人工濕地不同工藝對重金屬的去除研究
發(fā)布時(shí)間：2019-06-20 07:18
【摘要】：重金屬污染具有很嚴(yán)重的潛在危害,且重金屬污染一旦發(fā)生很難消除,重金屬在環(huán)境中通過食物鏈傳遞進(jìn)行富集以致對食物鏈終極消費(fèi)者人類的健康產(chǎn)生威脅。人工濕地作為污水處理的新型工藝,人工濕地有很強(qiáng)的抗沖擊負(fù)荷能力,較好的凈化水質(zhì)能力并且其基建運(yùn)行費(fèi)用低廉的優(yōu)點(diǎn)。人工濕地可以通過基質(zhì)、植物、微生物對水中的重金屬進(jìn)行去除。人工濕地常見工藝有垂直潛流、水平潛流、表面流等形式。目前被廣泛運(yùn)用的人工濕地基質(zhì)填料種類繁多。因此工程中針對不同污染物選用何種工藝、何種基質(zhì)的研究很有必要。本文選用皂河人工濕地示范工程系列1~系列5五種復(fù)合人工濕地系統(tǒng)為研究對象,其中系列1為垂直潛流+水平潛流復(fù)合人工濕地系統(tǒng)、系列2為水平潛流+表面流復(fù)合人工濕地系統(tǒng)、系列3為垂直潛流+水平潛流+表面流復(fù)合人工濕地系統(tǒng)、系列4為水平潛流+表面流復(fù)合人工濕地系統(tǒng)、系列5為表面流+表面流復(fù)合人工濕系統(tǒng)。研究不同工藝、不同基質(zhì)條件下人工濕地系統(tǒng)對水中Cd、Cr、Cu、Pb、Zn5中重金屬的去除效果。探討不同工藝下不同基質(zhì)中重金屬的沿程分布特征。分析系列5中(沙子+鋁泥)基質(zhì)對重金屬的累積量與其理化性質(zhì)的相關(guān)性。主要研究結(jié)果如下:1.人工濕地去除重金屬機(jī)理(1)人工濕地系統(tǒng)中重金屬與基質(zhì)之間通過物理過程、化學(xué)過程、生物過程共同作用達(dá)到固定重金屬的目的,且基質(zhì)對重金屬去除起主要作用。(2)人工濕地系統(tǒng)中重金屬通過植物過濾、植物鈍化、植物提取、植物揮發(fā)等方式實(shí)現(xiàn)重金屬的去除,但植物對重金屬的去除貢獻(xiàn)不大。2.系列1~系列5復(fù)合人工濕地系統(tǒng)對重金屬的去除效果(1)系列1系統(tǒng)~系列4系統(tǒng)復(fù)合型人工濕地對Cd、Cr、Cu、Pb、Zn5中重金屬都有一定的去除效果。系列5除對Cu和Zn有顯著釋放現(xiàn)象外對Cd、Cr、Pb三種重金屬也有一定的去除效果。各系列對Cd的去除率在75.00%~87.88%之間;對Cr的去除率在59.10%~73.10%之間;對Cu的去除率在24.14%~52.49%之間;對Pb去除率在57.79%~73.20%之間;對Zn去除率在27.86%~54.14%之間。(2)垂直潛流人工濕地對Cd、Cr、Pb的去除效果好于水平潛流和表面流人工濕地;多級復(fù)合型人工濕地對Cd、Cr、Pb的去除效果好于單級人工濕地;在表面流人工濕地中增加水力停留時(shí)間可提高對Cd、Cr、Pb的去除效果;垂直潛流和水平潛流人工濕地對Cu的去除差異不大。垂直潛流人工濕地對Zn的去除效果優(yōu)于水平潛流人工濕地;垂直潛流+水平潛流復(fù)合型人工濕地對Cu和Zn的去除效果優(yōu)于單種工藝的人工濕地。(3)表面流人工濕地對Cu和Zn均有釋放現(xiàn)象,其可能原因?yàn)?Zn的可還原態(tài)高于除殘?jiān)鼞B(tài)以外的其他形態(tài),Cu的弱酸可溶態(tài)高于除殘?jiān)鼞B(tài)以外的其他形態(tài)。由于人工濕地運(yùn)行時(shí)間已久,水環(huán)境偏酸性,溶解氧較低使得Cu和Zn釋放到水相中形成二次污染。3.人工濕地基質(zhì)中重金屬的沿程分布特征(1)重金屬在各人工濕地基質(zhì)中的平均含量大小依次為ZnCrPbCuCd。各種基質(zhì)對Zn的累積含量在247.76mg/kg~438.18mg/kg之間;對Cr的累積含量在114.89mg/kg~127.30mg/kg;對Pb的累積含量在73.75mg/kg~77.62mg/kg;對Cu的累積含量在39.42mg/kg~68.43mg/kg;對Cd的累積含量在1.46mg/kg~10.15mg/kg。(2)垂直潛流工藝(豆石+碎石空心磚)基質(zhì)、水平潛流工藝(沙子+爐渣+碎石空心磚)基質(zhì)對Zn的累積效果較好;垂直潛流工藝(豆石+礫石)基質(zhì)對Pb的累積效果較好;各工藝不同基質(zhì)對Cu、Cr的累積效果差異不明顯;水平潛流處理單元(沙子+爐渣+礫石)基質(zhì)對Cd的累積效果好于(沙子+爐渣+碎石空心磚)基質(zhì),表面流處理單元(沙子+粉煤灰)基質(zhì)對Cd的累積效果明顯好于(沙子+煤渣)基質(zhì)。(3)垂直潛流工藝(豆石+礫石)基質(zhì)中Cd、Cr、Pb、Zn的含量與沿程距離相關(guān)性顯著,(豆石+碎石空心磚)基質(zhì)中Cd、Pb、Zn的含量與沿程距離相關(guān)性顯著;水平潛流工藝(沙子+爐渣+礫石)基質(zhì)中Cd、Cr、Zn的含量與沿程距離相關(guān)性顯著,(沙子+爐渣+碎石空心磚)基質(zhì)、(豆石+爐渣)基質(zhì)中Cr、Cu、Pb、Zn的含量與沿程距離相關(guān)性顯著,(沙子+礫石)基質(zhì)中Pb、Zn的含量與沿程距離相關(guān)性顯著;表面流工藝(沙子+粉煤灰)基質(zhì)中Cr、Pb、Zn的含量與沿程距離相關(guān)性顯著,(沙子+煤渣)基質(zhì)中Cd、Cu、Pb、Zn的含量與沿程距離相關(guān)性顯著。4.系列5人工濕地(沙子+鋁泥)基質(zhì)中重金屬含量與其理化性質(zhì)的相關(guān)性(1)(沙子+鋁泥)基質(zhì)中Cd、Pb的累積量與pH顯著正相關(guān),而(沙子+鋁泥)基質(zhì)中Cr、Cu、Zn的累積量與pH相關(guān)性不顯著。(2)(沙子+鋁泥)基質(zhì)中Cd、Cr的累積量與有機(jī)質(zhì)極顯著負(fù)相關(guān),(沙子+鋁泥)基質(zhì)中Cu、Pb、Zn的累積量與有機(jī)質(zhì)顯著負(fù)相關(guān)。(3)(沙子+鋁泥)基質(zhì)中Cd、Pb的累積量與電導(dǎo)率顯著正相關(guān),而(沙子+鋁泥)基質(zhì)中Cr、Cu、Zn的累積量與電導(dǎo)率相關(guān)性不顯著。
[Abstract]:Heavy metal pollution is a serious potential hazard, and the heavy metal pollution is difficult to eliminate once the heavy metal pollution occurs, and the heavy metal is enriched in the environment through the food chain so as to threaten the health of the ultimate consumer of the food chain. The artificial wetland, as a new technology for sewage treatment, has the advantages of strong impact-resistant load capacity, better purification water quality and low cost of capital construction and operation. The artificial wetland can be removed by the heavy metal in the water through the substrate, the plant and the microorganism. The common process of artificial wetland has the form of vertical undercurrent, horizontal undercurrent, surface flow and so on. There are a wide variety of artificial wetland matrix fillers that are widely used at present. Therefore, what kind of process is selected for different pollutants in the project is necessary for the research of