摘要
人工湿地系统中湿地植物种类的选取是影响其去除重金属效率的关键因素。通过水培试验研究了Pb胁迫(CK,10 mg·L^(-1),20 mg·L^(-1))对18种挺水湿地植物的耐性及吸收的影响。结果表明:Pb胁迫条件下,供试湿地植物根部对Pb的积累能力较强,Pb被根系吸收后大部分被固定于根部,只有少量被转运至地上部分;不同湿地植物对Pb的吸收差异显著(P<0.01);在20 mg·L^(-1)处理条件下,Pb地上部分最高浓度的植物是小婆婆纳,为8226 mg·kg^(-1),独穗飘拂草Pb浓度最低,为50 mg·kg^(-1);此外,不同湿地植物对Pb的耐性指数差异显著(P<0.01),Pb耐性较高的植物如水花生的Pb含量远高于毒性阈值,表明湿地植物除了通过根的排斥作用减少Pb向上转运的策略外,还可能通过体内存在相应的解毒机制来减少过量Pb带来的毒害。本研究结果为湿地植物修复重金属污染土壤提供了有力的科学依据。
In a constructed wetland system, appropriate choice of plant species is a key factor affecting metal removal from metal-contaminated soils, sediments and wastewaters. A hydroponic experiment was conducted to compare lead （Pb） tolerance indices and uptake among 18 emergent-rooted wetland plants under 0, 10 and 20 mg·L^-1 Pb exposures. The results indicated that Pb translocation from root to shoot was generally low in all species tested. There were significant differences among the 18 wetland plants in their Pb tolerance indices and also Pb uptake under the same Pb treatment. Some wetland plants with higher Pb tolerance indices and Pb concentra- tions in shoot suggested that the detoxification system in plant may play an important role in alle- viating Pb toxicity. Under the 20 mg ·L^-1Pb exposure, Veronica serpyllifolia had the highest ac- cumulation of Pb in shoots （ 8226 mg Pb·kg^-1）, while Fimbristylis monostachya had the lowest accumulation of Pb in shoots （50 mg Pb ·kg^-1）. In addition, Alternanthera philoxeroides having higher accumulation of Pb in shoots still did not show any severe symptoms of Pb toxicity. The data obtained should help in future species selection in designing wetlands in Pb-contaminated environments.
作者
杨俊兴
胡健
郭庆军
万小铭
宋波
高猛
顾松圃
郭俊娒
李真理
卢一富
曹柳
YANG Jun- xing HU Jian GUO Qing-jun WAN Xiao-ming SONG Bo GAO Meng GUO Jun-mei LI Zhen-li LU Yi-fu CAO Liu(Center for Environmental Remediation, In- stitute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Bei- ring 100101, China College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541004, Guangxi, China yantai Institute of Coastal Zone Research, Chi- nese Academy of Sciences, Yantai 510006, Shandong, China Institute of Environmental Science of Jiyuan City, Jiyuan 459000, Henan, China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2016年第10期2738-2744,共7页
Chinese Journal of Ecology
基金
环保公益性行业科研专项(201409044)资助
关键词
铅
湿地植物
耐性
吸收
胁迫
lead
wetland plant
tolerance
uptake
stress
