【作者】 唐承佳；

【导师】 陈振楼； 许世远；

【作者基本信息】 华东师范大学 ， 自然地理学， 2010， 博士

【摘要】 富营养化日益严重的太湖贡湖湾水源地,面临有毒蓝藻的代谢产物微囊藻毒素和蓝藻腐烂分解或次生代谢含硫衍生物的污染威胁。微囊藻毒素是肝癌和肠癌的促发剂,通过生物累积或食物链从肝癌、肠癌高发到生育畸形等多方面对人类健康构成威胁。蓝藻腐烂分解含硫衍生污染物引起水源地水质恶化,使感官水质下降。为保障水源地供水安全,论文依托国家科技支撑计划课题“水源地取水口蓝藻水华削减与水质改善技术研究及示范”专题“水源地取水口蓝藻毒素以及衍生污染物监测”,以太湖贡湖湾水源地及其蓝藻应急消减工程示范区为研究区域,基于卫星遥感影像数据进行太湖蓝藻水华的暴发动态监测；基于酶联免疫吸附测试技术建立快速、简洁的微囊藻毒素检测方法,监测蓝藻应急消减工程示范区实施物理、生物控藻措施后,围格内、外水柱中微囊藻毒素的差异,为水源地水华蓝藻应急消减提供理论基础；基于青海弧菌Q67建立水源地水质急性毒性快速诊断方法,为水源地微囊藻毒素快速、应急监测提供技术支持；建立抽提-固相萃取预浓缩-高效液相色谱检测方法测试水源地生态系统各环境介质中累积的微囊藻毒素；以蓝藻粗提液研究微囊藻毒素对水稻种子萌发和梨形环棱螺的生物毒性；通过实验室内模拟蓝藻腐烂分解过程,建立SPME-GC/MS方法定性检测蓝藻腐烂分解产生的异味物质,定量研究蓝藻腐烂分解的含硫衍生污染物释放规律。主要研究结果如下：(1)应用卫星遥感影像数据监测太湖贡湖湾历年的蓝藻水华暴发动态,监测到2005年以来,以前很少发生蓝藻水华的贡湖湾,每年开始有大面积蓝藻水华覆盖,2007年以后发生水华的频率明显增加。2009年7、8月在贡湖湾发生大面积蓝藻水华。从太湖贡湖湾的历史水质数据发现,1987年-2003年太湖贡湖湾水质指标平稳波动(TP最高0.1mg·L-1),NH3-N缓慢上升。2005年贡湖水质迅速恶化,NH3-N最高达1.42mg·L-1,TP最高达0.25mg·L-1,Ch1-a最高达47.6μg·L-1。2009年在研究区域内测得TP最高达0.269mg·L-1,水华暴发时Ch1-a最高达703.04μg·L-1。(2) 2009年3月至2010年2月水源地水柱中溶解态微囊藻毒素浓度范围为ND-0.554μg·L-1。围格外各样点水柱中溶解态MCs 3、4月,7、8月和12月浓度较高。围格外各样点水柱中总MCs自水华暴发后明显增加,10月出现下降趋势。空白对照围格5水样中溶解态MCs低于其它围格,可能是由于生物控藻措施的生态胁迫效应和浮水植物的聚藻效应增加了围格内溶解态微囊藻毒素的释放。围格内各样点水柱中总MCs在蓝藻水华暴发后明显增加。除围格1总MCs低于空白对照围格5外,围格2、3、4总MCs均高于空白对照围格5。由此推断围格1采取的鲢鳙鱼控藻效果优于其它生物控藻工程措施。(3)围格内溶解态MCs由于生态胁迫效应高于同时期围格外水柱中溶解态MCs,水动力条件较好的围格外采样点9和10溶解态MCs含量较低,但受外源MCs污染的风险也较大。水柱中总MCs除围格1外,围格内总MCs平均浓度高于围格外水柱中总MCs,围格和浮水植物减弱了水动力条件,营造了蓝藻水华原地暴发的环境条件,因此利用围格等物理控藻工程阻挡外源水华蓝藻污染是可行的,但不适用于消减局部水域蓝藻。浮水植物在工程示范区内控藻效果较差,容易促使微囊藻聚集,并有可能因为生态胁迫效应加剧溶解态MCs污染。(4)基于淡水发光菌青海弧菌Q67建立了水源地水质的急性毒性快速诊断方法。确定了pH值5.0-9.0、起始菌密度10万-20万和测试时间20-30min为青海弧菌Q67急性毒性测试体系的最佳测试条件。微囊藻毒素MC-LR单一污染物发光细菌Q67半数发光抑制浓度(EC50)为1.96mg·L-1。(5)将青海弧菌用于检测微囊藻毒素的毒性时,Q67急性毒性效应不同于对重金属、有机污染等毒性物质的毒性效应,测试微囊藻毒素导致的微毒水体时,毒性效应不仅表现为轻微抑制发光,更多情况下表现为刺激发光。太湖贡湖湾水源地蓝藻应急消减工程区围格内各样点水质Q67急性毒性测试结果变化比较一致,3、4月水质急性毒性效应为刺激发光,6、7、8月为轻微抑制发光,9、10月为强刺激发光。不同时段各样点水柱溶解态MCs的平均浓度和Q67样点平均急性毒性效应之间相关性较明显,相关系数为0.643。考虑到微囊藻毒素对青海弧菌Q67急性毒性效应的独特性,水样Q67急性毒性相对发光率低于80%或刺激发光相对发光率高于120%,可作为水质急性毒性综合评价无毒趋向微毒的参考指标。(6) 2009年贡湖湾蓝藻水华以惠氏微囊藻为主,藻浆产毒能力9月初的藻类最大(174.27μgMC-LR·g-1DW、162.69μg MC-RR·g-1DW)。富集在野生茭白、四角野菱和红菱三种植物各器官内的微囊藻毒素以茭白叶内富集量最高(10.44μg MCs·g-1 DW),四角野菱幼果中微囊藻毒素的富集量为1.97μMC-LR·g-1DW、0.69μg MC-RR·g-1DW,高于四角野菱根的生物富集量。梨形环棱螺体内富集的MC含量与2005年在太湖梅梁湾和2006年在巢湖螺类测得的富集量相当(环棱螺(整体动物)的MCs最大值为4.66μg·g-1DW)。野生白鲢肠和肝脏中MC-LR的最大富集量分别为7.22μg·g-1 DW和7.63μg·g-1 DW,MC-RR的最大富集量分别为5.51μg·g-1 DW、3.75μg·g-1 DW。白鲢鱼肉中MC的富集量(3.69μg·g-1DW)与2006年在太湖梅梁湾采集的白鲢(1.65μg·g-1DW)相比稍有增加。太湖贡湖湾水源地采集的底泥样品中测得MC最大值为1.18μgMC-LR.g-1 DW和O.72μg MC-RR·g-1DW。4组样品共测试12个样品,只有1个样品中未检出MC-LR.(7)不同浓度梯度的微囊藻毒素对水稻种子萌发的生理学指标如吸水率、发芽率、根系活力TTC、叶绿素含量以及叶绿素a与叶绿素b的比值等均表现出高浓度微囊藻毒素的抑制效应较强。梨形环棱螺对微囊藻毒素的蓄积作用明显,蓄积系数为1.86。梨形环棱螺的MC-LR半致死剂量约为15.49 - 28.79μg·L-1。外推向人群时,人类的MC-LR安全限量参考浓度为0.025μg MC-LR eq·kg-1 BW(0.015-0.029μg MC-LR eq·kg-1 BW).(8)蓝藻腐烂分解时微囊藻毒素的最大释放量出现在第3或第4天,最大释放量MC-LR和MC-RR分别是本底值的60倍和64倍,最大浓度分别为8.32μg MC-LR·L-1、14.04μg MC-RR·L-1,换算成蓝藻的产毒能力分别为2.46μg MC-LR·g-1 FW和4.31μgMC-RR·g-1FW.(9)建立了固相微萃取-气质联用技术(SPME-GC/MS)检测含硫衍生污染物的方法。在水源地水样、蓝藻腐烂水样和腐烂藻样中以SCAN扫描方式均检测出β-环柠檬醛、吲哚、苯酚、甲基苯酚和硫醇硫醚类等蓝藻代谢产物或次生代谢产物。