汞在人工湿地中的迁移与转化古代英国牧羊犬
摘要
汞污染问题是不容忽视的全球性环境问题之一。混汞炼金区和汞矿山附近水体中汞含量远超出天然水体背景值，即便是城市路面径流也存在一定程度的汞污染。人工湿地是一种常用的水质改善技术，能有效去除水体中各类营养物质及重金属，在面源污染控制及河湖水生态修复方面得到了广泛应用。研究人工湿地对汞污染水体的修复具有重要的现实意义。
以城市道路径流和矿山周围水体为对象，配制总汞浓度为81.23±42.96 μg/L、分配系数为5.13±0.23的原水，探究水平潜流人工湿地沿程总汞(Total mercury, THg)、颗粒态汞(Particulate mercury, PHg)和溶解态汞(Dissolved mercury, DHg)的迁移变化规律，分析湿地运行条件对不同形态汞去除效果的影响，建立不同价态汞在人工湿地中转化的动力学模型，考察人工湿地中汞与其它水质参数的相关性，得到如下结果：（1）水平潜流人工湿地对THg、PHg、DHg的去除率分别可达94.7%、95.0%、92.7%。THg和PHg的去除主要发生在湿地前1/4段，分别占沿程总去除量的88.6%、97.8%，DHg的浓度随沿程大致以0.18μg·L-1·cm-1的速率匀速下降。
（2）HRT、有无植物和温度均显著影响汞的去除效果。HRT与PHg的去除无明显关系，但显著影响DHg的去除：HRT小于1天时，DHg的去除率与水力停留时间呈线性正相关关系，HRT大于1天后，DHg去除
英文论文
率基本稳定在90%以上。有无植物基本不影响PHg的去除，有植物湿地对DHg的去除率比无植物湿地高20%以上。在设定的温度范围内（5o C、10 o C、22 o C、28 o C），THg和Hg2+的去除率随温度升高而增加，分别在81.4~95.9%、75.7~91.7%之间。
（3）不同价态汞在人工湿地中的转化特征各不相同，原水中活性较强、生物利用度较高的Hg2+、Hg0去除率分别为97.8%、68.9%。湿地植物对THg、Hg2+的去除影响不明显，但显著影响Hg0的去除，三者在未种植物的湿地内的一级反应速率常数分别为0.468、0.534、0.129h-1，在种植菖蒲的湿地内一级反应速率常数分别为0.467、0.461、0.406h-1。
（4）沿程THg、PHg、DHg与TSS的相关性不显著，但与硫酸盐（SO42-）和pH 均存在显著的线性相关关系。SO42-与THg、PHg、DHg的Pearson相关性系数分别为
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0.854、0.807、0.960；pH与THg、PHg 、DHg的Pearson相关性系数为-0.909、-0.896、-0.900。需要时，利用SO42-和pH等易测量指标来间接指代湿地中汞浓度有一定可行性。
研究成果为水体汞污染的生态修复提供了一种可供选择的技术路径。
关键词：汞；人工湿地；水生态修复；不同形态；迁移转化
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Abstract
Mercury (Hg) pollution is one of the significant global environmental problems. Hg concentration in water near amalgamation gold mines and mercury mines far exceeds the normal value of the natural water. There is a certain amount of Hg pollution even in the urban road runoff. Constructed wetland (CW) is a common water treatment technology, which can effectively remove many nutrients and heavy metals. Constructed wetlands have been widely ud in non-point source pollution control and water ecological restoration. It is of great practical significance to study the restoration of Hg contaminated water systems by using CWs.
In the current study, synthetic water with a total Hg (THg) concentration of 81.23±42.96 μg/L and a partition coefficient of 5.13±0.23 was prepared to simulate the urban road runoff and the gold mines surrounding water. The migration of THg, particulate mercury (PHg) and dissolved mercury (DHg) along the horizontal subsurface flow constructed wetlands (HSSF-CWs) were investigated. Current study was aimed to analyze the effect of operating conditions on the removal of different Hg species; establish a kinetic model for the transformation of different valence states of mercury; and investigat
e the correlation between Hg and other water quality parameters. The findings of the current work are as follows:
(1) The removal effeciency of THg, PHg and DHg in HSSF CWs were 94.7%, 95.0% and 92.7%, respectively. The THg and PHg were mainly removed in the first quarter of the CWs, accounting for 88.6% and 97.8% of the total removal, respectively. The concentration of DHg was reduced at a constant rate of 0.18 μg·L-1·cm-1.
