Resistance of the diffusive boundary layer to salt release from saline sediments to freshwater

作     者：GAO Zengwen ZHENG Xilai XU Qinxuan 

作者机构：Key Laboratory of Ministry of Education for Marine Environmental Science and Ecology Ocean University of China Qingdao 266003 China 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2008年第27卷第1期

页      面：23-28页

核心收录：

学科分类：070704[理学-海洋地质] 0709[理学-地质学] 07[理学] 0707[理学-海洋科学] 

基　　金：The National Science Foundation of China under contract No.40572142 the Doctoral Foundation of the Ministry of Education of China under contract No.20040423016 

主　　题：sediment-water interface diffusive boundary layer molecular diffusion salt transport resistance effect 

摘      要：The diffusive boundary layer （DBL） is the zone for matter exchange between surface water and aquatic sediments. To elucidate the influence of DBL on salt release from saline sediments to freshwater, two experiments with or without wind blowing were conducted. According to the experiments, a 3.5 cm DBL is formed above the smoothed sediments at a steady wind field and this thickness is greater than other studies. The observed flux of salt through the DBL is 6% larger than the calculated value from Fick＇ s first law. The results indicate that molecular diffusion is the dominant mechanism for salt transport through the DBL. The presence of DBL suppresses the hydrodynamic enhancement for matter exchange between sediments and overlying water. Therefore, salts in the sediments of a polder reservoir may influence the water quality chronically.