蓝藻腐烂产物异味物质的组份分析证实2007年5月底贡湖湾的污水团是大量蓝藻堆积腐烂所致。(10)蓝藻腐烂水样中二甲基三硫的最大释放量出现在第7天或第8天,最大释放量达本底值的383倍。腐烂藻样释放的二甲基三硫10天内分别在第3天和第9天出现峰值；腐烂水样中二甲基二硫的释放过程平缓,持续时间较长；蓝藻腐烂水样二甲基硫在第8天或第9天出现最大释放量,其释放过程缓慢,释放量波动范围较大。基于上述研究结果,太湖贡湖湾水源地正经受着水华蓝藻代谢产物和含硫衍生物的污染威胁,建立完善的蓝藻水华预警体系和采取有效的蓝藻消减工程措施是水源地取水安全的重要保障。由于青海弧菌应用在微囊藻毒素污染的水体测试时生物急性毒性效应的独特性,应用青海弧菌Q67快速诊断蓝藻水华水质变化的快速诊断技术还需进一步完善；SPME-GC/MS定性地检测出蓝藻腐烂分解释放的含硫衍生异味物质,但由于从水样中萃取挥发性含硫有机物的回收率和重现性都较低,有待继续摸索和选择更有效的样品预处理方法进行精确定量以及分析蓝藻腐烂分解产物的释放规律。更多还原

【Abstract】 Mass growth of cyanobacteria (blue-green algae), leading to the production of blooms, accretion of pollutions occurs in eutrophic waterbodies of Gonghu Bay in Lake Taihu. The water source area planed for Wuxi city. Microcystins and derivative volatile organic surfocompound, the metabolites of harmful blue-green algae and decompound or secondary metabolites of algae, is primary pollutant. Microcystin is inducer of liver and intestinal cancer, which also could threat other aspects of human health through food chain or bioaccumulation such as liver cancer and intestinal cancer to the high incidence of birth deformities and volatile organic surfocompound derived from algae decompose pollutants cause deterioration of water quality water source, so that sensory deterioration of water quality. To protect the supply security from water sources, the paper subsidized by the national science and technology supporting project "The technical and demonstrative research of the cyanobacteria bloom subduction and water quality improvement at water intake in water sources area.", "The project of monitoring on cyanobacterial toxins and derivative volatile organic surfocompound in the water source".The area of cyanobacteria bloom subduction exemplars and water sources in Gonghu Bay in Lake Taihu was the Survey region, Based on ELISA, we built the fast and handy method to detect microcystins.and to monitor demonstration project in the region which was implemented the physical, biological algae control measures, both inside and outside the water column around barricading and provid technical support for emergency monitoring microcystins in water sources area. Based on luminous bacteria Vibrio qinghaiensis sp-Q67, we construct the acute toxicity diagnostic monitoring system on water quality in water sources area. Base on extraction and solid phase extraction method, we use HPLC to detect microcystions accumulated in ambient medium (eg. Substrate sludge and aquatic plant) in aquatic ecosystem. We study the MCs biotoxicity on the process of Hybrid rice seed germination and Bellamya purificata using the crude extract from cyanobacteria bloom. Through the simulation of the cyanobacteria decompose process, we construct SPME-GC/MS methods to detect the odor substances decomposed and to trace the release laws of derviative volatile organic sulfocompound from decayed cyanobacteria. The results are as follows:(1) Monitor the cyanobacteria blooms in Lake Taihu through