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Nanomaterials research on the biological effects of algae

Author: ZhangNing
Tutor: JinXingLong
School: Tianjin University of Technology
Course: Environmental Science
Keywords: Nanomaterials Chlorella Scenedesmus obliquus Four Scenedesmus Biological effects
CLC: Q948
Type: Master's thesis
Year: 2011
Downloads: 180
Quote: 1
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Abstract

In recent years, mass production of nano-materials and bio-security so widely used by more and more attention, how to effectively and accurately evaluate the toxicity of nanomaterials is a hot topic in today's research. Algae as primary producers in aquatic environments play an important role, it is also commonly used in toxicology studies of the test organisms, the study of nanomaterials toxicity to algae is very necessary. And the use of a series of algal toxicity of nanomaterials toxicity screening system that not many studies. In this paper, Chlorella (Chlorella vulgaris), using algae (Scenedesmus obliquus) and four algal (Scenedesmus quadricanda) three kinds of algae as a test organism to study nanomaterials on algal cell growth conditions, chlorophyll a content and soluble protein content, compared the toxicity of nanomaterials size and different algal species sensitivity of nanomaterials, and algae toxicity screening of nanomaterials applicability of this method is a preliminary exploration, designed to nanomaterials Safety evaluation of certain basis. This paper studies the content and made the following conclusions: (1) Based on algal growth inhibition experiments, carried out nine kinds of nano nano metal oxide powder, and two of the three dispersions Influence of algal growth conditions. The results showed that different nanomaterials on algae growth conditions produce different degrees of impact, lower concentrations of nano-materials, you can promote or inhibit the growth of algae is not obvious, with the increasing concentration of inhibitory effects of nanomaterials gradually increased. nZnO of three algae showed strong toxic effects, are highly toxic; nNiO, nTiO2 (anatase and rutile), nFe3O4 belongs poisoning; nSiO2, nFe2O3 (γ-and α-type), nAl2O3 low toxicity; nTiO2 Toxicity of anatase is greater than the toxicity of rutile, nFe2O3 the γ type is much less than the toxicity of α-type toxicity. Colorless nAg less toxic than the brown nAg, but were higher than nZnO. Chlorella toxic effects of nanomaterials are more sensitive, four Scenedesmus the least sensitive. (2) the effects of different nanomaterials on algal cells chlorophyll content of a preliminary study of the mechanism of toxicity of nanomaterials. The results showed that low concentrations of nanomaterials suspension on algal cells produce certain stimulation, can promote the synthesis of chlorophyll a, thus increasing algal biomass, and growth inhibition experiments in which the experimental results confirm each other. When nanomaterials suspension concentration increases to a certain extent, beyond the self-regulating capacity of algal cells, nano-materials on the show as a toxic substance, destroying algae cell chloroplast structure, affecting its normal physiological function. (3) by measuring nanomaterials on algal cells of soluble protein content, to further explore the toxic effects of nanomaterials. The results showed that nano-materials at lower concentrations when algal cells can promote protein synthesis, the concentration is too high will hinder protein synthesis, which fully verify the previous experimental research conclusions and further revealed Toxicity of nanomaterials mechanism. (4) Select a higher degree of sensitivity for the test organism chlorella study of the same type, different sizes of ZnO and the same size, different types of nano-titanium dioxide and nano silver material contained toxic effects, and to explore the algae toxicity screening of nanomaterials applicability of this approach. The results show that, according to the algal toxicity test can effectively distinguish between different types and sizes of nanomaterials toxicity differences between. In summary, nano-materials on algae growth conditions, chlorophyll a and soluble protein etc have certain biological effects; toxicity of nanomaterials and their particle size, crystal type and other factors; algae toxicity test method can filter series nanomaterials biological toxicity.

Nanomaterials research on the biological effects of algae

Abstract

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