菹草对微污水中重金属复合污染的净化效果

Purification of combined pollution of heavy metals in micro contaminated water by Potamogeton crispus L.

采用小型围隔中的沉水植物菹草(Potamogeton crispus L.)研究其对微污水中Cd2+、Cr3+、Cu2+、Zn2+、Ni2+、Mn2+等重金属复合污染的累积和去除效果。结果表明:在有沉水植物菹草生长的情况下,上覆水中重金属去除效果明显高于没有菹草生长时的情况;菹草对不同重金属有着不同的吸收富集能力,对重金属Cd2+、Mn2+、Ni2+具有超积累的富集作用,其中对Mn2+的富集作用最为显著,即菹草是一种喜锰和耐锰的水生植物;菹草不同部位重金属积累量也大不相同,菹草茎叶对Cd2+的单位富集能力很强,新叶中Cr3+、Cu2+、Zn2+、Ni2+、Mn2+等重金属单位含量高于老叶、根部和茎。

The accumulation and removal on combined pollution of Cd2＋ , Cr3＋ , Cu2 ＋ , Zn2＋ , Ni2＋ and Mn2＋ in micro contaminated water by submerged plant Potamogeton crispus were studied in small en- closures. Results showed that the removal of heavy metals in overlying water with the growth of P. cris- pus was significantly higher than that without P. crispus. P. crispus had different abilities to absorb heavy metals tested and super accumulation ability for Cd2＋ ,Mn2＋ and Ni2＋. Mn2＋ enrichment was the most significant indicating that P. crispus is an aquatic plant preferred manganese. The accumulation a- bilities of heavy metals were diverse among different parts of the plant. The enrichment of Cd〉 was stronger in leaves and the accumulation of Cra＋ , Cu2＋ , Zn2＋ , Ni2＋ and Mn2＋ in new leaves were higher than those of the old leaves, roots and stems.