鄱陽湖濕地土壤重金屬形態(tài)分布特征及吸附%2f解吸機理分析

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1、·摘要鹽結(jié)合態(tài)。采樣點中重金屬Zn形態(tài)變異系數(shù)在0.55-0.68之間，相對于Cu元素變異系數(shù)較小。（4）鄱陽湖濕地土壤綜合污染指數(shù)平均值為0.78，根據(jù)污染評價標(biāo)準(zhǔn)為警戒限。其中蔡家灣污染指數(shù)最高達(dá)到2.81，九江的土壤指數(shù)也達(dá)到了1.97，土壤中重金屬Cu、Zn含量明顯超標(biāo)。（5）通過SPSS軟件分析相關(guān)性得知：濕地土壤中Cu、Zn含量之間呈顯著正相關(guān)，濕地土壤中重金屬元素Cu、Zn含量與土壤有機質(zhì)含量表現(xiàn)出顯著正相關(guān)，與其他理化性質(zhì)無明顯相關(guān)性。采樣點土壤中重金屬Zn的碳酸鹽態(tài)與土壤PH呈極顯著負(fù)相關(guān)性，相關(guān)系數(shù)為-0.693。采樣點土壤中重金屬Zn、Cu殘渣態(tài)與土壤有機質(zhì)層極顯著正

2、相關(guān)性，相關(guān)系數(shù)分別為0.677、0.746。（6）九江、蔡家灣和饒河土壤對重金屬Cu、Zn吸附動力學(xué)實驗表明：三處土壤對重金屬Cu、Zn吸附在20min左右達(dá)到飽和。三點土壤對重金屬Cu等溫吸附都可用Langmuir方程和Freundlich方程來描述，從相關(guān)系數(shù)來看，以Langmuir方程擬合為佳，相關(guān)系數(shù)均大于0.9，達(dá)顯著水平。三點土壤對重金屬Zn等溫吸附都可以用Langmuir方程和Freundlich方程來描述。（7）在初始液重金屬濃度相同情況下，當(dāng)pH由5.5增至6.5時，土壤對銅和鋅的吸附隨著pH上升而增加。溫度的改變對土壤吸附Cu和Zn的特征不規(guī)律。（8）在Cu、Zn共存

3、條件下，土壤對重金屬離子吸附量都小于單一重金屬離子條件下吸附量，兩種重金屬離子之間存在共存競爭吸附，其中Cu的吸附能力大于Zn。關(guān)鍵詞：鄱陽湖；濕地土壤；重金屬；形態(tài)；吸附/解吸II···萬方數(shù)據(jù)···AbstractAbstractWiththegrowthofpopulation,industrializationandurbanizationbecomefaster,theenvironmentalpollutionofPoyangLakeisincreasinglyserious,especiallyinheavymetalpollutionofwetlandsoil.Sother

4、esearchforheavymetalsinsoilhasbecomeahotspot,However,thesamemetalastheyexistindifferentformsinthesoil,itstransportortransformationcharacteristicsandpollutionnaturearedifferent,heavymetaltoxicityisnotonlyrelatedtoitstotalmass,speciesdistributionisdeterminedbyagreaterextent.Inthispaper,thewetlandsoi

5、lofPoyangLakewatershedtheobjectof study,determinateditsamountofCu、Zn,anditscontentofvariousformswas determinedbyusingextractionmethod,anddiscussesitsdistributioncharacteristics, andthestatusofsoilheavymetalpollutioninthePoyangLakewetlandwere evaluatedbyusingintegratedpollutionassessmentmethod.Inor

6、dertounderstandthe migrationandtransformationofvariousformsofheavymetalinthesoil,throughthe correlation,determinatedtherelationshipsbetweenthetotalamountanditsvarious formsofheavymetalandsoilproperties.Bytheadsorptionkineticsexperiments, analysedtheheavymetaladsorptionrateofwetlandsoils.Bytheisoth

7、ermal adsorptionexperiments,analysedtheheavymetalsCu,Znadsorptioncharacteristics ofwetlandsoil.Bytheisothermaldesorptionexperiments,analyzedtherelationship betweentheamountofdesorptionandadsorption.Bychangingthes