application of satellite remote sensing data. There were cyanobacteria blooms occurring at Gonghu Bay since 2005, and it occurred more frequently after 2007. The water quality in Gonghu Bay had smooth fluctuations from 1987 to 2003 concluded from the historical data. The maximum TP was 0.1 mg-L-1 and total Nitrogen increased slowly. The pollution loading increased sharply in Gonghu Bay since 2005. The maximun total Phosphorus reached up to 0.25 mg·L-1 and NH3-N reached up to 1.42 mg·L-1. The maximum Chlorophyll a was 47.6μg·L-1. The Chlorophyll a in water blooms up to 703.04μg·L-1 and total Phosphorus reached up to 0.269 mg·L-1 in survey region in 2009.(2) The concentration range of MCs dissolved in water column of Gonghu Bay was between no detected and 0.554μg MC-LR eq·L-1 from Mar.2009 to Feb.2010. Dissolved MCs in all barricadings water column variated a higher concentration in March, April, July, August and December. The total MCs significantly increased after cyanobacterial bloom, downward trend in October. Around the barricading 5, dissolved MCs in water column more than dissolved MCs in other barricading, may be due to biological control measures of ecological stress effects of algae and floating plants, and the effect of increasing into a algae polymer, so as to cause release of microcystins. Various points around inside the total MCs in the water column after the outbreak of algal blooms increased significantly. In addition to the total MCs around barricading 1 than control barricading 5, barricading 2,3,4 were higher than the total MCs around the barricading 5. We conclude that Carps taken control cyanobacteria in barricading 1 works better than other biological measures.(3) Dissolved MCs of the waer column inside of barricading may be due to effects of ecological stress was higher than the same period, particularly around the water column dissolved MCs, hydrodynamic conditions is particularly good around September and October sampling points lower content of dissolved MCs, but the pollution risk is higher from external sources. In addition to the total MCs in the water column around a barricading, the barricading around the average concentration of total MCs especially around the water column above the total MCs, The barricading and floating plants around the hydrodynamic conditions weakened, creating an outbreak of cyanobacteria blooms in situ environmental conditions, so use around the physical control of cell blocks of exogenous cyanobacteria works cyanobacteria contamination is possible, but not to reduce the local water cyanobacteria, floating plants in the demonstration area of less effective control of cyanobacteria, Microcystins easy to promote aggregation, and possibly because Ecological effects of increasing stress dissolved MCs pollution.