Abstract:

The calcining modified vermiculite was applied in a biological fluidized bed system as fillings for enhancing the organic matter removal efficiency. The experimental results showed that the modified vermiculite had better NH⁺₄-N and COD removal, which were more than 2.1 and 2.7 times of the natural vermiculite. The best treatment condition of the biological fluidized bed system with calcining modified vermiculite as fillings for low C/N wastewater treatment was determined by the effect of reaction system under a series of temperature，pH and DO. Under the environmental condition of temperature 30℃, pH=8.0, ρ（DO）=2.0 mg/L, as the inlet containing 50 mg/L of NH⁺₄-N and 200 mg/L of COD, the reaction system had the highest removal rates of NH⁺₄-N and COD, which were 94.9% and 85.7%, respectively.

Key words: modified vermiculite, biological fluidized bed, low C/N, water pollution