what kind of matrix. In this paper, five kinds of composite artificial wetland systems are selected as the research object of the first series of five composite artificial wetland systems of the sapo-river artificial wetland, in which the series 1 is a vertical undercurrent + horizontal undercurrent composite artificial wetland system, and the series 2 is a horizontal undercurrent + surface flow composite artificial wetland system. The series 3 is a vertical subsurface flow + horizontal undercurrent + surface flow composite artificial wetland system, and the series 4 is a horizontal undercurrent + surface flow composite artificial wetland system, and the series 5 is a surface flow and surface flow composite artificial wet system. The removal of Cd, Cr, Cu, Pb and Zn5 in water by artificial wetland system under different conditions and different substrate conditions was studied. The distribution of heavy metals in different substrates under different processes is discussed. The relationship between the accumulation of heavy metals and the physical and chemical properties of the matrix in the series 5 (sand + aluminum paste) was analyzed. The main results are as follows:1. In that artificial wetland system, the heavy metal mechanism (1) is remove by a physical process, a chemical process and a biological process through a physical process, a chemical process and a biological process to achieve the purpose of fixing heavy metal, and the substrate plays a major role in the heavy metal removal. (2) The heavy metals in the artificial wetland system can be removed by plant filtration, plant passivation, plant extraction, and plant volatilization. The removal effect (1) of the series 1-series 5 composite artificial wetland system on the heavy metals has a certain removal effect on the heavy metals in Cd, Cr, Cu, Pb and Zn 5 in the composite artificial wetland of series 1 to series 4. The series 5 has a certain removal effect on the three heavy metals of Cd, Cr and Pb in addition to the remarkable release of Cu and Zn. The removal rate of Cd is between 75.00% and 87.88%; the removal rate of Cr is between 59.10% and 73.10%; the removal rate of Cu is between 24.14% and 52.49%; the removal rate of Pb is between 57.79% and 73.20%; and the removal rate of Zn is between 27.86% and 54.14%. (2) The effect of the vertical subsurface flow constructed wetland on the removal of Cd, Cr and Pb is better than that of the horizontal undercurrent and the surface-flow constructed wetland; the removal effect of the multi-stage composite artificial wetland on the Cd, Cr and Pb is better than that of the single-stage artificial wetland, and the increase of the hydraulic retention time in the surface-flow artificial wetland can improve the Cd, The removal effect of Cr and Pb, and the difference of the vertical undercurrent and horizontal undercurrent constructed wetland to the removal of Cu. The effect of vertical undercurrent artificial wetland on Zn removal is superior to that of horizontal undercurrent constructed wetland, and the removal effect of vertical undercurrent + horizontal undercurrent composite artificial wetland on Cu and Zn is superior to that of single-process artificial wetland. (3) The surface-flow constructed wetland has the release of Cu and Zn, which may be due to the fact that the reducible state of Zn is higher than the other forms other than the residue state, and the soluble state of the weak acid of Cu is higher than the other forms other than the residue state. Since the operation time of the artificial wetland is long, the water environment is acidic and the dissolved oxygen is low, so that the Cu and Zn can be released into the water phase to form secondary pollution. The average content of