Environmental effect of sediment dredging in lake (I): the role of sediment dredging in reducing internal phosphorous release

通过为期一年的疏浚模拟试验,在试验室培养疏浚与对照柱样研究了底泥疏浚对内源磷释放的控制效果.结果发现,疏浚表层30cm能够有效的消减沉积物中不同形态磷含量与孔隙水中PO43--P含量.在一年的试验周期内,疏浚和对照柱沉积物-水界面的PO43--P通量分别为-143.8至14.4与-237.3至3047.6μg/（m2·d）,疏浚柱沉积物-水界面的磷通量总体上低于未疏浚对照的磷通量,尤其是在温度较高的月份,从2006年3-10月疏浚柱沉积物-水界面磷释放通量显著低于未疏浚对照柱,疏浚沉积物的磷的释放潜力低于未疏浚对照沉积物研究结果表明,在外源磷得到有效控制的前提下,底泥疏浚是消减研究区内源磷负荷有效的技术手段.;A laboratory experiment was carried out to study the effects of sediment dredging on phosphorus (P) release from lake sediments using incubation of undredged (control) and dredged cores through a year. We found that dredging the upper 30cm layer of the sediment can efficiently reduce the interstitial PO43P concentration and different P forms in the sediment. The P fluxes of the undredged and dredged cores ranged from-237.3 to 3047.6ng/(m2·d) and-143.8 to 14.4ng/(m2·d), respectively. The fluxes of the dredged cores were generally lower than those of the undredged (control) cores, with significan P<0.05 Derences between the fluxes of the dredged and undredged cores occurring between March and October of 2006. The sediment P in the dredged cores had a lower release potential than those in the control cores. Our results suggested that dredging may be a useful approach for decreasing internal P loading in Lake Taihu once the external P loading is effectively controlled in advance.