循环水养殖系统脱氮技术及MBBR应用研究进展

Research Progress on Nitrogen Removal Technologies and MBBR Application in Recirculating Aquaculture System

摘要: 在高密度、集约化和设施化养殖快速发展的背景下，循环水养殖系统(recirculating aquaculture system, RAS)因节水、减排和过程可控等特点，成为水产养殖绿色转型的重要技术路线。RAS依靠固液分离、生物过滤、脱气增氧、消毒和在线监测等环节实现养殖水循环利用，但饲料投喂、残饵、粪便及鱼类代谢产物仍会持续输入TAN/$N{H}_4^{+}$ -N、$N{O}_2^{-}$ -N、$N{O}_3^{-}$ -N、TN和COD等污染物。本文围绕RAS组成、养殖废水污染物来源、脱氮工艺类型及移动床生物膜反应器(moving bed biofilm reactor, MBBR)在循环水处理中的应用进行综述，归纳MBBR填料、生物膜功能菌群、运行参数和模型调控等方面的研究进展。已有研究表明，MBBR可借助悬浮填料表面生物膜富集AOB、NOB及反硝化相关菌群，具有负荷适应性较强、占地小、抗冲击和运行维护相对简便等特点，适合作为RAS中TAN和$N{O}_2^{-}$ -N控制的核心单元。然而，低换水率条件下$N{O}_3^{-}$ -N累积、系统碳源不足、DO梯度、温盐度变化、填料挂膜状态及模型参数适配等问题仍会制约TN深度去除。未来应推动MBBR与旁路反硝化、微藻同化、厌氧氨氧化、污泥资源化及智能控制技术协同，以提升工厂化循环水养殖水质稳定性和尾水减排效果。

Abstract: With the rapid development of high-density, intensive and facility-based aquaculture, recirculating aquaculture systems (RAS) have become an important technical route for water saving, pollution reduction and controllable production. Although RAS can reuse culture water through solid-liquid separation, biofiltration, degassing, oxygenation, disinfection and online monitoring, feed input, residual bait, feces and fish metabolism continuously introduce TAN/$N{H}_4^{+}$ -N, $N{O}_2^{-}$ -N, $N{O}_3^{-}$ -N, TN and COD into the system. This paper reviews the composition of RAS, the sources of pollutants in aquaculture wastewater, nitrogen removal processes and the application of moving bed biofilm reactor (MBBR) in recirculating aquaculture water treatment. The progress in carrier materials, biofilm functional microorganisms, operating parameters and model-based regulation of MBBR is summarized. Existing studies indicate that MBBR can enrich AOB, NOB and denitrification-related microorganisms on suspended carrier biofilms, showing advantages of strong load adaptability, compact footprint, shock resistance and relatively simple operation. It is suitable as a core unit for controlling TAN and $N{O}_2^{-}$ -N in RAS. However, nitrate accumulation, insufficient carbon source, DO gradient, temperature and salinity fluctuation, biofilm start-up status and model parameter adaptation still restrict deep TN removal. Future studies should strengthen the coupling of MBBR with bypass denitrification, microalgal assimilation, anammox, sludge resource recovery and intelligent control, so as to improve water quality stability and tailwater nitrogen reduction in industrial RAS.