【摘要】：近年來,隨著我國工業(yè)化和城市化發(fā)展進程的加快促使能源在中國的需求越來越大,燃煤發(fā)電是中國電力能源的主要來源,中國是世界上最大的煤炭消費國,也是世界上粉煤灰排棄量最多的國家。由于粉煤灰具有低堆密度、高持水量、適宜的pH值等特點,可以提高土壤的耐久性、剛度和強度,利用粉煤灰作為土壤的充填物料,恢復土壤原有的利用方式,能夠提高土壤培肥效果,縮短復墾周期,具有礦區(qū)廢棄物的回收利用和土壤復墾的雙重功效,目前粉煤灰已經(jīng)成功應用于土壤修復、礦山復墾等方面。然而,在自然降水的條件下,降水的流動性將導致粉煤灰浸出液中的某些重金屬元素通過周圍的土壤或者巖石的間隙擴散到更深的地下間隙或者更遠處,當降水產(chǎn)生的間隙流動的輸送性增強,粉煤灰復墾土壤中的某些重金屬元素可能會對水環(huán)境造成較大的污染。本文通過逐級化學提取實驗研究實驗中粉煤灰的元素賦存狀態(tài),實驗結(jié)果表明,砷、鉻、銅、鋅的水溶態(tài)和可交換態(tài)的含量比例占總含量的0.2%~5.9%之間,屬于較容易被浸出的狀態(tài),而殘渣態(tài)占總量的比例較大,屬于比較穩(wěn)定的狀態(tài),較難浸出。在酸性條件下,元素的碳酸鹽結(jié)合態(tài)容易被釋放出。通過對粉煤灰復墾的土壤連續(xù)淋濾2h、8h、14h,對浸出液進行現(xiàn)場分批采樣,采用電感耦合等離子體質(zhì)譜儀(ICP-MS)對浸出液中的砷、鉻、銅、鋅、硒和銻元素進行分析測定,研究粉煤灰復墾土壤中重金屬含量的時空變異規(guī)律,分析其可能的污染。研究結(jié)果表明,隨著復墾土壤距離的增加,這些元素的濃度呈現(xiàn)規(guī)律性變化。在下游土壤中,砷元素與鉻元素隨著復墾距離的增加,濃度一直在增加,其最大平均濃度分別是水體背景值的三倍和五倍;相反,鋅元素的濃度隨著復墾距離的增加一直在減少。銅元素和銻元素的濃度隨著復墾距離的增加先增加后減少;然而,硒元素的濃度在整個淋濾過程中隨著復墾距離的增加先減少后增加。不同的元素在浸出液中有不同程度的富集。另一方面,砷元素和鋅元素的淋濾濃度排序均為14 h2 h8 h,鉻元素和銅元素的淋濾濃度排序均為2h8 h14 h,硒元素的淋濾濃度排序為14 h8 h2 h,而銻元素的淋濾濃度排序為8 h2 h14 h。研究結(jié)果可為粉煤灰在土壤復墾中的農(nóng)業(yè)利用提供有用的信息。
[Abstract]:In recent years, with the acceleration of industrialization and urbanization in China, the demand for energy in China is increasing, and coal-fired power generation is the main source of power energy in China, and China is the largest coal consumer in the world. It is also the country with the largest amount of fly ash disposal in the world. Because the fly ash has the characteristics of low pile density, high water holding capacity and suitable pH value, it can improve the durability, rigidity and strength of the soil. The fly ash is used as the filling material of the soil, and the original utilization mode of the soil can be restored. It can improve the effect of soil fertilization, shorten the period of reclamation, and has the dual effects of recycling and reclamation of mine wastes. At present, fly ash has been successfully used in soil remediation, mine reclamation and so on. However, under natural precipitation conditions, the fluidity of precipitation will cause certain heavy metals in the fly ash leachate to spread through the surrounding soil or rock gaps to deeper underground gaps or further away, When the transport capacity of interstitial flow caused by precipitation is enhanced, some heavy metal elements in the soil reclaimed by fly ash may cause great pollution to the water environment. In this paper, the occurrence state of fly ash elements in the experiment was studied by step chemical extraction experiment. The experimental results show that the water soluble and exchangeable state of arsenic, chromium, copper and zinc account for between 0.2% and 5.9% of the total content, so they are easy to be leached out. The residual state is relatively stable and difficult to be leached because of its large proportion of the total amount. In acidic conditions, the carbonate bound states of elements are easily released. The leaching solution was collected in batches by continuous leaching of fly ash for 2 h or 8 h for 14 h. The elements of arsenic, chromium, copper, zinc, selenium and antimony in the leachate were determined by inductively coupled plasma mass spectrometry (ICP-MS), and the results showed that the content of arsenic, chromium, copper, zinc, selenium and antimony in the leachate was determined by inductively coupled plasma mass spectrometry (ICP-MS). The temporal and spatial variation of heavy metal content in fly ash reclamation soil was studied and its possible pollution was analyzed. The results showed that the concentration of these elements changed regularly with the increase of soil reclamation distance. In the downstream soil, the concentration of arsenic and chromium has been increasing with the increase of reclamation distance, and the maximum average concentration is three times and five times of the background value of water body, respectively. The concentration of zinc decreases with the increase of reclamation distance. The concentration of copper and antimony increased first and then decreased with the increase of reclamation distance, however, the concentration of selenium decreased first and then increased with the increase of reclamation distance in the whole leaching process. Different elements are enriched in the leachate to different degrees. On the other hand, the order of leaching concentration of arsenic and zinc is 14 h 2 h 8 h, that of chromium and copper is 14 h 14 h, that of selenium is 14 h 8 h 2 h, and that of antimony is 8 h 2 h 14 h. The results can provide useful information for the agricultural utilization of fly ash in soil reclamation.
【學位授予單位】：合肥工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：X53

【參考文獻】

相關期刊論文 前10條

1 陳杰;劉永;石瑩;黃慶享;高尚勇;;矸石電廠粉煤灰基膏體充填材料研究[J];材料科學與工藝;2016年03期

2 朱靜;郭建陽;王立英;潘響亮;符志友;廖海清;吳豐昌;;銻的環(huán)境地球化學研究進展概述[J];地球與環(huán)境;2010年01期

3 朱靜;吳豐昌;;改性粉煤灰在處理銻礦選礦廢水中的應用[J];環(huán)境科學學報;2010年02期

4 傅叢;姜英;白向飛;;燃煤砷危害及相關標準中砷含量限值指標探討[J];煤質(zhì)技術;2009年06期

5 王永慶;史曉杰;孫川;;粉煤灰的綜合利用研究現(xiàn)狀[J];廣州化工;2009年07期

6 田賀忠;曲益萍;;2005年中國燃煤大氣砷排放清單[J];環(huán)境科學;2009年04期

7 申松梅;曹先仲;宋艷輝;劉穎;繩珍;覃路燕;;多環(huán)芳烴的性質(zhì)及其危害[J];貴州化工;2008年03期

8 吳豐昌;鄭建;潘響亮;黎文;鄧秋靜;莫昌t ;朱靜;劉碧君;劭樹勛;郭建陽;;銻的環(huán)境生物地球化學循環(huán)與效應研究展望[J];地球科學進展;2008年04期

9 江澤民;;對中國能源問題的思考[J];上海交通大學學報;2008年03期

10 趙修軍;鄭琳;趙東力;宋紅偉;郭艷鳳;;煤系固體廢棄物資源化再利用途徑分析[J];選煤技術;2007年06期

，

本文編號：2126822