向家坝库区沉积物磷形态分布及释放风险  

Distribution characteristics of sediments phosphorus species of Xiangjiaba Reservoir and release risk

作　　者：李清雪 靳慧慧 赵海萍 孙健[2] LI Qingxue;JIN Huihui;ZHAO Haiping;SUN Jian(School of Energy and Environmental Engineering,Hebei University of Engineering,Handan 056038;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084)

机构地区：[1]河北工程大学能源与环境工程学院,邯郸056038 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《环境科学学报》2022年第9期182-190,共9页Acta Scientiae Circumstantiae

基　　金：国家重点研发计划(No.2016YFC0502204)。

摘　　要：采用改进的连续提取法研究了向家坝库区沉积物中有机磷(OP)和无机磷(IP)的各赋存形态及分布特征,讨论了各形态磷的生物可利用性和释放风险.结果表明,向家坝库区沉积物总磷(TP)含量为388.9~616.4 mg·kg^(-1),总体处于安全级别.库区沉积物磷形态以惰性碎屑态无机磷(De-P_(i))和残渣态有机磷(Re-P_(o))为主,两者共占TP质量分数的60%以上,呈上游高下游低的趋势,流域地质背景是主要的影响因素.以可交换态无机磷(Ex-P_(i))、铝结合态无机磷(Al-P_(i))、铁结合态无机磷(Fe-P_(i))、可交换态有机磷(Ex-P_(o))、铁铝结合态有机磷(Fe/Al-P_(o))之和来估算生物可利用磷(BAP),BAP/TP来评价沉积物中磷的释放风险,BAP含量为23.0~91.1 mg·kg^(-1),BAP/TP为6.2%~17.1%.向家坝水库沉积物磷的释放风险较低.库区沉积物BAP储量为767.68 t,对向家坝水库上覆水磷浓度的潜在贡献为0.148 mg·L^(-1),是导致未来库区水质恶化的重要因素之一,应加强对库区内源磷的释放管理.The forms of phosphorous(P)species as well as the distribution characteristics of the sediments from Xiangjiaba reservoir were investigated by the modified sequential extraction method for inorganic phosphorous(IP)and organic phosphorous(OP).The bioavailability and release risk of P species were discussed.The results showed that total phosphorus(TP)in sediments ranged from 388.9 mg·kg^(-1)to 616.4 mg·kg^(-1),which was at the safety level as a whole.The main P species of sediments from Xiangjiaba reservoir were inert detrital apatite inorganic phosphorus(De-P_(i))and residual organic phosphorus(Re-P_(o)),which account for 60%of the TP totally,and represented the tendency of high in upstream and low in the downstream,the geological background of the basin was the main influencing factor.Bioavailable phosphorus(BAP)included exchangeable inorganic phosphorus(Ex-P_(i)),aluminum bound inorganic phosphorus(Al-P_(i)),iron bound inorganic phosphorus(Fe-P_(i)),occluded phosphorus(Oc-P_(i)),exchangeable organic phosphorus(Ex-P_(o))and Fe/Al bound organic phosphorus(Fe/Al-P_(o)).BAP/TP was used to evaluate the risk of P release in sediments.The content of BAP ranged from 23.0 mg·kg^(-1)to 91.1 mg·kg^(-1),while BAP/TP was from 6.2%to 17.1%,indicating a low risk of P release in Xiangjiaba Reservoir.The reserve of BAP in the sediments of the reservoir was 767.68 t,and the potential contribution to the P concentration in the overlying water of Xiangjiaba Reservoir was 0.148 mg·L^(-1),which was one of the vital factors for the water deterioration in the future Therefore,it’s crucial to strengthen the release management of internal phosphorus in the reservoir.

关 键 词：向家坝水库 沉积物 磷形态 生物可利用磷 释放风险 

分 类 号：X524[环境科学与工程—环境工程]