heavy metals in the artificial wetland matrix is ZnCrPbCuCd. The cumulative content of Zn in various substrates was between 247.76 mg/ kg and 438.18 mg/ kg, the cumulative content of Cr was 114.89 mg/ kg-127.30 mg/ kg, the cumulative content of Pb was 73.75 mg/ kg-77.62 mg/ kg, the cumulative content of Cu was 39.42 mg/ kg-68.43 mg/ kg, and the cumulative content of Cd was 1.46 mg/ kg-10.15 mg/ kg. (2) The matrix of the vertical undercurrent process (bean stone + crushed stone hollow brick) and the horizontal undercurrent process (sand + slag + crushed stone hollow brick) matrix have good effect on the accumulation of Zn; the accumulation effect of the matrix of the vertical undercurrent process (bean stone + gravel) on the Pb is good; and the different substrates of each process are used for Cu, the cumulative effect of the cr is not significant; the accumulation effect of the horizontal undercurrent processing unit (sand + slag + gravel) matrix on the cd is better than that of the (sand + slag + crushed stone hollow brick) matrix, The cumulative effect of the surface flow treatment unit (sand + fly ash) matrix on Cd is obviously better than that of the (sand + coal cinder) matrix. (3) The content of Cd, Cr, Pb and Zn in the matrix of the vertical undercurrent process (bean stone + gravel) is significantly related to the distance along the range, and the content of Cd, Pb and Zn in the matrix of the (bean stone + gravel hollow brick) matrix is significantly related to the distance along the range. The content of Cd, Cr and Zn in the horizontal undercurrent process (sand + slag + gravel) matrix is significantly related to the distance along the range, and the content of Cr, Cu, Pb and Zn in the matrix of (sand + slag + crushed stone hollow brick) matrix and (bean stone + slag) matrix is significant with the distance along the range. The content of Pb and Zn in the (sand + gravel) matrix is significantly related to the distance along the range; the content of Cr, Pb and Zn in the matrix of the surface flow (sand + fly ash) is significant with the distance along the range, and the content of Cd, Cu, and Pb in the matrix (sand + coal slag) is significant. There is a significant correlation between the content of Zn and the distance along the range. The accumulation of Cd and Pb in the matrix of the series 5 artificial wetland (sand + aluminum paste) and its physical and chemical properties (1) (sand + aluminum paste) was positively correlated with the pH, while the accumulation of Cr, Cu, and Zn in the matrix (sand + aluminum paste) was not significant with the pH. (2) The accumulation of Cd and Cr in the (sand + aluminum paste) matrix was negatively correlated with the organic matter, and the accumulation of Cu, Pb and Zn in the matrix (sand + aluminum paste) was negatively correlated with the organic matter. (3) The cumulative amount of Cd and Pb in the (sand + aluminum paste) matrix is positively correlated with the conductivity, and the correlation between the accumulation of Cr, Cu and Zn in the matrix (sand + aluminum paste) and the conductivity is not significant.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X703
本文編號：2503037
[Abstract]:Heavy metal pollution is a serious potential hazard, and the heavy metal pollution is difficult to eliminate once the heavy metal pollution occurs, and the heavy metal is enriched in the environment through the food chain so as to threaten the health of the ultimate consumer of the food chain. The artificial wetland, as a new technology for sewage treatment, has the advantages of strong impact-resistant load capacity, better purification water quality and low cost of capital construction and operation. The artificial wetland can be removed by the heavy