發(fā)布時間：2018-05-11 10:40

  本文選題：重金屬 + 土壤污染��； 參考：《西北農(nóng)林科技大學》2017年碩士論文

【摘要】：礦山開采和選冶過程會形成露天采礦場、尾礦庫等廢棄場地,產(chǎn)生大量固體廢物。尾礦渣中的重金屬在降雨和風蝕的作用下逐漸向周圍擴散,破壞生態(tài)環(huán)境,對水體和土壤造成了嚴重污染。因此,對重金屬污染土壤進行修復,使其恢復植被功能至關重要。本研究以陜西省潼關縣飲用水源保護地及歷史遺留重金屬企業(yè)周邊的土壤修復示范工程為例,從土壤污染現(xiàn)狀調查、工程修復技術的篩選、修復效果評價以及修復后土壤農(nóng)業(yè)生產(chǎn)安全性評價等角度進行了系統(tǒng)分析,科學評估了客土法,石灰、磷酸鈣、粉煤灰和Na_2S作為重金屬鈍化劑的原位穩(wěn)定化修復技術在實際重金屬污染土壤修復中的應用潛力。研究得到的結果如下:(1)“三小”冶煉行為和鉛鋅礦的冶煉對周邊土壤造成了嚴重的污染。西街子土壤的污染源為礦渣堆,主要受Pb、Cd、Hg的污染,其濃度范圍分別為25.1～1116mg·kg~(-1),2.30～5.20mg·kg~(-1),0.15～20.0mg·kg~(-1)。鑫欣土壤的污染源為廢渣堆、堆料場和冶煉區(qū),主要受Zn、Cd、Pb和Hg的污染,其濃度范圍分別為89.2～742mg·kg~(-1),1.59～362mg·kg~(-1),88.4～7622mg·kg~(-1),0.21～35.0mg·kg~(-1)。(2)重金屬的濃度呈現(xiàn)出由污染源向周邊農(nóng)田土壤逐漸遞減且在污染源處向下遷移的特點。部分剖面土壤污染嚴重,在0～120cm范圍內(nèi)重金屬濃度全部超過土壤環(huán)境質量二級標準。(3)西街子表層土壤的污染評價結果:內(nèi)梅羅綜合污染指數(shù)分析表明項目區(qū)域土壤都受到污染,97.1%的土樣受到重污染。采用潛在生態(tài)危害指數(shù)法進行評價,Cd、Hg和Pb是項目區(qū)域土壤重金屬污染的主要貢獻因子。該區(qū)域潛在生態(tài)危害指數(shù)(RI)范圍為668～10969,具有很強的生態(tài)危害。地積累指數(shù)法的統(tǒng)計結果表明5種重金屬污染程度由強到弱依次為:CdPbHgZnCu。(4)鑫欣表層土壤的污染評價結果:內(nèi)梅羅綜合污染指數(shù)分析表明土樣受到輕污染、中污染和重污染的比例分別為5.88%、35.3%和58.8%。從潛在生態(tài)危害指數(shù)(Eri)來看,Cd是潛在生態(tài)危害最嚴重的金屬元素,所有的土樣都存在極強的生態(tài)危害。從綜合潛在生態(tài)風險(RI)分析,該項目區(qū)域土壤具有很強的生態(tài)危害。(5)對兩個項目區(qū)域重污染土壤采用客土法,輕污染土壤采用原位穩(wěn)定化進行修復,修復效果顯著,土壤中重金屬的總量和有效態(tài)濃度均明顯降低。除Cd外,工程修復后的土壤中重金屬的總量均低于土壤二級標準中的限值。土壤重金屬有效態(tài)濃度與土壤pH、有機質濃度和重金屬全量之間存在顯著的相關關系。隨著修復時間的增長,土壤有效態(tài)的濃度有增加趨勢。(6)西街子修復后的土壤上主要種植玉米、花生、四季豆和毛豆,鑫欣修復后的土壤上主要種植玉米和芝麻,對農(nóng)作物的重金屬污染評價發(fā)現(xiàn):部分農(nóng)作物中Cd、Pb和Hg的累積量高于國家食品安全標準中規(guī)定的限值,因此修復后土壤上種植的農(nóng)作物不能進入市場流通,需要統(tǒng)一進行處理。(7)為了探索最適宜的種植模式,在西街子修復后第二年的土壤上嘗試種植一些常見蔬菜,發(fā)現(xiàn)不同蔬菜對重金屬的富集能力有差異,具體表現(xiàn)為:葉菜類蔬菜非葉菜類蔬菜。(8)并非所有農(nóng)作物可食部分中重金屬的濃度與土壤中重金屬全量、有效態(tài)濃度之間都存在顯著相關性。Cd、Pb和Hg在作物中轉移系數(shù)(TF)值很小,說明重金屬在修復后的土壤-作物系統(tǒng)中遷移量較小。玉米各重金屬元素的轉移系數(shù)(TF)均最高,因此繼續(xù)大面積種植存在一定的風險。(9)在重金屬污染修復后的土壤上不建議立刻進行糧食生產(chǎn),應改變原有生產(chǎn)模式同時持續(xù)監(jiān)測,在確保糧食安全后再進行生產(chǎn)。
[Abstract]:Mining and smelting process will form open pit, tailings and other waste sites, producing a large amount of solid waste. Heavy metals in the tailings slag gradually spread to the surrounding area under the action of rainfall and wind erosion, destroying the ecological environment and causing serious pollution to the water and soil. Therefore, the heavy metal contaminated soil is restored to restore the vegetation. This study takes the example of the demonstration project of soil remediation around the drinking water source in Tongguan County of Shaanxi and the surrounding heavy metal enterprises left over by history, and systematically analyzes the status of soil pollution, the screening of Engineering remediation technology, the evaluation of restoration effect and the safety evaluation of soil agricultural production after restoration. The application potential of soil method, lime, calcium phosphate, fly ash and Na_2S as heavy metal passivating agent in situ remediation technology in the remediation of heavy metal contaminated soil was evaluated. The results were as follows: (1) "three small" smelting behavior and lead-zinc smelting have caused serious pollution to the surrounding soil. The source is slag pile, which is mainly contaminated by Pb, Cd and Hg, and its concentration ranges from 25.1 to 1116mg. Kg~ (-1), 2.30 to 5.20mg. Kg~ (-1), 0.15 to 20.0mg. Kg~ (-1). The pollution sources of Xinxin soil are waste residue, heap yard and smelting area. The concentration range is 89.2 ~ 1.59. 