本文關(guān)鍵詞： 河套平原 地下水化學 高砷地下水 高鐵地下水 高氟地下水　出處：《中國地質(zhì)大學(北京)》2015年博士論文　論文類型：學位論文

【摘要】：本文詳細總結(jié)了全球及河套平原地下水砷研究狀況,以及砷在自然環(huán)境中的分布與富集規(guī)律。以河套平原為研究區(qū),在深入分析研究地質(zhì)構(gòu)造、水文地質(zhì)條件、地下水流場、補給徑流條件的基礎(chǔ)上,依據(jù)800余組地下水、地表水樣品和巖土樣品測試數(shù)據(jù),對地下水的主要物理化學指標如:p H、ORP、礦化度、Cl-、SO42-、HCO3-、總砷As、總鐵Fe、總磷P、F-等進行了詳細的分析研究,刻畫了各組分(指標)的區(qū)域分布和超標狀況,同時進行了水環(huán)境分區(qū),研究了水化學類型特征以及各測試指標內(nèi)在相關(guān)性等。在上述研究的基礎(chǔ)上,重點論述了As、Fe、F等超標組分的成因機制。主要結(jié)論如下:1.通過詳細調(diào)查研究,查明了河套平原(13000 km2)地下水水化學特征和主要超標組分超標率、分布范圍。1)河套平原屬于典型的干旱半干旱地區(qū),地下水化學特征主要表現(xiàn)為以堿金屬-非重碳酸型為主(占49.29%)為主,其次是堿金屬-重碳酸型(占29.76%)和堿土金屬-重碳酸型(占16.06%),堿土金屬-非重碳酸型較少(占4.88%);2)主要超標組分為As、Fe、Cl-、F-、SO42-、NO3-、總硬度,超標率分別是28.80%(As≥0.05mg/L)、61.56%、52.71%、20.74%、55.21%、2.50%;3)高砷地下水在平原西部以條帶狀分布在山前低洼地帶;在中東部,呈不規(guī)則的面狀或片狀分布,覆蓋范圍較廣,砷含量短距離內(nèi)變化大,垂向上(80m以淺)隨深度有增大趨勢;高鐵水主要分布在平原中部的沖湖積平原,地勢低洼地帶和地下水的排泄地帶含量最高,高氟水主要以條帶狀分布在山前的沖洪積扇地帶。2.通過多元統(tǒng)計分析,查明了河套平原的地下水化學組分的相關(guān)性特征。在全區(qū)及西部高砷區(qū),As與P、Fe、F-和p H均呈顯著的正相關(guān)關(guān)系。As與ORP、SO42-呈顯著的負相關(guān)關(guān)系;F-與Ca2+顯著負相關(guān),F-與p H值顯著正相關(guān)。3.通過對主要超標組分成因機理研究,查明了:1)地下水中的砷主要來源于第四紀沉積物和斷裂運移的深部地下水;2)高鐵地下水主要來源于由黃河攜帶來的大量的第四系沉積物,其溶出的主要原因是地下氧化還原條件的變化;3)高F地下水主要來源于平原周邊的山區(qū),氣候、地質(zhì)構(gòu)造、水文地質(zhì)和水化學條件是氟富集的主要因素。
[Abstract]:This paper summarizes in detail the research status of arsenic in groundwater of the whole world and Hetao Plain, as well as the distribution and enrichment of arsenic in the natural environment. Taking Hetao Plain as the study area, the geological structure, hydrogeological conditions and groundwater flow field are studied in depth. On the basis of recharge runoff conditions, based on the test data of more than 800 groups of groundwater, surface water samples and rock and soil samples, the main physical and chemical indexes of groundwater, such as: 1 / p HP ORP, Cl-so _ 4 _ 2-HCO _ 3-, total arsenic, total iron and Fe, total phosphorus Pf- and so on, are analyzed and studied in detail. The regional distribution and exceeding standard of each component (index) are described. At the same time, the water environment zoning is carried out, and the characteristics of hydrochemical type and the inherent correlation of each test index are studied. On the basis of the above research, The main conclusions are as follows: 1. Through detailed investigation and study, the chemical characteristics of groundwater in Hetao Plain (13000 km ~ 2) and the rate of exceeding the standard of main components are found out. (1) the Hetao Plain is a typical arid and semi-arid area, and the chemical characteristics of groundwater are mainly alkaline metal-non-bicarbonate type (49.29%). Secondly, alkali metal-bicarbonate type (29.76%), alkali earth metal-bicarbonate type (16.06%), alkaline-non-bicarbonate type (4.88%) mainly exceeded the standard, and the total hardness, The rates of exceeding the standard are 28.80mg / L ~ (-1) as 鈮，

本文編號：1514001