(4) Based on freshwater luminous bacteria Vibrio qinghaiensis sp Q67, we established a rapid diagnostic method of acute toxicity test. The Vibrio qinghaiensis sp Q67 acute toxicity best test conditions is determined as pH value of 5.0-9.0, the initial bacterial density of 0.1-0.2 million and the test time 20 - 30 min. The median effect concentration (EC50) of MC-LR on Vibrio qinghaiensis sp Q67 was 1.96 mg·L-1.(5) The acute toxic effects of Vibrio qinghaiensis sp Q67 is different from the toxic effect by heavy metals and organic pollutants when Vibrio qinghaiensis sp Q67 used to detected the toxicity of microcystin.Detecting the toxic water result in microcystin, the toxic effects not only appearing a slightly inhibitory action,but also stimulatory effect. The detect results of Vibrio qinghaiensis sp Q67 acute toxic effects in different sampling sites in the cyanobacteria subduction exemplars of Gonghu Bay are identical. Water acute toxic effects appearances stimulatory effect in Mar and April, slight inhibitory action in Aug and strong stimulatory effect in Sept and Oct. In different period of time, the correlation of average concentration of dissolved MCs and the mean acute toxic effects of Vibrio qinghaiensis sp Q67 is obvious in each sampling sites, and the correlation coefficient is 0.643. The acute toxic effects of Vibrio qinghaiensis sp Q67 is particular when detected by microcystin. When relative luminous efficiency of Q67 acute toxic effects is less than 80% or the stimulatory ratio is more than 120%, the non-toxic water transformed into toxic, which can be used as a reference for water acute toxic assessment.(6) Cyanobacteria blooms occurred in Gonghu Bay in Lake Taihu, Microcystis wesenbergii was primary algae in summer 2009. The maximum microcystins producted by cyanobacteria appear early in September (174.27μg MC-LR·g-1 DW and 162.69μg MC-RR·g-1 DW). microcystin accumulated in various organs of Zizania aquatica, Trapa quadrispinosa Roxb and Trapa bispinosa Osbeck, concentration in leaves of Zizania aquatic is highest (10.44μg MCs·g-1 DW), The amount of microcystin concentration in putkin of Trapa quadrispinosa Roxb are 1.97μg MC-LR·g-1DW and 0.69μg MC-RR·g-1 DW, higher than bioaccumulation in root of Trapa quadrispinosa Roxb. Bioaccumlation of microcystin was the same concentration in Bellamya purificata collected from Meiliang Bay in Lake Taihu 2005 and Lake Caohu 2006 (maximum concentration is 4.66μg·g-1DW). The maximum concentration of MC-LR in Silver carp intestine and liver was 7.22μg·g-1 DW and 7.63μg·g-1 DW, the maximum concentration of MC-RR was 5.51μg·g-1 DW and 3.75μg·g-1 DW. Bioaccumulation of MCs in muscle of silver carp collected in Gonghu Bay 2009 is 3.69μg·g-1DW and Bioaccumlation of MCs in muscle of silver carp collected from Meiliang Bay in 2006 is 1.65μg·g-1 DW. There was a little increase. The maximum microcystin accumulated in sediment collected from Ginghu Bay is 1.18μg MC-LR·g-1 DW and 0.72μg MC-RR·g-1DW. The detected samples were 12, but MC-LR was not detecte only in one sample.