微生物和藻类分解对荣成天鹅湖沉积物氮磷释放的影响

以荣成天鹅湖的沉积物和硬毛藻为试材，模拟研究了不同微生物活性和藻类条件下上覆水体氮磷的含量变化，探讨了藻类分解和微生物活性对沉积物营养盐释放的影响。在无藻条件下，不同处理水体的总氮和总磷含量随时间的波动较大，分别变化在0.42~11.71 mg/L和0.02~0.32 mg/L之间；中后期各微生物处理氮磷含量的顺序为氯化汞>葡萄糖、对照>甲醛。藻类分解条件下，水体的总氮和总磷含量远高于无藻条件，含量变幅分别为5.43~34.76 mg/L和0.28~1.80 mg/L；初期水体氮磷含量较高，之后随时间呈下降趋势。试验前期，有藻各处理总氮表现为氯化汞>葡萄糖>对照>甲醛，总磷为氯化汞>葡萄糖、甲醛>对照；后期各处理间差异减小。相同微生物活性下，有藻处理水体的氮磷含量均明显高于无藻条件。试验结束时，无藻组各处理沉积物的微生物活性均较低；而有藻条件下相对较高，各处理顺序为对照>葡萄糖、氯化汞>>甲醛。绿潮藻类分解条件下，微生物对天鹅湖沉积物的氮磷释放有着明显影响；微生物活性越强，沉积物氮磷的释放量越大。

Effects of microorganism and algal decomposition on nitrogen and phosphorus release from the sediments in Rongcheng Swan lake

In Rongcheng Swan lake, the sediments and Chaetomorpha were collected to study the changes of nitrogen and phosphorus contents in water under different microbial activities and algae conditions in the laboratory, and the influence of algal decomposition and microbial activity on the release of nutrients from the sediments was discussed.Under the condition without algae, the contents of total nitrogen and total phosphorus in water at different treatments changed at the range of 0.42~11.71 mg/L and 0.02~0.32 mg/L, which fluctuated over time during the experiment.In the middle and late stages, the order of nitrogen and phosphorus contents at different microbial treatments was mercuric chloride > glucose, control > formaldehyde.Under the condition with algal decomposition, the contents of total nitrogen and total phosphorus in water were much higher than those without algae, which ranged at 5.43~34.76 mg/L and 0.28~1.80 mg/L, respectively.The contents of nitrogen and phosphorus in water were high in the early stage, which decreased with time after that.In the early stage, total nitrogen and total phosphorus contents at different treatments followed the orders of mercuric chloride > glucose > control > formaldehyde and mercuric chloride > glucose, formaldehyde > control, respectively, while the difference among treatments decreased at the late period.Under the same microbial activity, the contents of nitrogen and phosphorus with algae were significantly higher than those without algae.At the end of experiment, microbial activities in sediments were relatively high under the condition with algae, which followed the order of control > glucose, mercuric chloride >> formaldehyde.Under the condition with algal decomposition, microbial activity had a significant effect on nitrogen and phosphorus releases from the sediments in Swan lake.The release amount of nitrogen and phosphorus from the sediments was high when microbial activity was stronger.