沉积物磷形态空间分布特征及释放风险评估——以沱江流域为例  

Spatial distribution characteristics and release risk assessment of phosphorus forms in sediments:A case study of the Tuojiang River Basin

作　　者：唐金勇 尹月鹏 曹熙 张瑜[1,2] 张雯[1,2,3] TANG Jin-yong;YIN Yue-peng;CAO Xi;ZHANG Yu;ZHANG Wen(College of Environment and Ecology,Chengdu University of Technology,Chengdu 610059,China;State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil and Water Pollution(SEKL-SW),Chengdu University of Technology,Chengdu 610059,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]成都理工大学生态环境学院,四川成都610059 [2]国家环境保护水土污染协同控制与联合修复重点实验室(成都理工大学),四川成都610059 [3]地质灾害防治与地质环境保护国家重点实验室(成都理工大学),四川成都610059

出　　处：《中国环境科学》2022年第9期4264-4273,共10页China Environmental Science

基　　金：国家自然科学基金资助项目(42007148)。

摘　　要：为阐明沉积物磷赋存形态的空间分布特征及潜在释放风险,提供更准确合适的风险评估指标,分析了沱江干流及其支流12个样点表层沉积物的磷赋存形态,测定了水溶性磷(WSP)及磷平衡浓度(EPC0),计算沉积物磷吸附指数(PSI)、磷吸附饱和度(DPS)及其衍生的磷释放风险指数(ERI).结果表明,沉积物5种形态磷含量顺序为:铁/铝结合磷(CDB-P,60.63%)>钙磷(Ca-P,30.84%)>有机磷(OP,3.92%)>亚铁磷(Fe(Ⅱ)-P,3.48%)>松散态磷(Loosely-P,1.13%).CDB-P是沉积物磷的主要存在形态(0.468~2.287mg/g),由上游至下游逐渐降低,这主要与上游工业污染有关.DPS、EPC0和PSI在空间分布上均呈现由上游至下游逐渐增大的趋势,变化范围分别为44.28%~80.39%、0.012~0.084mg/L和0.153~1.526L/g;上游大部分采样点ERI均超过了25%;各指标综合表明:上游存在较高的磷释放风险.回归分析与相关性表明,EPC0与上覆水磷、CDB-P、OP、有机质(OM)以及粒径均呈极显著相关性,且相关性远高于其他指标(ERI,DPS,PSI,WSP).因此,EPC0是评估沱江流域沉积物磷释放风险潜力更准确高效的指标,Fe/Al含量、粒径的增加以及有机质的减少会增加磷释放风险,因此应控制工业污染以及农业面源污染的输入.In order to clarify the spatial distribution characteristics of the phosphorus(P)in sediments and provide more accurate and suitable indicators for assessing P release risk,samples of surface sediments were taken from 12 sites in the main stream of the Tuojiang River and its tributaries for determining water-soluble phosphorus(WSP),equilibrium P concentration(EPC0),sediment P adsorption index(PSI)and adsorption saturation(DPS),and the derived P release risk index(ERI).The results show that the order of the P contents in the five forms of sediments is as follows:iron/aluminum combined P(CDB-P,60.63%)>calcium P(Ca-P,30.84%)>organic P(OP,3.92%)>ferrous P(Fe(Ⅱ)-P),3.48%>loosely P(Loosely-P,1.13%).CDB-P is the main form of sediment P(0.468~2.287mg/g)and decreases gradually from the upstream to the downstream,which is mainly related to upstream industrial pollution.The spatial distribution of DPS,EPC0and PSI tends to gradually increase with downstream,varying from 44.28%to 80.39%,0.012 to 0.084mg/L and 0.153 to 1.526L/g,respectively.ERI exceeded 25%at the most upstream sampling sites,indicating a higher risk of P release in the upstream.Regression analysis and correlation show that EPC0 and the overlying water P,CDB-P,OP,OM,and particle size were significantly correlated.Therefore,EPC0can be thought to be a more accurate and efficient indicator for assessing the potential of P release from sediments in the Tuojiang River Basin.An increase in Fe/Al content,particle size,and the reduction of organic matter will elevate the P release risk,so the input of industrial pollution and agricultural non-point source pollution should be controlled.

关 键 词：磷形态 空间分布 磷平衡浓度 磷释放风险 

分 类 号：X171[环境科学与工程—环境科学]