本文選題：生源要素 + 痕量元素��； 參考：《中國科學(xué)院大學(xué)(中國科學(xué)院海洋研究所)》2017年博士論文

【摘要】：伴隨社會經(jīng)濟的迅猛發(fā)展,大氣人為污染物質(zhì)的排放也不斷增多,它們可以通過沉降的方式進入海洋。因此,大氣沉降作為陸源人為污染物質(zhì)輸送入海的重要途徑之一,受到了國內(nèi)外學(xué)者、政府的廣泛關(guān)注。本學(xué)位論文聚焦我國北方地區(qū)受人類活動影響顯著的典型半封閉海灣——膠州灣,系統(tǒng)研究了其化學(xué)組分的大氣干濕沉降、生態(tài)效應(yīng)與營養(yǎng)物質(zhì)收支。本研究通過采集膠州灣2015年6月~2016年5月的氣溶膠及大氣干、濕沉降樣品,聚焦高強度人類活動影響下近海半封閉性海灣主要生源要素(N、P、Si、S)及溶解態(tài)痕量元素(Al、Fe、Mn、Co、Zn、Se、Pb、Cd、Cr)的大氣干、濕沉降(包括酸沉降)通量及其影響因素,綜合運用多種方法(統(tǒng)計分析、富集因子、主成分分析以及氣團后向軌跡模型)解析其來源及大氣傳輸過程。同時,著重從大氣營養(yǎng)物質(zhì)沉降對海洋初級生產(chǎn)力、營養(yǎng)鹽結(jié)構(gòu)影響的角度,系統(tǒng)探討了大氣沉降對膠州灣生態(tài)系統(tǒng)的影響。在此基礎(chǔ)上,系統(tǒng)綜合大氣沉降、河流輸入、點源排污、海水養(yǎng)殖、沉積物—水界面擴散釋放以及與黃海的水交換等營養(yǎng)物質(zhì)收支過程,評估其收支狀況,闡明膠州灣水體的營養(yǎng)物質(zhì)源/匯格局。獲得了如下的系統(tǒng)新認識:(1)膠州灣大氣N污染極為嚴重,氣象條件(降水量、風(fēng)向)、當(dāng)?shù)刈匀?人為污染物的排放強度以及遠距離傳輸是影響大氣營養(yǎng)鹽干、濕沉降濃度及通量的主要因素;氣溶膠水溶性營養(yǎng)鹽(N、P、Si)的干沉降速率呈現(xiàn)較為明顯的月際變化;由于不同營養(yǎng)鹽成分干沉降速率的較大差異,導(dǎo)致氣溶膠中各營養(yǎng)鹽濃度的比例與干沉降中相應(yīng)成分的比例之間存在較大差異;氣溶膠以及大氣干、濕沉降中N、P、Si比例嚴重失衡,有機態(tài)N、P的大氣沉降不容忽視;干、濕沉降,尤其是強降水會對表層海水的生源要素產(chǎn)生強力加富作用,促進浮游植物生長以及初級生產(chǎn)力的提高、改變表層水體的營養(yǎng)鹽結(jié)構(gòu),進而對膠州灣浮游植物群落結(jié)構(gòu)和粒級結(jié)構(gòu)產(chǎn)生影響,加劇膠州灣生態(tài)系統(tǒng)的失衡。膠州灣大氣各形態(tài)營養(yǎng)鹽的干、濕沉降通量分別為NH_4-N(29.4、92.8)、NO_3-N(29.9、54.5)、NO_2-N(0.058、0.427)、DON(15.4、47.5)、PO_4-P(0.099、0.274)、DOP(0.165、0.448)、DSi(8.48、1.73)mmol·m~(-2)·yr~(-1);除DSi之外,濕沉降均占據(jù)主導(dǎo)地位。運用干沉降模型間接估算的膠州灣氣溶膠NH_4-N、NO_3-N、NO_2-N、DON、PO_4-P、DOP以及DSi的干沉降速率分別為0.17±0.11、0.35±0.20、0.34±0.25、0.30±0.22、0.43±0.28、0.91±0.60和1.31±1.27 cm·s~(-1),季節(jié)變化較為明顯。干、濕沉降均以無機氮為主,DON在N干、濕沉降中的比例分別為20.6%和24.3%,而DOP在P干、濕沉降中均占優(yōu)勢地位(62.5%和62.0%),表明有機態(tài)N、P的大氣沉降不容忽視。膠州灣大氣N、Si、P的主要來源分別為農(nóng)業(yè)活動、土壤沙塵、人為排放與自然源的混合源。氣團后向軌跡分析顯示,來自西北(34.7%)和東南方向(42.8%)的降水氣團對濕沉降的影響較大,而對于干沉降,來自西北方向氣團(57.9%)的影響占據(jù)絕對主導(dǎo)地位。由于膠州灣表層海水的P限制,根據(jù)Redfield比值估算的大氣沉降輸入的P所支持的新生產(chǎn)力在春、夏、秋、冬季分別為1.94,1.15,1.86,1.15 mg C·m~(-2)·d~(-1)。盡管大氣沉降所輸入的P支持的平均新生產(chǎn)力較低,但雨季短時強降雨帶來的大量營養(yǎng)物質(zhì)的輸入所支持的新生產(chǎn)力最高可達膠州灣平均初級生產(chǎn)力的25%。此外,干、濕沉降中極高的N:P比和極低的Si:N比加之NH_4-N的絕對優(yōu)勢地位,會改變表層水體的營養(yǎng)鹽結(jié)構(gòu),惡化水體的P限制和Si限制,這可能是近年來膠州灣浮游植物群落結(jié)構(gòu)和粒級結(jié)構(gòu)改變以及優(yōu)勢種演替的一個重要原因。(2)膠州灣大氣降水明顯酸化,加之較高的電導(dǎo)率和S、N沉降通量,揭示了該區(qū)域處于較為嚴重的大氣二次污染過程;SO_4~(2-)和NO_3~-是主要的致酸成分,而NH_4~+和nss-Ca~(2+)是主要的酸性中和成分,Ca~(2+)的嚴重缺乏可能是導(dǎo)致雨水酸性較強的一個重要原因;人為源是膠州灣大氣水溶性離子的主導(dǎo)源。膠州灣大氣降水的p H范圍為3.84~6.91,雨量加權(quán)均值(VWM)低至4.77,酸雨頻率高達71.4%。NH_4~+、SO_4~(2-)、NO_3~-、Ca~(2+)和Cl~-是主要的大氣水溶性無機離子成分,其占比在氣溶膠和雨水中均超過80%。NH_4~+超過Ca~(2+)成為最主要的陽離子,而SO_4~(2-)則為最主要的陰離子。S、N的大氣沉降通量分別為20.17和28.92kg·ha~(-1)·yr~(-1),均以濕沉降為主。盡管目前膠州灣大氣降水仍為硫酸型,但隨著大氣NO_x排放的增強以及對SO_2排放的嚴格控制,酸雨類型正逐漸向硝酸型轉(zhuǎn)化。定量分析結(jié)果表明,海洋源、地殼源以及人為源對膠州灣大氣化學(xué)成分的貢獻率分別為28.7%、14.5%和56.8%。鑒于海洋浮游植物對大氣SO_4~(2-)的貢獻被忽視,其海洋源可能被低估。(3)膠州灣大氣溶解態(tài)痕量元素濃度和沉降通量處全球中等水平,受復(fù)雜的氣象條件(降水量、風(fēng)速、風(fēng)向)和污染物排放強度的影響,干、濕沉降痕量元素呈現(xiàn)較為明顯的月際變化;膠州灣大氣溶解態(tài)Al和Fe主要為地殼源,而其余7種元素主要是人為源,來自西北方向的氣團/云團對研究區(qū)域大氣溶解態(tài)痕量元素的濃度起主導(dǎo)作用;Mn、Zn、Co具有較高的干沉降速率,而典型人為源元素Pb、Cd、Cr的干沉降速率較低;短時強降雨會對表層海水的痕量元素產(chǎn)生加富作用,污染海洋環(huán)境,進而對浮游植物生長同時產(chǎn)生營養(yǎng)和毒害作用。