底泥再悬浮对磷的吸收和固定作用研究

Laboratory Investigation on Phosphorus Adsorption and Immobility Under Sediment Re-suspension

研究了周期性加入外源磷的情况下,底泥再悬浮对上覆水中磷的吸收和固定效果。结果表明,底泥再悬浮可以促进上覆水中磷向底泥迁移。36 d内共吸收17.5 mg磷(以DIP计),远高于底泥静止状态下磷的吸收量。底泥吸收外源磷后,磷平衡浓度EPC0显著升高。尽管再悬浮状态下EPC0高于静止状态,但在相同EPC0值情况下,再悬浮底泥可吸附更多的磷,说明底泥再悬浮增强了底泥对磷的固定作用。

The efficiency of phosphorus （P） adsorption and immobility was investigated in laboratory experiments. Addition of KH2PO4 into the operated experimental units, with and without （i.e., static） sediment re-suspension, were made similar to the external P input and carried out periodically. The results show that sediment re- suspension could promote the migration of P from the overlying water to the sediments. The amount of the accumulative P adsorption onto the sediments was up to 17.5 mg P under the conditions of sediment resuspension over a 36-day period, and it was evidently higher than that （12.04 mg P） under static conditions. After 36 d of P adsorption by the both sediments, the value of equilibrium phosphate concentration （EPCo） increased obviously. Although the value of EPCo under sediment re-suspension was more than that under static conditions, under the conditions of the same EPCo, the sediments under re-suspension could adsorb more P than that under static conditions. It is suggesting that sediment re-suspension could enhance the immobility of P.