溶解氧对底泥扰动状态下水体中磷去除和固定的影响

以太湖梅梁湾底泥和上覆水为研究对象，通过实验室实验研究了底泥扰动状态下溶解氧水平（2～4mg／L、5～6mg／L、7～8mg／L）对上覆水中磷去除和固定的影响。结果表明，底泥扰动和溶解氧水平对上覆水中磷迁移有明显影响。扰动时间延长，溶解性磷酸盐（DIP）和溶解性总磷（DTP）均呈降低的趋势；但溶解氧水平提高，上覆水中DIP和DTP浓度有所增加。底泥扰动和溶解氧水平改变了悬浮物上不同形态磷的数量分布。随着溶解氧水平提高，NH4Cl-P（1～5d平均值）和Fe／Al—P（1～5d平均值）含量及其占总磷（Tot—P）的百分比均呈逐渐降低的趋势。另外，闭蓄态铁铝结合态磷（Fe／Al—P）占Fe／Al—P的比值从51．2％（2～4mg／L）增加至54．1％（7～8mg／L）。

Effect of dissolved oxygen on phosphorus removal and immobilization under sediment disturbance conditions

The effect of the concentration of dissolved oxygen （2- 4 mg/L, 5 -6 mg/L, 7 .8 mg/L） on phosphorus removal and immobilization was investigated under sediment disturbance conditions in lab. The sedi- ments and overlying water were taken from Meiliang Bay in Taihu Lake as the materials. The results show that sediment disturbance and the concentration of DO affected phosphorus removal from overlying water and the dis- tribution of phosphorus forms in suspended solids. The dissolved inorganic phosphorus （DIP） and dissolved total phosphorus （DTP） decreased gradually with the increase of disturbance time. However, The DIP and DTP in- creased with the increase of DO. The distribution of phosphorus forms in the suspended solids changed due to sediment disturbance and DO. The concentrations of NH4Cl-P （mean, from 1 d to 5 d） and Fe/Al-P （mean, from 1 d to 5 d） decreased gradually and the percentage of both phosphorus forms to Tot-P decreased. In addi- tion, the percentage of occluded Fe/Al-P in Fe/Al-P increased from 51.2% （2 -4 mg/L） to 54.1% （7 . 8 mg/L）.