.

TheCucontentwasthenexthighestcontent,whichwas289.43mg/kg.ThecontentofCdwasthe

lowestone.AccordingtotheChinesesewagesludgecriteriaforagriculturaluse,allthesemetalconcen􀀁

trationswerelessthanthecriterion（soilpH∀6.5）.Sothiskindofsludgecouldbeusedincropproduc􀀁

tionfromtheviewpointoftotalcontentsofheavymetals.

Thedeterminationoftotalheavymetalcontentofsludgewasnotsufficienttoevaluatethepossible

mobilityandconsequently,thebioavailabilityoftoxicmetalstolivingorganisms[6].Theenvironmental

effectsofheavymetalsvaryindifferentchemicalfractions:

Exchangeablemetalswereeasytotransport

andtransformandcouldbeabsorbedbyplants;

CarbonateboundmetalsweresusceptibletopH,itcould

beremobilizedandreleasedintheacidicenvironmentintherhizosphereandbetakenupbycrops[7,8],

andtherefore,couldharmhumanhealththroughthesoil􀀁

plant􀀁

humanbodychain;

Fe􀀁

Mnoxidesbound

metalswerenoteasytoreleaseundernormalconditionsfortherelativelystrongionicbon