【作者】 王志刚；

【导师】 刘文清； 张玉钧；

【作者基本信息】 中国科学技术大学 ， 环境科学， 2008， 博士

【摘要】 水体富营养化导致浮游植物过度增殖,形成“水华”和“赤潮”,严重危害人类健康和经济可持续性发展。浮游植物浓度实时在线分类测量是“水华”和“赤潮”预警的基础。然而,目前尚缺少可用于浮游植物浓度实时在线分类测量的方法和设备。因此,本文研究了基于活体荧光光谱的浮游植物分类测量方法,在此基础上研发了浮游植物水下原位荧光仪,实现了浮游植物浓度的实时在线分类测量。本文通过对16种淡水富营养化优势浮游植物的活体三维荧光光谱和激发荧光光谱特征的研究,将淡水浮游植物分成三种光谱组:蓝色组、绿色组和褐色组。由于淡水浮游植物中绝大多数生成藻毒素的种类都属于蓝色组,因此该光谱分类方法实现了有毒浮游植物和无毒浮游植物的区分。在浮游植物光谱分类的基础上,本文提出了三种基于活体荧光光谱的浮游植物分类测量方法,分别是基于三维荧光光谱和PARAFAC模型的浮游植物分类测量测量方法,基于激发荧光光谱和多元线性回归算法的浮游植物分类测量方法和基于特征激发荧光波段和多元线性回归算法的浮游植物分类测量方法。对实验室配制的混合浮游植物样品的测量结果证明了上述三种浮游植物分类测量方法的可行性。根据特征激发荧光波段浮游植物分类测量原理,本文进一步提出了基于多波长LED的浮游植物分类测量方法。在此基础上设计了以多波长LED阵列为激发光源的浮游植物水下原位荧光仪系统,利用该系统可实现对浮游植物浓度的实时、在线的分类测量。文章详细介绍了整个系统的设计思路以及硬件和软件系统的设计方案。同时,通过实验室配制的浮游植物样品测量实验分析了系统的测量性能。利用水下原位荧光仪系统对巢湖西半湖20个点的总叶绿素α浓度和三种光谱组叶绿素α浓度进行了测量。同时以分光光度法和HPLC标志色素法分别测量了上述各点水样的总叶绿素α浓度和三种光谱组叶绿素α浓度。结果表明,原位荧光仪测得各点总叶绿素α浓度与分光光度法测量结果具有良好的线性相关性,相关系数为0.93861。原位荧光仪和HPLC标志色素法测得的蓝色组、绿色组和褐色组叶绿素α浓度值线性相关系数分别为0.79158、0.97896和0.58063。外场实验结果表明了多波长LED浮游植物水下原位荧光仪在实际应用的可靠性。更多还原

【Abstract】 Eutrophication causes excess proliferation of phytoplankton in water and usually brings into water bloom and red tide,which greatly damages to human health and sustainable development of economy.Real time,on line and classified determination of phytoplankton concentration is the basis of early alarming of water bloom and red tide.However,proper determining methods and instruments which can be used for real time,on line and classified determination of phytoplankton concentration are not available.Therefore,based on in vivo fluorescence spectra,classified determining methods of phytoplankton concentration were studied and a phytoplankton fluorometry which can be used for real time,on line and classified determination of phytoplankton concentration was designed in this dissertation.In vivo three dimensional excitation-emission fluorescence spectra and excitation fluorescence spectra of 16 species of phytoplankton which are dominant in eutrophic fresh water were studied.Fresh water phytoplankton were divided into three spectra groups according to the in vivo fluorescence spectra characteristics, which are blue group,green group and brown group.Due to the fact that nearly all of the phytoplankton in freshwater which release toxins are included in the blue group, the above spectral classification realized the differentiation of the phytoplankton which release toxins and those which do not release toxins.Based on the spectral classification,in this dissertation three classified determining methods for phytoplankton concentration were put forward.The first one is based on three dimensional excitation-emission fluorescence spectra and PARAFAC model,the second one is based on excitation fluorescence spectra and multivariate linear regression,and the third one is based on the characteristic excitation fluorescence wavelength band and multivariate linear regression.The analysis results of mixed phytoplankton cultures which are prepared in laboratory proved the feasibility of the three classified determining methods.According to the principle of the classified determining method which is based on the characteristic excitation fluorescence wavelength band,another classified determining method for phytoplankton concentration using multi-wavelength LEDs as excitation light source was further put forward.Based on the determining method, a phytoplankton fluorometry which used multi-wavelength LED array as excitation light source was designed.With the phytoplankton fluorometry,real time,on line and classified determination of phytoplankton concentration can be realized.The entire design idea for the fluorometry and the design scheme for the hardware and software were detailed introduced.The measurement performance of the fluorometry was analyzed by the determination experiments for the phytoplankton cultures which were prepared in laboratory.Total chlorophyll a concentration and chlorophyll a concentration of three spectra groups of 20 sites in western Chaohu lake were determined by the phytoplankton fluorometry.Meanwhile total chlorophyll a concentration and chlorophyll a concentration of three spectra groups were measured by spectrophotometer method and marker pigment HPLC method in laboratory respectively.The results show that total chlorophyll a concentration determined by phytoplankton fluorometry has a good linear relationship with that determined by spectrophotometer method,the linear correlation coefficient is 0.93861.The linear correlation coefficients for chlorophyll a concentration of blue group,green group and brown group determined by phytoplankton fluorometry and those determined by marker pigment HPLC method were 0.79158、0.97896 and 0.58063 respectively.The field experiment results proved the reliability of the phytoplankton fluorometry in practical application.更多还原