某矿区酸性矿山废水污染土壤及湿地处理系统的调查研究

发布时间：2018-03-05 04:31

本文选题：重金属　切入点：酸水库　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：酸性矿山废水(AMD)是矿山开采和利用过程中产生的特殊酸性废水,含有大量的重金属离子和硫酸盐,任意排放会导致矿区周边生态系统破坏,其引起的环境问题已经不容忽视,亟待解决。本文以马鞍山某矿区AMD污染土壤和处理AMD的湿地为研究对象,分析采集样品的理化特性和微生物群落结构,以评价当地土壤污染情况,考察湿地系统对AMD的处理效果。结果表明,该酸水库周边土壤受金属Fe、Mn、Cd以及硫酸盐污染严重,有机质、总氮等营养物质流失较为严重;土壤样品AMD污染程度随着与酸水库距离的增加而降低,土壤pH、有机碳和总氮含量亦逐渐增加,土壤微生物种类逐渐增加,多样性指数也随之提高;采样土壤的菌群功能较为完整,Bacillus、Lactococcus等具有水解产酸功能的细菌占了细菌总菌群的55.0%以上,参与硫元素代谢的Desulfuromonas、Desulfobulbus等属占总菌群的24.0%以上;此外,参与氮素循环的Nitrosophaera、Nitrosopumilus属和产甲烷古菌Methanoregula、Methanosphaerula属等,为采样土壤中优势菌属。该地酸水库的AMD经过沉淀预处理后排入湿地系统中进行处理,水环境中的pH由5.18逐渐上升至7.41,稳定在中性;COD、硫酸盐、硫化物、Fe、Mn、Zn、Co、Ca和Mg的去除率分别为:63.6%、59.3%、59.8%、100%、61.8%、92.0%、48.6%、56.4%和60.6%。去除的金属离子主要以残渣态形式存在于湿地沉积物中,并且金属的三种生物可利用形态含量在逐渐降低,对环境的潜在危害较小;湿地中存在有大量的硫酸盐还原菌、铁还原菌、产甲烷菌等,它们作为C、N、S、Fe元素循环的纽带,将有机物矿化、反硝化、甲烷产生、重金属固定等环境过程紧密相连,其中,Latescibacteria、Bacillus、Optitutus等可以分解有机质的细菌占总菌群的21.0%以上;Geobacter、Azotobacter、Nitrosopumilus等参与氮素循环的细菌占总菌群的32.2%~33.8%;参与硫元素代谢的Desulfobacca、Desulfarculus等和参与铁、锰循环的Sideroxydans、Thiobacillus菌属等分别占总菌群的24.0%~25.8%、21.1%~27.1%。
[Abstract]:Acid mine wastewater (AMD) is a special acid wastewater produced in the process of mining and utilization. It contains a lot of heavy metal ions and sulfate. Arbitrary discharge will lead to the destruction of the ecological system around the mining area, and the environmental problems caused by it can not be ignored. In this paper, AMD contaminated soil and wetland treated with AMD in a mining area of Ma'anshan were taken as the research objects. The physicochemical characteristics and microbial community structure of collected samples were analyzed to evaluate the soil pollution in the area. The effect of wetland system on AMD treatment was investigated. The results showed that the soil around the reservoir was seriously polluted by Fe, mn, CD and sulphate, and the loss of nutrients such as organic matter and total nitrogen was serious. The AMD pollution degree of soil samples decreased with the increase of the distance from the acid reservoir. The soil pH, organic carbon and total nitrogen content also increased gradually, the species of soil microorganisms increased gradually, and the diversity index also increased. The bacteria such as Lactococcus with hydrolytic acid production accounted for more than 55.0% of the total bacterial flora, and Desulfuromonas Desulfobulbus, which were involved in sulfur metabolism, accounted for more than 24.0% of the total flora. Nitrosophaera Nitrosopumilus and Methanoregula Methanosphaerula, which are involved in nitrogen cycling, are the dominant bacteria in the sampling soil. The AMD of the acid reservoir in this area is discharged into the wetland system after precipitation pretreatment. The pH value in the water environment gradually increased from 5.18 to 7.41, and stabilized at neutral COD, sulfate, sulfides, Fehmann, and ZnCoC Ca and mg removal rates were 63.62.00%, 59.82.02%, 48.66.4% and 60.6%, respectively. The metal ions removed were mainly in the form of residue in wetland sediments. The contents of available forms of three species of metals are decreasing gradually, and the potential harm to the environment is relatively small. There are a lot of sulfate reducing bacteria, iron reducing bacteria and methanogenic bacteria in the wetland. Organic matter mineralization, denitrification, methane production, heavy metal fixation and other environmental processes are closely linked, Among them, the bacteria that can decompose organic matter such as Latescibacter Bacillus Optitutus and so on account for more than 21.0% of the total flora. The bacteria such as Azotobacter nitrosopumilus and so on, which participate in the nitrogen cycle, account for 32.2% of the total flora; Desulfacca Desulfarculus and iron, which are involved in sulfur metabolism; and SideroxydansThiobacillus, which are involved in manganese cycle, account for 24.025.8% of the total flora, respectively.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X751;X53

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