【作者】 蔡莎莎；

【导师】 李取生；

【作者基本信息】 暨南大学 ， 环境工程， 2007， 硕士

【摘要】 本文以南沙围垦滩涂土壤类型作为研究对象，通过实地调查采样分析测试和盆栽试验，重点研究了不同作物对重金属吸收累积和胁迫响应特征，为实现围垦滩涂污染土壤的安全利用提供科学依据。调查结果显示：南沙围垦农田表层土壤Cu、Zn、Pb、Ni、Cr、Cd的平均含量分别为59.57、277.91、81.96、43.50、157.29、2.60 mg／kg，其中，Cd是最主要的污染元素，最高超出土壤环境质量标准二级指标25.93倍；除Zn和Cu外，作物中的Pb、Ni、Cr、Cd含量均超出食品卫生标准；重金属被作物吸收的难易程度大致为Cd＞Zn＞Cu＞Ni＞Pb＞Cr；不同作物对重金属的富集能力不同，表现为：叶菜类＞根茎类＞瓜果类。盆栽试验结果表明：随着土壤重金属含量增加，蔬菜生长受到抑制，叶绿素含量以及可溶性糖含量呈显著降低趋势；蔬菜PPO活性随重金属浓度提高有显著的增加，而POD活性则表现出“低—高—低”的变化趋势。此外，不同种类蔬菜对重金属的毒性响应不同。各种蔬菜对同种重金属及同种蔬菜对不同重金属的吸收均存在着差异性。蔬菜对Cu、Zn、Pb、Ni、Cr、Cd富集系数分别为0.0040-0.0278、0.0046-0.0186、0.0050-0.0290、0.0034-0.0107、0.0024-0.3196、0.0222-0.0977，以对Cd吸收能力最强；蔬菜累积重金属的能力存在着显著的种间差异，其中以通心菜的富集能力最强，西红柿的富集能力最弱。更多还原

【Abstract】 Based on the reclaimed soil in Nansha, heavy metal accumulations in differentcrops and their responses to pollution stress were investigated through field surveyand the potted experiment, in order to provide a scientific support for the safe use ofpolluted soil.The results show that:(1) average contents of Cu、Zn、Pb、Ni、Cr and Cd in thetopsoils are 59.57、277.91、81.96、43.50、157.29 and 2.60mg/kg respectively. Amongthem, Cd is the major pollutant and its maximum content exceeds the second grade ofsoil environmental quality standard 25.93 times;(2)Excepted for Cu and Zn、Pb、Ni、Cr and Cd in crops all exceed the permitted level.(3)The cumulated rate of heavymetals: Cd＞Zn＞Cu＞Ni＞Pb＞Cr; (4) The order of the cumulate abilities of crops is:leafy vegetables＞rhizome class vegetables＞fruits.The potted experiment results show that:(1) With the increase of heavy metalsconcentrations, the growth of vegetables are stressed more seriously, and theconcentration of chlorophylls and dissolved sugar are decreased significantly;(2) Theactivity of PPO showes an increasing trend as a whole, while the activeity of PODincreases firstly and then decreases. (3) The effect of heavy metals on vegetables isdependent on discrepancy of vegetable species.The same type of vegetable has different responses to different heavy metals.Different vegetables have different accumulations for the same heavy metal. Thebioaccumulation factor(BF) of the vegetables for Cu、Zn、Pb、Ni、Cr and Cd are0.0040-0.0278、0.0046-0.0186、0.0050-0.0290、0.0034-0.0107、0.0024-0.0196、0.0222-0.0977, respectively. Cd is the element accumulated by plants most easily.Moreover, the enrichment abilites of various vegetables for heavy metals are differentamong the species. Water spinach has the strongest ability of uptaking heavy metalsfrom soil, while the cumulated ability of tomato is lowest.更多还原