河道底泥再悬浮状态对磷平衡浓度的影响

Influence of sediment re-suspension on the equilibrium phosphate concentration (EPC_0) of river course sediments.

研究了河道底泥再悬浮状态下,底泥磷平衡浓度(EPC0)的变化规律,并分析了底泥中不同形态磷与EPC0的相关性.结果表明,底泥再悬浮可以促进上覆水中溶解性磷酸盐(SRP)向底泥迁移.与原底泥相比,底泥再悬浮预处理后,EPC0明显下降.EPC0在10d左右达到平衡状态(0.032mg/L),显著低于原底泥(0.059mg/L)与对照实验底泥(0.062mg/L).预处理后的EPC0与总磷(TP)、生物有效磷(BAP)、铁结合态磷(BD-P)呈显著负相关.因此推测,与原底泥和对照实验底泥相比,底泥再悬浮状态下形成的形态磷的性质显著改变.

The variations of equilibrium phosphate concentration （EPC0） under sediment re-suspension condition were investigated in laboratory experiments with sediments taken from the campus canal. The correlations between EPCo and the different phosphorus forms in the sediments were analyzed. Sediment re-suspension could promote the migration of soluble reactive phosphorus （SRP） from overlying water to sediments. EPC0 of re-suspended sediments was decreased obviously compared with that of the original sediments. The equilibrium state of EPC0 was reached after about 10 days for the re-suspended sediments （0.032mg/L）, evidently lower than the original sediments （0.059mg/L） and the sediments in control experiment （0.062mg/L）. Remarkable negative correlations were shown between the EPC0 of re-suspended sediments and its total phosphorus （TP）, bioavailable phosphorus （BAP） and iron-bond phosphorus （BD-P）. Therefore, it was supposed that the sediment re-suspension may obviously change the properties of sedimentary phosphorus forms.