8 8.4 ~ 7622mg / kg~ (-1), 0.21 to 35.0mg. Kg~ (-1). (2) the concentration of heavy metals is gradually decreasing from the pollution source to the surrounding farmland and moving downward in the source of pollution. The soil pollution is serious in some sections, and the concentration of heavy metals in the range of 0 to 120cm is more than the standard of the soil environmental quality two. (3) the surface soil of the West Street subsoil The results of pollution assessment: the analysis of Nemero's comprehensive pollution index indicates that the soil in the project area is polluted and 97.1% of the soil samples are heavily polluted. The potential ecological hazard index method is used to evaluate the soil heavy metal pollution in the project area. Cd, Hg and Pb are the main contributors to the soil heavy metal pollution in the project area. The area of the potential ecological hazard index (RI) in this region is 668~10969. The statistical results of the land accumulation index method showed that the pollution degree of 5 kinds of heavy metals from strong to weak was in turn: CdPbHgZnCu. (4) Xinxin surface soil pollution evaluation result: the Nemero comprehensive pollution index analysis showed that the soil samples were exposed to light pollution, the proportion of medium pollution and heavy pollution were 5.88%, 35.3% and 58.8%. from potential birth, respectively. The state hazard index (Eri) shows that Cd is the most serious metal element of potential ecological hazards, and all soil samples have very strong ecological hazards. From the comprehensive potential ecological risk (RI) analysis, the soil of this project has a strong ecological hazard. (5) the soil method is used for the heavy polluted soil in the two projects, and the soil in the light polluted soil is stabilized in situ. In addition to Cd, the total amount of heavy metals in soil after engineering repair is lower than that in the two level of soil. There is a significant correlation between the effective concentration of soil heavy metals and soil pH, the concentration of organic matter and the total heavy metal content. The concentration of soil effective state increased. (6) corn, peanuts, four season beans and peas were mainly planted on the soil after the restoration of West Street. The main planting corn and sesame on the soil after Xinxin restoration showed that the accumulation of Cd, Pb and Hg in some crops was higher than that of national food. The limit set in the safety standard, therefore, the crops planted on the soil after repair can not enter the market circulation and need to be treated in a unified way. (7) in order to explore the most suitable planting pattern, we try to plant some common vegetables on the soil of second years after the restoration of West Street, and find that the enrichment ability of different vegetables on heavy metals is different. The leaf vegetables are not leafy vegetables. (8) there is a significant correlation between the concentration of heavy metals in the edible parts of the crops and the total heavy metals in the soil, and the significant correlation between the effective concentrations and the.Cd. The transfer coefficient (TF) of the Pb and Hg in the crops is small, indicating that the heavy metal has a small migration in the soil crop system after the restoration. The transfer coefficient (TF) of each heavy metal element is the highest, so there is a certain risk for continuing large area planting. (9) it is not recommended to carry out grain production immediately after the remediation of heavy metal pollution. It should change the original production mode and keep monitoring at the same time, and then make production after the food security is ensured.

