扰动对水体富营养化的改善作用

Effect disturbance on the improvement of eutrophic water

利用人工构建的模拟水体系统,观察搅拌和曝气条件下水体中氮磷含量和形态的变化规律,研究和探讨了扰动对水体富营养化的改善。结果表明:(1)扰动对上覆水体氮的去除效果不明显,但是能够有效促进底泥中氨氮向水体扩散,从而使底泥中氮含量明显降低,运行99 d后,曝气反应器中底泥总氮含量从初始3.46 g.kg-1降至0.68 g.kg-1,仅为对照反应器的1/4;(2)搅拌对上覆水中磷的去除效果最佳,反应器运行期间,总磷的平均去除率为37%左右;(3)扰动能增加底泥中微生物的数量和多样性,为污染物的生物降解提供了良好的基础。合理运用扰动能够提高水中溶解氧含量,改善微生态环境,增加微生物的数量和种类,有利于水体富营养化的改善。

A simulated river system was used to investigate the change of nitrogen and phosphorous concentration and form transformation under control, stirring and aeration conditions. The influence of disturbance on the improvement of eutrophic water was also discussed. Results showed as followings： （1）the affect of disturbance on nitrogen removal from overlying water is not distinct, however, disturbance can enhance nitrogen release from the sediment, thus can decrease the nitrogen concentration in the sediment significantly. After 99 days＇ operation, the total nitrogen in the sediment of stirring reactor decreased from the initial 3.46 g/kg to 0.68 g/kg, which is only approximately 1/4 of the control reactor; （2）Stirring has the best performance to the removal of phosphorous from overlying water. During 55 days＇ operation, the average phosphorous removal is approximately 37%. （3） Disturbance can enhance the microbial quantity and diversity effectively, which provides a good foundation for the biodegradation of pollutants. Reasonable application of disturbance can help the increase of DO in the water and improvement of the ecological environment, thus can enhance the microbial quantity and diversity and benefit the improvement of eutrophic water.