底泥扰动下藻类对不同形态磷在水体中分布的影响

研究了反复扰动与藻类共存条件下,水体中溶解性磷、颗粒态磷、生物有效磷的分布规律,并分析了颗粒物质物理化学吸附与藻类生物利用对水体中磷消失的贡献率.结果表明,扰动抑制了水体中藻类生长,叶绿素a增加量仅为3.53μg/L(初始30μg/L)和4.80μg/L(初始120μg/L),而无扰动下该值分别为21.36μg/L(初始30μg/L)和14.49μg/L(初始120μg/L).并且,溶解氧水平和p H值均低于无扰动状态.扰动导致水体中总磷和颗粒态磷显著增加,但溶解性总磷(DTP)和溶解性磷酸盐(DIP)均有所降低.对于DTP而言,扰动状态下,颗粒物质吸附占90%,而无扰动下,则降低至60%,相应地,藻类生物利用则增加至40%.无论扰动与否,BAP基本处于稳定状态,而BAPP占BAP的百分比则有所增加.扰动状态下BAPP占PP的百分比明显低于无扰动状态.这暗示了扰动对水体中磷迁移和转化的作用大于藻.

Distribution of different phosphorus forms in the overlying water under sediment disturbance with algae

Distribution of dissolved phosphorus (P), particulate P (PP) and biavailable P (BAP) was investigated in the overlying water under sediment disturbance with algae. In addition, the contribution to P disappearance by particulate matter adsorption and algae uptake was investigated. The results show that sediment disturbance handled the algae growth and the concentration of chlorophyll a increased by 3.53 μg/L (initial chlorophyll a 30 μg/L) and 4.80 μg/L (initial chlorophyll a 120 μg/L). But, the value increased by 21.36 μg/L (initial chlorophyll a 30 μg/L) and 14.49 μg/L (initial chlorophyll a 120 μg/L) without disturbance. Accordingly, the concentration of dissolved oxygen and pH value with disturbance was lightly higher than that without disturbance. Under sediment disturbance, total P and PP increased, while dissolved total P (DTP) and dissolved inorganic P (DIP) decreased. The degradation was attributed to the particulate matter adsorption and algae uptake. The contribution of particulate matter adsorption is up to 90% under sediment disturbance. On the contrary, the contribution decreased to 60% without disturbance, but the algae uptake increased to 40%. The concentration of BAP stabilized in the experiment with and without disturbance, but the percentage of bioavailable particulate P (BAPP) increased. The percentage of BAPP to PP with disturbance is lower than that without disturbance. It is suggested that the contribution of P migration and transformation by particulate matter adsorption is more important, compared with algae uptake.