Biofilm reactors retain microbial cells in the form of biofilm which is attached to free moving or fixed carrying materials, thus providing a high active biomass concentration and automatic liquid and solid separation. Nowadays, microbial biofilm reactors have been widely used in high-strength wastewater treatment where very high pollutant removal efficiency is required, which usually requires excessive space and aeration energy for conventional activated sludge-based treatment. This paper provides an overview of microbial biofilm reactors developed over the last half-century, including moving bed biofilm reactor (MBBR), trickling filter (TF) reactor, rotating biological contactor (RBC), membrane biofilm reactor (MBfR), passive aeration simultaneous nitrification and denitrification (PASND) biofilm reactor, for their applications in high-strength wastewater treatment of not only removing carbon, nitrogen, sulphur but also a variety of oxidized contaminants including perchlorate and bromate. Despite the advance of biofilm reactor that exhibits high resistance to excessive pollutants loading, its drawbacks both from engineering and microbiological point of view are reviewed. The future prospects of biofilm reactor are also discussed in this review paper.

中文翻译：

---

使用微生物生物膜反应器的高强度废水处理：批判性评论

生物膜反应器以生物膜的形式保留微生物细胞，生物膜附着在自由移动或固定的承载材料上，从而提供高活性生物质浓度和自动液体和固体分离。如今，微生物生物膜反应器已广泛应用于需要非常高污染物去除效率的高强度废水处理，而传统的基于活性污泥的处理通常需要过多的空间和曝气能量。本文概述了过去半个世纪发展起来的微生物生物膜反应器，包括移动床生物膜反应器 (MBBR)、滴滤器 (TF) 反应器、旋转生物接触器 (RBC)、膜生物膜反应器 (MBfR)、被动曝气同步硝化反硝化（PASND）生物膜反应器，因其在高强度废水处理中的应用，不仅可以去除碳、氮、硫，还可以去除包括高氯酸盐和溴酸盐在内的各种氧化污染物。尽管生物膜反应器对过量污染物负载表现出很高的抵抗力，但从工程和微生物学的角度来看，它的缺点也得到了审查。本综述还讨论了生物膜反应器的未来前景。