摘要
底泥再悬浮时,颗粒和孔隙水会交替影响底泥污染物的释放通量。通过循环水槽实验,分别以氯化钠和磷来代表典型的非吸附性污染物和吸附性污染物,研究了再悬浮颗粒和孔隙水释放污染物的不同特征。研究表明,再悬浮磷的释放对底面切应力的反应要比氯化钠迟缓,但前者释放通量要比后者大。恒定水流下底泥再悬浮污染物释放过程可以分为两个显著阶段:起动初期2 h内,颗粒和孔隙水共同作用,两者对上覆水体中水溶性污染物的贡献之比最高为3∶1,此时悬浮颗粒处于解吸污染物状态;2 h后,悬浮颗粒转为吸附污染物状态,释放通量时正时负。长期悬浮时泥沙颗粒始终为负释放状态,而孔隙水对总通量的贡献之比最高可达到60∶1。上覆水体中吸附性污染物液固相浓度比值先增大后减小,悬浮后期始终处于较低值。推导了底泥释放通量的理论公式,理论结果是线性缓慢增加的,而实验值的增加趋势是先快后慢。
During the process of pollutants release due to sediment re-suspension, particles and pore water alternately affect the release flux to the overlying water. Conservative tracer （NaC1） and reactive tracer （Phosphorus） were re- spectively used as the contaminants to characterize the different ways of particles and pore water under hydrodynamic conditions in a laboratory flume. Studies have shown that reactive tracer responded more slowly to the bed shear stress than the conservative tracer did. Pollutants release process under constant flow can be divided into two significant sta- ges： The suspended particles were in the desorption state during the first two hours, the ratio of water-soluble pollu- tants contribution between particles and pore water got a maximum values of 3： 1. After two hours, the particles begun to adsorb contaminants instead, and the contribution rate of the particles was always negative while pore water＇s contri- bution rate peak reached 60： 1. The partition coefficient of pollutants first increased and then stays low, and the reac- tive pollutants mainly made an impact on water quality in the form of particular. Comparing derived formulas with the experimental dates, the theoretical result increased linearly while the increasing trend of experimental one is slow after the first rapid increment.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2013年第4期537-542,共6页
Advances in Water Science
基金
国家自然科学基金资助项目(10972134
11032007)~~
关键词
底泥污染物
再悬浮颗粒
孔隙水
释放通量
液固浓度比
sediment pollutants
suspended particle
pore water
release flux
partition coefficient
