本文關(guān)鍵詞： 汞污染 年輪化學(xué) 污染歷史 重建　出處：《貴州師范大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：汞是一種廣泛分布于環(huán)境介質(zhì)中且對人體具有嚴(yán)重生理和神經(jīng)毒性的重金屬污染物,其被視為六種最嚴(yán)重的污染物之一,是聯(lián)合國環(huán)境規(guī)劃署(UNEP)、世界衛(wèi)生組織(WHO)和美國環(huán)保署(USEPA)等多個國際機構(gòu)規(guī)定的優(yōu)先控制污染物。汞是唯一主要以氣態(tài)單質(zhì)(Hg095%)形態(tài)存在于大氣中的重金屬元素,并且在大氣中的居留時間長達(dá)數(shù)月至一年,能夠隨大氣環(huán)流遷移到數(shù)千乃至上萬公里后在偏遠(yuǎn)地區(qū)沉降,因此被認(rèn)為是一種全球性污染物。我國是世界上第三大產(chǎn)汞國,排在西班牙和意大利之后,而貴州萬山地區(qū)是我國最大的汞礦區(qū)。21世紀(jì)初期研究者對萬山地區(qū)進(jìn)行了系統(tǒng)的汞污染評估,發(fā)現(xiàn)土壤、表層水、糧食、蔬菜等超出國家標(biāo)準(zhǔn)數(shù)倍乃至數(shù)十倍之多,引起了我國政府對當(dāng)?shù)毓廴镜闹匾�。本文研究目的之一就是通過年輪化學(xué)技術(shù)重建該地區(qū)的污染歷史,反映其歷史開采強度的變化趨勢,為當(dāng)?shù)氐奈廴痉乐翁峁v史借鑒,同時為當(dāng)?shù)氐墓廴狙芯吭u價提供數(shù)據(jù)支持。由于汞具有較高飽和蒸氣壓的特性,大氣中的汞95%以上以氣態(tài)單質(zhì)汞(Hg0)的形態(tài)存在,大氣中的汞可被植物吸收(尤其是植物的地上部分如葉片和木質(zhì)部)從而固定在植物體內(nèi)。因此,植物的生長過程可能記錄了大氣汞污染的歷史變化特征。1975年Lepp首次將年輪化學(xué)方法用于檢測環(huán)境中痕量金屬元素的長期變化而獲得成功,提出年輪化學(xué)的概念。年輪化學(xué)相比于沉積物、土壤等在標(biāo)記時間序列上有其獨特的優(yōu)越性,比如年代分辨率高、活動穩(wěn)定、時間跨度大、地理學(xué)分布廣泛等。開展年輪化學(xué)重金屬污染示蹤研究具有多方面的意義,如再現(xiàn)高分辨率環(huán)境污染歷史、判斷樹木生態(tài)系統(tǒng)重金屬元素污染來源、研究重金屬在大氣-植物體和土壤-植物間的遷移過程等,為污染環(huán)境的修復(fù)治理及社會可持續(xù)發(fā)展建設(shè)等提供科學(xué)指導(dǎo)。本研究工作主要是通過采集典型汞污染區(qū)的樹輪樣品,分析不同年代樹輪樣品中汞含量,利用年輪化學(xué)理論重建重污染區(qū)歷史汞污染特征;分析輪寬與汞積累強度的相關(guān)性,探究年輪生長速率對汞的年輪化學(xué)研究的影響;研究距離萬山汞礦不同梯度的植物體汞累積含量,探討萬山地區(qū)汞污染的影響范圍;應(yīng)用汞的年輪化學(xué)技術(shù)成功重建了赫章縣媽姑鎮(zhèn)土法煉鋅地區(qū)以及旬陽縣紅軍鄉(xiāng)青銅溝汞礦開采區(qū)的汞污染歷史。通過研究得出以下主要結(jié)論:1、同一棵樹同年的木質(zhì)中,其木質(zhì)總Hg量以及Hg濃度都沒有呈現(xiàn)均勻分布的特點,其中木質(zhì)總Hg量與該年份木質(zhì)生長寬度相關(guān)性較好,相關(guān)系數(shù)在0.9以上,而木質(zhì)Hg濃度與輪寬并未發(fā)現(xiàn)相關(guān)性。雖然木質(zhì)Hg濃度在木質(zhì)中不是均勻分布的,但是在各自方向上它們所反映出來的時間變化趨勢是一致的。2、年木質(zhì)Hg濃度只與污染區(qū)當(dāng)年環(huán)境汞污染程度有關(guān),因此可以作為當(dāng)?shù)匚廴練v史的指示數(shù)據(jù);而年木質(zhì)的總Hg量由于與該年的氣候特點和環(huán)境汞濃度都有相關(guān)關(guān)系,所以不能單獨作為當(dāng)?shù)匚廴練v史的指示數(shù)據(jù)。3、萬山地區(qū)樹木年輪的木質(zhì)Hg濃度變化特點成功反映出當(dāng)?shù)氐墓V污染歷史,證明汞的年輪化學(xué)研究的現(xiàn)實可行性。4、在樹木指示汞污染方面,樹葉的靈敏度是最高的,其次是土壤、樹皮、木質(zhì)。距離汞礦40公里以外的地區(qū),其樹木受到的汞污染影響已十分有限。5、應(yīng)用汞的年輪化學(xué)技術(shù)成功重建赫章縣媽姑鎮(zhèn)黑坭寨土法煉鋅地區(qū)近四十年來的汞污染歷史,發(fā)現(xiàn)在1995-2010年間當(dāng)?shù)毓廴据^為嚴(yán)重,尤其是2003-2006期間當(dāng)?shù)毓廴具_(dá)到高峰。樹皮與木質(zhì)的Hg濃度具有顯著相關(guān)性,表明大氣是木質(zhì)汞的主要來源。6.應(yīng)用汞的年輪化學(xué)技術(shù)重建陜西省旬陽縣紅軍鄉(xiāng)青銅溝地區(qū)的汞污染歷史,發(fā)現(xiàn)當(dāng)?shù)氐沫h(huán)境汞污染有減緩趨勢,這可能與當(dāng)?shù)匾睙捁緦欧欧乐渭夹g(shù)的改進(jìn)有關(guān);但是當(dāng)?shù)貥淙~、樹皮和土壤仍然具有較高的汞濃度,表明當(dāng)?shù)毓廴救匀皇鞘謬?yán)峻的環(huán)境問題。
[Abstract]:Mercury is a heavy metal is widely distributed in environment medium and has serious physiological and neurotoxic pollutants to human, which is regarded as one of the six most serious pollutant, the United Nations Environment Programme (UNEP), WHO (WHO) and the U.S. Environmental Protection Agency (USEPA) priority pollutants and other international institutions regulations. Mercury is the only major (Hg095%) in gaseous elemental speciation of heavy metals in the atmosphere, and in the atmosphere of the residence time for several months to a year, with the atmospheric circulation can migrate to thousands or even tens of thousands of kilometers of settlement in remote areas, so it is considered to be a global pollutant in our country is the world. The third mercury country, after Spain and Italy, and Guizhou mountains area is China's largest mercury mining area in the early.21 century researchers conducted the mercury pollution assessment system in the Wanshan area, found The soil, surface water, grain, vegetables exceeded the national standard several times or even ten times, the Chinese government attaches great importance to the mercury pollution in the local. One of the purposes of this paper is to rebuild the pollution history of the region by dendrochemistry, reflecting the trend of the history of mining intensity, to provide historical reference for the prevention and control of pollution of the local at the same time, to provide data support for the local assessment on mercury pollution. Because Mercury has the characteristics of high saturated vapor pressure, more than 95% of mercury in the atmosphere by gaseous elemental mercury (Hg0) form, mercury in the atmosphere can be absorbed by plants (especially