城市黑臭河道底泥内源氮硝化-反硝化作用研究

氮超标是目前许多城市黑臭河道治理过程中急需解决的突出问题。在外源输入有效控制后,底泥内源氮成为水体氮污染的主要来源。硝化与反硝化过程是削减底泥氮负荷和控制内源氮释放的重要途径,从硝化与反硝化耦合作用角度探讨底泥内源氮的行为,对于有效解决黑臭河道氮超标治理难题具有重要的现实意义。对此,文章首先通过理论分析探讨了影响底泥内源氮硝化-反硝化有效耦合的重要因素,认为溶解氧水平和缺氧微环境分布是非常重要的参数,在这矛盾平衡中影响着硝化-反硝化作用的进行。其次评述了黑臭河道底泥内源氮硝化-反硝化作用的研究现状,指出对于污染严重且受人为干扰频繁的城市黑臭河道,曝气扰动是影响底泥内源硝化-反硝化作用的重要因素。为了实现对底泥内源氮的有效控释,往往需要通过选择合理的曝气条件从影响溶解氧水平和缺氧微环境分布两方面来控制硝化-反硝化反应平衡。最后探讨了今后相关研究的发展动态,包括曝气扰动的合理界定、模拟试验装置的有效构建、水动力条件下底泥硝化与反硝化性能的合理评定以及其微生物机制系统分析。

Research of nitrification-denitrification regarding endogenous nitrogen from urban malodorous river sediments： A review

The effective removal of nitrogen has become a big challenge in treating urban malodorous rivers. Since these rivers have been the receptacles of industrial discharge, urban sewage and rain runoffs for years, the sediments have been heavily polluted and thus will become a major source of nitrogenous contaminants after the effective interception of pollutants discharged into the river systems. Nitrification and denitrification are key pathways to reduce N-loadings and inhibit endogenous N-release from polluted sediments. Hence, it is of great significance for solving the above-mentioned problem to investigate the main factors that affects the coupling of nitrification and denitrification. Based on this, this paper first discusses the key elements that dominate the coupled nitrification-denitrification pathway from malodorous river sediments by way of theory analysis. It is considered that the level of dissolved oxygen （DO） and the distribution of anoxic microzones are important parameters that manipulate the nitrification-denitrification process. Secondly, this paper also reviews the research status of nitrification-denitrification from malodorous river sediments, and thus points out that the disturbance via aeration is one critical factor for the control of endogenous N-release from malodorous river sediments,for the aerated disturbance can mainly regulate the DO level and anoxic microzone profiles. Therefore, it is essential to select proper aeration conditions for the control of endogenous N-release from malodorous river sediments. In the finality, further studies are discussed in terms of the definition of aerated disturbance, the set-up of simulated river experimental device, the evaluation of sediment nitrification-denitrification performance with hydrodynamic condition as well as the comprehensive molecular analyses of microbial community in malodorous river sediments.