重金属 污染土壤 生物蓄积性 耐受性.pdf

Journal of Environmental Sciences 20(2008) 62–67 Potential of Pteris vittata L. for phytoremediation of sites co-contaminated with cadmium and arsenic: The tolerance and accumulation XIAO Xiyuan, CHEN Tongbin?, AN Zhizhuang, LEI Mei, HUANG Zechun, LIAO Xiaoyong, LIU Yingru Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China. E-mail: xiaoxy@mail.csu.edu.cn Received 10 April 2007; revised 21 June 2007; accepted 11 July 2007 Abstract Field investigation and greenhouse experiments were conducted to study the tolerance of Pteris vittata L. (Chinese brake) to cadmium (Cd) and its feasibility for remediating sites co-contaminated with Cd and arsenic (As). The results showed that P. vittata could survive in pot soils spiked with 80 mg/kg of Cd and tolerated as great as 301 mg/kg of total Cd and 26.8 mg/kg of diethyltriaminepenta acetic acid (DTPA)-extractable Cd under ?eld conditions. The highest concentration of Cd in fronds was 186 mg/kg under a total soil concentration of 920 mg As/kg and 98.6 mg Cd/kg in the ?eld, whereas just 2.6 mg/kg under greenhouse conditions. Ecotypes of P. vittata were di?erentiated in tolerance and accumulation of Cd, and some of them could not only tolerate high concentrations of soil Cd, but also accumulated high concentrations of Cd in their fronds. Arsenic uptake and transportation by P. vittata was not inhibited at lower levels (620 mg/kg) of Cd addition. Compared to the treatment without addition of Cd, the frond As concentration was increased by 103.8% at 20 mg Cd/kg, with the highest level of 6434 mg/kg. The results suggested that the Cd-tolerant ecotype of P. vittata extracted e?ectively As and Cd from the site co-contaminated with Cd and As, and might be used to re