双穗雀稗等5种水草对汞的富集能力

Mercury accumulation in five different aquatic plants

为研究不同水草对汞的生物富集作用和硒元素对汞在水草中的富集之影响,选取杭州市临安区高虹镇典型节能灯生产集聚区2条河道内5种主要水生植物为研究对象,测定其不同部位的无机汞、甲基汞及硒质量分数。结果表明:水草对甲基汞的富集能力强于无机汞,且不同水草对无机汞或者甲基汞的富集能力也有较大差异。双穗雀稗Paspalum paspaloides在汞污染地区对无机汞的富集能力分别是稗草Echinochloa crusgalli,石菖蒲Acorus tatarinowii,一点红Emilia sonchifolia和空心莲子草Alternanthera philoxeroides的18.9, 37.4, 72.1和14.8倍;对甲基汞的富集能力分别是稗草、石菖蒲、一点红和空心莲子草的3.2, 4.2, 40.2和3.5倍,对汞的富集能力明显强于其他水草。环境汞质量分数对植物富集能力也有一定影响,双穗雀稗在汞污染地区对无机汞的富集能力是未污染地的11.1倍,对甲基汞的富集能力是未污染地的3.3倍,是可用来作为污染地汞富集植物的潜在品种。水草根中硒和汞质量分数之间呈负相关关系,说明硒对汞的吸收有抑制作用。

To study mercury(Hg)accumulation in aquatic plants and the role of selenium(Se)on Hg accumulation,five kinds of aquatic plants(Paspalum distichum,Echinochloa crusgalli,Acorus tatarinowii,Emilia sonchifolia,and Alternanthera philoxeroides)were collected from the Typical Energy-Saving Lamps Production Area in Gaohong Town,Lin’an District,Hangzhou City,Zhejiang Province.Inorganic Hg(IHg),methylmercury(MeHg),and Se concentrations in different plant tissues were analyzed.Results showed that aquatic plants could accumulated significantly higher(P<0.01)of MeHg than IHg.The Hg accumulation in different aquatic plants was also different with the bioaccumulation factor(BAF)of IHg in P.distichum for the Hg contaminated area being 18.9 times higher than Echinochloa crusgalli,37.4 times higher than Acorus tatarinowii,72.1 times higher than Emilia sonchifolia,and 14.8 times higher than Alternanthera philoxeroides.The BAF of MeHg in P.distichum was 3.2 times higher than Echinochloa crusgalli,4.2 times higher than Acorus tatarinowii,40.2 times higher than Emilia sonchifolia,and 3.5 times higher than Alternanthera philoxeroides.The accumulation capability of total Hg in P.distichum for the Hg contaminated area was 11.1 times higher than in a non-contaminated area and for MeHg 3.3 times higher than in the non-contaminated area.Also the presence of Se showed less Hg in roots of aquatic plants meaning selenium could inhibit the accumulation of Hg by aquatic plants,although the correlation between Hg and Se in roots were not significantly correlated(P>0.05).Therefore,Paspalum distichum could be used as a potential species to uptake Hg from Hg contaminated rivers.