膠州灣大氣水溶性痕量元素的干、濕沉降通量分別為Al(19.3、29.2)、Fe(10.2、14.2)、Mn(21.6、24.2)、Co(0.154、0.090)、Zn(101.5、24.1)、Se(0.862、0.725)、Pb(0.175、2.21)、Cd(0.035、0.131)、Cr(0.083、0.669)mg·m~(-2)·yr~(-1),除Co、Zn、Se之外,均以濕沉降為主。利用干沉降模型間接估算的上述9種溶解態(tài)痕量元素的干沉降速率分別為1.29±1.60、1.27±1.66、2.33±1.48、1.67±0.94、1.98±2.22、0.51±0.29、0.12±0.13、0.15±0.12、0.17±0.10cm·s~(-1),表現(xiàn)出一定的季節(jié)變化特征。除Al、Fe之外,地殼源對其它痕量元素的貢獻幾乎可以忽略;來自西北方向的氣團/云團在調(diào)查期間含有相對較高的溶解態(tài)痕量元素濃度,且發(fā)生頻率最高,因此對調(diào)查區(qū)域大氣溶解態(tài)痕量元素濃度起主導(dǎo)作用。干、濕沉降輸入的溶解態(tài)Fe可以支持的生物固氮量為4.5×10~8~94.9×10~8 g N·yr~(-1),可占膠州灣總生物固氮量的4.9%~100%。(4)在膠州灣營養(yǎng)物質(zhì)收支中,相對于河流輸入、點源排污等陸源輸入以及海水養(yǎng)殖排泄,大氣沉降輸入的營養(yǎng)物質(zhì)占比較低,但與往年相比有所提高,表明大氣沉降對陸源物質(zhì)輸送入海的作用逐漸增強;南黃海與灣內(nèi)的水交換是膠州灣DOP和Cr的重要來源;除Zn以外,膠州灣水體整體表現(xiàn)為各類營養(yǎng)鹽及痕量元素的匯;由于留存于水體中的N:P比較高,膠州灣今后仍可能長期處于P限制狀態(tài);量化膠州灣營養(yǎng)鹽及痕量元素的各種來源/歸宿以及輸入/輸出通量,對于評估膠州灣水體的富營養(yǎng)化特征和環(huán)境演變趨勢有重要意義。近年來大氣干濕沉降在膠州灣營養(yǎng)物質(zhì)總外源輸入中的比重有所上升;對于個別痕量元素如Zn,大氣沉降也占據(jù)較大比例,表明大氣沉降是膠州灣痕量元素的一個重要來源,且隨著人為活動的增強,其近年來的輸入作用有所增強。通過一年的水交換,留存于水體中可用于浮游植物初級生產(chǎn)的DIN、DIP和DSi分別為193×10~9 mol、2.04×10~9 mol和106×10~9 mol,N:P比接近100,而Si:N比接近0.5,因此可以預(yù)測,在沒有大的環(huán)境演變前提下,膠州灣水體可能將長期保持P限制,而Si限制的狀況將會有所減輕。本研究全面探討了膠州灣生源要素及痕量元素的大氣干、濕沉降特征及其來源和生態(tài)環(huán)境效應(yīng),進一步加深了對人為影響下膠州灣營養(yǎng)元素生物地球化學(xué)循環(huán)過程的理解,同時為深入研究半封閉型海灣對人類活動影響日益增強的響應(yīng)過程及機制提供了數(shù)據(jù)支持和理論依據(jù)。
[Abstract]:With the rapid development of the social economy, the emission of atmospheric pollution materials is increasing, and they can enter the ocean through settlement. Therefore, the atmospheric settlement, as one of the important ways to transport the polluted materials into the sea, is widely concerned by the scholars at home and abroad and the government. This dissertation focuses on the north of China. The typical semi closed Bay, Jiaozhou Bay, which is significantly affected by human activities, has systematically studied the atmospheric dry and wet settlement, ecological effects and nutrient balance of its chemical components. This study was conducted by collecting aerosols and atmospheric dry, wet settling samples in the May ~2016 year of June 2015, and focusing on the semi closure of the coastal waters under the influence of high intensity human activities. The main source elements of the Bay (N, P, Si, S) and the dissolved trace elements (Al, Fe, Mn, Co, Zn, Se, Pb, Cd, etc.) are the atmospheric dry, wet deposition (including acid deposition) flux and its influencing factors, and use a variety of methods (statistical analysis, enrichment factor, principal component analysis and air mass backward trajectory model) to analyze its source and atmospheric transport process. The influence of atmospheric sedimentation on the primary productivity of the sea and the structure of the nutrient salt was discussed. The effects of atmospheric sedimentation on the Jiaozhou Bay ecosystem were systematically discussed. On this basis, the system integrated atmospheric sedimentation, river input, point source discharge, marine aquaculture, sediment water interface diffusion release, and water exchange with the Yellow