Prof Wei Chaohai’s team have 20+ years’ experience in the research and applications of biological fluidized bed reactor (BFBR)-based wastewater treatment processes. They have developed BFBRs with various configurations. The fluid mechanics and mass transfer, the biological mediums, bacterial community, pollutant removal mechanisms, and process demonstration, design and management were studied systematically. The processes have found their applications in the treatment of coking, petrochemical, printing and dyeing, pulping, food, and brewing industries. A novel OHO process was proposed and applied in the full-scale treatment of coking wastewater treatment in the Baowu Steel Group, Tianjin Coal Chemical Industry, Hebei Jinniu Tianjin Steel Group. To date, these OHO based wastewater treatment plants have been steadily operated for 8-12 years, showing excellent carbon and nitrogen removal performance. On the design of the reactor, the team have overcome the challenges in air-liquid/ air-liquid-solid mass transfer via fluid re-direction and structure optimization. There have been 32 full-scale wastewater treatment plants employing the BFBR reactors and processes developed by Prof. Wei, within which, 15 are in the printing and dyeing industry, 5 are in the coal chemical industry and 3 are in the food manufacturing industry.