三峡水库典型支流磷素赋存形态特征及其成因  

Characteristics of Phosphorus Speciation and Genesis in Typical Tributaries of the Three Gorges Reservoir

作　　者：杨凡 王丽婧[2] 纪道斌[1] 李虹[2] 李莹杰[2] 李鑫 许杨 田盼 吴雅婷 YANG Fan;WANG Li-jing;JI Dao-bin;LI Hong;LI Ying-jie;LI Xin;XU Yang;TIAN Pan;WU Ya-ting(College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China;Eco-Environment Research Center of Yangtze River Economic Belt,Chinese Research Academy of Environmental Sciences,Bejing 100012,China;College of Foreign Languages,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学水利与环境学院,宜昌443002 [2]中国环境科学研究院长江经济带生态环境研究中心,北京100012 [3]三峡大学外国语学院,宜昌443002

出　　处：《环境科学》2021年第2期688-698,共11页Environmental Science

基　　金：国家重点研发计划项目(2017YFC0404702);三峡后续工作项目(2017HXXY-05);国家自然科学基金重大计划项目(91647207);国家自然科学基金青年科学基金项目(51709096)。

摘　　要：采用2018年三峡水库低水位期(6月)、蓄水期(9月)和高水位期(12月)对库区内的典型一级支流——香溪河与神农溪回水区水质、水动力及环境因子的监测数据,对比分析了三峡水库内的典型支流在水库不同调度期时水体中磷素的存在形态及成因.结果表明,香溪河与神农溪库湾水体总磷(TP)质量浓度变化范围分别为0.049~0.168 mg·L^(-1)和0.059~0.152mg·L^(-1),均满足水华暴发0.02 mg·L^(-1)这一阈值.支流库湾水体中总磷(TP)质量浓度均表现为:蓄水期>高水位期>低水位期,正磷酸盐(DP)质量浓度表现为:蓄水期低水位期>高水位期,颗粒态磷(PP)质量浓度表现为:低水位期>高水位期>蓄水期,Pearson相关性分析显示,支流库湾水体中的总磷和正磷酸盐与水体的温度和pH之间存在显著相关性,温度与pH是影响沉积物及消落带土壤磷素释放的关键因素.三峡水库在低水位期与高水位期运行时,支流库湾水体中总磷(TP)均以颗粒态磷(PP)为主要存在形态,颗粒态磷(PP)所占总磷(TP)的质量分数分别均达到了75%和60%以上,蓄水期时库湾水流流速减缓,颗粒态磷(PP)的沉降作用增强,总磷(TP)以溶解态磷(DTP)为主要存在形态.A comparative analysis of phosphate occurrence and its genesis during different dispatching periods of representative level I tributaries of the Three Gorges Reservoir was conducted. For this,water quality,hydrodynamic force,and environmental data were examined for backwater areas of the Xiangxi River and Shennong River during the low-water-level period(June),storage period(September) and high-water-level period(December) in 2018. The results suggest that the mass concentration of total phosphorus(TP) in the water body of the coves of Xiangxi River and Shennong River range from 0. 049 mg·L^(-1) to 0. 168 mg·L^(-1) and 0. 059 mg·L^(-1) to 0. 152 mg·L^(-1),respectively,surpassing the 0. 02 mg·L^(-1) threshold for algal blooms. The mass concentration of TP,DP(orthophosphate),and PP(particulate phosphorus) in the coves of the tributaries were ranked as follows: storage period > high-waterlevel period > low-water-level period for TP;storage period > low-water-level period > high-water-level period for DP;low-water-level period > high-water-level period > storage period for PP. Based on Pearson’s correlation coefficients,TP and DP were significantly correlated as well as temperature and pH,which are the key factors influencing the phosphorus in soils and sediments in the waterlevel-fluctuation zone. During the low-water-level and high-water-level periods of the Three Gorges Reservoir,the TP in the coves of the tributaries mainly exists as PP,accounting for more than 75% and 60%,respectively. The flow in the coves of the tributaries slows during storage periods,meaning that settlement of PP is enhanced,changing the dominance of TP to dissolved total phosphorus(DTP).

关 键 词：三峡水库 低水位期 蓄水期 高水位期 香溪河 神农溪 总磷 正磷酸盐 颗粒态磷 

分 类 号：X522[环境科学与工程—环境工程]