本文選題：有機(jī)螯合劑 + 生物表面活性劑��； 參考：《西南大學(xué)》2015年碩士論文

【摘要】：2014年《全國土壤污染狀況調(diào)查公報(bào)》顯示,我國耕地土壤點(diǎn)位超標(biāo)率為19.4%,其中輕微、輕度、中度和重度污染分別占13.7%、2.8%、1.8%和1.1%,主要受到Cd、As、Hg、口Cr等重金屬污染,尤以西南和中南地區(qū)最為嚴(yán)重；Cd、Hg、As和Pb等4種重金屬含量呈現(xiàn)沿西北向東南、東北向西南逐漸升高的態(tài)勢,工礦業(yè)、農(nóng)業(yè)和交通運(yùn)輸業(yè)等人類活動(dòng)是造成土壤重金屬污染和超標(biāo)的主要原因。進(jìn)入土壤中的Pb、Cd不被微生物降解,不僅能使土壤肥力、作物的產(chǎn)量與品質(zhì)下降,還能在動(dòng)植物體內(nèi)富集積累,最終通過食物鏈進(jìn)入人體,影響人體健康。近年來,我國相繼出現(xiàn)Pb、Cd污染事件,如陜西鳳翔的“血鉛事件”、湘和化工廠的“Cd污染事件”、廣東和湖南等省的“鎘米污染事件”等,引起政府、公眾和學(xué)術(shù)界的廣泛關(guān)注。因此,發(fā)展Pb、Cd污染土壤的修復(fù)技術(shù)成為環(huán)境科學(xué)領(lǐng)域的熱點(diǎn)研究問題。目前,Pb、Cd污染土壤的修復(fù)技術(shù)主要有客土法、熱處理法、電動(dòng)修復(fù)法、植物修復(fù)法、化學(xué)固定法和淋洗法等,這些方法存在修復(fù)時(shí)間長、成本高、效率低或造成二次污染等問題,采用多種技術(shù)聯(lián)合修復(fù)重金屬污染土壤逐漸受到學(xué)術(shù)界的青睞。通過淋洗提高土壤中Pb、Cd的生物有效性,結(jié)合植物修復(fù)治理Pb、Cd污染土壤,具有廣闊的發(fā)展前景。為此,本研究制備了模擬Pb、Cd的單一和復(fù)合污染土壤,設(shè)置3個(gè)污染水平(輕度、中度和重度污染),采用振蕩淋洗實(shí)驗(yàn),考察有機(jī)螯合劑(EDTA、EDDS和檸檬酸)和生物表面活性劑(鼠李糖脂)對模擬污染土壤的淋洗效果,篩選出對Pb、Cd具有最佳淋洗效果的螯合劑,研究有機(jī)螯合劑、生物表面活性劑淋洗土壤中Pb、Cd的動(dòng)力學(xué)特征；采用土柱淋溶實(shí)驗(yàn),優(yōu)化EDTA和鼠李糖脂的配比,獲得聯(lián)合淋洗復(fù)合污染土壤中Pb、Cd的動(dòng)力學(xué)特征；比較土柱淋溶前后土壤中Pb、Cd形態(tài)的變化,揭示EDTA和鼠李糖脂對Pb、Cd的聯(lián)合淋溶機(jī)制,為植物修復(fù)Pb、Cd污染土壤提供基礎(chǔ)。取得了如下主要研究結(jié)果：1.考察了EDTA、EDDS和檸檬酸(CIT)的濃度和初始pH對污染土壤中Pb、Cd的淋洗效果,獲得3種污染水平的土壤中Pb、Cd的最佳淋洗條件：淋洗劑濃度為0.025 mol/L,初始pH 7。淋洗劑對Pb、Cd復(fù)合污染土壤與單一污染土壤的淋洗率變化趨勢相同,均隨土壤污染程度的增加而增加；3種螯合劑對單—污染土壤的淋洗率比復(fù)合污染土壤高,對Cd的淋洗率大于Pb。準(zhǔn)二級動(dòng)力學(xué)方程能夠很好地描述3種有機(jī)螯合劑對污染土壤中Pb、Cd的淋洗過程。EDTA和EDDS淋洗單一污染土壤是一個(gè)慢速過程,Pb、Cd淋洗分別在120和180 min達(dá)到平衡；CIT淋洗Pb、Cd相對較快,分別在45和60 min達(dá)到淋洗平衡。EDTA對Pb輕度、中度和重度污染土壤的最大淋洗率分別為81.89%、82.91%和84.4%,Cd污染土壤分別為93.16%、93.62%和94.09%；EDTA對Pb、Cd的最大淋洗率比EDDS和CIT高。對于單一和復(fù)合污染土壤,3種螯合劑對Pb、Cd的淋洗速率常數(shù)均為輕度污染土壤中度污染土壤重度污染土壤,淋洗能力表現(xiàn)為CIT EDDS EDTA, Pb的淋洗速率常數(shù)大于Cd�？傮w來看,單一污染土壤中Pb、Cd的淋洗速率常數(shù)大于對應(yīng)的復(fù)合污染土壤,而EDTA和EDDS對重度復(fù)合污染土壤中Pb的淋洗速率常數(shù)比對應(yīng)的單一污染土壤高。2.考察了鼠李糖脂的濃度和初始pH對污染土壤中Pb、Cd的淋洗效果,獲得3種污染水平的土壤中Pb、Cd的最佳淋洗條件：鼠李糖脂濃度為0.025 mol/L,初始pH 7。鼠李糖脂對Pb、Cd復(fù)合污染土壤與單一污染土壤的淋洗率變化趨勢相同,均隨污染程度的增加而增加；鼠李糖脂對Pb單一污染土壤的淋洗率小于復(fù)合污染土壤,而Cd恰好相反。鼠李糖脂淋洗Pb、Cd是一個(gè)快速過程,分別在30和25 mmin達(dá)到淋洗平衡,且對Cd的淋洗速率常數(shù)大于Pb,明顯快于3種有機(jī)螯合劑。對于單一和復(fù)合污染土壤,Pb、Cd的淋洗速率常數(shù)均為輕度污染土壤中度污染土壤重度污染土壤；復(fù)合污染土壤中Pb、Cd的淋洗速率常數(shù)大于對應(yīng)的單一污染土壤。3.采用土柱淋溶實(shí)驗(yàn),用EDTA和鼠李糖脂聯(lián)合淋洗復(fù)合污染土壤中的Pb、Cd。隨著混合淋洗液體積的增加,兩種重金屬的淋溶率均呈現(xiàn)逐漸升高到趨于平衡的過程；隨著EDTA與鼠李糖脂配比的增加,兩種重金屬的淋溶率呈現(xiàn)先升高、達(dá)到最大值、再降低的變化趨勢。當(dāng)EDTA和鼠李糖脂的配比為1.5：1時(shí),Pb、Cd的淋溶率達(dá)到最大,輕度、中度和重度污染土壤中Pb的淋溶率分別為82.97%、87.61%和91.45%,Cd分別為85.45%、89.25%和93.88%,以重度污染土壤的淋溶效果最好。準(zhǔn)二級動(dòng)力學(xué)方程可以很好地描述EDTA和鼠李糖脂對復(fù)合污染土壤中Pb、Cd的聯(lián)合淋洗過程,獲得輕度、重度和重度污染土壤中Pb的淋溶速率常數(shù)分別為0.00092、0.00080和0.00072 kg.mg-1.min-1,Cd分別為0.0004、0.00025和0.00021kg.mg-1.min-1,淋溶速率常數(shù)均比它們單獨(dú)淋洗時(shí)低。4.研究了聯(lián)合淋洗前后污染土壤中Pb、Cd的形態(tài)變化,發(fā)現(xiàn)聯(lián)合淋洗能夠有效去除土壤中可交換態(tài)和碳酸鹽結(jié)合態(tài),其次為有機(jī)結(jié)合態(tài),對鐵錳氧化物結(jié)合態(tài)的淋洗效果較差,幾乎不淋洗殘?jiān)鼞B(tài)。EDTA與鼠李糖脂聯(lián)合淋洗污染土壤中Pb、Cd是配位螯合和膠束增溶共同作用的結(jié)果。
[Abstract]:The national survey of soil pollution status in 2014 showed that the excess rate of soil point in cultivated land was 19.4%, of which mild, mild, moderate and severe pollution accounted for 13.7%, 2.8%, 1.8% and 1.1% respectively, mainly by heavy metals such as Cd, As, Hg, and mouth Cr, especially in southwest and middle south areas; the contents of 4 heavy metals such as Cd, Hg, As and Pb were along the edge. The main reason for the heavy metal pollution and exceeding the standard in the soil, such as industry, mining, agriculture and transportation, is