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污染底泥对水体自净的影响及强化自净模式

Effect of Polluted Sediment on Water Self-purification adn Its Enhanced Self-purification Mode

【作者】 史文霞

【导师】 孙井梅;

【作者基本信息】 天津大学 , 环境工程, 2010, 硕士

【摘要】 目前我国淡水资源遭到严重破坏,尤其是江河流域均遭到不同程度的污染,并且呈发展的趋势,河道的修复已成为环境保护的重要组成部分。目前国内外的各种河道修复方法,如人工曝气复氧、微生物修复等在治理过程中各种弊端逐渐暴露,其可控性较差,易造成经济和技术的损失。底泥疏浚的治理方法是近几年来河道修复研究的热点,但是此方法容易造成二次污染,从而带来不良的环境效应,不利于水体环境的长期发展。目前研究者逐渐转向了河道底泥的原位修复方法,但相关方面的基础研究和理论依据很少。本课题主要针对上述各种修复方法所缺乏的基础研究,通过实验观察不同条件下水体中污染物形态及微生物种群和数量的变化规律。从而研究搅拌、曝气以及底泥的存在对污染物的水体行为的影响,有利于加强河道治理工程中条件的控制,同时为河道底泥的原位修复提供理论基础。本实验中自制了一套模拟河道系统,系统包含六个相同的反应器,每两个组,向三组反应器分别施以静置、曝气和搅拌条件,连续监测进水和出水中各污染物的浓度,并分析各自的变化趋势。结果表明:曝气和搅拌能够在一定程度上提高河流中的溶氧含量,对氮、磷等污染物形态的转化及微生物的活性均有很大影响。同时为了研究底泥的存在对于河道水体环境的影响,每组条件均设有底泥和无底泥的对照。结果表明:河道底泥的存在能够使得微生物的食物链复杂化,有利于微生物的生存和生长,并且能加大河流的抗冲击负荷的能力以及其自净能力,从而保证整个水体环境的稳定性。

【Abstract】 The destruction of freshwater resources became more and more serious in China. Most of the surface waters were polluted in different degree and in an increasing trend. Restoration of rivers has become more and more important. The restoration methods of rivers such as artificial aeration and microbial remediation, etc. exposed their disadvantages in the application. Some factors were too difficult to control on the process of river restoration, thus bring great technical and economic loss. In recent years, sediment dredging as an effective restoration method attracts more attention in research. However, this method is not beneficial to the development of river environment since it may bring secondary pollution and negative environmental impact. The researchers turned to the in-situ restoration of river sediment gradually, while the basic research and theory is shortage.Considering the shortage of basic research on in-situ restoration methods, the variation of water behaviors was observed through experiment of various contaminants as well as the species and quantity of microorganism. The effect of aeration, mixing or bottom sediment on the river contamination was also investigated, which is beneficial to control the facts of river regulation, and provides the theory to river in-situ restoration.Six simulating rivers were used in this study. Every two reactors as a group were subjected to different conditions, e.g. static, aeration and mixing respectively. Influent and effluent water quality was monitored and the variation trends were analyzed. Experimental results indicate that aeration or mixing can improve DO of the river in some degree. It will make a great effect on transformation of nitrogen, phosphorus, or microbial activity. Moreover, the effect of sediment on restoration was also investigated. Results show that the existence of the sediment can complex the food chain structure, which is helpful for the growth and survival of microorganisms. It can also enhance the resistant ability and the stability of the river environment system.

  • 【网络出版投稿人】 天津大学
  • 【网络出版年期】2012年 02期
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