浒苔衰亡过程中营养盐的释放过程及规律

为探究浒苔衰亡过程中营养盐的释放规律，在实验室内模拟浒苔衰退过程中主要营养盐氮、磷的释放过程。结果表明:浒苔藻体重量和叶绿素含量分别呈现下降趋势，第12 d时，漂浮浒苔和培养浒苔的藻体重量分别下降到0.46 g和0.79 g，叶绿素含量分别下降到0.64 mg/g和0.99 mg/g。实验组水体中的磷和总无机氮（DIN）浓度均呈现先下降后上升的趋势，漂浮浒苔实验组的磷和DIN浓度增加量高于培养浒苔实验组，到第12 d时，漂浮浒苔实验组的磷和DIN浓度分别达到3.95 μmol/L和76.55 μmol/L。从第6 d开始漂浮浒苔向水体中大量释放NH₄-N，使得总无机氮浓度迅速升高。大量聚集漂浮浒苔的衰亡会引起水体缺氧，并释放大量的营养盐，导致水体的恶化，因此必须及时的清理海面聚集的漂浮浒苔。

Study on process of nutrient release during the decay of Ulva Prolifera

The decaying process of floating Ulva prolifera was simulated in laboratory to study laws of the nutrient release.Results showed that the weight and chlorophyll content of U.prolifera had a declining trend, respectively.Floating and cultured U.prolifera weight decreased to 0.46 g and 0.79 g at 12 d, respectively.The chlorophyll content of floating and cultured U.proliferaalso decreased to 0.64 mg/g and 0.99 mg/g at 12 d.The phosphorus and total inorganic nitrogen (DIN) concentrations in the experimental group had an upward trend after the first drop.Besides, increased amount of phosphorus and DIN concentrations in the floating U.prolifera experimental group was higher than the cultured U.prolifera group.At 12 d, the phosphorus and DIN concentrations in the floating U.prolifera experimental group reached to 3.95 μmol/L and 76.55 μmol/L.Ammonia nitrogen was released to water from 6th day in the floating U.prolifera experimental group, leading to the rise of DIN.The decay of a large amount of floating U.prolifera resulted in oxygen deficiency in water and released large amounts of nutrients, leading to deterioration of water quality.Therefore, floating U.prolifera should be cleaned up quickly.