【學位授予單位】：西北農(nóng)林科技大學
【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 施亞星;吳紹華;周生路;王春輝;陳浩;;土壤-作物系統(tǒng)中重金屬元素吸收、遷移和積累過程模擬[J];環(huán)境科學;2016年10期

2 陳遠其;張煜;陳國梁;;石灰對土壤重金屬污染修復研究進展[J];生態(tài)環(huán)境學報;2016年08期

3 張連科;李海鵬;黃學敏;李玉梅;焦坤靈;孫鵬;王維大;;包頭某鋁廠周邊土壤重金屬的空間分布及來源解析[J];環(huán)境科學;2016年03期

4 陶雪;楊琥;季榮;李愛民;;固定劑及其在重金屬污染土壤修復中的應用[J];土壤;2016年01期

5 宋波;曾煒銓;;土壤有機質對鎘污染土壤修復的影響[J];土壤通報;2015年04期

6 李榮華;沈鋒;李曉龍;張增強;王姣;;陜西某鉛鋅冶煉廠區(qū)及周邊農(nóng)田重金屬污染土壤的穩(wěn)定化修復理論與實踐[J];農(nóng)業(yè)環(huán)境科學學報;2015年07期

7 晏聞博;柳丹;彭丹莉;李松;陳俊任;葉正錢;吳家森;王海龍;;重金屬礦山生態(tài)治理與環(huán)境修復技術進展[J];浙江農(nóng)林大學學報;2015年03期

8 化玉謹;張敏英;陳明;張佳文;馮流;;煉金區(qū)土壤中汞形態(tài)分布及其生物有效性[J];環(huán)境化學;2015年02期

9 侯李云;曾希柏;張楊珠;;客土改良技術及其在砷污染土壤修復中的應用展望[J];中國生態(tài)農(nóng)業(yè)學報;2015年01期

10 吳烈善;曾東梅;莫小榮;呂宏虹;蘇翠翠;孔德超;;不同鈍化劑對重金屬污染土壤穩(wěn)定化效應的研究[J];環(huán)境科學;2015年01期

相關博士學位論文 前1條

1 石平;遼寧省典型有色金屬礦區(qū)土壤重金屬污染評價及植物修復研究[D];東北大學;2010年

相關碩士學位論文 前1條

1 陳宏文;南方紅壤區(qū)某重金屬污染場地調查、風險評估及修復效果評估研究[D];南昌大學;2013年

，

本文編號：1873613