南方某鈾礦山尾礦庫周邊水環(huán)境污染與評價
發(fā)布時間:2018-06-05 17:00
本文選題:鈾礦山 + 尾礦庫。 參考:《東華理工大學(xué)》2015年碩士論文
【摘要】:鈾礦山開采過程中會產(chǎn)生的大量酸性廢水和廢渣均排到尾礦庫中,由于酸性礦山廢水和廢渣一般都含有大量的重金屬、放射性核素以及氟化物等有毒有害物質(zhì),對尾礦庫周邊地表水以及淺層地下水都會造成重大污染。本文選取南方某鈾礦山尾礦庫周邊地表水及淺層地下水為研究對象,通過野外取樣,室內(nèi)測定等過程,研究了淺層地下水和地表水的水化學(xué)性質(zhì)和形態(tài),重金屬及放射性核素的含量特征及分布,運用單指標(biāo)評價法評價了水質(zhì)量狀況并對進(jìn)行了污染評價。主要成果如下:(1)尾礦庫的水化學(xué)類型表現(xiàn)為Ca SO_4型水,淺層地下水的水化學(xué)類型是Ca-Na-SO_4型水,且研究區(qū)淺層地下水的水化學(xué)類型很可能受到尾礦庫的影響。研究區(qū)內(nèi)淺層地下水p H為5.75-6.70,排放水p H為4.65-7.40,滲濾水p H為4.50-8.70。淺層地下水中TDS主要受Ca2+和F-的影響,與Na+和Mg2+呈較強(qiáng)的正相關(guān)關(guān)系,與Cl-和SO_42-呈弱正相關(guān)關(guān)系,與HCO3-呈負(fù)相關(guān)關(guān)系。(2)淺層地下水中Cd和Cr的相關(guān)系數(shù)達(dá)到0.714,在0.05水平上呈顯著正相關(guān),Cd和Pb的相關(guān)系數(shù)達(dá)到0.619,Cr和Pb的相關(guān)系數(shù)達(dá)到了0.625,互相都呈很強(qiáng)的正相關(guān)關(guān)系。地表水中,Cd和Pb的相關(guān)系數(shù)達(dá)到了0.725,兩者在0.05水平上呈顯著正相關(guān),Cu和Cr的相關(guān)系數(shù)為0.595,也呈較強(qiáng)的正相關(guān)關(guān)系。(3)尾礦庫排放水氟的含量均未達(dá)到排放要求;周邊淺層地下水氟污染嚴(yán)重。影響鈾尾礦庫周邊水系中氟含量的最主要因素是人為開采鈾礦山,使氟元素釋放進(jìn)入水體。p H值、TDS以及氣候條件對水系中氟含量影響可能較大,水系包括HCO3-在內(nèi)其它陰陽離子對氟含量也有一定影響。(4)~(226)Ra在地下水中的遷移可能受到巖石的性質(zhì)、生物吸附、溫度、水化學(xué)特征、水動力條件等多種因素的影響。尾礦庫排放水中~(226)Ra的濃度最高,達(dá)到5.73 Bq·L-1,可能是尾礦庫周邊地表水和地下水中~(226)Ra的主要污染源。(5)運用單指標(biāo)評價法得出,研究區(qū)淺層地下水中Ⅴ類水占100%,不能直接飲用,需經(jīng)過特殊處理后才能飲用。研究區(qū)地表水中Ⅴ類水占80%,需經(jīng)過特殊處理后才能飲用,Ⅳ類水占20%,經(jīng)適當(dāng)處理后可飲用。研究區(qū)淺層地下水中U和NO_2~-的污染最為嚴(yán)重,超標(biāo)率均達(dá)到100%,U污染最高倍數(shù)達(dá)到了112。氟化物的超標(biāo)率達(dá)到85.71%,Pb的超標(biāo)率達(dá)到14.29%。同樣,研究區(qū)地表水中U、NO_2~-及氟化物的污染最為嚴(yán)重,超標(biāo)率均達(dá)到100%,U污染最高倍數(shù)達(dá)到了219.3。NO3-的超標(biāo)率達(dá)到20%。
[Abstract]:A large amount of acid waste water and waste residue produced in uranium mining process are discharged into tailings. Because acid mine wastewater and waste slag generally contain a large number of toxic and harmful substances, such as heavy metals, radionuclides, fluoride, etc. It can cause serious pollution to surface water and shallow groundwater around the tailings reservoir. In this paper, the surface water and shallow groundwater around the tailings reservoir of a uranium mine in the south of China are selected as the research objects. The hydrochemical properties and forms of the shallow groundwater and surface water are studied through field sampling and indoor measurement. The content and distribution of heavy metals and radionuclides were evaluated by single index evaluation method and pollution was evaluated. The main results are as follows: (1) the hydrochemical type of tailings reservoir is Ca SO_4 type water, and the hydrochemical type of shallow groundwater is Ca-Na-SO_4 type water, and the hydrochemical type of shallow groundwater in the study area is probably affected by the tailings reservoir. In the study area, the pH of shallow groundwater is 5.75-6.70, that of discharged water is 4.65-7.40, and that of leachate is 4.50-8.70. TDS in shallow groundwater is mainly affected by Ca2 and F-, and has strong positive correlation with Na and Mg2, and weakly positive correlation with Cl- and SO42-. The correlation coefficient of CD and Cr in shallow groundwater is 0.714, and the correlation coefficient of CD and Pb in shallow groundwater reaches 0.619, Cr and Pb at 0.05 level. The correlation coefficient between CD and Pb is 0.625, and there is a strong positive correlation between CD and Cr. The correlation coefficient of CD and Pb in surface water is 0.725, and the correlation coefficient of Cu and Cr is 0.595.The correlation coefficient of Cu and Cr is 0.595. The fluorine pollution of peripheral shallow groundwater is serious. The main factor affecting the fluorine content in the water system around the uranium tailings reservoir is the artificial mining of uranium ore mountains, which releases fluorine elements into the water body. The pH value of TDs and the climatic conditions may have a great influence on the fluoride content in the water system. The migration of 226Ra in groundwater may be affected by the properties of rocks, biosorption, temperature, hydrochemical characteristics, hydrodynamic conditions and so on. In the tailings reservoir, the highest concentration of Tempe 226Ra is 5.73 Bq / L -1, which may be the main source of pollution in the surface water and groundwater around the tailings reservoir. (5) by using the single index evaluation method, it is concluded that in the shallow groundwater of the study area, V type water accounts for 100% and cannot be drunk directly. It needs special treatment before drinking. In the surface water of the study area, the proportion of class V water is 80%, which needs special treatment before drinking, and the proportion of category 鈪,
本文編號:1982762
本文鏈接:http://sikaile.net/kejilunwen/huanjinggongchenglunwen/1982762.html
最近更新
教材專著