Sea. The quality of revenue and expenditure process is evaluated and the source / sink pattern of the water body in Jiaozhou Bay is clarified. The following new knowledge is obtained: (1) the atmospheric N pollution in the Jiaozhou Bay is extremely serious, the weather conditions (precipitation, wind direction), the local natural / man-made pollutant emission intensity and the long distance transmission are the influence of the atmospheric nutrient salt dry, the wet settlement concentration The main factors of flux, the dry settlement rate of N, P, Si, showed obvious intermonthly change, and the proportion of the concentration of different nutrients in the aerosol and the proportion of the corresponding precipitation in the dry settlement, as a result of the large difference in the dry sedimentation rate of different nutrients, and the aerosol as well as the atmosphere. Dry, wet settlement, N, P, Si ratio is seriously unbalanced, organic state N, P atmospheric sedimentation can not be ignored; dry, wet settlement, especially strong precipitation will produce strong additive effect on the source elements of surface sea water, promote the growth of phytoplankton and increase the primary productivity, change the nutrient structure of the surface water body, and then to the phytoplankton community in Jiaozhou Bay The influence of structure and grain level structure aggravate the imbalance of the ecosystem in the Gulf of Jiaozhou. The dry of various forms of nutrients in the atmosphere of the Jiaozhou Bay are NH_4-N (29.4,92.8), NO_3-N (29.9,54.5), NO_2-N (0.058,0.427), DON (15.4,47.5), PO_4-P (0.099,0.274), DOP (0.165,0.448). The dry sedimentation rate of NH_4-N, NO_3-N, NO_2-N, DON, PO_4-P, DOP and DSi is 0.17 + 0.11,0.35 + 0.20,0.34 + 0.25,0.30 + 0.60 and 1.31 + 1.27 respectively, and the seasonal variation is more obvious. Dry and wet deposition is mainly inorganic nitrogen. The proportion of DON in N dry and wet settlement are 20.6% and 24.3% respectively, while DOP is dominant in P dry and wet settlement (62.5% and 62%), indicating that the atmospheric sedimentation of organic N and P can not be ignored. The main sources of N, Si and P in Jiaozhou Bay are agricultural activities, soil dust, human emissions and natural sources. The influence of precipitation from Northwest (34.7%) and southeast direction (42.8%) on wet settlement is great, and the influence of the northwest direction air mass (57.9%) is dominant for dry settlement. Due to the P limit of the surface sea water in the Jiaozhou Bay, the new productivity supported by the P of atmospheric sedimentation calculated according to the Redfield ratio is in spring, summer and autumn. In winter, 1.94,1.15,1.86,1.15 mg C / m~ (-2). D~ (-1). Although the average new productivity supported by the P supported by atmospheric sedimentation is lower, the new productivity supported by the input of a large number of nutrients brought by short rainfall in the rainy season is up to the 25%. of the average primary yield of the Jiaozhou Bay, in addition to the high N:P ratio