高磷沉积物有机磷形态分布及释放动力学特征——以宜昌西北口水库为例  

Distribution and release kinetics of organic phosphorus in phosphorus-rich sediments:A case study of Xibeikou Reservoir in Yichang

作　　者：马晓阳 牛凤霞[1,2,3] 肖尚斌[1,2,3] 康满春 刘佳[1] 胡杰茗 MA Xiao-yang;NIU Feng-xia;XIAO Shang-bin;KANG Man-chun;LIU Jia;HU Jie-ming(College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China;Engineering Research Center of Eco-environment in Three Gorges Reservoir Region,China Three Gorges University,Yichang 443002,China;Hubei Field Observation and Scientific Research Stations for Water Ecosystem in Three Gorges Reservoir,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学水利与环境学院,湖北宜昌443002 [2]三峡大学,三峡库区生态环境教育部工程研究中心,湖北宜昌443002 [3]三峡大学,三峡水库生态系统湖北省野外科学观测研究站,湖北宜昌443002

出　　处：《中国环境科学》2022年第1期293-301,共9页China Environmental Science

基　　金：国家自然科学基金资助项目(41807513,51979148);湖北省自然科学基金资助创新群体项目(2019CFA032);宜昌市科技局资助项目(A19-302-07)。

摘　　要：为探究高磷背景水库沉积物中有机磷(OP)的空间分布及OP释放动力学特征,本文采用Ivannoff法对西北口水库沉积物中的OP进行分级提取,通过沉积物OP释放动力学模拟实验,探讨了表层沉积物OP的释放特征,以及沉积物理化性质对其响应.结果表明,西北口水库沉积物OP含量为210.3~455.2mg/kg,平均含量为322.9mg/kg,占总磷(TP)的18.3%.OP含量空间分布呈现库中(363.2mg/kg)>库首(339.3mg/kg)>库尾(266.1mg/kg)的变化规律,垂向上随深度的增加而减小.西北口水库不同形态OP的含量表现为:非活性有机磷(NOP)>中活性有机磷(MLOP)>活性有机磷(LOP),其中NOP含量占OP的65.3%,是西北口水库沉积物OP的主要存在形式.准一级动力学模型是描述西北口水库库首、库中和库尾沉积物OP释放动力学曲线的最优方程(R^(2)=0.98~0.99,P<0.01),在0~1h表征为快速释放过程,所释放的OP含量占最大释放量(Q_(max))的55.68%~79.55%,随后进入慢速释放过程,逐渐达到Q_(max),Q_(max)在1.4~3.1mg/kg之间.该水库沉积物中LOP和MLOP是主要向上覆水体释放的磷形态.In order to explore the spatial distribution of organic phosphorus(OP)and its release dynamics in phosphorus-rich sediments of the reservoir,the Ivannoff method was used to extract sequentially different forms of OP in the sediments of Xibeikou Reservoir.Simulation experiments on OP kinetic release were performed the release characteristics of different OP fractions from the surface sediments,as well as the physicochemical properties of sediments and their responses to the OP release.The results showed that the OP content of the sediments in Xibeikou Reservoir was 210.3~455.2mg/kg,with an average content of 322.9mg/kg,accounting for 18.3% of the total phosphorus(TP).The spatial patterns of OP contents were characterized by the midstream(363.2mg/kg)>the downstream(339.3mg/kg)>the upstream of the reservior(266.1mg/kg),and longitudinally the OP contents decreased with the depth increasing.The patterns of different OP forms in Xibeikou Reservoir were shown as:inactive organic phosphorus(NOP)>medium active organic phosphorus(MLOP)>active organic phosphorus(LOP).NOP occupied 65.3%of OP,serving as the main forms of OP in the sediments of Xibeikou Reservoir.The quasi-first-order kinetic model was the optimal equation to describe the OP kinetic release curve of the sediments in the upstream,midstream and downstream of the Xibeikou Reservoir(R^(2)=0.98~0.99,P<0.01).The 0~1h period was the rapid-release stage,with released OP contents accounting for 55.68%~79.55% of the maximum release content(Q_(max)).Then it got to the slow-release stage,and gradually the release content reached Q_(max),ranging between 1.4mg/kg and 3.1mg/kg.In the sediments of the reservoir,both LOP and MLOP were the main OP forms releasing to the overlying water.

关 键 词：西北口水库 沉积物 有机磷 磷形态 释放动力学 

分 类 号：X524[环境科学与工程—环境工程]