【摘要】 土壤重金属和有机污染物复合污染是当前面临的重要环境问题.采集野外老化多年的污染土壤,利用室内盆栽实验,研究了重金属(Cd,Cu)和溴代阻燃剂(四溴双酚A、十溴联苯醚)单一及复合污染对小白菜的毒性效应.结果表明,单一重金属Cd和Cu胁迫下,小白菜生物量分别显著降低了约9.2%和9.0%,叶绿素含量下降,且诱导产生超氧自由基并引起脂质过氧化.单一四溴双酚A和十溴联苯醚未对小白菜产生显著的毒性效应.与单一重金属污染相比,四溴双酚A和Cd,Cu复合污染后,抑制了Cd和Cu在小白菜茎叶中的累积,叶片中重金属的富集系数分别降低25.5%和15.9%,生物量增加9.3%和14.6%,叶绿素含量上升,MDA(malondialdehyde)降低,四溴双酚A和重金属Cd,Cu产生拮抗效应;而十溴联苯醚对重金属植物体内富集、植物生长等无显著影响,但减弱了重金属导致的脂质过氧化.更多还原

【Abstract】 The combined pollution of heavy metals and organic chemicals in soil is a fact that can not be ignored.It is significant to acquire environmental behavior and combined effect of heavy metals and organic chemicals for adealing with soil remediation problem and evaluating ecological security.A 45-day pot experiment using aged field soil was performed to investigate the effects of cadmium,copper,tetrabromobisphenol A(TBBPA)and decabromodiphenyl ether(BDE209)on the growth of pakchoi.Results showed that Cd or Cu alone caused a significant reduction in pakchoi biomass(by 9.2% and 9.0%,respectively)and leaf chlorophyll content.They also induced leaf reactive oxygen species(ROS)and malondialdehyde(MDA)level.TBBPA or BDE209 alone showed limited effects on pakchoi.When compared with effects by Cd or Cu alone,TBBPA significantly decreased bioconcentration factor(BCF)of heavy metals in leaves(by 25.5%and 15.9%,respectively),increased total biomass by 9.3%and 14.6%in Cd and Cu treatments respectively,alleviating the inhibition effects of Cd or Cu on pakchoi chlorophyll content.However,BDE209 showed no signifi-cant effect on BCF values of Cd or Cu and oxidant stress to pakchoi.Itcouldonly alleviate the lipid peroxidation induced by Cd or Cu,but could not alleviate the growth and chlorophyll inhibition to pakchoi.更多还原