采煤沉陷区水域环境OCPs多介质归趋模型研究

发布时间：2018-03-10 19:04

本文选题：采煤塌陷区　切入点：有机氯农药　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：采煤沉陷区是由于过量采煤,导致采空区上方出现大面积沉陷塌落,经过降雨和地下水渗透后出现大面积的水域,原先的陆生环境变成水域环境,其中的持久性有机污染物也会发生一系列的迁移转化行为。鉴于环境中的有机氯农药具有持久性和生物累积性,会在生物体内蓄积,最后危害人类健康,研究OCPs的归趋行为具有十分重要的意义。本文通过选取淮南市杨庄采煤沉陷区作为研究对象,通过采集杨庄沉陷区水样和底泥样品,分析其中的OCPs含量,并建立了沉积物-水稳态逸度模型,对沉陷区域γ-HCHs和p,p'-DDT的归趋行为进行了数学模拟,计算出了底泥中γ-HCHs和p,p'-DDT预测浓度,并对模型的可行性做出了分析和比较,得出以下结论:1、通过分析15年和16年杨庄沉陷区水体样中的OCPs含量,发现受附近煤矸石堆和泥河的影响,一些采样点位处有机氯农药含量出现偏高的情况,纵向分布基本呈现为表层水上覆水间隙水的规律,并且γ-HCH在两年的水样组成中均占较多比例,是HCHs的主要成分之一;p,p'-DDT在15年和16年DDTs中的占比较大,是DDTs的主要成分之一。故而选择这两个有机氯农药进行逸度模拟更有代表性。2、通过分析15年和16年杨庄沉陷区底泥样中的OCPs含量结果可以发现:9号、10号、11号点位(靠近泥河入口和煤矸石堆)处HCHs和DDTs浓度较其他点位高;并且纵向上呈现随着底泥深度的增加,有机氯农药含量逐渐减少的规律。3、水体中TOC含量分布也与周边环境有密切关系,靠近泥河流域和居民区的水域TOC含量较高。并且通过分析水体和底泥中的OCPs含量和TOC含量的相关性,发现底泥中的OCPs含量与TOC含量之间具有显著相关性,也即底泥中TOC含量越高,有机氯农药也就越高。4、以2016年OCPs中的y-HCH和p,p'-DDT为例,通过实测和引用文献值等方法确定参数值,然后建立了沉积物-水两相间的稳态逸度模型,对有机氯农药在塌陷区水域环境中的迁移转化行为进行模拟计算,并将预测值与实测值进行比较,发现吻合度较好,数值偏差在一个数量级内,说明模型建立较为成功,能够反映有机氯农药在杨庄塌陷区中的迁移转化行为。5、通过分析计算关键性参数的灵敏度系数找出对模型影响较大的参数,并分析发现悬浮物沉降速率灵敏度系数最大,说明沉积物-水系统中悬浮物沉降对污染物向底泥迁移的过程起重要作用。
[Abstract]:The coal mining subsidence area is caused by excessive coal mining, resulting in a large area of subsidence and collapse above the goaf. After rainfall and groundwater infiltration, a large area of water area appears, and the original terrestrial environment becomes the water environment. In view of the persistence and bioaccumulation of organochlorine pesticides in the environment, they can accumulate in organisms and eventually endanger human health. It is of great significance to study the fate behavior of OCPs. This paper selects Yangzhuang coal mining subsidence area of Huainan city as the research object, and analyzes the content of OCPs by collecting water samples and sediment samples from Yangzhuang subsidence area. The sediment-water steady-state fugacity model was established, and the regression behavior of 纬 -HCHs and pPH-DDT in the subsidence zone was simulated. The predicted concentrations of 纬 -HCHs and pPH-DDT in sediment were calculated, and the feasibility of the model was analyzed and compared. By analyzing the OCPs content in the water samples of Yangzhuang subsidence area for 15 and 16 years, it is found that the content of organochlorine pesticides in some sampling sites is on the high side under the influence of nearby coal gangue piles and mud rivers. The longitudinal distribution is basically the law of overlying interstitial water on the surface water, and 纬 -HCH accounts for a large proportion of the water samples in two years. It is one of the main components of HCHs, which accounts for a large proportion of DDTs in 15 and 16 years. It is one of the main components of DDTs. Therefore, it is more representative to select these two organochlorine pesticides for fugacity simulation. By analyzing the OCPs content in sediment samples of Yangzhuang subsidence area for 15 and 16 years, it can be found that: site 9, 10, 11. The concentrations of HCHs and DDTs (near the entrance of Nihe River and coal gangue heap) are higher than those at other points. And longitudinally, with the increase of sediment depth, the content of organochlorine pesticides decreased gradually. The distribution of TOC content in water was closely related to the surrounding environment. By analyzing the correlation between OCPs content and TOC content in water and sediment, it was found that there was a significant correlation between OCPs content and TOC content in sediment. In other words, the higher the TOC content in the sediment, the higher the organochlorine pesticide. Taking the y-HCH and pHP-DDT in OCPs in 2016 as an example, the parameter values were determined by the method of measuring and quoting the reference values, and then the steady-state fugacity model between sediment and water was established. The migration and transformation behavior of organochlorine pesticides in the collapsing water area was simulated and calculated, and the predicted value was compared with the measured value. It was found that the numerical deviation was within one order of magnitude, which indicated that the model was established successfully. It can reflect the migration and transformation behavior of organochlorine pesticides in Yangzhuang subsidence area. By analyzing and calculating the sensitivity coefficient of key parameters, the parameters that have great influence on the model are found out, and it is found that the sensitivity coefficient of settling rate of suspended matter is the largest. The sedimentation of suspended matter in sediment-water system plays an important role in the process of pollutant migration to sediment.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X592

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