and pole in wet deposition. The absolute dominance of lower Si:N than adding NH_4-N will change the structure of the nutrient salt of the surface water body and deteriorate the P and Si limits of the water body. This may be an important reason for the changes of the phytoplankton community structure and grain grade structure and the succession of the dominant species in the Jiaozhou Bay in recent years. (2) the precipitation in the Jiaozhou Bay is obviously acidified, and the higher conductivity is also found. The rate and S, N sedimentation flux reveal that the region is in a more serious two pollution process in the atmosphere; SO_4~ (2-) and NO_3~- are the main acid causing components, and NH_4~+ and nss-Ca~ (2+) are the main acid neutralization components. The serious lack of Ca~ (2+) may be an important cause of the strong rain acidity; the human source is the water solubility of the air in the Jiaozhou Bay. The P H range of the atmospheric precipitation in Jiaozhou Bay is 3.84~6.91, the rainfall weighted mean (VWM) is as low as 4.77, the acid rain frequency is as high as 71.4%.NH_4~+, SO_4~ (2-), NO_3~-, Ca~ (2+) and Cl~- are the main components of the water soluble inorganic ions, which are more than the most important cations in aerosols and rain water. SO_4~ (2-) is the most important anion.S, and the atmospheric deposition flux of N is 20.17 and 28.92kg. Ha~ (-1). Yr~ (-1), which are mainly wet precipitation. Although the atmospheric precipitation in Jiaozhou Bay is still sulphuric acid type, the acid rain type is gradually converted to the nitrate type with the increase of NO_x emission in the atmosphere and the strict control of the SO_2 emission. The results show that the contribution rates of marine sources, crustal sources and human sources to atmospheric chemical components in Jiaozhou Bay are 28.7%, 14.5% and 56.8%., respectively, in view of the neglect of the contribution of marine phytoplankton to atmospheric SO_4~ (2-), and its marine sources may be underestimated. (3) the concentration of dissolved trace elements in the atmosphere of the Gulf of Jiaozhou and the middle level of the settlement flux at the global level are complex. The influence of meteorological conditions (precipitation, wind speed, wind direction) and pollutant emission intensity, the trace elements in dry and wet deposition are more obvious monthly changes; the dissolved Al and Fe in Jiaozhou Bay are mainly crustal source, while the other 7 elements are mainly human sources. The concentration plays the leading role; Mn, Zn and Co have higher dry sedimentation rate, while the dry sedimentation rate of typical human source elements Pb, Cd, Cr is low; short time strong rainfall will enrich the trace elements in the surface water, pollute the marine environment, and then produce the nutrient and poison effects on the growth of phytoplankton. The water soluble trace in Jiaozhou Bay The wet settlement flux is Al (19.3,29.2), Fe (10.2,14.2), Mn (21.6,24.2), Co (0.154,0.090), Zn (101.5,24.1), Se (0.862,0.725). The dry sedimentation