水环境中光活性人工纳米材料的团聚/分散特性及其与蓝藻水华相互作用机制研究

In recent years, the environmental impact of manufactured nanomaterials (MNs), which is one type of new pollutant, has been attracted more and more attention.The MNs would influence the growth activity of cyanobacteria significantly because of their special physical and chemical properties, especially some of them can be activated by solar light to form reactive radicals. Thus, the MNs would influence the occurence of cyanobacteria bloom and the production of microcystin. On the other hand, the wind-induced wave and solar light will influence significantly the aggregation/disaggregation properties of NMs, thus influence the interaction of NMs and cyanobacteria. Therefore,in this project, titania and ZnO are chosen as typical light active nanomaterials.Two typical kinds of cyanobacterias (Microcystis aeruginosa and Anabaena) are chosen as models. Then,the effects of as-nanomaterials on the growth activity, production and releasing of microcystin for the two cyanobacterias are investigated under the considerasion of solar irradiation and wind-induced wave. The aim is to exposure the integrated effect and mechanism of occurance of cyanobacteria bloom affected by wind-induced wave,light active nanomaterials.The results would provide academic evidence for the remediation of lakes coexisted with MNs and cyanobacteria.

人工纳米材料作为一种新型的污染物，其对环境的影响近年来受到广泛关注。由于人工纳米材料具有一系列特殊的物理化学特性，特别是光活性的纳米材料在太阳光的激发下能够产生各种活性自由基，在进入水环境后，可能会影响蓝藻的生长活性、毒素产生及释放规律，从而影响蓝藻水华的发生；另一方面，风浪扰动、太阳光照等对纳米材料的团聚/分散特性也具有重要的影响，从而影响纳米材料与蓝藻的相互作用。针对以上问题，本项目拟选择金属氧化物TiO2和ZnO为典型光活性人工纳米材料；选择富营养化水体中的典型水华蓝藻铜绿微囊藻和鱼腥藻作为研究模型；在综合考虑太阳光照、风浪扰动条件的情况下，研究光活性人工纳米材料对水华蓝藻生长活性、毒素产生和释放规律的影响机理，旨在揭示实际水环境中光活性人工纳米材料对蓝藻水华发生影响的复合效应及作用机制。研究结果将为人工纳米材料与蓝藻共存条件下蓝藻水华的调控和湖泊复合污染治理提供理论依据。

随着纳米技术的快速发展，纳米工业迅速崛起，纳米材料在生产及使用的过程中将不可避免的进入到水域环境中。由于纳米材料特殊的理化特性，他们可能威胁到环境安全甚至影响人体健康。其中，光活性纳米材料所带来的影响尤为重要，在太阳光的激发下，纳米材料能够产生自由基，这将改变水生生物的生长环境，甚至影响其生长发育。本研究选择金属TiO2和ZnO作为代表性的光活性纳米材料；选择水生食物链的初级生产者铜绿微囊藻，同时也是蓝藻水华的典型藻种作为研究对象。深入研究在铜绿微囊藻存在的情况下纳米材料的环境行为（聚集、沉降）和光化学特性的改变，也详细的研究了纳米材料对藻类的生长、胞外有机物及藻毒素释放的影响。结果表明藻类引起纳米材料的环境行发生改变，进而影响其光化学特性，另一方面，纳米材料的变化也改变了藻类的生长特性。本研究结果对了解复杂水域环境下纳米材料的环境行为及其毒性具有重要意义，同时也对控制蓝藻水华发生具有一定的指导作用。