堆肥污泥对不同杨树品种重金属富集变化的影响1）

摘要

By a pot experiment in greenhouse, with Populus×euramaricanacl‘Lingfeng 3’ and Populus×euramericana‘Guarien-to’, we studied the effect of composted sewage sludge (CSS) on the changes of heavy metal accumulations in different plant parts.There were four treatments including three different dosage CSS of 15 t· hm-2( LS) , 30 t· hm-2( MS) , 60 t· hm-2( HS) and control ( no application of sewage sludge, CK) .The application of CSS significantly influenced the changes of copper (Cu), zinc (Zn), arsenic (As), mercury (Hg) and cadmium (Cd) accumulations of poplar seedlings, and varied with the varieties, sludge dosages, growth period and the parts of plants.Cu, Zn, Hg and As mainly enriched in the roots, while Cd was mainly in leaves.The basic features of accumulated metals (Cu, Zn and As) in the plants were in the order of root>leaf>stem, and Hg and Cd were basically in the order of root>stem>leaf and leaf>root>stem, respectively. With an increase in the amount of CSS, heavy metal accumulations in the leaf, stem and root mostly presented the increas-ing trend and especially significant in the root.Therefore, the phytoremediation of heavy metal pollution in sewage sludge and the appropriate disposal of sewage sludge by using poplar would be effective measures.%采用温室盆栽试验，研究堆肥污泥对两个杨树品种[凌丰三号（ Populus×euramaricanacl‘Lingfeng 3’）和欧美杨108号（Populus×euramericana‘Guariento’）]幼苗各部分重金属富集变化的影响，并分别设置低量污泥（15 t· hm－2，LS）、中量污泥（30 t· hm－2，MS）、高量污泥（60 t· hm－2，HS）和对照（不施污泥，CK）4个处理。结果表明：堆肥污泥对杨树幼苗Cu、Zn、As、Hg和Cd重金属富集变化的影响显著，且因品种、污泥用量、生长时期和植物各部分而异。 Cu、Zn、As、Hg 4种重金属则主要富集于根部，而Cd则主要富集于叶部，即由大到小的顺序，Cu、Zn和As的富集基本特征均为根、叶、茎， Hg 基本表现为根、茎、叶，而Cd基本表现为叶、根、茎。随着污泥用量的增加，在植物叶、茎和根部重金属富集态势大部分呈现递增趋势，且在根部表现尤为明显。速生杨植物修复污泥的重金属污染以及合理处置污泥，都将可能不失为一种有效措施。