(7) Different concentrations of microcystins on seed germination in physiological indicators such as water absorption, germination rate, root activity TTC, chlorophyll content and chlorophyll a and chlorophyll b ratio of Hybrid Rice showed high concentrations of the inhibitory effect of microcystin more serious. Bellamya purificata is the role of microcystins accumulation significantly, the storage coefficient is 1.86. semi-lethal dose of MC-LR on Bellamya purificata is about 15.49-28.79μg·L-1. To analogize, the human MC-LR safety limit reference concentration maybe 0.025μg MC-LR eq·kg-1 BW (0.015-0.029μg MC-LR eq·kg-1 BW).(8) On the third or the fourth day of cyanobacterial decomposing, microcystins has the biggest release emission, the release emission of MC-LR and MC-RR is 60 and 64 times higher than the background value, respectively. The maximum concentration was 8.32μg MC-LR·L-1, 14.04μg MC-RR·L-1, converted into a algae toxin production capacity were 2.46μg MC-LR·g-1 FW and 4.31μg MC-RR·g-1FW.(9) In this study, a new method, (SPME-GC/MS) was built to detect the derivative volatile organic surfocompound. The primary or secondary metabolites by Cyanobacteria in the kinds of water samples, such asβ-cyclocitral, indol, methylphenol, mercaptan and thioether were detected with SCAN. With the analyzes of the components of the odour substances, which is the production of the putrefactive Cyanobacteria, we can proved that the polluted water in the Gonghu Bay in May,2007 is as a result of the bulk decayed Cyanobacteria.(10) The maximum emission of Dimethyl trisulfide in water samples of decaying blue-green algae was appeared on the first 7 days or 8 days, which is amounted to 383 times of the background value. The peaks of the Dimethyl trisulfide emission in the decaying algae samples was appeared on the third day or the ninth day during ten days; dimethyl disulfide released gently in rot water samples, and lasted a long time; The maximum emission of dimethyl sulfide was appeared on the eighth day or the ninth day in blue-green algae decompose water. In water source samples, the maximum detected concentration of Dimethyl trisulfide is 2344.79 ng·L-1.Based on these above-mentioned results, the water source of Gonghu Bay is suffering the cyanobacteria metabolites and sulfur derivatives the pollution threat, cyanobacterial blooms in the establishment of comprehensive early warning system and to take effective measures algae abatement project is to get water safety important safeguard. We established a rapid toxicity diagnostic technique for Vibrio qinghaiensis sp. Q67. The technique needs to be further improved; SPME-GC/MS accurately detect the release of algae decompose odor of sulfur derivative materials, but extracted from water samples of volatile organic sulfur recovery and reproducibility are low, yet continue to explore and select the sample preparation method for accurate quantitative analysis of the release law of the sulfur in the decaying cyanobacteria.更多还原