水环境中硅藻水华预警和控制技术研究

我国长江以南地区近年来出现了日益严重的硅藻水华污染,对城市水环境生态安全产生了重大影响。本文采用先进的浮游植物分类荧光仪、荧光显微镜和紫外线准平行光束仪,研究了硅藻生长规律,探讨了光合活性、叶绿素含量和藻细胞数量之间的变化规律,识别了其机理性的逻辑关系。结果表明,硅藻细胞数量能够达到108个/L,具有形成硅藻水华的风险。"光合活性"适合作为硅藻预警指标,预警时间能够提前5 d左右。紫外线UV-C能够有效控制硅藻的生长,辐照时间1~16min,有效辐照剂量为100 m J/cm2,应急处理辐照剂量为200 m J/cm2以上。紫外线辐照技术需要周期性地实施,以防止藻类复活。

Study on early-warning ofdiatom bloom in water environment and its control technology

The growth law of diatom is studied herein with the advanced instruments including PHYTO-PAM， fluorescence microscope and UV-C collimated beam apparatus， in which the changing law among the photosynthesis activity， chlorophylla content and cell density of diatom is explored and its intrinsic mechanistic logic relationship is identified as well. The result shows that the cellular amount of diatom can reach to 108 cells/L and then has the risk to form the diatom bloom. The photosynthesis activity is adaptable to be taken as the index for the early-warning， thus the early warning time can be advanced by about 5 days. Meanwhile， the irradiation with UV-C can effectively inhibit the growth of diatom with the irradiation time of 1 to 16 min， effective dosage of 100 mJ/cm2 and emergent treatment dosage of over 200 mJ/cm2. The UV irradiation is necessary to be periodically implemented， so as to prevent diatom bloom from regrowth.