不同浓度镉、砷对海链藻生长特征的影响研究  

Effects of different concentrations of cadmium and arsenic on biological behaviors of Thalassiosira weissflogii

作　　者：魏辉煌 刘冬[1,2,3,4] 袁鹏 田倩[1,2,3] 周洁玉 王顺 李梦圆 周军明 WEI Huihuang;LIU Dong;YUAN Peng;TIAN Qian;ZHOU Jieyu;WANG Shun;LI Mengyuan;ZHOU Junming(CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,Guangdong,China;CAS Center for Excellence in Deep Earth Sciences,Guangzhou 510640,Guangdong,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Marine Environmental Science,Xiamen University,Xiamen 361005,Fujian,China)

机构地区：[1]中国科学院,广州地球化学研究所,矿物学与成矿学重点实验室/广东省矿物物理与材料研究开发重点实验室,广东广州510640 [2]中国科学院深地科学卓越创新中心,广东广州510640 [3]中国科学院大学,北京100049 [4]厦门大学近海海洋环境科学国家重点实验室,福建厦门361005

出　　处：《地球化学》2022年第5期540-548,共9页Geochimica

基　　金：国家自然科学基金面上项目(41772041);国家高层次人才特殊支持计划项目和近海海洋环境科学国家重点实验室(厦门大学)“访问学者基金”(MELRS2006)联合资助。

摘　　要：近年来重金属Cd和类金属As造成的海洋污染日益严重。水生藻类,如硅藻等因其对水体中离子态污染物吸附具有独特的优势,在对Cd和As污染物处理中有巨大的应用潜力。然而,目前的研究大多集中于硅藻对Cd、As等污染物离子吸附能力的评估,而对于处理过程中硅藻生长特性的变化等鲜有涉及,这必然影响到硅藻生物处理法的进一步应用。针对该问题,本研究以典型海洋硅藻——海链藻(Thalassiosira weissflogii)为研究对象,通过分别添加Cd和As的方法,开展实验室硅藻培养,对海链藻的生殖、生产力和个体形貌等特性进行研究,借助细胞计数、叶绿素比色分析、高分辨扫描电子显微形貌观察等方法,探测Cd和As不同浓度梯度下培养所获海链藻的细胞浓度、叶绿素含量及藻体形态等,用以判明不同浓度Cd和As胁迫下硅藻的生长情况和变化特征,为以海链藻为主体的生物修复工程实施提供理论和数据支持。结果表明:海链藻对水体中的Cd与As具有一定耐受性, Cd比As对海链藻毒性更强, 96 h半最大效应浓度(EC50)为3.3 mg/L,因此在实际污水处理工程中,应控制污水中Cd浓度低于该值。在不同生长阶段,较低的Cd添加浓度(0.1、0.5、1.0 mg/L)对海链藻细胞浓度增长表现为“前促后抑”;另外, Cd对单位个数海链藻中叶绿素a含量的作用为“低促高抑”。另一方面,As可使海链藻形态发生明显畸变,因此可作为海洋中As污染的生物指示剂。值得指出的是,海链藻在所有上述环境中,培养168~240 h时,其总叶绿素a增量明显减缓,表明该阶段其光合作用效率降低。上述结果将为海链藻应用于环境污染物Cd和As的生物清除提供理论和基础数据支持。Seawater pollution caused by the release of cadmium(Cd) and arsenic(As) from industrial production is increasing and causing serious environmental problems. Aquatic organisms such as diatoms have potential as phycoremediation agent for Cd and As polluted water. Treating heavy metals using this kind of biological method has recently attracted great interest, and most studies have focused on the adsorption efficiency of biological treatments to remove ionic pollutants in marine waters. However, the effects of Cd and As on the growth and physiology of diatoms using these processes have not been clear, limiting the potential applications of the biological method. In this study, the typical marine diatom Thalassiosira weissflogii were cultivated under different concentrations of Cd and As, and their growth and physiological status were monitored and investigated via cell counting, analysis, and morphology observation using high resolution scanning electron microscope. We obtained cell numbers, chlorophyll a concentrations, and the Cd and As concentrations in the diatom cells from culture medium to evaluate the influence of these two ions. The results indicated that Thalassiosira weissflogii showed a certain degree of tolerance to Cd and As and was a promising phycoremediation agent. Compared to As,Cd showed more toxicity to Thalassiosira weissflogii, with a half-maximum effect concentration(EC50) of 3.3 mg/L. Therefore, the Cd concentration when treating Cd pollution using diatoms should be controlled using less than 3.3 mg/L. At lower concentrations(0.1, 0.5, and 1.0 mg/L) of As in the medium, the diatom cell showed different effects on growth at various growth stages, displaying promotion at the beginning and inhibition at the latter stage during the culturing processes. In addition, low Cd concentration increased the chlorophyll a concentration in a single diatom, whereas high Cd concentration decreased the chlorophyll a concentration.Moreover, a high As concentration(10.0 mg/L) resulted in a great change in the di

关 键 词：硅藻 生物修复 镉 砷 海水污染 

分 类 号：P735[天文地球—海洋生物学] X55[天文地球—海洋科学]