Ye Qing-Qing, Guan Bao-Hong, Li Jun
Department of Environmental Engineering, Zhejiang University, Hangzhou 310027, China.
Huan Jing Ke Xue. 2009 May 15;30(5):1351-6.
The phosphorus pollution of the sediment from Dongxin River, an urban river in Hangzhou, was surveyed. Phosphorus release under various flow velocity (0.002-0.02 m x s(-1)), quality of overlying water (the total phosphorus concentration: 0.18, 0.072 and 0.007 mg x L(-1)), depth of overlying water (5, 10 cm) were carefully studied in a hydraulic simulation setup. The results indicate that phosphorus was feasible to release from the sediment with high ratio of water content (40.09%-68.57%) under alkali condition (pH 7.2-8.3). The phosphorus release was also influenced by high content of phosphorus (1.04-2.51 g x kg(-1)) in the sediment. Phosphorus release was mainly in the form of suspended solid under dynamic hydraulic condition, and depended definitely on flow velocity. The release rate reached 147.36 g x (m2 x h)(-1), which approached the maximum value, at flow velocity 0.008 m x s(-1) (i.e. 0.05 m x s(-1) in archetype). Phosphorus release, especially the initial release rate, was obviously affected by the quality of overlying water. Phosphorus tended to release under river water than tap water. However, the depth of overlying water had little influence on phosphorus release in shallow water. Therefore, it is possible to restrain or enhance phosphorus release by adjusting the hydraulic conditions and the quality of overlying water.
对杭州城市河流东新河沉积物的磷污染情况进行了调查。在水力模拟装置中，仔细研究了不同流速（0.002 - 0.02 m·s⁻¹）、上覆水水质（总磷浓度：0.18、0.072和0.007 mg·L⁻¹）、上覆水深度（5、10 cm）条件下的磷释放情况。结果表明，在碱性条件（pH 7.2 - 8.3）下，含水量较高（40.09% - 68.57%）的沉积物释放磷是可行的。沉积物中高含量的磷（1.04 - 2.51 g·kg⁻¹）也会影响磷的释放。在动态水力条件下，磷的释放主要以悬浮固体的形式进行，且肯定取决于流速。在流速为0.008 m·s⁻¹（即原型中的0.05 m·s⁻¹）时，释放速率达到147.36 g·(m²·h)⁻¹，接近最大值。磷的释放，尤其是初始释放速率，明显受到上覆水水质的影响。与自来水相比，磷在河水中更容易释放。然而，在浅水情况下，上覆水深度对磷释放的影响较小。因此，通过调节水力条件和上覆水水质，有可能抑制或增强磷的释放。
