Abstract:

The biological nutrients removal (BNR) process is inevitably affected by salinity changes. Understanding how bacteria adapt to high-salinity environments and regulating the operation mode of the system are crucial essential to maintain the stability of the system economically and efficiently. This study summarizes current research findings, demonstrating that salt-tolerant microorganisms are capable of quickly exchanging water, small molecules of amino acids, glycerol, polysaccharides and inorganic substances such as potassium and sodium ions with the environment to coordinate osmotic pressure with the change of environmental salinity. Extremophilic bacteria have developed unique cellular structures that take advantage of various types of energy sources, including light, electricity, and electron donors with lower chemical potentials than fatty acids, to achieve the energy-enriched-biopolymers accumulation (e.g. polysaccharides, polyphosphates, polyhydroxyalkanoates and polysulfides). Employing alternating anaerobic/anoxic/aerobic biofilm processes, along with cyclic accumulation and uptake of various energetic substances, introducing saline-adapted biomass, and feeding the reactor with seawater to acclimate biofilm communities, can enhance the efficiency of simultaneous nitrification and denitrification (phosphorus removal) in hypersaline environments. Finally, the study points out that how to configure a reasonable process with good stability, and to enhance microorganisms salt tolerance by appropriate external energy amendments are of urgent importance in the future research as well as in the BNR engineering practices.

Key words: waste water, bioreactors, biofilm, salinity stress and tolerance, compatible solutes, photosystems, electrical stimulation, nitrogen and phosphorus removal

摘要：

生物脱氮除磷（BNR）工艺在氮磷等营养物生物去除过程难免受到盐度变化的冲击，掌握细菌的应对机制，策略性调控系统运行方式，对经济、高效地维持系统的稳定至关重要。本文汇总简述了以下最新研究成果：①耐盐微生物能根据环境中盐度的变化，快速地与环境交换水、小分子氨基酸、甘油、多糖类有机物以及钾、钠离子等无机物来平衡细胞渗透压；②极端嗜盐菌具有特殊的细胞结构，能够充分利用各类能源（光、电以及化学势比脂肪酸更低的电子供体），促进高能量贮存物（聚糖、聚磷、聚羟基烷酸酯、聚硫）的积累；③利用交替厌氧/缺氧/好氧生物膜工艺，接种高盐污泥并同步利用海水驯化生物膜菌群，且借助各种高能物质存储与消耗的偶联反应，可驱动高盐环境中同步硝化/反硝化(除磷)过程的高效运行。最后指出，如何高效地在维持系统稳定性同时设计出合理的工艺与反应器形式，如何通过外源性能源（光、电、化能物质）的输入来调控微生物高盐环境的适应性，是生物脱氮除磷系统的理论研究以及工程实践中亟待解决的问题。

关键词: 废水, 生物反应器, 生物膜, 盐胁迫与耐盐调控, 相容性溶质, 光系统, 电刺激, 脱氮除磷