|CHI Jie,YANG Rui,WANG Aili.Effect of wetland plant species and growth strategy on the distribution of PAEs and their monoester metabolites in the rhizosphere. J. Lake Sci.2012,24(3):416-421. DOI:10.18307/2012.0313
|选取天津大学校内两个相邻的小型湖泊(青年湖和爱晚湖)为研究对象,研究了湿地植物种类(芦苇和香蒲)和生长方式(单生和混生)对根际酞酸酯(PAEs)及其单酯代谢物(PAMs)分布特征的影响.结果显示:几乎所有的样品中都能检测到酞酸丁二酯(DBP)和酞酸二异辛酯(DEHP)及其单酯代谢物(MBP和MEHP),并且DBP和DEHP的浓度比相应的单酯代谢物高1~2个数量级;沉积物和根样品中DEHP的浓度高于DBP;芦苇和香蒲根对DEHP的富集系数(RCF)大于DBP.当芦苇和香蒲单生时(即青年湖),芦苇根际沉积物中DBP和DEHP浓度 ≤ 香蒲根际沉积物的浓度,并且芦苇根的RCF值也小于香蒲.当芦苇和香蒲混生时(即爱晚湖),芦苇根际沉积物中DBP和DEHP浓度 < 香蒲根际沉积物的浓度,而芦苇根的RCF值 ≥ 香蒲根的RCF值,与青年湖中不同.青年湖香蒲根际沉积物中DBP和DEHP的浓度小于爱晚湖,而香蒲根的RCF值与此刚好相反.芦苇根对这两种PAEs的富集没有这种关系,可能是由于这两个湖中芦苇的生长状况不同,与香蒲混生时,芦苇的生长受到抑制.对PAEs的单酯代谢产物分析发现,沉积物中MBP/DBP > MEHP/DEHP.MEHP在根中的浓度多数情况高于MBP,表明MEHP比MBP具有较强的根富集能力.同种植物单生时,根中PAM浓度均 ≥ 混生.
|关键词: 酞酸酯 单酯代谢物 芦苇 香蒲 根际
|Effect of wetland plant species and growth strategy on the distribution of PAEs and their monoester metabolites in the rhizosphere
CHI Jie, YANG Rui, WANG Aili
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, P. R. China
|The field study was conducted in two adjacent shallow ponds (Lake Qingnian and Lake Aiwan) located within the campus of Tianjin University. The effect of wetland plant species (Phragmites australis and Typha orientalis) and growth strategy (single or mix) on the distribution of phthalic acid esters (PAEs) and their monoester metabolites (MBP and MEHP) were investigated. The results showed that dibutyl phthalate (DBP), ethylhexyl phthalate (DEHP) and their monoester metabolites were detected in nearly all of the samples and concentrations of DBP and DEHP were 1-2 order of magnitude higher than those of their corresponding monoester metabolites. The facts that concentrations of DEHP in sediments and root were higher than that of DBP, and root concentration factor (RCF) of DEHP was higher than that of DBP suggest that when P. australis and T. orientalis grew alone (i. e. Lake Qingnian), concentrations of DBP and DEHP in rhizosphere sediments were no more than those in non-rhizosphere sediments; concentrations of DBP and DEHP in the rhizosphere of P. australis were no more than those in the rhizosphere of T. orientalis, and RCF values of the two PAEs by P. australis were also lower than those by T. orientalis. When P. australis and T. orientalis grew together (i. e. Lake Aiwan), concentrations of DBP and DEHP in the rhizosphere of P. australis were lower than those in the rhizosphere of T. orientalis, while RCF values of the two PAEs by P. australis were higher than those by T. orientalis. This is different from that in Lake Qingnian. Concentrations of DBP and DEHP in the rhizosphere of P. australis from Lake Qingnian were lower than those from Lake Aiwan, while T. orientalis RCF values in Lake Qingnian were higher than those in Lake Aiwan. However, this phenomenon was not observed in the PAE accumulation by P. australis, which may be due to the different growth conditions of P. australis in the two lakes during the sampling period. The growth of P. australis was significantly inhibited when the two plants grew together. Results of monoester metabolites of the two PAEs showed that concentration ratio of MBP to DBP was higher than that of MEHP to DEHP. Concentrations of MEHP were mostly higher than those of MBP, showing stronger root accumulation of MEHP than MBP. PAM concentrations in roots under the condition of growing separately were higher than those under the condition of growing together.
|Key words: PAEs monoester metabolites Phragmites australis Typha orientalis rhizosphere