外源DOM条件下K^(+)、Na^(+)、Ca^(2+)、Mg^(2+)对湿地苔草吸收Cu的影响  

Effects of K,Na,Ca and Mg on the Absorption of Cu by Wetland Mosses under Exogenous DOM

作　　者：吴莉 弓晓峰 罗婧 熊捷迁 林媛 曾慧卿 WU Li;GONG Xiaofeng;LUO Jing;XIONG Jieqian;LIN Yuan;ZENG Huiqing(Key Laboratory of Poyang Lake Environment and Resource Utilization of Ministry of Education,School of Resources Environmental&Chemical Engineering,Nanchang University,Nanchang 330031,China)

机构地区：[1]南昌大学资源环境与化工学院,鄱阳湖环境与资源利用教育部重点实验室,江西南昌330031

出　　处：《环境科学与技术》2021年第1期49-57,共9页Environmental Science & Technology

基　　金：国家自然科学基金(41761095)。

摘　　要：文章在重金属Cu胁迫下,通过水培实验探究了外源溶解性有机质(DOM)存在下不同浓度K^(+)、Na^(+)、Ca^(2+)、Mg^(2+)对鄱阳湖湿地优势植物苔草(Carex cinerascens)吸收Cu的影响。在苔草的生长完全受到抑制的30 mg/L Cu^(2+)浓度和缓解Cu胁迫效果最佳的1 mg/L DOM条件下,通过设置培养液中不同浓度的K^(+)、Ca^(2+)、Na^(+)、Mg^(2+)水化学特性,观察苔草水生根形态,分析苔草体内和水培液中Cu^(2+)浓度水平。研究表明,K^(+)、Mg^(2+)、Na^(+)浓度为20 mg/L,Ca^(2+)浓度为1 mg/L时能有效缓解Cu胁迫,使苔草水生根恢复生长。20 mg/L Mg^(2+)与不同浓度的K^(+)、Na^(+)、Ca^(2+)对苔草水生根形态的影响存在显著差异(P<0.05)。苔草根系部分的Cu富集能力明显高于茎叶部分,富集能力顺序为浓度水平10 mg/L K^(+)>5 mg/L Mg^(2+)>10 mg/L Ca^(2+)>20 mg/L Na^(+),转运能力为浓度水平10 mg/L K^(+)>5 mg/L Mg^(2+)>20 mg/L Na^(+)>10 mg/L Ca^(2+)。在不同水化学特性下苔草地上部分与地下部分的Cu富集无显著差异(P>0.05)。K^(+)、Ca^(2+)、Na^(+)、Mg^(2+)可能在水培液中与游离Cu^(2+)竞争,影响Cu-DOM的结合,从而改变溶液中剩余Cu^(2+)浓度。Under the stress of heavy metal Cu,the effects of different concentrations of K^(+),Na^(+),Ca^(2+)and Mg^(2+)on the absorption of Cu in Carex cinerascens,the dominant plant in Poyang Lake wetland,were investigated by hydroponics experiments.Under the conditions of 30 mg/L Cu^(2+)concentration with completely inhibited growth of C.cinerascens and 1 mg/L DOM(dissolved organic matter)with the best relief effect of Cu stress,by setting the water chemistry characteristics of different concentrations of K^(+),Ca^(2+),Na^(+),and Mg^(2+)in the culture solution,the rooting morphology of C.cinerascens was observed,and the Cu concentration levels in C.cinerascens and the hydroponic solution were analyzed.The concentration of K^(+),Mg^(2+)and Na^(+)as20 mg/L,and the concentration of Ca^(2+)as 1 mg/L can effectively alleviate Cu stress and restore the growth of C.cinerascens aquatic roots.There was a significant difference between 20 mg/L Mg^(2+)and different concentrations of K^(+),Na^(+),Ca^(2+)on C.cinerascens aquatic root morphology(P<0.05).The Cu enrichment ability of the root part of C.cinerascens is significantly higher than that of the stem and leaf,the order of enrichment ability is the concentration level of 10 mg/L K^(+)>5 mg/L Mg^(2+)>10 mg/L Ca^(2+)>20 mg/L Na^(+),and the transport capacity is concentration levels 10 mg/L K^(+)>5 mg/L Mg^(2+)>20 mg/L Na^(+)>10 mg/L Ca^(2+).There was no significant difference in Cu enrichment between the upper part and the lower part of the C.cinerascens under different water chemistry characteristics(P>0.05).K^(+),Ca^(2+),Na^(+),Mg^(2+)may compete with free Cu^(2+)in hydroponic solution,affect the binding of Cu-DOM,and thus change the remaining Cu^(2+)concentration in the solution.

关 键 词：重金属CU 苔草根系 植物毒性 水化学特性 DOM 鄱阳湖湿地 

分 类 号：X524[环境科学与工程—环境工程]