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Study of Biodegradable Polyurethane Foam as Carriers for Low C/N Ratio Wastewater

In this study, the performance of nitrification and denitrification were investigated in a sequencing batch biofilm reactor (SBBR) with biodegradable polyurethane foam. The study aimed at solving the shortage of carbon sources for denitrification treating wastewater with a low C/N ratio. Ammonium, nitrite, nitrate, pH and Dissolved oxygen (DO) were carried out to monitor the process of nitrification-denitrification in every cycle. The results showed that Total nitrogen (TN) removal efficiency of 67.5% was achieved during a monitoring period of three months. The SBBR showed good behavior in terms of total nitrogen removal as the biodegradable polymer was an effective substrate providing reducing power for denitrification. According to scanning electron microscope, the biofilm from the inside of the Polyurethane (PU) carriers comprised predominately of small rod-shaped and spherical clusters were dominant, while clusters of filamentous form and few long rod shaped were observed on the surface. The used PU carriers after being washed with distilled water were found some cavities due to corrosion by microorganisms.