the role of media type on the performance of the moving bed biofilm reactor in removal of 4-nitrophenol from wastewater

Oily pollutants, such as 4-nitrophenol, are unavoidable problems. one of the methods employed for treating wastewater polluted with 4-nitrophenol is the use of moving bed biofilm reactors (mbbrs). the present research compared, for the first time, the two common types of media (kaldness k1 and bee cell 2000) in mbbr for treating wastewater polluted with 4-nitrophenol, and determined and reported the optimum conditions for media types and heat. a biofilm layer was first formed on the surface of the media in each reactor, and then the microorganisms were acclimatized to the contaminants. following that, changes in efficiency with variations in initial cod concentration (400-2,500 mg/l), retention time (8, 12, 24, and 48 h), and filling ratio (30, 50, and 70 %) in the two reactors were determined and compared. the highest efficiencies (84 and 80 percent for the reactor with bee cell 2000 media and that with kaldness k1 media, respectively) were observed. both reactors containing bee cell 2000 media and kaldness k1 media were very capable of treating wastewater polluted with 4-nitrophenol at 20 °c. still, the reactor that included the bee cell 2000 media yielded better results compared to that containing the kaldness k1 media.