metal in the water through the substrate, the plant and the microorganism. The common process of artificial wetland has the form of vertical undercurrent, horizontal undercurrent, surface flow and so on. There are a wide variety of artificial wetland matrix fillers that are widely used at present. Therefore, what kind of process is selected for different pollutants in the project is necessary for the research of what kind of matrix. In this paper, five kinds of composite artificial wetland systems are selected as the research object of the first series of five composite artificial wetland systems of the sapo-river artificial wetland, in which the series 1 is a vertical undercurrent + horizontal undercurrent composite artificial wetland system, and the series 2 is a horizontal undercurrent + surface flow composite artificial wetland system. The series 3 is a vertical subsurface flow + horizontal undercurrent + surface flow composite artificial wetland system, and the series 4 is a horizontal undercurrent + surface flow composite artificial wetland system, and the series 5 is a surface flow and surface flow composite artificial wet system. The removal of Cd, Cr, Cu, Pb and Zn5 in water by artificial wetland system under different conditions and different substrate conditions was studied. The distribution of heavy metals in different substrates under different processes is discussed. The relationship between the accumulation of heavy metals and the physical and chemical properties of the matrix in the series 5 (sand + aluminum paste) was analyzed. The main results are as follows:1. In that artificial wetland system, the heavy metal mechanism (1) is remove by a physical process, a chemical process and a biological process through a physical process, a chemical process and a biological process to achieve the purpose of fixing heavy metal, and the substrate plays a major role in the heavy metal removal. (2) The heavy metals in the artificial wetland system can be removed by plant filtration, plant passivation, plant extraction, and plant volatilization. The removal effect (1) of the series 1-series 5 composite artificial wetland system on the heavy metals has a certain removal effect on the heavy metals in Cd, Cr, Cu, Pb and Zn 5 in the composite artificial wetland of series 1 to series 4. The series 5 has a certain removal effect on the three heavy metals of Cd, Cr and Pb in addition to the remarkable release of Cu and Zn. The removal rate of Cd is between 75.00% and 87.88%; the removal rate of Cr is between 59.10% and 73.10%; the removal rate of Cu is between 24.14% and 52.49%; the removal rate of Pb is between 57.79% and 73.20%; and the removal rate of Zn is between 27.86% and 54.14%. (2) The effect of the vertical subsurface flow constructed wetland on the removal of Cd, Cr and Pb is better than that of the horizontal undercurrent and the surface-flow constructed wetland; the removal effect of the multi-stage composite artificial wetland on the Cd, Cr and Pb is better than that of the single-stage artificial wetland, and the increase of the hydraulic retention time in the surface-flow artificial wetland can improve the Cd, The removal effect of Cr and Pb, and the difference of the vertical undercurrent and horizontal undercurrent constructed wetland to the removal of Cu. The effect of vertical undercurrent artificial wetland on Zn removal is superior to that of horizontal undercurrent constructed wetland, and the removal effect of vertical undercurrent + horizontal undercurrent composite artificial wetland on Cu and Zn is superior to that of single-process artificial wetland. (3) The surface-flow constructed wetland has the release of Cu and Zn, which may be due to the fact that the reducible