太湖梅梁湾和月亮湾春夏两季沉积物扰动下BAPP的转化规律

采用室内模拟试验研究了沉积物扰动下上覆水中可被生物利用颗粒态磷(BAPP)的变化规律,并分析了BAPP与悬浮物中内源磷间的内在联系.试验用沉积物分别于春季和夏季采自太湖梅梁湾和月亮湾.结果表明,沉积物扰动降低了上覆水中生物有效磷(BAP)含量,降至初始状态的40%左右.BAPP也明显降低,其占BAP的百分比稳定在50%左右,梅梁湾春季除外.扰动状态下颗粒态磷(PP)生物有效性显著降低,第12h时,BAPP占PP的百分比仅为10%左右;这与悬浮物中NH₄Cl-P和Fe/Al-P的降低明显相关,但其与 (AAP+NH₄Cl-P)占Tot-P的百分比相关性更好[r=0.565(n=48)].这暗示,沉积物扰动可能延缓了水体富营养化发展进程.

Transformation of BAPP under sediment disturbance of Meiliang Bay and Moon Bay in Lake Tai during spring and summer

The variation of BAPP under sediment disturbance conditions in the overlying water was investigated in the lab, and the relationship between BAPP and internal phosphorus forms on suspended solids was analyzed. The sediments were taken from Meiliang Bay and Moon Bay in Tai Lake during spring and summer. The results show that the concentrations of BAP decreased due to sediment disturbance and were reduced to about 40% of the initial state. At the same time, the concentrations of BAPP were reduced obviously, and the percentages of BAPP to BAP remained at 50%, except of Meiliang Bay in spring. Sediment disturbance improved the reduction of bioavailability of PP. The percentage of BAPP to PP was reduced to about 10% at 12 h, which was attributed to the decrease of NH₄Cl-P and Fe/Al-P on the suspended solids. The relationship between the bioavailability of PP and the percentage of (AAP+NH₄Cl-P) to Tot-P [r=0.565(n=48)] was better. This study implied that sediment disturbance may hurdle the development of water eutrophication.