炼金区汞污染场地化学固定修复研究

发布时间：2018-03-23 12:49

本文选题：汞　切入点：赋存形态　出处：《北京化工大学》2015年硕士论文

【摘要】：人们对重金属各形态与植物吸收之间相关性研究的深入,发现进入土壤中汞的毒性不仅和其总量有关,更和它赋存状态相关。习惯上,研究者一般通过逐步回归分析法或者简单地通过相关性分析法来确定哪一种赋存形态的汞污染物或几种赋存形态的加和汞量作为有效态汞。而在土壤这一复杂系统中,各形态汞并不是独立存在的,相互间存在着竞争、吸附-解吸、转化等过程,而使各形态汞含量发生变化。研究以福建泉州某炼金区汞污染土壤为研究对象,采用修正的Tessier五步土壤汞提取方法和偏相关、回归分析等数据处理分析技术,研究土壤中汞的赋存状态、相互之间的转化关系及其生物有效性等问题,提出针对该区汞污染土壤的化学固定修复措施及修复评价标准；然后通过实验室小试确定化学固定剂NTSH的各项参数；然后在野外进行推广中试实验,以确定NTSH的固化效果。研究显示,该区土壤中五种赋存状态汞污染物的含量排布为：Organ Resid Exch Fe-Mn-Ox Carb,有机结合态汞含量占总汞含量的60%以上；土壤中这五种形态汞含量是变化的,各组分间不是独立存在的,内部之间是可以相互转化的,这种转化处于一种动态的平衡状态。研究还表明,土壤中具有生物活性的汞的主要赋存状态是可交换态汞和弱有机结合态汞。固化剂NTSH的加入能够明显地降低土壤中能被植物吸收的活性态汞含量,减少从土壤组分转移到植物体内的汞含量。研究还表明,在不影响植物正常生长的前提下,化学固定剂NTSH的添加量越大、固化稳定时间越长,其固化效果就越好。单因素分析表明,对该区汞污染土壤,采用添加0.36%的NTSH、稳定两月的情况下,其固化率可达80%。且NTSH处理后的汞污染土壤对不同pH值、有机质、温度具有一定耐受性,固化效果受外界环境的影响不大。野外中试实验得出了与实验室小试相似的结论,其对土壤有效态汞固化率可达75%,降低植物体内汞含量近80%,且稳定时间越长,效果越佳。NTSH可用于修复该区汞污染场地。
[Abstract]:In the study of the correlation between the forms of heavy metals and plant uptake, it was found that the toxicity of mercury entering the soil is not only related to its total amount, but also to its occurrence state. Researchers generally use stepwise regression analysis or simply correlation analysis to determine which forms of mercury pollutant or several forms of mercury are added as available mercury. Each form of mercury does not exist independently, and there is competition, sorption-desorption, transformation and other processes among the forms of mercury. The mercury pollution soil in a gold-smelting area in Quanzhou, Fujian Province, was studied in this study. Using the modified Tessier five-step soil mercury extraction method, partial correlation, regression analysis and other data processing techniques, the occurrence status of mercury in soil, the transformation relationship between each other and the bioavailability of mercury were studied. The chemical fixation remediation measures and remediation evaluation criteria for mercury contaminated soils in this area were put forward, and then the parameters of chemical fixator NTSH were determined by laboratory tests, and then the pilot experiments were carried out in the field. In order to determine the solidification effect of NTSH, the study showed that the five kinds of mercury pollutants in the soil of the region were distributed in the order of: Organ Resid Exch Fe-Mn-Ox carb, and the organic-bound mercury content accounted for more than 60% of the total mercury content, and the five forms of mercury in the soil varied. Each component does not exist independently, but interiorly can be transformed into each other, which is in a dynamic equilibrium state. The main occurrence states of bioactive mercury in soil are exchangeable mercury and weakly organic bound mercury. The addition of curing agent NTSH can obviously reduce the active mercury content that can be absorbed by plants in soil. The study also showed that, without affecting the normal growth of plants, the larger the amount of chemical fixator NTSH was, the longer the solidification time was. The results of univariate analysis showed that the solidification rate of mercury-contaminated soil in this area could reach 80 by adding 0.36% NTSH0.The mercury contaminated soil treated with NTSH had different pH and organic matter. The temperature has some tolerance, and the curing effect is not affected by the outside environment. The results of the field pilot-scale experiment are similar to those of the laboratory test. The solidification rate of available mercury to soil can reach 75%, and the mercury content in plants is reduced by 80%, and the longer the stabilization time is, the better the effect is. NTSH can be used to repair mercury contaminated sites in this area.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53

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