不同水温时底泥扰动对不同形态磷分布的影响

研究了江南地区典型水温条件下,底泥扰动对上覆水中不同形态磷迁移的影响.结果表明,不同水温条件下,底泥扰动均有利于上覆水中溶解态磷(即溶解性总磷酸盐(DTP),包括溶解性正磷酸盐(DIP)和溶解性有机磷(DOP))向底泥迁移.与对照试验相比,不同水温时的扰动均导致DIP/TP和DTP/TP明显降低.与初始状态(第0天时)相比,扰动导致DIP/TP分别降低了39.61百分点(冬季水温)和17.38百分点(夏季水温),而DTP/TP则分别降低了39.16百分点(冬季水温)和19.06百分点(夏季水温).相反,对照试验中,DTP/TP分别上升了24.90百分点(冬季水温)和23.37百分点(夏季水温).这说明底泥扰动促进了溶解态磷向颗粒态磷(PP)的转化.

Effect of sediment disturbance on the phosphorus forms migration under different water temperature

Base on the batch experiments, the effects of sediment disturbance on the migration of phosphorus forms in overlying water were investigated under the conditions of the typical water temperature of South China. The variation of different phosphorus forms (DIP, DTP, PP, TP) under winter water temperature (WWT) and summer water temperature (SWT) was monitored, the results showed that sediment disturbance could promote the migration of dissolved phosphorus (DIP and DTP) from overlying water to sediments. DIP and DTP in overlying water was re-duced rapidly with the sediment disturbance, while in control group (without sediment disturbance), the DIP and DTP in overlying water varied slowly. Compared with the control group(at 0 d), sediment disturbance could reduce the value of DIP/TP and DTP/TP under WWT and SWT. After 40 days experiments period, the average DTP/TP value in control group increased by 24.90%(WWT) and 23.37% (SWT), while with the help of sediment disturb-ance, average DIP/TP value decreased by 39.61% (WWT) and 17.38% (SWT) and DTP/TP decreased by 39.16% (WWT) and 19. 06 % (SWT), respectively. These result pointed that sediment disturbance could facilitate the trans-formation of phosphorus from dissolved forms to particulate forms.