rate is 1.29 + 1.60,1.27 + 1.66,2.33 + 1.48,1.67 + 0.94,1.98 + 2.22,0.51 + 0.29,0.12 + 0.12,0.17 + 0.10cm s~ (-1), showing some seasonal variation characteristics. Apart from Al, the contribution of the crust source to other trace elements is almost negligible; the air mass / cloud from the northwest direction is contained in the investigation period. There is a relatively high concentration of dissolved trace elements and the highest frequency, so it plays a leading role in the investigation of the concentration of trace elements in the atmosphere. The dissolved Fe can support 4.5 * 10~8~94.9 x 10~8 g N. Yr~ (-1), and can occupy 4.9%~100%. (4) of the total biological nitrogen fixation in the Gulf of Jiaozhou Bay. In the nutrient budget, the input of land source and aquaculture are relatively low compared to the input of river, point source discharge and aquaculture, but it is higher than that in previous years, indicating that the effect of atmospheric sedimentation on the transport of terrestrial materials to the sea gradually increased, and the water exchange between south the Yellow Sea and the bay is important for the DOP and Cr in the Gulf of China. In addition to Zn, the Jiaozhou bay water body is the aggregate of all kinds of nutrients and trace elements. Because of the high N:P remaining in the water body, the Jiaozhou Bay may still be in the P limit for a long time, and the various sources / destination and input / output flux of the nutrients and trace elements in the Jiaozhou Bay are quantified to assess the wealth camp of the Jiaozhou bay water body. In recent years, the proportion of atmospheric and wet precipitation in the total exogenous input of nutrients in Jiaozhou Bay has risen, and the atmospheric sedimentation is also a large proportion for some trace elements, such as Zn, indicating that atmospheric sedimentation is an important source of trace elements in the Gulf of Jiaozhou and increases with human activities. Its input effect has been enhanced in recent years. Through a year of water exchange, DIN, DIP and DSi are 193 x 10~9 mol, 2.04 x 10~9 mol and 106 x 10~9 mol, N:P ratio close to 100, and Si:N ratio close to 0.5, so that the Jiaozhou bay water body may be predicted without large environmental evolution. The P limit will be maintained for a long time, while the condition of the Si limit will be reduced. This study comprehensively explored the atmospheric dry, the characteristics of the wet deposition, the source and the ecological environment effect of the source and trace elements of the Jiaozhou Bay, and further deepened the understanding of the biogeochemical cycle process of the nutrient elements in the Jiaozhou Bay under the influence of human beings. The semi closed bay provides the data support and theoretical basis for the response process and mechanism of the increasing impact of human activities.

【學(xué)位授予單位】：中國科學(xué)院大學(xué)(中國科學(xué)院海洋研究所)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：X51;X55
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本文編號：1801160