不同流速下沉积物中六溴环十二烷的释放及再分配规律  

Release and redistribution of hexabromocyclododecane in sediments under different flow velocities

作　　者：王榕 胡煜 高寒 王超[1] 王沛芳[1] 陈娟 WANG Rong;HU Yu;GAO Han;WANG Chao;WANG Pei-fang;CHEN Juan(Key Laboratory of Integrated Regulation and Resource Department on Shallow Lakes,Ministry of Education,College of Environment,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学环境学院,河海大学浅水湖泊综合治理与资源开发教育部重点实验室,江苏南京210098

出　　处：《中国环境科学》2023年第5期2553-2559,共7页China Environmental Science

基　　金：国家重点研发计划(2022YFC3203902);国家自然科学基金资助项目(52022028,52279061)。

摘　　要：六溴环十二烷(HBCD)作为一种典型卤代有机污染物已在河湖沉积物中被广泛检出,但流速变化下HBCD的迁移和释放行为尚不清楚.本文通过模拟5种流速条件,分析不同流速下表层沉积物中HBCD的释放规律以及HBCD在水-沉积物系统的再分配特征.结果表明,沉积物再悬浮的临界流速为0.4m/s,上覆水中HBCD浓度随流速增大而增加,且不同流速下HBCD向上覆水中的释放过程均符合准二级动力学模型.与上覆水不同,流速变化对悬浮颗粒物(SS)中HBCD浓度并无明显影响.相比静水和低流速条件,高流速条件下沉积物中HBCD的释放总量较高,0.6m/s流速下HBCD的释放总量是静水条件的31.6倍.流速是引起沉积物中HBCD再分配的关键因素,HBCD的再分配随流速增大而更加明显.不同流速下,SS中HBCD的分配量在HBCD释放总量中均占主导地位;表层沉积物中HBCD更易向较小粒径沉积物中分配.Hexabromocyclododecane(HBCD),a typical halogenated organic pollutant,has been widely detected in river and lake sediments,but how its migration and release behaviors vary with flow velocity still remains unclear.In this paper,five flow velocities were simulated to characterize the release of HBCD from surface sediments and its redistribution in water-sediment systems.The results show that the 0.4m/s was a critical flow velocity of sedimentary resuspension,and the concentration of HBCD in overlying water increased with flow velocity.The processes of HBCD releasing into overlying water under different flow velocities were in accordance with the quasi-second-order kinetic model.The concentration of HBCD in suspended solid(SS)was not affected by flow velocity changes,which was different from the overlying water.The total amount of HBCD release from the sediment was much higher under high flow velocity than under static water and low flow velocity conditions,being 31.6 times higher under the 0.6m/s than under static water condition.Under different flow velocities,the total amount of HBCD release from sediments were always dominated by the HBCD in SS,and the HBCD in surface sediments was more easily distributed to sediments.Obviously,the flow velocity was the key factor driving the release of HBCD from sediments and its redistribution.

关 键 词：六溴环十二烷 流速变化 水-沉积物系统 释放行为 再分配 

分 类 号：X524[环境科学与工程—环境工程]