發(fā)布時(shí)間：2018-01-08 01:22

  本文關(guān)鍵詞：尾礦庫植物根系發(fā)育的分形特征及對(duì)植物鈾分布的影響　出處：《南華大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 分形結(jié)構(gòu) 植物根系 分維數(shù) 鈾濃度 鈾尾礦

【摘要】：尾礦庫是一個(gè)長(zhǎng)期潛在的放射性污染源,它的環(huán)境治理是各國所面臨的嚴(yán)峻問題,其中植物生態(tài)修復(fù)已成為學(xué)術(shù)界的熱點(diǎn)。植物修復(fù)對(duì)尾礦生態(tài)環(huán)境質(zhì)量的改善具有重要的現(xiàn)實(shí)意義,因此放射性污染物與植物的相互作用也得到了重視。植物根系分維數(shù)與體內(nèi)累積鈾含量關(guān)系的研究,可為植物修復(fù)的環(huán)境風(fēng)險(xiǎn)評(píng)價(jià)提供指導(dǎo)意義。本文以生長(zhǎng)在尾礦之上的常見植物為研究對(duì)象,分析植物根系發(fā)育的分形特征,探究植物重量、長(zhǎng)度與分維數(shù)之間的關(guān)系;研究尾礦庫植物根系發(fā)育的分形特征對(duì)植物鈾分布的影響關(guān)系,探尋適宜生長(zhǎng)在尾礦庫環(huán)境且對(duì)鈾元素具有一定吸附優(yōu)勢(shì)的植物。本文得出結(jié)果如下:(1)茅草植物根系分維數(shù)介于1.3305到1.5214之間變化,小蓬草根系分維數(shù)介于1.25787到1.42802之間變化,碎米莎草根系分維數(shù)分別為1.44350和1.45141。生長(zhǎng)在尾礦之上的茅草、小蓬草、碎米莎草植物的根系發(fā)育都具有典型的分形特征。茅草植物根系分維數(shù)對(duì)根系重量和長(zhǎng)度有一定的影響關(guān)系,植物根系分形維數(shù)越高,植物根系長(zhǎng)度以及重量也就越高。(2)在尾礦之上生長(zhǎng)出來的茅草植物根系鈾濃度明顯高于生長(zhǎng)于尾礦周邊環(huán)境的根系鈾濃度,說明尾礦庫周邊環(huán)境受污染影響較低。茅草和小蓬草體內(nèi)鈾濃度的整體變化趨勢(shì)是隨著植物根系分維數(shù)的增長(zhǎng)而增長(zhǎng)。植物根系分維數(shù)越高,根系越發(fā)達(dá)復(fù)雜,植物體內(nèi)富集的鈾元素越高。(3)茅草等四種植物根部鈾濃度都明顯高于莖和葉部位鈾濃度,甚至有些植物的根系鈾濃度是其他部位的上百倍。說明植物體內(nèi)鈾元素主要分布在植物根系。四種植物中碎米莎草根部富集的鈾濃度最高,馬唐其次,說明碎米莎草與馬唐對(duì)鈾元素具有一定的吸附優(yōu)勢(shì)。
[Abstract]:Tailings reservoir is a long-term potential source of radioactive pollution, its environmental management is a serious problem facing countries. Among them, phytoecological restoration has become a hot spot in academic circles. Phytoremediation has important practical significance to improve the ecological environment quality of tailings. Therefore, the interaction between radioactive pollutants and plants has also been paid attention to. The relationship between the fractal dimension of plant roots and the accumulation of uranium in the body is studied. It can provide guidance for environmental risk assessment of phytoremediation. This paper takes common plants growing on tailings as the research object, analyzes the fractal characteristics of plant root development, and probes into plant weight. The relationship between length and fractal dimension; The effects of fractal characteristics of root system development on uranium distribution in tailings reservoir were studied. In this paper, the results are as follows: 1) the root fractal dimension of the plant varies from 1.3305 to 1.5214. The fractal dimension of the root line of Psorbium vulgaris ranged from 1.25787 to 1.42802, and the fractal dimension of the root system was 1.44350 and 1.45141.The root fractal dimension was 1.44350 and 1.45141.The root fractal dimension was 1.25787 to 1.42802, respectively. The root system development of Phaeopodium mongolicum and Cyperus mollissima had typical fractal characteristics. The fractal dimension of root system had a certain influence on the weight and length of root system, and the higher the fractal dimension of root system was. The higher the root length and weight of the plant, the higher the uranium concentration of the root system of the grass growing on the tailings was significantly higher than that of the roots growing in the surrounding environment of the tailings. The results showed that the environment around the tailings reservoir was less affected by the pollution. The overall change trend of uranium concentration in the plants was increasing with the increase of plant root fractal dimension. The higher the plant root fractal dimension, the more complex the root system developed. The higher the uranium content in the plant, the higher the uranium concentration in the roots of the four plants was significantly higher than that in the stems and leaves. Even some plants have hundreds of times more uranium in their roots than in other parts, indicating that uranium is mainly distributed in the roots of plants. The highest concentration of uranium is found in the roots of Cyperus crassifolia, followed by Cortex angustifolia. It is concluded that the sorption of uranium elements by seagrass and Carthopsis chinensis has a certain advantage.
【學(xué)位授予單位】：南華大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X751;X173;Q945

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本文編號(hào)：1395058