本文選題：珠江三角洲 + 酸化機(jī)理��； 參考：《中國地質(zhì)大學(xué)(北京)》2015年碩士論文

【摘要】：隨著珠江三角洲地區(qū)經(jīng)濟(jì)建設(shè)的快速發(fā)展,不恰當(dāng)?shù)呐欧潘l(fā)的環(huán)境問題逐漸顯現(xiàn),地下水環(huán)境污染問題日益突出,尤其是地下水酸化問題嚴(yán)重。調(diào)查研究顯示,區(qū)域地下水pH超標(biāo)率為68.6%,pH6.5的偏酸性地下水已占全區(qū)面積的3/4。以往的研究多是對酸性地下水的分布狀況以及主要成因進(jìn)行了簡略的討論,其最重要的酸化機(jī)理并未指明。所以,研究珠江三角洲地區(qū)地下水酸化的問題時,機(jī)理的研究尤為重要。本研究從酸性地下水分布規(guī)律入手,從機(jī)理角度剖析影響酸化的各個因素。分別以區(qū)域尺度(整個珠江三角洲地區(qū))、剖面尺度(典型研究區(qū)剖面)以及微觀尺度(土壤構(gòu)成組分)開展研究,得出的結(jié)論可以為珠江三角洲區(qū)域地下水污染的防治提供科學(xué)的指導(dǎo)。本研究取得了如下主要成果：在區(qū)域尺度上,以2005-2008年珠江三角洲地區(qū)的地下水污染調(diào)查評價為基礎(chǔ),從地下水中S042-的來源反推引起地下水酸化的主要因素,分析每個可能的來源,最終確定酸雨為導(dǎo)致地下水酸化的主要因素。引入酸雨危害指數(shù)(AHI)的概念,以表征酸雨的危害程度,并應(yīng)用主成分分析(PCA)方法研究珠江三角洲地下水的水化學(xué)組分以及酸雨的影響。在剖面尺度,以包氣帶為主要研究對象,研究了典型酸化區(qū)剖面上的pH、土壤鹽基離子以及A1的變化。包氣帶為砂礫石,滲透性好,地勢高坡度大,徑流條件良好,酸化現(xiàn)象不顯著。表層為粘土或粉質(zhì)粘土,滲透性很差,部分區(qū)域地勢凹陷,徑流條件較差,酸化較為嚴(yán)重。按照土壤中酸緩沖體系的三個階段(游離碳酸鹽溶解-沉淀階段、鹽基離子交換階段、鋁硅酸鹽礦物溶解-沉淀階段)分析其變化特征。采用酸緩沖曲線法進(jìn)行實驗,測定典型研究區(qū)未酸化的水稻土和紅壤的緩沖容量,進(jìn)而計算該土壤對酸沉降的臨界負(fù)荷值,并預(yù)測其達(dá)到酸害所需的時間分別為：86.5年和45.5年。采用土壤固相組分順序提取的方法研究了區(qū)內(nèi)典型土壤的三種土壤(未酸化水稻土、已酸化水稻土、紅壤)的緩沖能力差異。由于土壤固相組分的差異,三種土壤所具有的緩沖能力大小為：未酸化的水稻土紅壤酸化的水稻土。
[Abstract]:With the rapid development of economic construction in the Pearl River Delta region, the environmental problems caused by improper discharge gradually appear, and the problem of groundwater environmental pollution is becoming increasingly prominent, especially the serious problem of groundwater acidification.The investigation shows that the partial acid groundwater whose pH exceeds the standard rate of 68.6% and pH 6.5 has accounted for 3 / 4 of the total area of the region.The most important acidification mechanism of acid groundwater has not been pointed out.Therefore, it is very important to study the mechanism of groundwater acidification in Pearl River Delta.This study starts with the distribution of acidic groundwater and analyzes the factors affecting acidification from the point of view of mechanism.The regional scale (the whole Pearl River Delta region), the profile scale (typical study area section) and the micro scale (soil composition) were studied, respectively.The conclusions can provide scientific guidance for the prevention and control of groundwater pollution in the Pearl River Delta region.The main results of this study are as follows: on a regional scale, based on the investigation and evaluation of groundwater pollution in the Pearl River Delta region from 2005 to 2008, the main factors causing groundwater acidification are derived from the source of S042- in groundwater.Each possible source was analyzed and acid rain was identified as the main factor leading to groundwater acidification.The concept of acid rain hazard index (AHI) was introduced to characterize the damage degree of acid rain. The method of principal component analysis (PCA) was used to study the hydrochemical composition of groundwater in the Pearl River Delta and the influence of acid rain.The changes of pH, soil base ions and A1 in typical acidified zone were studied at the profile scale, taking the aeration zone as the main research object.The aeration zone is sandy and gravel with good permeability, high slope, good runoff condition and no significant acidification.The surface layer is clay or silty clay, the permeability is very poor, some regional topography sag, runoff condition is poor, acidification is more serious.According to the three stages of acid buffer system in soil (free carbonate dissolution-precipitation stage, base-based ion-exchange stage, aluminosilicate mineral dissolution-precipitation stage), the change characteristics were analyzed.The buffer capacity of unacidified paddy soil and red soil in typical study area was measured by acid buffer curve method. The critical loading value of the soil to acid deposition was calculated, and the time required to reach acid damage was predicted as 86.5 years and 45.5 years, respectively.The buffer capacity of three typical soils (unacidified paddy soil, acidified paddy soil and red soil) was studied by sequential extraction of soil solid components.Because of the difference of soil solid composition, the buffer capacity of the three soils is as follows: unacidified paddy soil, red soil, acidified paddy soil.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X523

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本文編號：1735046