水溶性壳聚糖强化三七景天修复Cd/Pb单一或复合污染土壤机制  

Effect and Mechanism of Water-soluble Chitosan Promoting Phytoremediation of Cd and/or Pb-contaminated Soils by Sedum aizoon L.

作　　者：郭俊娒 卫月星 王柳月 刘晓娜 钱天伟 郑国砥[2] 杨俊兴[2] 陈同斌[2] 郭冰欣 GUO Jun-mei;WEI Yue-xing;WANG Liu-yue;LIU Xiao-na;QIAN Tian-wei;ZHENG Guo-di;YANG Jun-xing;CHEN Tong-bin;GUO Bing-xin(Shanxi Engineering Research Center of Low Carbon Remediation for Water and Soil Pollution in Yellow River Basin,Shanxi Key Laboratory of Earth Surface Processes and Resource Ecological Security in Fenhe River Basin,College of Environmental Science and Engineering,Taiyuan University of Technology,Jinzhong 030600,China;Center for Environmental Remediation,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China)

机构地区：[1]太原理工大学环境科学与工程学院,山西省黄河流域水土污染低碳修复工程中心,汾河流域地表过程与资源生态安全山西省重点实验室,晋中030600 [2]中国科学院地理科学与资源研究所环境修复中心,北京100101

出　　处：《环境科学》2024年第11期6665-6676,共12页Environmental Science

基　　金：国家自然科学基金项目(42277237,41907125);山西省应用基础研究计划项目(20210302124220);太原理工大学横向科研基金项目(RH2200002532,RH2300002821)。

摘　　要：采用盆栽试验研究了水溶性壳聚糖(WSC)不同添加量对三七景天在我国南北方4种典型Cd/Pb单一或复合污染土壤上生长响应和Cd/Pb吸收转运的影响,同时分析了WSC对土壤理化性质、Cd/Pb形态以及红外光谱特征(FTIR)的影响,以进一步明晰WSC促进三七景天富集Cd/Pb的作用机制.结果表明,WSC可改善根际土壤理化性质,提高碱解氮和有机质含量,显著降低了土壤pH,同时使土壤弱酸提取态Cd和Pb含量分别显著提高了16.3%~34.5%和88.9%~272.4%.FTIR分析结果表明,土壤中氨基(—NH_(2))和羟基(—OH)均随WSC添加而显著提高,因此,土壤中—NH_(2)和—OH与Cd/Pb发生配合形成络合物可能是WSC促进土壤中Cd/Pb活化的重要机制.此外其对土壤根际环境的改善也对三七景天Cd/Pb吸收具有一定的促进作用.在4种污染土壤上,WSC添加对三七景天生长无明显抑制作用,而使其Cd和Pb总积累量分别显著增加14.5%~72.1%和55.0%~128.5%.综上所述,WSC可应用于促进三七景天修复Cd/Pb污染土壤,但在实际应用中需进一步考虑其添加量、土壤污染程度和修复植物的匹配性.A pot experiment was conducted to investigate the growth response,concentration,and transportation characteristics of Cd and Pb in Sedum aizoon L.in four typical Cd/Pbcontaminated soils from northern and southern China with the addition of different levels of water-soluble chitosan(WSC).The effect of WSC on physicochemical properties,Cd and Pb forms,and functional groups in contaminated soils was determined to clarify the internal mechanism of WSC promoting Cd and Pb accumulation by S.aizoon.The results showed that WSC improved the physicochemical properties of rhizosphere soil by increasing alkaline nitrogen and organic matter contents and significantly reducing pH values.In addition,WSC significantly increased the acid-extractable Cd and Pb in contaminated soils by 16.3%-34.5%and 88.9%-272.4%,respectively.Fourier transform infrared spectra analysis showed that amino(—NH_(2))and hydroxyl(—OH)groups in soils were significantly increased by adding WSC.Therefore,the coordination of Cd/Pb with—NH_(2) and—OH may play important roles in forming complexes and mobilizing Cd/Pb in soils.Moreover,the improvement in the rhizosphere environment of contaminated soils by WSC contributed to promoting Cd and Pb accumulation by S.aizoon.WSC significantly increased the total Cd and Pb accumulation by 14.5%-72.1%and 55.0%-128.5%,respectively,without obvious growth inhibition.Therefore,it is feasible to apply WSC to promote Cd/Pb accumulation using S.aizoon,while the matching of WSC addition amount,soil pollution condition,and plant materials should be further considered in practical application.

关 键 词：镉(CD) 铅(Pb) 污染土壤 植物修复 三七景天 水溶性壳聚糖(WSC) 

分 类 号：X171.5[环境科学与工程—环境科学]