parts such as leaves and xylem of plants on the ground) and fixed in plants. Therefore, the growth process of plants may be recorded the.1975 variation of atmospheric mercury pollution in Lepp for the first time dendrochemistry method for the long term variation of Trace Elements Detection in the environment But to succeed, put forward the concept of dendrochemistry. Dendrochemistry compared to sediment, soil has its unique superiority in the marked time series, such as in high resolution, stable activity, time span, geography is widely distributed. It has significance in many aspects to carry out the research on Heavy Metal Pollution Tracing chemical rings, such as high reproduction the resolution of environmental pollution history, sources of heavy metal pollution of heavy metal in the trees ecosystem, plant atmosphere plant body and soil between the migration process, to provide scientific guidance for environmental pollution remediation and sustainable development of the society construction. This research work is mainly through the acquisition of typical mercury contaminated area of the tree ring samples, analysis of mercury the content of tree ring samples of different ages, characteristics of mercury pollution in the heavily polluted area of historical reconstruction by means of dendrochemistry theory; analysis of wheel width and intensity related to accumulation of mercury Dendrochemistry, influence research on mercury into ring growth rate; distance of Wanshan mercury mine plants of different gradient mercury accumulation content, impact on the scope of mercury pollution in Wanshan area; dendrochemistry application of mercury successful reconstruction of Hezhang County town of Ma Gu area and Xunyang County Red zinc smelting Xiang qingtonggou mercury mine mining area of mercury pollution in history. The main results are as follows: 1. The wood with a tree in the same year, the total amount of Hg and Hg lignin concentration did not show uniform distribution characteristics, the total amount of the year and Hg wood wood growth width has good correlation, the correlation coefficient is above 0.9, and the concentration of Hg and the wooden wheel width did not find correlation. Although the concentration of Hg in wood wood is not evenly distributed, but the time trend in their respective directions reflect the consistent.2 year Hg concentration Only concerned with the pollution area year mercury pollution degree, so it can be used as indicator data of local pollution history; and the total amount of Hg in wood because with the climatic characteristics and environmental mercury concentration the year relationship, it is not alone as indicator data.3 local history of pollution, Hg concentration changes of wood in trees in mountains the ring success reflects the pollution history of mercury mine the feasibility of.4 that dendrochemistry study of mercury, mercury pollution indicator in trees, leaves the sensitivity is the highest, followed by soil, bark and wood. The distance of mercury mine 40 kilometers outside the area, the effect of mercury pollution is limited by the trees.5, dendrochemistry application of mercury successful reconstruction of Hezhang county. In the past forty years mercury pollution history Gu Zhen Hei Ni Zhai zinc smelting area, found in the 1995-2010 between local mercury pollution is serious 2003-2006, especially during the local mercury pollution. The peak was significantly correlated with the concentration of Hg bark and wood, wood is indicated that the atmospheric dendrochemistry mercury from mercury.6. application of the reconstruction of the Red Army Xunyang County township of Shaanxi province qingtonggou mercury pollution area history, found that when the mercury pollution has slowed down, the improvement this may be related to the local smelting company of mercury emission control technology; but the leaves, bark and soil mercury concentration was still high, indicating that mercury pollution of local environmental problems is still very serious.

【學(xué)位授予單位】：貴州師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X75;X142

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本文編號：1457632