【作者】 江成；

【导师】 何义亮；

【作者基本信息】 上海交通大学 ， 环境工程， 2014， 博士

【摘要】 青草沙（QCS，Qingcaosha）水库作为上海市新水源地，淡水资源充足，供水规模占全市原水供应的50%以上，受益人口超过1000万人，其水质好坏直接关系到人民群众的生命健康。QCS水库一旦发生蓝绿藻暴发，大量的藻毒素等有害物质就可能进入水体，这将给整个上海市的工业用水、居民生活用水带来极大的危害，给各方面带来严重的负面影响。QCS水库位于长江入海口，处于亚热带季风气候区，因此QCS库区水域常年会受到小、中、大等不同等级风力影响，风力的作用会引起库区水体不同程度的波浪，不同强度的“风生浪”对水体产生不同程度的扰动，直接影响着藻类微生物的生长；由于水流的水力作用，在局部范围水体形成紊流，对水体中的浮游植物产生扰动作用，影响水体中藻类微生物的生长。为了探讨QCS水库中水体扰动对藻类微生物生长和水体富营养化的影响，本研究以铜绿微囊藻和水华鱼腥藻为目标蓝藻微生物，以月牙藻、蛋白核小球藻和斜生栅藻为目标绿藻微生物，在实验室人工气候箱内进行培养。通过模拟“风生浪”及水流等产生的水体扰动，研究不同强度的扰动对蓝绿藻微生物生长以及光合作用的影响；以水华鱼腥藻和月牙藻为目标蓝藻微生物和绿藻微生物，探讨水体扰动对共培养中的藻属之间的生长与竞争关系；通过研究CO2限制、光限制以及温差等影响藻类微生物生长的机制，分析水循环物理控藻技术在QCS水库的应用；对QCS水库营养化指标与状态进行分析，分析库区藻类微生物影响因素。通过一系列深入的、系统的机制实验研究和QCS水库工程实验研究，可以得出以下研究结论：1）在低浓度氮磷和高浓度氮磷两种培养条件下，设计不同扰动强度对代表性蓝绿藻微生物进行纯培养实验。结果表明，扰动可以促进藻类微生物的生长，其影响机理并非单纯地影响营养盐的分布与传输，而是可以直接对藻类微生物的光合作用产生影响，即提高其光合效率和电子传递速率等。水体扰动在一定程度上会促进水体表面CO2和O2的交换，增加藻类微生物的光合活性和光合速率，从而对控制藻类微生物的生长与暴发产生不利影响；2）在低浓度氮磷和高浓度氮磷两种培养条件下，设计代表性蓝绿藻微生物在不同扰动强度下共培养与纯培养的对照实验。结果表明，蓝藻微生物和绿藻微生物之间存在明确的生长竞争机制。扰动可以对蓝藻微生物和绿藻微生物的光合作用竞争机制产生影响并对蓝藻微生物的生长形成一定程度的抑制。由于蓝藻微生物是藻毒素的主要生产者，这种竞争性抑制是具有积极意义的；3）水循环物理控藻系统通过在一定范围内产生垂向提升和平向扩散的水力扰动，一方面形成较大的CO2受限、光受限以及温差等干扰和抑制藻类微生物的生长；另一方面通过扰动对蓝绿藻微生长竞争机制产生影响从而抑制蓝藻微生物的生长。QCS水库的实证实验也验证了这一结果；4）QCS水库位于长江入海口，库区常年受到季风和海陆风的强烈影响，使得库区水体受“风生浪”影响明显，另外水库引水与取水的周期较短的特点，水体的流动性较大，因此“风生浪”、水体流速等产生的扰动对库区藻类微生物的生长产生着复杂和综合的影响。扰动总体上会通过加速藻类微生物的光合作用和水体表面CO2和O2的交换而促进藻类微生物的生长；另一方面，这种扰动也会对蓝绿藻微生物的光合作用竞争机制产生影响从而抑制蓝藻微生物的生长，有利于对藻毒素产生的控制。更多还原

