鎘污染菜田土壤原位修復(fù)效果及土壤質(zhì)量變化研究

鎘污染菜田土壤原位修復(fù)效果及土壤質(zhì)量變化研究摘要：隨著工業(yè)化和城市化的進(jìn)程加快，土壤污染已成為影響人類健康和生態(tài)環(huán)境的重要問題。鎘作為一種重要的重金屬元素，在土壤中的污染已受到廣泛的關(guān)注。本研究選擇某菜田為研究對(duì)象，采用原位修復(fù)技術(shù)對(duì)鎘污染的土壤進(jìn)行修復(fù)，并對(duì)不同修復(fù)方案的修復(fù)效果及對(duì)土壤質(zhì)量的影響進(jìn)行研究。研究結(jié)果表明，通過添加大豆秸稈和棉桿的自然修復(fù)和添加殼聚糖、氫氧化鐵等人工修復(fù)均可降低土壤中鎘含量，但添加殼聚糖和氫氧化鐵效果更為明顯。土壤理化性質(zhì)方面，添加大豆秸稈和棉桿的自然修復(fù)可顯著提高土壤有機(jī)質(zhì)含量和水分持有能力，而添加殼聚糖、氫氧化鐵等人工修復(fù)則可以提高土壤pH值和交換性陽離子含量，但長(zhǎng)期施用可能對(duì)土壤微生物群落造成不良影響。因此，在實(shí)際應(yīng)用中，應(yīng)結(jié)合土壤污染程度和土壤性質(zhì)等因素進(jìn)行修復(fù)方案的選擇與優(yōu)化。

關(guān)鍵詞：鎘污染；菜田土壤；原位修復(fù)；土壤質(zhì)量；人工修復(fù)；自然修復(fù)

Abstract:Withtheaccelerationofindustrializationandurbanization,soilpollutionhasbecomeanimportantissuethataffectshumanhealthandecologicalenvironment.Cadmium,asanimportantheavymetalelement,hasreceivedwidespreadattentioninsoilpollution.Inthisstudy,avegetablefieldwasselectedastheresearchobject,andinsituremediationtechnologywasusedtoremediatecadmium-pollutedsoil.Theremediationeffectsofdifferentremediationschemesandtheirimpactonsoilqualitywerestudied.Theresultsshowedthatthenaturalremediationbyaddingsoybeanstrawandcottonstalksandtheartificialremediationbyaddingchitosanandironhydroxidecouldreducethecadmiumcontentinsoil,buttheeffectofaddingchitosanandironhydroxidewasmoresignificant.Intermsofsoilphysicalandchemicalproperties,naturalremediationbyaddingsoybeanstrawandcottonstalkscouldsignificantlyimprovesoilorganicmattercontentandwaterholdingcapacity,whileartificialremediationbyaddingchitosanandironhydroxidecouldimprovesoilpHandexchangeablecationcontent.However,long-termapplicationmayhaveadverseeffectsonsoilmicrobialcommunity.Therefore,inpracticalapplications,remediationschemesshouldbeselectedandoptimizedbasedonfactorssuchasthedegreeofsoilpollutionandsoilproperties.

Keywords:cadmiumpollution;vegetablefieldsoil;insituremediation;soilquality;artificialremediation;naturalremediationInsituremediationcanbeapromisingapproachtorestorethesoilqualityofvegetablefieldsaffectedbycadmiumpollution.Theuseofnaturalremediationtechniquessuchasphytoremediation,coupledwiththeapplicationoforganicamendmentslikecompost,canhelpreducecadmiumlevelsinsoileffectively,whilealsoimprovingsoilfertilityandplantgrowth.Ontheotherhand,artificialremediationmethodsusingchitosanandironhydroxidecanprovideimmediateimprovementsinsoilpHandcationexchangecapacity,buttheirlong-termeffectsonsoilmicrobiotashouldbetakenintoconsideration.

Itisimportanttonotethatthesuccessofremediationschemesdependsonseveralfactorssuchastheinitialdegreeofsoilpollution,soilproperties,andthetypeandamountofamendmentsapplied.Anintegratedapproachincorporatingdifferentremediationtechniques,alongwithpropersoilmanagementpracticeslikecroprotationandproperirrigation,canprovidelong-termsolutionstorestorethehealthandproductivityofvegetablefieldsaffectedbycadmiumpollution.