the main cause of heavy metal pollution and exceeding the standard in the northwest to the southeast and northeast to the southwest. In the soil, Pb, Cd can not be degraded by microorganisms, not only the soil fertility, the yield and quality of the crops, but also the accumulation and accumulation in the plants and animals. In recent years, Pb, Cd pollution events, such as "blood lead events" in Shaanxi Fengxiang, "Cd pollution events" in Hunan and chemical plants, "cadmium pollution events" in Guangdong and Hunan provinces, have aroused widespread concern in the government, the public and the academia. Therefore, the development of Pb and Cd contaminated soil Soil remediation technology has become a hot research issue in the field of environmental science. At present, the remediation techniques of Pb and Cd contaminated soil mainly include soil method, heat treatment, electric repair, phytoremediation, chemical fixation and leaching. These methods have many problems, such as long repair time, high cost, low efficiency or two pollution. The combined remediation of heavy metal contaminated soil has gradually been favored by the academic community. Through leaching to improve the bioavailability of Pb and Cd in soil, combined with phytoremediation and remediation of Pb and Cd contaminated soil, it has broad prospects for development. Therefore, this study has prepared a single and compound contaminated soil of Pb, Cd, and set 3 levels of pollution (mild, moderate and heavy). The leaching effect of organic chelating agent (EDTA, EDDS and citric acid) and bioactive agent (rhamnolipid) on simulated contaminated soil was investigated by oscillatory leaching, and the chelating agent for the best leaching effect of Pb and Cd was screened, the kinetic characteristics of the organic chelating agent and the bioactive agent in the leaching of soil Pb and Cd were studied. The soil column leaching experiment, optimizing the ratio of EDTA and rhamnolipid, obtained the dynamic characteristics of Pb and Cd in the combined leaching soil, compared the changes of Pb and Cd in soil before and after the leaching of soil column, and revealed the joint leaching mechanism of EDTA and rhamnolipid on Pb and Cd, which provided the basis for the plant to repair Pb and Cd contaminated soil. The results were as follows: 1. the concentration of EDTA, EDDS and citric acid (CIT) and the leaching effect of initial pH on Pb and Cd in contaminated soil were investigated. The optimum leaching conditions of Pb and Cd in 3 polluted soils were obtained: the concentration of the leaching agent was 0.025 mol/L, the initial pH 7. leaching agent was to Pb, and the leaching rate of the contaminated soil was the same as that of the single contaminated soil. The leaching rate of 3 kinds of chelating agents to single polluted soil is higher than that of compound contaminated soil. The leaching rate of Cd is more than Pb. quasi two dynamic equation, and the leaching process of 3 organic chelating agents for contaminated soil can be well described by 3 kinds of organic chelating agents in contaminated soil. The leaching process of.EDTA and EDDS in the leaching process of single contaminated soil is a slow speed over the leaching process of contaminated soil. Process, Pb, and Cd leaching are balanced at 120 and 180 min, respectively, and CIT leaching Pb, Cd relatively faster, respectively, in 45 and 60 min to achieve the leaching equilibrium.EDTA to Pb mildly, the maximum leaching rate of moderate and severe contaminated soil is 81.89%, 82.91% and 