【Abstract】 The Qingcaosha reservoir (QCS reservoir) is located along the Yangtze Estuary in thenorthern part of Changxing Island in Shanghai, China. QCS reservoir is a new water sourcein Shanghai, and is rich in freshwater resources from the Yangtze River. The water supplycapacity covers50%of the total water supply in Shanghai. More than10million peoplebenefit from it. The water quality of QCS reservoir is directly related to people’s lives andhealth. As an important water source, QCS reservoir plays a crucial role in affectingShanghai citizen’s health. Like other lakes and reservoirs, the QCS reservoir is also facingthe challenge of environmental deterioration: eutrophication and algae bloom. If algaebloom is excessive in the reservoir, a lot of harmful matters such as algae toxins enter thewater body. The water will pose a serious threat to the industrial water and domestic waterin Shanghai. The QCS reservoir is located in the Yangtze River estuary, which is thesubtropical monsoon climate zone. The water forms different turbulence intensities under“wind generating wave”. Water turbulence may directly affect the algal growth. On theother hand, the water flow may also form water turbulence, which also directly affects thealgal growth.In order to further explore how water turbulence affects the algal growth andeutrophication in the QCS reservoir water, the following work was done as shown in thepaper:1) We studied the effect of water turbulence on the growth and photosynthesis ofblue-green algae in the laboratory. The experimental blue algae include Microcystisaeruginosa and Anabaena flos-aquae, the green algae include Selenastrum bibraianum,Chlorella pyrenoidosa and Scenedesmus obliqnus.2) The paper studied the effect of waterturbulence on competition and photosynthetic responses of Anabaena flos-aquae andSelenastrum bibraianum in the laboratory.3) We studied the effect mechanisms which water turbulence affects on growth and photosynthesis of the algae in the laboratory.4) Byanalyzing the mechanisms CO2-limited，light-limited and the temperature differenceaffecting the algal growth, we studied the effect of water circulation algae controltechnology (WCACT) in controlling algal growth and eutrophication in QCS reservoir.5)We analyzed the eutrophication status of the water in QCS reservoir, and analyzed theeffect factors of the algal growth in QCS reservoir water.By a series of laboratory and engineering experiments in QCS reservoir, the followingresults were obtained:1) Under two culture modes of low nitrogen&phosphorus concentrations media andhigh nitrogen&phosphorus concentration media, the difference in water turbulenceintensity affected growth and photosynthesis of the single-culture blue-green algae. Theresults showed that water turbulence may accelerate algal growth. The effect mechanism isthat water turbulence accelerates algal growth by affecting its photosynthesis (includingphotosynthetic efficiency and electron transport rate), it does not only affects thedistribution and transmission of nutrient in media or water. Water turbulence increasesexchange between CO2and O2in water surface, having adverse effect on controlling thealgal growth and breakouts in water.2) Under two culture modes of low nitrogen&phosphorus concentrations media andhigh nitrogen&phosphorus concentration media, the experiment studied the growth of theco-culture blue-green algae. The results showed that there is definite competitionmechanism between the blue algae and the green algae. Water turbulence affectscompetition by affecting blue-green algae photosynthesis, and may inhibit the blue algalgrowth to a certain extent. Because the blue algae is the main producer of algae toxins, thecompetition mechanism may decrease the content of algae toxins in water. Thecompetition mechanism has a positive significance and importance for water quality safetyin QCS reservoir.3) The WCACT formed the vertical water flow by vertical ascending and diffusedwater flow by horizontal diffusion in its controlling range. Then the water flow generateswater turbulence. On one hand, CO2-limited，light-limited and the temperature differenceinhibited the algal growth. On the other hand, water turbulence inhibited the blue algalgrowth by the competition mechanism of blue-green algae. The result was verified byengineering experiment in QCS reservoir. 4) In QCS reservoir, there are many factors that affect the algal growth. Interaction ofthese factors results in complex and comprehensive effects of water turbulence on theblue-green algal growth. On the whole, water turbulence accelerates the algal growth byincreasing algal photosynthesis and exchange between CO2and O2in water surface. On theother hand, water turbulence inhibits the blue algal growth by the photosynthesiscompetition mechanism of blue-green algae, and may decrease the content of algae toxinsin QCS reservoir water.更多还原