本文選題：湖泊沉積物　切入點(diǎn)：總有機(jī)碳　出處：《湘潭大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：長江流域是我國淡水湖泊分布最密集地區(qū),由于排放的重金屬與營養(yǎng)鹽等超過水體環(huán)境容量,各湖泊出現(xiàn)不同程度的水體污染和富營養(yǎng)化問題,而這些污染物質(zhì)通過一系列的物理、化學(xué)和生物反應(yīng)進(jìn)入沉積物。本文通過對(duì)該流域典型湖泊沉積物的垂直研究,很好的了解長江地區(qū)古環(huán)境氣候、污染來源、環(huán)境演變歷程和規(guī)律,以期為長江流域環(huán)境保護(hù)和治理提供一定參考。根據(jù)這一角度,選取長江中游典型的湖泊,研究了武漢東湖、海口湖、鐘祥南湖的柱狀沉積物和梁子湖、洪湖的表層沉物,主要內(nèi)容如下：(1)采集長江中游地區(qū)武漢東湖、海口湖、鐘祥南湖3個(gè)不同類型湖泊的柱狀沉積物,研究了總有機(jī)碳(TOC)、總氮(TN)的垂直分布特征,揭示各湖泊沉積物營養(yǎng)鹽的變化規(guī)律和污染程度。結(jié)果表明：3個(gè)湖泊沉積物TOC、TN總體變化趨勢(shì)是50～30 cm波動(dòng)不大,30～10 cm增加,10 cm后減少,與各湖泊環(huán)境演變時(shí)間一致；其TOC含量最大的是海口湖,TN含量最大的是武漢東湖,且TOC和TN具有同源性。武漢東湖、�？诤袡C(jī)指數(shù)和有機(jī)氮均為等級(jí)Ⅳ,屬于嚴(yán)重污染范疇；鐘祥南湖總體上處于等級(jí)Ⅲ,有機(jī)尚清潔。(2)武漢東湖、�？诤㈢娤槟虾鶢畛练e物中重金屬(Zn、Cu、Ni、Cr、 Pb)的垂直分布特征表明：研究區(qū)Zn、Cu、Pb人為影響較大,Cr主要來自土壤環(huán)境,5種金屬污染程度為武漢東湖海口湖鐘祥南湖。主成分分析和相關(guān)性分析說明武漢東湖污染主要來自工業(yè)及生活廢水,海口湖污染是人工種植,鐘祥南湖是生活與農(nóng)業(yè)廢水,三個(gè)湖泊污染人為貢獻(xiàn)率大于自然貢獻(xiàn)率,營養(yǎng)鹽和重金屬Pb是共有的污染問題。地累積指數(shù)和內(nèi)梅羅指數(shù)評(píng)價(jià)表明,研究區(qū)內(nèi)三個(gè)湖泊Ni、Cr的潛在生態(tài)危害均較小,�？诤臀錆h東湖Zn、Cu、Pb具有潛在污染風(fēng)險(xiǎn),鐘祥南湖沉積物中五種金屬均無污染。(3)運(yùn)用TOC、TN、C/N、δ13C和δ15N研究了梁子湖和洪湖的表層沉積物和有機(jī)質(zhì)的貢獻(xiàn)率,結(jié)果表明：梁子湖C/N變化范圍為6.16～8.16,TN含量變化范圍為0.19%～0.54%,δ15N值最高處為B點(diǎn),最低處是C點(diǎn),δ13C平均值是-27.19‰,最低處δ13C在B處-30.98‰,最高處于梁子島附近F點(diǎn)為-23.09‰。δ13C來源于C3型植物水生藻類,δ15N顯示梁子湖受到較大范圍農(nóng)業(yè)污染,其東北角有水土流失風(fēng)險(xiǎn)。洪湖表層沉積物C/N變化范圍較大為13.71～65.9,有機(jī)質(zhì)TN含量變化范圍是0.03%～1.19%,屬于高等類植物,陸源輸入較明顯；洪湖表層沉積物的δ13C平均值是-18.96‰,最低處δ13C在B處-28.02‰,最高處E為-8.31‰,顯示洪湖表層沉積物主要來源屬于C4型植物,除來源水生植物外,岸邊點(diǎn)位陸源輸入較明顯,整個(gè)湖泊濕地水土流失有增加的風(fēng)險(xiǎn)。
[Abstract]:The Yangtze River Basin is the most densely distributed region of freshwater lakes in China. Due to the discharge of heavy metals and nutrients that exceed the environmental capacity of water bodies, various lakes have different degrees of water pollution and eutrophication problems. These pollutants enter the sediments through a series of physical, chemical and biological reactions. Through the vertical study of the sediments of typical lakes in this basin, we have a good understanding of the paleoenvironmental climate and the sources of pollution in the Yangtze River region. In order to provide some reference for the environmental protection and management of the Yangtze River basin, the typical lakes in the middle reaches of the Yangtze River are selected to study the columnar sediments and Liangzi Lake in East Lake, Haikou Lake, Zhongxiang South Lake in Wuhan. The surface sediments of Honghu Lake were collected from three different types of lakes, Donghu Lake, Haikou Lake and Zhongxiang South Lake in the middle reaches of the Yangtze River. The vertical distribution characteristics of total organic carbon (TOC) and total nitrogen (TNN) were studied. The results showed that the total variation trend of TOC TN in the sediments of three lakes was that 50 ~ 30 cm fluctuated slightly and then increased 30 ~ 10 cm and then decreased after increasing 10 cm, which was consistent with the evolution time of each lake environment. The largest content of TOC is the East Lake of Wuhan, and the content of TOC and TN is the same. The organic index and organic nitrogen of Donghu Lake and Haikou Lake in Wuhan are grade 鈪，

本文編號(hào)：1641174