84.4%, Cd contaminated soil is 93.16%, 93.62% and 94.09%, respectively, EDTA against Pb, the maximum leaching rate of Pb For single and compound contaminated soil, the leaching rate constants of 3 chelating agents for Pb and Cd were all moderately polluted soil in mild contaminated soil, and the leaching ability of the soil was CIT EDDS EDTA, and the leaching rate constant of Pb was larger than Cd., and the leaching rate constant of Cd was greater than that of the corresponding compound pollution in the single contaminated soil. Soil, while the leaching rate constant of EDTA and EDDS for severe compound contaminated soil was higher than that of the corresponding single contaminated soil.2., and the concentration of rhamnolipid and the leaching effect of initial pH on Pb and Cd in contaminated soil were obtained, and the best leaching strips of Pb and Cd in 3 polluted soils were obtained: the concentration of rhamnolipid was 0.025 mol/L, and the initial pH 7. was 7.. The leaching rate of rhamnolipid on Pb, Cd compound contaminated soil and single contaminated soil was the same, which increased with the increase of pollution degree; the leaching rate of rhamnolipid on Pb single contaminated soil was less than that of compound contaminated soil, while Cd was just the opposite. The leaching of rhamnolipid in Pb and Cd was a rapid process, which was washed in 30 and 25 mmin respectively. The leaching rate constant of Cd is greater than Pb, and it is faster than 3 kinds of organic chelating agents. For single and compound contaminated soil, the leaching rate constants of Pb and Cd are mild contaminated soil contaminated soil with moderate pollution, and the leaching rate of Pb and Cd in compound contaminated soil is greater than that of the corresponding single contaminated soil.3. using soil column drenching. EDTA and Shu Li sugar grease were used to rinse the Pb in the contaminated soil, and the leaching rate of the two heavy metals increased gradually to the balance with the increase of the volume of the mixed lotion. With the increase of the ratio of EDTA and Shu Li sugar and fat, the leaching rate of the heavy metals increased first, reached the maximum and then decreased. When the ratio of EDTA and rhamnolipid was 1.5:1, the leaching rate of Pb and Cd reached the maximum. The leaching rates of Pb in the mild, moderate and severe contaminated soils were 82.97%, 87.61% and 91.45%, respectively 85.45%, 89.25% and 93.88%, respectively. The leaching effect of severe contaminated soil was the best. The quasi two kinetics equation could describe EDTA well. The leaching rate of Pb and Cd in soil contaminated with rhamnolipid and rhamnolipid in the mixed contaminated soil was 0.00092,0.00080 and 0.00072 kg.mg-1.min-1 respectively, respectively, and Cd was 0.0004,0.00025 and 0.00021kg.mg-1.min-1 respectively, and the constant number of leaching rates was lower than that of them when they were washed separately. The morphological changes of Pb and Cd in the contaminated soil before and after washing were found. It was found that the joint leaching could effectively remove the exchangeable and carbonate binding states in the soil, followed by the organic binding state, and the leaching effect of the iron and manganese oxide binding state was poor, and the residue state.EDTA was washed with rhamnolipid in the contaminated soil Pb, and Cd was the coordination chelation and micelle. The result of the combination of solubilization.
【學(xué)位授予單位】：西南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X53

