摘要
湿地是灌区农业面源污染物的汇集地,沉积物中的营养盐和重金属含量是指示水体营养状况的地球化学指标之一。该文分析了宁夏黄灌区湿地沉积物剖面中TOC、TN、TP、Zn、Cu含量的垂向分布特征,并与湿地周围农田、排水沟和猪场排污口沉积物相应层次元素的含量进行了比较。结果表明,湿地沉积物剖面中TOC、TN垂向分布规律相似,在0-50cm有富集,湿地沉积物中TOC的含量是农田和排水沟的5～7倍、是猪场排污口的2.4倍,湿地沉积物中TN的含量是农田和排水沟的3倍左右,是猪场排污口的1.24倍。湿地沉积物中TP的含量与农田、排水沟土壤剖面中的含量差别不大,但远低于猪场排污口。湿地沉积物中Zn的含量小于农田、排水沟和猪场排污口,Cu的含量高于农田和排水沟但远低于猪场排污口。湿地沉积物剖面中TP、Zn、Cu垂向分布规律相似,在湿地入口处0-10cm表层有富集,10cm以下基本均匀分布,且在湿地腹地整个剖面基本均匀分布。湿地沉积物中TOC、TN、TP间均存在显著相关性,湿地沉积物剖面中的TOC、TN、TP与农田土壤剖面中相应层次元素的含量呈显著线性相关关系。湿地沉积物表层明显有TOC、TN、TP、Zn、Cu的富集,由于元素本身化学性质和来源影响的差异,在沉积物剖面中富集的深度不同,农田退水携带的营养型污染物及养殖排污是湿地沉积物的主要来源之一。
Nutrients and heavy metals in sediment profiles of wetland are indicators for water quality and environmental history.The paper analyzed the concentration distributions of TOC,TN,TP,Zn and Cu in sediment profiles of a wetland in Ningxia irrigation area of upper reaches of the Yellow River.The results shows that the concentrations of TOC and TN in sediment profiles of a wetland have a similar distribution,have high accumulation from surface to 50 cm in sediment depths of wetland grown with Phragmites communis T.and Acorus calamus L.The mean concentrations of TOC in sediment profiles of wetland is five to seven times higher than that in cropland and ditches sediment profiles,and 2.4 times higher than that in sediment from piggery swage outlet.The mean concentrations of TN in sediment profiles of wetland is about three times as high as that in cropland and ditches sediment profiles,and 1.24 times higher than that in piggery swage outlet sediment.Concentrations of TP,Zn and Cu in sediment profiles of a wetland have a similar distribution,have high enrichments in sediment depths from surface to 10 cm,and distribute evenly in the sediments depths lower than 10 cm.The Zn content in sediment profiles of wetland is lower than that in cropland,ditches and piggery swage outlet sediment profiles.The Cu content in sediment profiles of wetland is higher than that in cropland and ditches sediment profiles,but far lower than piggery swage outlet sediment.The concentrations of TOC,TN and TP in sediments profiles of wetlands have significant correlation,but relations between Zn,Cu and TOC,TN,TP are all significant only in sediments profiles of wetland inlet.The TOC,TN and TP in sediments profiles of wetlands have significant correlation with that in soil profiles of cropland.
出处
《水土保持学报》
CSCD
北大核心
2011年第1期74-80,共7页
Journal of Soil and Water Conservation
基金
国家科技重大专项(2009ZX07212-004)
国家自然科学基金(No.40701099)
中央级公益性科研院所基本科研业务费专项资金
关键词
宁夏灌区
湿地
沉积物
营养盐
重金属
Ningxia irrigation area
wetland
sediments
nutrients
heavy metals