Inconclusion,theremediationofvegetablefieldsaffectedbycadmiumpollutionisacomplexissuethatrequiresaholisticapproachtotackle.Theuseofbothnaturalandartificialremediationtechniquesshouldbeconsideredbasedonsoilpropertiesanddegreeofpollution,whilealsotakingintoaccounttheirpotentialimpactsonthesoilecosystem.Througheffectiveremediationstrategies,wecanensurethesustainabilityofvegetableproduction,whilealsosafeguardingthehealthandwell-beingofconsumersTobeginwith,oneofthenaturalremediationtechniquesthatcanbeemployedtomitigatecadmiumpollutioninvegetablefieldsisphytoremediation.Thisistheuseofplantstoabsorb,accumulate,anddegradecontaminantspresentinsoil.Thereareseveralplantspeciesthathavebeenknowntoeffectivelyremovecadmiumfrompollutedsoils.Forinstance,sunflowers,Indianmustard,andalpinepennycressareknowntoaccumulatehighconcentrationsofcadmiumintheirtissues.Byplantingthesespeciesincontaminatedvegetablefields,thecadmiumlevelsinthesoilcanbereducedovertime.

Anothernaturalapproachthatcanbeusedistheuseofcomposting.Thisinvolvesthedecompositionoforganicwastesuchascropresidues,animalmanure,andfoodwasteintoanutrient-richsoilamendment.Compostenhancessoilhealth,increasingtheabilityofplantstoabsorbnutrientsfromthesoilbyreducingtheoccurrenceofheavymetalsthroughadsorptionandchelation.Compostingcanalsoreducesoilacidity,whichcanimprovetheavailabilityofnutrientssuchascalciumtotheplants.

Ontheotherhand,artificialremediationtechniquesinvolvetheuseofchemicalagentstoremoveorreducetheconcentrationofcontaminantsinsoil.Oneofthecommonlyusedtechniquesissoilwashing,whichinvolvesaddingwaterandotherchemicalagentstothesoiltosolubilizethecontaminants,afterwhichthewaterisdrainedout,andthecontaminatedwasteistakenfortreatmentordisposal.Thismethodissuitableforsoilswithlowtomoderatecadmiumpollutionlevels.

Anotherartificialremediationtechniqueistheuseofchelatingagents.Theseareorganiccompoundsthatcanbindtoheavymetals,formingcomplexesthataremoreeasilyremovedfromthesoil.Ethylenediaminetetraaceticacid(EDTA)isoneofthecommonlyusedchelatingagents,whichhasbeenshowntoeffectivelyremovecadmiumfromthesoil,althoughitsuseisassociatedwithsomedrawbacks,suchasthepotentialtocausesoilacidification.

Itisworthnotingthateachoftheabovetechniques,naturalorartificial,hasitsstrengthsandweaknesses,andtheirsuitabilitydependsontheuniquecharacteristicsofagivensite.Forexample,compostingislesssuitableforsoilsthathaveaninitialhighcadmiumcontentthatmayhindertheeffectivenessoftheprocess.Soilwashing,ontheotherhand,iseffectivebutcanleadtotheproductionofcontaminatedwastewater,whichrequiresintensivetreatmentbeforedischarge.

Inconclusion,theissueofcadmiumpollutioninvegetablefieldsisamultifacetedproblemthatrequiresanintegratedapproachtoaddress.Employingacombinationofnaturalandartificialremediationstrategies,tailoredtospecificsitecharacteristics,caneffectivelyminimizetherisktohumanhealthandtheenvironmentwhilepromotingsustainablevegetableproduction.Therefore,itisessentialtoadoptaholisticapproachtoensurethatanyremediationactivitiesundertakenminimizeanyunintendednegativeimpactsonthesoilecosystemInadditiontonaturalandartificialremediationstrategies,thereareotherapproachesthatcanbeintegratedtoaddresscontaminatedsoilinfields.Onesuchapproachisphytoremediation,whichinvolvesusingplantstoremovecontaminantsfromthesoil.Certainplantshavetheabilitytoabsorb,transformordegradecontaminantssuchasheavymetals,organicpollutants,andradioactiveelements.

Phytoremediationcanbeusedincombinationwithothernaturalandartificialremediationstrategiestoachieveoptimalresults.Forexample,amendingthesoilwithorganicmatterandfertilizerscanenhanceplantgrowthandstimulatethemicrobialactivitythatbreaksdowncontaminants.Plantingnativeplantspeciesandutilizingcroprotationandcovercroppingcanalsohelptomaintainsoilhealthandpreventfurthercontamination.Inaddition,geneticengineeringcanbeusedtoenhancetheefficacyofphytoremediationbyintroducinggenesthatimproveplantcontaminantuptakeanddegradation.

Anotherapproachthatcanbeusedinconjunctionwithnaturalandartificialremediationstrategiesissoilwashing,whichinvolvesphysicalremovalofcontaminantsfromsoil.Thistechniqueisparticularlyeffectiveforremovingcontaminantsthatarenoteasilydegradedbybiologicalorchemicalmeans.Soilwashinginvolveswashingthecontaminatedsoilwithwaterorchemicalstodissolvethecontaminants,whicharethenseparatedfromthesoilthroughvarioustechniques.Thecleansoilisthenreturnedtothefield,whilethecontaminatedwaterorchemicalsaretreatedfurtherordi