中文摘要：

对因藻华大量聚集死亡而造成水体呈强还原环境（DO=0.14 mg·L^-1,Eh=-89.3 mV）的黑水团区中Fe-S-P的生物地球化学变化特征进行研究.结果表明,藻细胞残体的沉降使得黑水区沉积物表层有机质含量显著增加;因藻细胞残体的贡献,沉积物表层中Org-P含量急剧增加（比非黑水区多72 mg·kg^-1）;受较低Eh的影响,沉积物中与Fe结合的磷出现解析,使得黑水区沉积物中活性铁和PO43-P含量增加,黑水区中沉积物间隙水PO43--P要远高于非黑水团区,表明其有向上覆水释放的趋势;造成沉积物中Fe-P含量比非黑水区中的要低.在强还原条件下沉积物中铁的氧化物呈现出由结晶态向无定形态转化的趋势（Dithio-Fe比非黑水区高达30μmol.g-1）,从而使得可供生物利用的活性铁含量增加,这为藻华再次发生提供了有利条件.黑水区表层沉积物中酸可挥发性硫化物（AVS）在初始阶段大量增加,但后期由于形成了H2S气体逸散到水体中其含量反而减少;表层沉积物硫化物含量也呈增加现象（比非黑水区表层沉积物中要高50μmol·g^-1）.

英文摘要：

The purpose of the paper was to study the biogeochemical response of Fe-S-P in sediments in an extremely conditions（DO=0.14mg·L^-1, Eh=-89.3 mV）,which was caused by the dead-cyanobacterial mats.The results showed that organic matter concentration in surficial sediment was higher,and also the Org-P concentration in surface sediments increased 72mg·kg^-1 than those of natural sediments for the dead-cyanobacterial cells sedimentation on the sediment.The phosphorus bound Fe was dissolved in lower Eh and anoxia in water and it increased the content of activated Fe andPO^3-4-P in sediments,also the concentration of Fe-P in sediment was lower than that of natural sediments.The concentration ofPO^3-4-P in interstitial water in sediments was higher than that of natural sediments,it would release to the overlying water and could be helpful to the next algae blooms outbreak.Also the activated Fe^2＋ concentration increased in the sediment in reducing environment（the Dithio-Feincreased 30 μmol than that the natural sediments）; moreover,the increased Fe^2＋ caused the crystalline iron oxides to transform to the amorphous iron oxides.The anaerobic conditions of the water caused the AVS concentration increased and formed massive sulfides,including the production of H2S,which would escape to the atmosphere,but it would be harmful to water column ecological health;the sulfides also increased in surficial sediment for the more production of AVS（the sulfides in dead-cyanobacterial mats district was 50μmol·g-1 higher than natural water column）.