好氧反硝化细菌及其在微污染水源水修复中的应用研究进展

Aerobic denitrifiers and the application in remediation of micro-polluted water source

摘要:

相比于氨氮，天然水体中的硝酸盐氮通常更稳定，导致更难将其从水中去除。由于好氧反硝化可以在有氧环境下进行反硝化作用去除硝酸盐氮，该过程对含有较高溶解氧的天然水体中硝酸盐氮处理有重要作用。本文综述了好氧反硝化菌的分离纯化现状、微生物代谢机制和环境影响因子，并介绍了功能菌群在微污染饮用水源水生物修复的应用研究进展。与一般的厌氧反硝化类似，好氧反硝化菌的种属分布较广，常见的如假单胞菌属(Pseudomoas)、产碱杆菌属(Alcaligenes)、副球菌属(Paracoccus)和芽孢杆菌属(Bacillus)等所属部分微生物均有好氧反硝化能力。大部分好氧反硝化菌株在最佳生长条件下(25-37 ℃、溶解氧浓度为3-5 mg/L、pH为7-8、碳氮比为5-10)具有高效的脱氮效率。但目前好氧反硝化作用在微污染饮用水源水的生物修复方面的应用仍有着脱氮性能不稳定、菌剂流失等不足。此外，目前较少相关中试及实际工程应用的研究，需要进一步的深入探究。

Abstract:

Nitrate is more stable in natural water than ammonia and thus is more difficult to be removed. Conventionally, the removal of nitrate relies on anaerobic denitrification, which is hard in natural water containing high concentration of dissolved oxygen. In this sense, aerobic denitrification is of particular importance for nitrate removal in natural water. This study reviewed the isolation, purification, microbial metabolism, and environmental influencing factors of aerobic denitrifiers. Moreover, the application of aerobic denitrification in remediation of micro-polluted drinking water sources is also introduced. Similar to their anaerobic counterparts, aerobic denitrifiers affiliate to a wide range of genera, such as Pseudomoas, Alcaligenes, Paracoccus, and Bacillus. Most of the aerobic denitrifiers have a satisfactory nitrate removal efficiency under suitable conditions (25-37 ℃, DO (dissolved oxygen)=3-5 mg/L, pH 7-8, C/N ratio=5-10). However, aerobic denitrification still has drawbacks of unstable removal efficiency and the loss of microbes. Moreover, little efforts are made in relevant study on pilot-scale and full-scale application and thus further investigation is needed.