摘要
磷是一种重要的生命必需元素,其与氮都是引起水体富营养化的重要元素。红碱淖是中国最大的沙漠淡水湖,在区域生态系统中的功能十分显著。采用连续提取法对陕西红碱淖湖泊表层沉积物磷形态进行分析,得到弱吸附态磷(NH4Cl-P)、铁锰螯合态磷(BD-P)、铁铝氧化态磷(NaOH-P)、钙磷(HCl-P)、惰性磷(Res-P)五种磷形态。结果表明:总体上,红碱淖表层底泥磷向水体释放的风险较低,但在湖泊水体pH值上升背景下,一些碱溶解磷(如NaOH-P)向湖泊水体释放的风险可能增加。五种形态磷在全湖的空间分布表明:NH4Cl-P与BD-P呈现大致相似的特征,NaOH-P主要在湖泊南岸附近富集,HCl-P和Res-P呈大致相反的变化趋势,总磷(TP)在全湖近乎均匀分布。与国内典型湖泊沉积物的对比显示:红碱淖表层底泥无论是总磷还是活泼磷均处于较低水平,也说明该湖泊表层底泥磷向水体释放的风险相对较低。
Background,aim,and scope Phosphorus is an important essential element for life.Together with nitrogen,it is also an important element that cause water eutrophication.In the lake environment,the risk of phosphorus release from the sediment to the water is closely related to the occurrence form of phosphorus in the sediment.The more the active form of phosphorus,the easier the phosphorus releases to the water environment.In addition,phosphorus also has a great influence on the form and abundance of nitrogen in the environment.As the largest desert freshwater lake in China,Lake Hongjiannao is an important habitat for Larus relictus.Therefore,the study of phosphorus form in lake sediment is of great importance to evaluate the eutrophication risk of lake water.Materials and methods In order to characterize various phosphorus species in the sediment,a total of 12 samples from Lake Hongjiannao and 5 samples from rivers entering the lake were collected and treated using a sequential extraction method improved by Hupfer et al.(1995).The content of phosphorus in the extracted solution was determined by the Mo-Sb anti-spectrophotometry method.Results The mean of five phosphorus species in the surface sediment samples of Lake Hongjiannao are:NH4Cl-P 3.55 mg∙kg-1,BD-P 35.63 mg∙kg-1,NaOH-P 42.57 mg∙kg^(-1),-1 HCl-P 144.45 mg∙kg and Res-P 227.90 mg∙kg^(-1).In the sediment of Lake Hongjiannao,phosphorus is mainly present in the form of non-reactive HCl-P and Res-P,while the contents of soluble reactive NH4Cl-P and BD-P are low.Except for NaOH-P and HCl-P,the variation of other phosphorus species at different sampling sites was not significant.Discussion The spatial analysis shows that the distribution of NH4Cl-P and BD-P has roughly similar characteristics,and there is a high value in the centers of eastern and western simi-lakes respectively.NaOH-P is mainly enriched near the south bank of the lake.Interestingly,the distribution of HCl-P and Res-P showed roughly opposite trends.TP is almost evenly distributed in the whole lake.Based on comparison with other lakes in China,TP content in the surface sediment of Lake Hongjiannao is lower than that of other lakes,except for the Chaohu Lake and Poyang Lake in the Yangtze River Basin.According to comparison of the contents of soluble reactive phosphorus with other lakes,the contents of NH4Cl-P,BD-P and NaOH-P in Lake Hongjiannao are also at a lower level.Conclusions The risk of phosphorus release from the surface sediment to the water in the Lake Hongjiannao is generally low,but the risk of the release of some alkaline dissolved phosphorus is likely to increase under the trend of alkaline enhancement.The relationship between the spatial distribution of different phosphorus species and lake hydrodynamics,grain size of sediment and so on remains to be further studied.Recommendations and perspectives The results in this study are valuable for evaluating the potential risk of phosphorus release of surface sediment to the lake water and the eutrophication of lakes in the climatic sensitive zone.
作者
刘晓清
刘昱含
刘钊
于学峰
LIU Xiaoqing;LIU Yuhan;LIU Zhao;YU Xuefeng(Shaanxi Environmental Protection Industry Group Co.,Ltd.,Xi’an 710075,China;School of Environmental and Chemical Engineering,Xi’an Polytechnic University,Xi’an 710600,China;Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710061,China)
出处
《地球环境学报》
CSCD
2024年第1期164-172,共9页
Journal of Earth Environment
基金
水质较好湖泊生态安全调查与评估专项。
关键词
红碱淖
表层底泥
磷形态
释放风险
Lake Hongjiannao
surface sediment
phosphorus species
release risk