state of Zn is higher than the other forms other than the residue state, and the soluble state of the weak acid of Cu is higher than the other forms other than the residue state. Since the operation time of the artificial wetland is long, the water environment is acidic and the dissolved oxygen is low, so that the Cu and Zn can be released into the water phase to form secondary pollution. The average content of heavy metals in the artificial wetland matrix is ZnCrPbCuCd. The cumulative content of Zn in various substrates was between 247.76 mg/ kg and 438.18 mg/ kg, the cumulative content of Cr was 114.89 mg/ kg-127.30 mg/ kg, the cumulative content of Pb was 73.75 mg/ kg-77.62 mg/ kg, the cumulative content of Cu was 39.42 mg/ kg-68.43 mg/ kg, and the cumulative content of Cd was 1.46 mg/ kg-10.15 mg/ kg. (2) The matrix of the vertical undercurrent process (bean stone + crushed stone hollow brick) and the horizontal undercurrent process (sand + slag + crushed stone hollow brick) matrix have good effect on the accumulation of Zn; the accumulation effect of the matrix of the vertical undercurrent process (bean stone + gravel) on the Pb is good; and the different substrates of each process are used for Cu, the cumulative effect of the cr is not significant; the accumulation effect of the horizontal undercurrent processing unit (sand + slag + gravel) matrix on the cd is better than that of the (sand + slag + crushed stone hollow brick) matrix, The cumulative effect of the surface flow treatment unit (sand + fly ash) matrix on Cd is obviously better than that of the (sand + coal cinder) matrix. (3) The content of Cd, Cr, Pb and Zn in the matrix of the vertical undercurrent process (bean stone + gravel) is significantly related to the distance along the range, and the content of Cd, Pb and Zn in the matrix of the (bean stone + gravel hollow brick) matrix is significantly related to the distance along the range. The content of Cd, Cr and Zn in the horizontal undercurrent process (sand + slag + gravel) matrix is significantly related to the distance along the range, and the content of Cr, Cu, Pb and Zn in the matrix of (sand + slag + crushed stone hollow brick) matrix and (bean stone + slag) matrix is significant with the distance along the range. The content of Pb and Zn in the (sand + gravel) matrix is significantly related to the distance along the range; the content of Cr, Pb and Zn in the matrix of the surface flow (sand + fly ash) is significant with the distance along the range, and the content of Cd, Cu, and Pb in the matrix (sand + coal slag) is significant. There is a significant correlation between the content of Zn and the distance along the range. The accumulation of Cd and Pb in the matrix of the series 5 artificial wetland (sand + aluminum paste) and its physical and chemical properties (1) (sand + aluminum paste) was positively correlated with the pH, while the accumulation of Cr, Cu, and Zn in the matrix (sand + aluminum paste) was not significant with the pH. (2) The accumulation of Cd and Cr in the (sand + aluminum paste) matrix was negatively correlated with the organic matter, and the accumulation of Cu, Pb and Zn in the matrix (sand + aluminum paste) was negatively correlated with the organic matter. (3) The cumulative amount of Cd and Pb in the (sand + aluminum paste) matrix is positively correlated with the conductivity, and the correlation between the accumulation of Cr, Cu and Zn in the matrix (sand + aluminum paste) and the conductivity is not significant.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X703
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 朱亞琴;徐樂中;李大鵬;;給水廠污泥處置與資源化利用[J];廣東化工;2011年12期
，本文編號：2503037
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