【作者】 王林；

【导师】 黄跃飞；

【作者基本信息】 清华大学 ， 水利工程， 2009， 硕士

【摘要】 石油类污染占地下水污染的三分之一左右,其溶解度一般都非常的小,一般称为非亲水相流体(Non Aqueous Phase Liquid,NAPL)。这类污染物对于人体健康和生态环境具有很大的危害,而且进入土壤地下水后会形成长期、大范围的污染,危害巨大。由于污染的土壤与地下水修复费用大、时效长,因此要求高效、低费用的修复技术成为研究热点,而原位生物修复技术因其费用低、效果好、无二次污染而受到了广泛关注,各种室内实验及现场研究广泛开展以研究原位生物修复。但是现在的室内一维、二维实验难以反映野外实际情况,现场试验高费用又限制了原位生物修复的研究,这也是目前生物原位生物修复技术没有广泛应用的原因之一。本研究主要通过在室内开展的三维中试试验,探索石油类污染在地下水中的输移特征,并开展原位生物修复。具体研究内容包括:(1)设计为室内地下水在土壤中水动力模拟的三维条件,通过三维反应器中增加不同土层,同时控制上下游水位以模拟地下水的流动,通过预埋井观测地下水水位变化。(2)在中试反应器中,通过上游添加汽油,同时利用预埋井采样,对BTEX利用GC(气相色谱仪)分析其浓度,以观察在不同要求下石油污染物的迁移、扩散过程。(3)设计抽提修复过程方案,上游选择三口预埋井,下游选择三口预埋井,通过蠕动泵分别注水、抽水,通过采样,分析地下水中BTEX变化,改变下游抽水井的位置,评价不同修复条件下的污染去除效果。(4)通过实验接种三类嗜油菌株,并在一定条件下培养,接种激活后的微生物、配比相应的N、P营养物以及双氧水以提供氧气,连同水一起,以一定速率通过蠕动泵灌入地下水,以开展原位生物修复技术,探讨生物修复效果。本论文成功研制了地下水石油类污染原位修复三维中试条件,并开展了不同的原位修复试验,对比分析了不同方案下的修复效果,为后续进一步开展原位生物修复过程设计提供基础。更多还原

【Abstract】 Petroleum-hydrocarbon leakage is one of the main causes of soil and groundwater contamination. Petroleum pollutants, generally voted as non aqueous phase liquid, NAPL due to low solubility, have great threaten to humanity health and ecological system. It needs huge cost and long time to restore contaminated sites, therefore, approaches on high efficiency and low cost remediation techniques have been undertaken extensively. In-situ bioremediation has been widely concerned due to its high efficiency and low cost characteristics. Many lab experiments and field tests were undertaken to study in-situ bioremediation. However, one- and two-dimensional lab physical models can’t reflect real field conditions, and expensive cost of field test limits efficient approaches to be undertaken. This is one of the main reasons that in-situ bioremediation techniques have not been widely used to practices.In this thesis, it is expected to reveal movement characteristics of petroleum contaminants in subsurface, and to undertaken in-situ bioremediation processes through carrying pilot-scale experiments in designed 3-D reactor. The tasks entail:(1) designing a 3-D reactor for simulating hydrodynamic characteristics of groundwater in subsurface. Different soils are loaded into 3-D reactor at different level to reflect subsurface complex. Water levels of upstream and downstream are controlled to simulate groundwater flow. Wells are installed to reach different layers to facilitate observing water level.(2) The gasoline is added into soil through a well located at upstream to simulate petroleum contamination. Water samples are taken through wells, and BTEX concentration are analyzed with GC. The nature attenuation process of pollutants is observed.(3) Various Pump & Treat scenarios are designed. Three wells in upstream and three wells in downstream are selected to undertake P&T operation according to observing pollutant plumes. During experiments pumping wells are re-selected to evaluate its impacts on pollutant removal efficiency.(4) The microbial strains, which are petroleum-hydrocarbon oriented trained are re-activated. Nutrients of N、P、H 2 O2 and activated biomass are pumped into subsurface with water flow. The in-situ bioremediation process is undertaken and its efficiency is investigated through monitoring BTEX concentration variation in groundwater.In this thesis, a 3-D pilot-scale experiment system is designed and produced for undertaking in-situ bioremediation of petroleum contaminated groundwater. Various in-situ remediation experiments are undertaken. The efficiencies are compared under different remediation scenarios. The achievements supply useful information for further approaches on remediation conditions of in-situ bioremediation.更多还原