三峡库区香溪河库湾水体磷含量对消落带土壤铅和镉迁移转化的影响  

Effect of Phosphorus Content in Xiangxi River on the Migration and Transformation of Lead and Cadmium in Fluctuation Zone Soil

作　　者：刘琪 席颖[1,2] 罗玉红 袁喜[1,3] 张久红 张军 黄应平 刘慧刚[2] LIU Qi;XI Ying;LUO Yu-hong;YUAN Xi;ZHANG Jiu-hong;ZHANG Jun;HUANG Yingping;LIU Hui-gang(College of Hydraulic&Environmental Engineering,China Three Gorges University,Yichang 443002,China;Engineering Research Center of Eco-environment in Three Gorges Reservoir Region of Ministry of Education,China Three Gorges University,Yichang 443002,China;Forest Resources Monitoring Station,Yichang,443000)

机构地区：[1]三峡大学水利与环境学院,湖北宜昌443002 [2]三峡库区生态环境教育部工程研究中心(三峡大学),湖北宜昌443002 [3]宜昌市森林资源监测站,湖北宜昌443000

出　　处：《林业科学研究》2023年第5期91-99,共9页Forest Research

基　　金：国家自然科学基金(21972073);宜昌市森林抚育效益监测(SDHZ2020313);111引智项目(D20015)。

摘　　要：[目的]明晰磷对干湿交替消落带土壤重金属的形态与释放的影响,对三峡库区土壤重金属防治具有很大的意义。[方法]本文选取三峡库区香溪河库湾内6个采样点,采集水体和消落带及上缘土壤样品,对水体磷和土壤重金属铅(Pb)和镉(Cd)含量进行为期4个季度(2020年6月—2021年3月)的采样监测。依据香溪河水体磷浓度范围,在水体不同外加磷浓度添加下,进行室内干湿交替模拟试验。[结果]香溪河水体总磷含量与土壤的Pb含量呈显著正相关(P<0.05),土壤有效态Pb与有效态Cd含量呈极显著正相关(P<0.01)。干湿交替试验结果显示,随干湿交替次数增加,水体总磷含量也显著增加(P<0.05);在第2次淹水落干期间,水体外加磷浓度≤0.2 mg·L^(−1)时,淹水期土壤总磷含量高于落干期;土壤中的Pb和Cd呈现由迁移性强的可交换态向迁移性弱的残渣态的转变趋势;水体外加低浓度磷(0.05 mg·L^(−1))时,土壤Pb含量均明显降低(P<0.05),土壤Cd含量随水体磷浓度的增加而升高(P<0.05),尤其是Cd的形态变化更加显著且与水体磷含量相关。[结论]干湿交替过程中,磷在水与土壤之间存在迁移转化,水体磷促进土壤Pb向水体迁移,而抑制土壤Cd向水体的迁移。[Objective]To clarity the impact of phosphorus content in water on the migration and transformation of heavy metals in the soil of the alternating dry-wet fluctuation zone is of great significance for the prevention and control of heavy metals in the soil of the Three Gorges Reservoir area.[Method]In this paper,6 sampling points in Xiangxi River reservoir bay,including fluctuation zone and upper edge soil were selected to collect samples.Soil and water samples were monitored for 4 quarters(June 2020 to March 2021)with water phosphorus and soil heavy metals Pb and Cd.In the indoor dry-wet alternation simulation test,6 phosphorus additions were set up according to the range of phosphorus concentration in Xiangxi River and with the soil of its fluctuation zone.And soil water volume ratio was 1:2.[Result]The results showed that total phosphorus in Xiangxi River water was significantly positively correlated with Pb(P<0.05).Effective Pb was significantly positively correlated with effective Cd(P<0.01).The total phosphorus content in the water increased significantly(P<0.05)with increasing dry-wet alternation times.The total phosphorus content of soil in the flooding period was higher than that in the drying period when added concentration of phosphorus was lower than 0.2 mg·L^(−1)during the second flooding and drying period.Pb and Cd in the soil showed a transition trend from a highly mobile exchangeable state to a weakly mobile residual state;adding low concentrations of phosphorus(0.05 mg·L^(−1)),the soil Pb content decreased significantly(P<0.05),and the soil Cd content increased with the increase of water phosphorus concentration(P<0.05),especially the form change of Cd was more significant and related to the water phosphorus content.[Conclusion]There is a migration and transformation of phosphorus between water and soil in the process of dry wet alternation.Phosphorus in the water promote the migration of Pb from soil to water,while inhibiting the migration of Cd from soil to water.

关 键 词：香溪河 消落带 磷 重金属 迁移转化 

分 类 号：S718.516[农业科学—林学]