纳米二氧化钛沿多级水生食物链的传递

发布时间：2018-06-22 04:23

本文选题：纳米TiO_2 + SDBS　；参考：《浙江工业大学》2015年硕士论文

【摘要】：随着纳米材料广泛并大量应用于人们的日常生活和生产中,其生物效应与环境效应也逐渐引起人们的关注。纳米材料可通过多种途径进入水环境,从而对水生生态系统造成一定的影响。纳米二氧化钛(nano-TiO_2)是重要的纳米材料之一,目前对纳米二氧化钛的研究报道有很多,但大部分集中于对环境中单一生物的毒性效应研究,而沿多级食物链传递的研究报道甚少。纳米二氧化钛由于本身粒径很小且比表面积较大,容易发生团聚而沉降,但是一些表面活性剂如十二烷基苯磺酸钠(SDBS)能吸附在纳米材料上,产生体积斥力或静电斥力使纳米材料稳定悬浮,而表面活性剂是否对纳米材料的生物有效性造成影响尤未可知。故研究纳米二氧化钛沿多级水生食物链传递与富集以及表面活性剂对其生物有效性的影响,对准确评估纳米二氧化钛的环境风险及生态效应至关重要。为了更全面的评价纳米二氧化钛的生物效应,本课题通过建立不同链长的水生食物链,初步探究了纳米二氧化钛以及表面活性剂-十二烷基苯磺酸钠(SDBS)沿二级(丰年虫-斑马鱼)和三级(丰年虫-斑马鱼-鲤鱼)水生食物链的传递与富集规律,测定了纳米二氧化钛在各营养级生物体内的含量及组织分布,并对最高营养级生物进行了组织病理学观察。研究发现,8mg/L的SDBS对100mg/L的纳米TiO_2悬浮液的分散性最好;纳米TiO_2可以沿二级(丰年虫-斑马鱼)和三级(丰年虫-斑马鱼-鲤鱼)水生食物链发生传递与富集。在暴露期,随着时间的延长,纳米TiO_2在鱼体内的蓄积量逐渐增加;在净化期,鱼体内的蓄积量有所降低,说明鱼自身具有一定的自净和解毒机能。经食物链传递后,纳米TiO_2在鱼体内呈现一定的组织分布,蓄积量表现为心最高,肝、肠、腮次之,脑最低。鱼的部分组织也检查出明显的病变,且三级食物链最高营养级生物的损伤组织比二级食物链的要多,受损情况更严重一些。随着SDBS的加入,纳米TiO_2在受试生物体内和组织内的蓄积量明显增加,组织受损程度也有所加剧。
[Abstract]:With the extensive and extensive application of nanomaterials in people's daily life and production, the biological and environmental effects of nanomaterials have attracted more and more attention. Nanomaterials can enter the water environment through many ways, which has a certain impact on aquatic ecosystem. Nano-titanium dioxide (nano-TiO-2) is one of the most important nano-materials. There are a lot of reports on nano-TiO _ 2, but most of them focus on the toxic effect of single organism in the environment, but there are few reports on the transmission of nano-TiO _ 2 along the multi-level food chain. Due to its small particle size and large specific surface area, nano-TiO _ 2 is prone to agglomeration and deposition. However, some surfactants such as sodium dodecylbenzene sulfonate (SDBs) can adsorb on nanometer materials. Volume repulsive force or electrostatic repulsive force is produced to stabilize the suspension of nanomaterials, and it is not known whether surfactants have an effect on the bioavailability of nanomaterials. Therefore, it is very important to study the transfer and enrichment of nano-TiO _ 2 along the multi-stage aquatic food chain and the effect of surfactant on its bioavailability, which is very important to accurately evaluate the environmental risk and ecological effect of nano-TiO _ 2. In order to evaluate the biological effect of nano-TiO _ 2 more comprehensively, this paper established the aquatic food chain with different chain length. The transfer and enrichment of nanometer titanium dioxide and surfactant sodium dodecylbenzene sulfonate (SDBs) along the aquatic food chain of secondary (bumper wormfish zebrafish) and tertiary (bumper insect-zebrafish carp) were studied. The content and tissue distribution of nano-TiO _ 2 in various nutritive organisms were determined, and histopathological observation of the most nutritious organisms was carried out. It is found that the SDBs of 8mg / L have the best dispersity to the suspension of 100mg / L TiO-2, and nano-TiO-2 can be transferred and enriched along the secondary (bumper worms-zebrafish) and third-order (bumper worms-zebrafish-carp) aquatic food chain. During the exposure period, the volume of nano-tio _ 2 in fish gradually increased with the extension of time, and decreased in the purification period, indicating that the fish itself has a certain self-purification and detoxification mechanism. After transmission through the food chain, nano-tio _ 2 showed a certain tissue distribution in the fish, with the highest volume of heart, followed by liver, intestine, gills and brain. Some tissues of fish also showed obvious pathological changes, and the damage of the highest nutritious organisms in the tertiary food chain was more than that in the secondary food chain, and the damage was more serious. With the addition of SDBs, the amount of TIO _ 2 in the tested organisms and tissues increased obviously, and the degree of tissue damage was also increased.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X171

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