Liu Guo-Feng, Zhong Ji-Cheng, He Jun, Zhang Lei, Fan Cheng-Xin
State Key Laboratory of Lake & Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Huan Jing Ke Xue. 2009 Sep 15;30(9):2520-6.
The purpose of the paper was to study the biogeochemical response of Fe-S-P in sediments in an extremely conditions (DO = 0.14 mg x 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 72 mg x 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 and PO4(3-) -P in sediments, also the concentration of Fe-P in sediment was lower than that of natural sediments. The concentration of PO4(3-) -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 Fe2+ concentration increased in the sediment in reducing environment (the Dithio-Fe increased 30 micromol than that the natural sediments); moreover, the increased Fe2+ 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 50 micromol x g(-1) higher than natural water column).
本文的目的是研究极端条件下（溶解氧=0.14毫克/升，氧化还原电位=-89.3毫伏）沉积物中Fe-S-P的生物地球化学响应，这种极端条件是由死亡的蓝藻席引起的。结果表明，表层沉积物中的有机质浓度较高，而且由于死亡的蓝藻细胞沉降到沉积物上，表层沉积物中的有机磷浓度比天然沉积物增加了72毫克/千克。与铁结合的磷在较低的氧化还原电位和水中缺氧的情况下溶解，这增加了沉积物中活性铁和磷酸根 - 磷的含量，沉积物中铁磷的浓度也低于天然沉积物。沉积物间隙水中磷酸根 - 磷的浓度高于天然沉积物，它会释放到上覆水中，可能有助于下一次藻华爆发。此外，在还原环境中沉积物中活性二价铁浓度增加（二硫代铁比天然沉积物增加了30微摩尔）；而且，增加的二价铁导致结晶态铁氧化物转变为非晶态铁氧化物。水体的厌氧条件导致酸挥发性硫化物浓度增加并形成大量硫化物，包括硫化氢的产生，硫化氢会逸散到大气中，但这对水柱生态健康有害；表层沉积物中的硫化物也因更多的酸挥发性硫化物产生而增加（死亡蓝藻席区域的硫化物比天然水柱高50微摩尔/克）。
