摘要
大气复氧是水体中溶解氧的一个重要来源,复氧能力的研究是正确确定水中溶解氧浓度的一个重要课题。通过对大气复氧理论简要分析,指出水体中存在大量气泡情况下,如大坝泄洪下游水体或波浪破碎水体中,不仅需考虑自由液面质量传输,更需考虑气泡界面传质。概括了水体自由界面传质和气泡界面传质计算公式,指出目前还没有一个公式对所有河流水体有较好适用性,而误差较小的公式,也可能漏掉了一个或多个主要的影响因素。引入水体中溶解氧的"有效"饱和浓度和气泡穿透水体的"有效"水深两个参数,指出水中溶解氧的饱和浓度与水深相关,水深越大,溶解氧的"有效"饱和浓度越大,水体中溶解氧浓度愈有可能超饱和。
Reaeration is one of the main sources of dissolved oxygen in water, so the reaeration ability is an important research topic related with determinination of dissolved oxygen concentration in water . The paper first discusses some theoretical aspects of reaeration and points out that air bubble interface transfer must be considered together with free water surface interface transfer when there are many air bubbles in water, such as in the water-body downstream of high dam during spillage or in the wave breaking water. Currently there is no universal equation suitable for every river with respect to air bubble interface transfer coefficient or free water surface transfer coefficient, with most equations having omitted one or several important factors. The effective saturation concentration and the effective depth where air bubbles are entrapped into water are introduced in this paper to explain the relation between DO saturation concentration and water depth. The two parameters see to it that if the water depth increases, the DO effective saturation concentration will increase and the DO concentration in water will be more likely supersaturated.
出处
《科技导报》
CAS
CSCD
2008年第17期89-92,共4页
Science & Technology Review
基金
国家自然科学基金项目(50609011)
关键词
非饱和复氧
超饱和复氧
气泡界面传质
自由液面传质
non-saturated reaeration
supersaturated reaeration
air bubble interface transfer
free water surface transfer
作者简介
程香菊，广州市新港西路135号中山大学工学院海洋工程中心，副教授．E—mail：chengxj@mail．sysu．edu．cn
