4种典型沉水植物对去除镉污染底泥的应用效果  

Application Effect of Four Typical Submerged Macrophytes on Removing Cadmium from Polluted Sediment

作　　者：陶理 王沛芳[1,2] 袁秋生 王洵[1,2] 胡斌[1,2] TAO Li;WANG Pei-fang;YUAN Qiu-sheng;WANG Xun;HU Bin(College of Environment,Hohai University,Nanjing 210098,China;Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes,Ministry of Education,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学环境学院,南京210098 [2]河海大学浅水湖泊综合治理与资源开发教育部重点实验室,南京210098

出　　处：《环境科学》2021年第9期4311-4318,共8页Environmental Science

基　　金：国家重点研发计划项目(2016YFC0502203);国家自然科学基金重大研究计划重点支持项目(92047201);中央高校建设世界一流大学(学科)和特色发展引导专项。

摘　　要：本研究选取4种典型沉水植物黑藻(Hydrilla verticillata)、伊乐藻(Elodea canadensis)、菹草(Potamogeton crispus)和金鱼藻(Ceratophyllum demersum),通过对植物叶绿素含量及抗氧化酶活性的检测来分析植物对镉的耐受效应,并借助生物/底泥富集因子(BSAF)和植物转运因子(TF)来了解植物的富集能力,最后通过植物组织化学方法来揭示镉在沉水植物体内的分布情况,以期为沉水植物的实际应用提供理论支持.结果表明,除金鱼藻以外的3种植物对底泥镉污染有不同耐受能力,其中黑藻和伊乐藻的耐受能力最强.在底泥镉含量不超过20 mg·kg^(-1)时,菹草的富集能力最强(BSAF为2.32).金鱼藻在本实验中BSAF均小于1.0,说明根在镉污染底泥的植物修复中起着重要作用.比较不同植物的TF可以发现,黑藻根部对镉的地上转运能力最强,而菹草主要将镉富集于植物根部,同时与其他植物不同,在镉含量为50 mg·kg^(-1)时,镉已均匀分布在菹草茎部细胞器中.综合植物对镉污染的耐受和富集机制,并结合实际情况,最终将黑藻和菹草选为修复含镉底泥的理想植物,同时结合植物不同的转运能力,建议可仅去除黑藻的地上部分,而及时定期连根拔除菹草.In this study,four typical submerged macrophytes,namely Hydrilla verticillata,Elodea canadensis,Potamogeton crispus,and Ceratophyllum demersum,were tested for their chlorophyll content and antioxidant enzyme activity,to analyze their cadmium tolerance. The biota-sediment accumulation factor( BSAF) and plant transport factor( TF) were utilized to understand the accumulation capacity of the plants. Finally, the distribution of cadmium in submerged macrophytes was revealed through phytohistochemical methods,to provide theoretical support for the practical application of submerged macrophytes. The results showed that three of the plants,excluding C. demersum,exhibited varying tolerances to cadmium pollution in sediments,among which the tolerance of H. verticillata and E. canadensis were the strongest. P. crispus had the strongest accumulation capacity( BSAF was 2. 32)at relatively low pollution levels( ≤20 mg·kg^(-1)). In this study,because of its weak root system,the BSAF of C. demersum was less than 1. 0,indicating that macrophyte roots play an important role in phytoremediation of Cd-contaminated sediments. Comparing the TF of different plants,it can be found that the roots of H. verticillata had the strongest above-ground cadmium transport capacity,while P.crispus mainly accumulated cadmium in its roots. At the same time,when the cadmium concentration was 50 mg·kg^(-1),cadmium was found to be evenly distributed in the stem organelles of P. crispus,in contrast to the other plants. Based on the cadmium tolerance and accumulation mechanism of the plants,and in consideration of real-world factors,H. verticillata and P. crispus were selected as ideal plants for repairing cadmium-containing sediments. Meanwhile, based on the different transport capabilities of plants, it is recommended that only the above-ground part of H. verticillate should be removed,while P. crispus should be uprooted regularly.

关 键 词：沉水植物 底泥 镉污染 耐受能力 富集能力 

分 类 号：X52[环境科学与工程—环境工程]