水体黑臭演化过程及挥发性硫化物的产生机制初步研究

发布时间：2018-04-30 02:09

  本文选题：黑臭水体 + 水质　； 参考：《中国科学院烟台海岸带研究所》2017年硕士论文

【摘要】：随着城镇化以及工业化进程的加快,生活污水的过度排放造成了河道富营养化,甚至导致水体呈现黑臭状态。水体黑臭是河道水环境污染极其严重的表现,认识水体黑臭演化过程对开展水污染防治至关重要。国内外关于水体黑臭的研究主要集中在黑臭水形成机理、水体黑臭的评价方法等方面,对于黑臭水体形成条件以及水体中恶臭挥发性硫化物形成过程的研究明显不足。本研究在实验室模拟条件下,结合滨海河流水质特点,重点研究了总有机碳(TOC)、总氮(TN)、Fe~(2+)浓度及水体盐度等水质因子对水体黑臭演化过程的影响,同时分析了不同水质条件下甲硫醇(MT)和H_2S等挥发性硫化物的产生机制。通过采用河流原水进行接种制备人工黑臭水,设定不同的TOC,TN、Fe~(2+)浓度和水体盐度梯度进行模拟实验,分析了单一水质因素对水体黑臭形成的影响;为了进一步认识各种水质因素之间的相互作用及其对黑臭水体形成的综合影响,本文同时开展了多因素正交试验。主要有以下结论:(1)微生物作用在水体黑臭过程中发挥关键作用。研究发现河流水体黑臭状态的形成与水体中的微生物量具有显著相关性,当水体中的厌氧微生物数量增多时,水体黑臭时间变短,黑臭现象更明显,表明水体在厌氧的状态更易形成黑臭现象。(2)碳源是黑臭形成的重要条件。TOC浓度小于50 mg/L时,水体不会变黑,产生的挥发性硫化物总量较少,有臭味产生但不强烈;TOC浓度大于100mg/L时,TOC浓度越高,水体黑臭的时间越短,黑臭程度越明显,产生的MT和H_2S量越多,实验结束时,色度均大于500度,MT和H_2S总量都超过了1 g/L。(3)氮源也是黑臭形成的重要因素。TN浓度为0时,水体不变黑臭;C/N小于2:1,此时总氮浓度过高,水体致黑臭的过程较慢,C/N在3:1至4:1的范围内较容易形成黑臭现象;TN浓度在一定范围内,随着浓度增大,水体发生黑臭时间变短,并且黑臭程度越来越明显。(4)Fe~(2+)浓度不仅与色度有关,也是臭味产生的重要条件。研究发现Fe~(2+)浓度大于10 mg/L的水体会出现明显的黑色浑浊现象,而Fe~(2+)浓度小于5 mg/L时水体仅会变浑浊。这表明Fe~(2+)浓度越高的水体变黑的程度越显著。此外,Fe~(2+)浓度越高的水体中MT和H_2S浓度越高,这可能是由于Fe~(2+)能促进硫酸盐还原菌的代谢过程,进而促进了恶臭硫化物的产生。因此,Fe~(2+)浓度对黑臭水体的形成有显著影响。(5)高盐度水体,抑制黑臭水形成。盐度过高,会抑制微生物的生长代谢过程,盐度达到15‰以上时,抑制作用显著。盐度在小于10‰的范围内,盐度较高时,对水体黑臭的形成有一定促进作用。盐度为10‰的水体实验结束时水体黑臭程度最显著,生成的主要挥发性硫化物MT和H_2S的总量超过850μg/L。(6)正交试验的研究结果发现,TOC对水体黑臭的影响显著,TN和Fe~(2+)浓度对水体黑臭的影响较明显,其中Fe~(2+)浓度在水体变臭的过程中起到一定的促进作用。
[Abstract]:With the acceleration of urbanization and industrialization, excessive discharge of domestic sewage has resulted in eutrophication of river channels and even black-smelling state of water bodies. Water black-smelling is an extremely serious manifestation of river water environmental pollution. It is very important to understand the evolution process of water black-odor for water pollution prevention and control. The research on the formation mechanism of black-smelly water and the evaluation methods of black-smelly water at home and abroad are mainly focused on the formation conditions of black-smelly water and the formation process of stench volatile sulphide in water. In this study, the effects of water quality factors, such as total organic carbon (TOC) concentration, total nitrogen (TN), and water salinity, on the evolution of black and smelly water were studied under the condition of laboratory simulation and combining with the water quality characteristics of coastal rivers, such as total organic carbon (TOC), total nitrogen (TNN) and water salinity. At the same time, the production mechanism of volatile sulfides such as methyl mercaptan (MTO) and Hass under different water quality conditions were analyzed. By inoculating raw water of rivers to prepare artificial black and odorous water, setting different concentrations of TOCX TNN Feanfen 2) and the gradient of water salinity, the effects of a single water quality factor on the formation of black and smelly water were analyzed. In order to further understand the interaction of various water quality factors and their comprehensive influence on the formation of black and smelly water, this paper also carried out multi-factor orthogonal experiments. The main conclusions are as follows: (1) microbial action plays a key role in the process of black-smelling in water. It was found that the formation of black-smelling state in river water was significantly related to the microbial biomass in water body. When the number of anaerobic microorganisms in water increased, the black-smelling time became shorter and the black-smelly phenomenon became more obvious. The results showed that when the concentration of TOC was less than 50 mg/L, the water would not turn black and the total amount of volatile sulfides would be less when the carbon source was an important condition for the formation of black and odour. The higher the concentration of 100mg/L is, the shorter the time of black-odor is, the more the amount of MT and H2S is, the more MT and H2S are produced at the end of the experiment. When the concentration of nitrogen is 0, when the concentration of TN is 0, the C / N ratio is less than 2: 1, the total nitrogen concentration is too high. In the range of 3:1 to 4:1, it is easy to form the black-smelly phenomenon and TN concentration. With the increase of water concentration, the black-smelling time becomes shorter. And the black and odour degree is more and more obvious. The concentration is not only related to the chroma, but also an important condition for the odour generation. It was found that the black turbidity appeared when the concentration of Fe~(2 was more than 10 mg/L, but when the concentration of Fe~(2 was less than 5 mg/L, the water would only become turbid. This indicated that the higher the concentration of Fe~(2, the more the degree of blackening. In addition, the higher the concentration of MT and H2s in the water with the higher concentration of Feb2), the higher the concentration of MT and H2S, which may be due to the fact that Fe~(2) can promote the metabolic process of sulfate-reducing bacteria and thus promote the production of sulfides. Therefore, the concentration of Feb2) has a significant effect on the formation of black-smelly water body. It can inhibit the formation of black-smelly water and inhibit the formation of black-smelly water. When the salinity is too high, the growth and metabolism of microorganisms will be inhibited. When the salinity is above 15 鈥，

本文编号：1822590