铅、镉在典型植烟土壤中的形态分布及转化趋势研究  

Effects of aging on the fractionation of Lead and Cadmium in tobacco planting soils

作　　者：杨欣[1] 陈江华 张艳玲[1] 尹启生[1] 张仕祥[1] 

机构地区：[1]中国烟草总公司郑州烟草研究院,郑州高新区枫杨街2号450001 [2]中国烟叶公司,北京100055

出　　处：《中国烟草学报》2010年第5期44-49,共6页Acta Tabacaria Sinica

基　　金：郑州烟草研究院科技项目资助(112008CZ0310)

摘　　要：以我国主要产烟区4种典型植烟土壤(红壤、水稻土、黄壤、褐土)为试材,采用tisser分级提取法,研究了4种植烟土壤中铅、镉的形态分布及转化趋势。结果表明:未污染土壤中残留态及铁锰氧化物结合态是铅的主要化学形态,分别占土壤中铅总量的30.27%～58.80%和29.41%～53.29%。除褐土外,镉主要以残留态、铁锰氧化物结合态和交换态存在,分别占土壤中镉总量的33.64%～49.59%、22.32%～53.15%和23.94%～37.72%。在污染土壤中,铅主要积累在铁锰氧化物结合态和碳酸盐结合态,其中,红壤和水稻土交换态铅含量较高,占铅总量的25.59%和28.58%。镉主要以交换态存在,占总量的42.20%～61.33%,其次为碳酸盐结合态和铁锰氧化物结合态,分别占总量的11.36%～29.40%和15.10%～27.43%,重金属污染土壤中,交换态镉所占比例高于交换态铅,且不易转化其他形态,镉在土壤中的移动性更强,生物有效性更高。外源铅、镉在水稻土和红壤中的交换态含量更高,移动性和生物有效性更强,而在褐土和黄壤中则相对较低。外源铅、镉进入土壤后的前30d,交换态含量迅速降低,铁锰氧化物结合态和有机结合态含量相应升高,30d后,随着培养时间推移,各形态间的转化趋于平衡,但残留态铅、镉含量未表现出明显的变化趋势。Distribution and transformation of lead and cadmium chemical forms in Ustic Feerisols,Hydragric Anthrosols,Perudic Ferrisoils and Ustic Luvisols collected from four major tobacco growing regions were investigated.Results showed that in unpolluted soils,the bulk of the Pb distributed between residual （30.27-58.80%） and Fe/Mn oxides bound fractions （29.41-53.29%）.Most Cd was associated with residual （33.64%-49.59%）,Fe/Mn oxides bound （22.32-53.15%）,and exchangeable fractions （23.94%-37.72%） except in Ustic Luvisols.In contaminated soils,the majority of Pb was contained in Fe/Mn oxides bound and carbonate bound fractions.The proportion of Cd presented as exchangeable fractions （42.20-61.33%） was higher than that of Pb （3.65-28.58%）,which means Cd had higher potential of downward leaching,runoff transport and bio-availability.The concentration of spiked Pb and Cd which was found in exchangeable fraction was higher in Ustic Feerisols and Hydragric Anthrosols than in Perudic Ferrisoils and Ustic Luvisols.The proportions of heavy metals associated with the most weakly bound fraction （exchangeable） tended to decrease markedly within the first month,with corresponding increases in more strongly binding fractions （Fe/Mn oxides bound and organic bound） during incubation,but the residual form shows no trends in distribution pattern.

关 键 词：铅 镉 植烟土壤 形态转化 

分 类 号：S572.061[农业科学—烟草工业]