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 吳青;崔延瑞;湯曉曉;楊慧娟;孫劍輝;;生物可降解螯合劑谷氨酸N,N-二乙酸四鈉對污泥中重金屬萃取效率的研究[J];環(huán)境科學(xué);2015年05期

2 鄧紅俠;楊亞莉;李珍;許巖;李榮華;孟昭福;楊亞提;;不同條件下皂苷對污染X土中Cu、Pb的淋洗修復(fù)[J];環(huán)境科學(xué);2015年04期

3 吳少飛;丁竹紅;胡忻;張宇峰;吳海露;;EDTA及其與檸檬酸交替對污染水稻土壤重金屬元素的分步連續(xù)提取研究[J];江蘇農(nóng)業(yè)科學(xué);2014年11期

4 郭廣慧;陳同斌;楊軍;鄭國砥;高定;;中國城市污泥重金屬區(qū)域分布特征及變化趨勢[J];環(huán)境科學(xué)學(xué)報(bào);2014年10期

5 吳烈善;呂宏虹;蘇翠翠;曾東梅;莫小榮;;環(huán)境友好型淋洗劑對重金屬污染土壤的修復(fù)效果[J];環(huán)境工程學(xué)報(bào);2014年10期

6 尹雪;陳家軍;蔡文敏;;EDTA與檸檬酸復(fù)配洗滌修復(fù)多重金屬污染土壤效果研究[J];環(huán)境科學(xué);2014年08期

7 鄧紅俠;劉霞;王建濤;王力;楊亞莉;楊亞提;;不同淋洗劑對污染土婁土中Cu、Pb的淋洗修復(fù)研究[J];西北農(nóng)林科技大學(xué)學(xué)報(bào)(自然科學(xué)版);2014年08期

8 劉宇;;重金屬污染土壤修復(fù)技術(shù)及其修復(fù)實(shí)踐[J];中國高新技術(shù)企業(yè);2014年17期

9 藍(lán)梓銘;莫?jiǎng)?chuàng)榮;段秋實(shí);李小明;明聰聰;吳小寅;;鼠李糖脂對剩余污泥中銅和鎳的去除[J];環(huán)境工程學(xué)報(bào);2014年03期

10 孟蝶;萬金忠;張勝田;馮艷紅;趙欣;姚歡;林玉鎖;;鼠李糖脂對林丹-重金屬復(fù)合污染土壤的同步淋洗效果研究[J];環(huán)境科學(xué)學(xué)報(bào);2014年01期

相關(guān)博士學(xué)位論文 前1條

1 鄭順安;我國典型農(nóng)田土壤中重金屬的轉(zhuǎn)化與遷移特征研究[D];浙江大學(xué);2010年

相關(guān)碩士學(xué)位論文 前4條

1 張賽;凍融作用對我國東北典型農(nóng)田黑土重金屬Cd遷移轉(zhuǎn)化的影響[D];吉林大學(xué);2014年

2 梁振飛;土壤中鎘的吸附和淋失動(dòng)力學(xué)及植物富集規(guī)律研究[D];中國農(nóng)業(yè)科學(xué)院;2013年

3 周楠楠;EDTA強(qiáng)化茶皂素對土壤中Cu、Zn、Cd淋洗修復(fù)的影響研究[D];山東農(nóng)業(yè)大學(xué);2011年

4 杜沛;有機(jī)酸淋洗法修復(fù)鉻污染土壤[D];沈陽航空航天大學(xué);2011年

，

本文編號：1972503