(2) The removal of Hg was mainly affected by HRT, plants and temperature significantly. Findings reveal that no significant relationship was found between HRT and PHg removal, but affected the removal of DHg. Results reveal that when the HRT was less than 1 day, the removal rate of DHg was positively correlated with HRT. The removal rate of DHg was stable at above 90% when HRT was higher than 1 day. Results also reveal that plants have no role in PHg removal, whereas the removal rate of DHg多梦的原因
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in planted wetland was 20% higher than that in unplanted wetland. Current study also aimed to investigate the removal of THg and Hg2+ in different temperatures (5o C, 10o C, 22o C, 28o C). The
removal rate of THg and Hg2+ incread with temperature, between 81.4~95.9% and 75.7~91.7%, respectively.
(3) The transformation of different valence states of Hg in CWs were found different. The removal rate of Hg2+and Hg0 were 97.8% and 68.9%, respectively. Results reveal that the first order reaction kinetic constants of THg, Hg2+ and Hg0 in the unplanted CWs were 0.468, 0.534, and 0.129 h-1, respectively. While the first order reaction kinetic constants of three Hg species in the planted CWs were 0.467, 0.461, and 0.406 h-1, respectively. It shows that plants have no effect on the removal of THg and Hg2+, but have a noticiable effect on the removal of Hg0.
(4) Finding reveal that there is no significant correlation between different Hg species with TSS, but significant linear correlation with sulfate (SO42-) and pH. The pearson correlation coefficients between SO42- and three Hg species were 0.854, 0.807 and 0.960, respectively. The pearson correlation coefficients between pH and three Hg species were -0.909, -0.996 and -0.900, respectively. If required, it is possible to indirectly replace the Hg concentration in the CWs using the easy measure indicators such as SO42- and pH.
The current study provided an alternative for the ecological restoration of Hg contaminated water.
Keywords: Mercury; Constructed wetland; Eco-restoration；Forms；Migration and transformation
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目录
摘要................................................................................................................................ I II 第一章绪论 (1)
1.1研究背景 (1)
1.1.1课题来源 (1)
1.1.2汞的性质和用途 (1)
1.1.3汞——全球性污染物 (4)
1.1.4有关汞的国际公约 (5)
1.2水体汞污染及防治概述 (6)
1.2.1水体汞污染现状 (6)
1.2.2水体汞污染防治技术 (9)
1.3人工湿地用于净化汞污染水体的研究进展 (10)
1.3.1国外研究进展 (11)
1.3.2国内研究进展 (12)
1.4研究内容与技术路线 (13)
1.4.1研究内容 (13)
1.4.2技术路线 (14)
第二章试验准备 (16)
2.1试验装置、材料、方法 (16)
2.1.1装置搭建 (16)
2.1.2仪器与试剂 (18)
五色石南叶
我的年度汉字2.1.3研究方法 (20)
2.2无汞胁迫下装置的通水挂膜 (21)
2.3汞胁迫下装置的稳定运行 (23)
剪纸春
第三章汞在人工湿地中的迁移 (25)
3.1试验内容与步骤 (25)
3.2试验结果与分析 (25)
3.2.1 颗粒态汞（PHg）的沿程变化 (25)
树苗简笔画
3.2.2溶解态汞（DHg）的沿程变化 (27)
3.2.3总汞（THg）的沿程变化 (28)
3.2.4汞在固液两相中的分配关系 (29)
3.3本章小结 (30)
第四章运行条件对人工湿地中汞去除效果的影响 (31)
4.1试验内容与步骤 (31)
4.2试验结果与分析 (31)
4.2.1水力停留时间的影响 (31)
4.2.2有无植物的影响 (33)
4.2.3温度的影响 (36)
4.3本章小结 (36)
第五章汞在人工湿地中的转化 (38)
5.1试验内容与步骤 (38)
淘宝秒杀技巧V
