混合充氧对分层水库水质改善及微生物种群结构调控研究

发布时间：2018-01-13 23:27

本文关键词：混合充氧对分层水库水质改善及微生物种群结构调控研究　出处：《西安建筑科技大学》2017年博士论文　论文类型：学位论文

【摘要】：以分层型水源水库黑河金盆水库为研究对象,采用现场监测、原位试验与实验室研究相结合的方法,在分析水库自身水质演变和外部径流污染输入的基础上研究了混合充氧对水质的改善,并从微生物种群结构的角度分析了水质改善的机理,主要研究内容包括:a)黑河金盆水库水体分层结构演变规律及水质响应特征、分层时期沉积物耗氧及污染物释放规律;b)不同强度入库径流变化特征及其对水库水质的影响、入库径流悬浮物污染特征及其淤积规律;c)人工强制混合与自然混合有效衔接、充氧过程对水体及沉积物微生物代谢活性的强化;d)混合充氧过程对水体微生物种群结构的影响及其对碳、氮、氢、硫、铁、锰等元素循环相关细菌的调控。得到了以下主要成果与结论:(1)每年5~8月为黑河金盆水库水体稳定分层期,水体底部溶解氧耗尽,导致水体化学氧化修复能效降低,温跃层的存在阻碍了垂向水体物质交换,分层时期,厌氧层厚度高达22 m,恒温层水体总氮、总磷、铁、锰浓度超标分别达到2.30、0.125、0.97和0.32 mg/L。分层时期水体及沉积物耗氧速率达到4.13μmol O2 L-1?d-1和14.34 mmol O2 m-2?d-1。进入9月份在自然过程及人为干预的条件下,水体分层结构稳定性迅速降低,分层结构逐步消亡。(2)中低流量径流一般不会对主库区水质造成恶劣影响,其在向主库区行进过程中逐步消亡,而高流量径流(入库流量579 m3/s)不仅破坏了水体分层结构还造成主库区水体浊度升高至266 NTU,主库区总磷、总有机碳和氨氮浓度升高至0.107、3.9和0.48 mg/L,藻密度降低幅度达51.3%。相关性分析发现沉降颗粒粒径、含水率、烧失量是影响沉降颗粒污染负荷的主要因素。黑河金盆水库淤积速率约为0.111 g·cm-2·a-1,处在相对较低的水平。(3)人工强制混合破坏了水体的稳定分层结构促使水体提前2个月进入混合状态。与自然混合相比人工强制混合使混合水温提高了6~8°C,水库水质得到明显改善,与人工强制混合之前相比,水体总氮、总磷、总有机碳、氨氮、铁和锰削减率分别达到47.8%、66.7%、22.9%、62.5%、76.2%和80%。在水体温差尚有3~4°C时,停止人工强制混合过程,发现人工强制混合与自然混合的有效衔接能使水体藻密度、总有机碳、总氮和总磷有50%、23.5%、7.7%和16%的削减。人工强制混合与自然混合有效衔接及二者协同作用可以有效改善水质并且使水质的良好状态保持至次年水体分层再次形成。(4)混合充氧通过改变水体分层及溶解氧状态进而影响微生物群落结构,冗余分析(RDA)得出物理环境因子(水温和溶解氧)、化学环境因子(叶绿素a、总有机碳和总氮)是影响水库水体微生物群落变化的关键性因素。混合充氧改变了碳、氮、氢、硫、铁、锰等元素循环相关细菌结构变化,如Lactobacillus、Pseudomonas以及Rhodobacter等主要的反硝化菌种得到明显增加,强化了水体碳、氮等元素的去除。
[Abstract]:Taking Heihe Jinpan reservoir as the research object, the method of field monitoring, in-situ test and laboratory research is adopted. On the basis of analyzing the evolution of water quality and the input of external runoff pollution, the improvement of water quality by mixed oxygenation was studied, and the mechanism of water quality improvement was analyzed from the point of view of microbial population structure. The main contents of the study include the evolution law of water stratification structure and water quality response characteristics, sediment oxygen consumption and pollutant release law during stratification period in the Jinpan Reservoir of the Heihe River. B) the variation characteristics of inflow runoff with different intensities and its influence on reservoir water quality, the pollution characteristics of suspended solids in inflow runoff and its deposition law; C) artificial forced mixing and natural mixing can effectively link up and strengthen the metabolic activity of microorganisms in water and sediment during oxygenation. D) the effect of mixed oxygenation on microbial population structure and its effects on carbon, nitrogen, hydrogen, sulfur and iron. The main results and conclusions are as follows: from 5 to August of each year, the stable stratification period of Heihe Jinpan reservoir and the depletion of dissolved oxygen at the bottom of the water body are obtained. As a result, the energy efficiency of chemical oxidation and remediation of water body decreased, and the existence of thermocline hindered the vertical water body material exchange. In the stratification period, the thickness of anaerobic layer was as high as 22 m, and the total nitrogen, total phosphorus and iron in the isothermal layer were up to 22 m. The oxygen consumption rate of water and sediment reached 4.13 渭 mol O2L-1 during stratification period, and the manganese concentration exceeded the standard of 2.30 渭 mol 0.125 渭 g / L and 0.32 mg / L 路L ~ (-1), respectively. D-1 and 14.34 mmol O2 m-2? D-1. In September, under the condition of natural process and human intervention, the stability of water stratification structure decreased rapidly. The stratified structure gradually wither out. (2) the low and middle flow runoff will not cause bad influence on the water quality of the main reservoir area, and it will die out gradually in the process of moving to the main reservoir area. The high discharge runoff (579 m3 / s) not only destroyed the stratified structure of the water, but also increased the turbidity to 266 NTU and the total phosphorus in the main reservoir area. The concentration of total organic carbon and ammonia nitrogen increased to 0.1073.9 and 0.48 mg / L, and the algae density decreased by 51.3%. The deposition rate of Heihe Jinpan Reservoir is about 0.111g 路cm-2 路a-1. At a relatively low level. Artificial forced mixing destroys the stable stratification structure of the water body and causes the water to enter into the mixing state two months ahead of time. Compared with the natural mixing, the artificial forced mixing increases the mixing water temperature by 6 掳8 掳C. Compared with the artificial forced mixing, the total nitrogen, total phosphorus, total organic carbon, ammonia nitrogen, iron and manganese were reduced by 47.8% and 66.7% respectively. 62.5% and 80% respectively. When the water temperature difference is 3 掳C, the artificial forced mixing process is stopped, and it is found that the effective connection between artificial forced mixing and natural mixing can make the algae density in the water body. Total organic carbon, total nitrogen and total phosphorus accounted for 50%. Reduction of 7.7% and 16%. Effective connection between artificial forced mixing and natural mixing and their synergistic effects can effectively improve water quality and keep water quality in good condition until the next year water stratification is formed again. Mixed oxygenation affects microbial community structure by changing water stratification and dissolved oxygen state. The physical environmental factors (water temperature and dissolved oxygen) and chemical environmental factors (chlorophyll a) were obtained by redundancy analysis (RDAs). Total organic carbon (TOC) and total nitrogen (TN) are the key factors affecting microbial community changes in reservoir water. Mixed oxygenation changes the structure of bacteria related to the circulation of carbon, nitrogen, hydrogen, sulfur, iron, manganese and so on. The main denitrification bacteria species such as Lactobacillus sp. Omonas and Rhodobacter were obviously increased, and the removal of carbon and nitrogen in water was strengthened.
【学位授予单位】：西安建筑科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：Q93;X524

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