The application of UASB-MBR with partial nitrification-denitrification in wastewater reclamation in warm climate

An up-flow anaerobic sludge blanket (UASB) process has been successfully applied for the treatment of municipal wastewaters with methane production for energy recovery. A membrane bioreactor (MBR) was coupled to the UASB to further improve carbon removal. Nitrogen removal was conducted with the UASB-MBR integrated system under optimum conditions which promoted nitrogen removal through a shortcut nitrification-denitrification process. The process achieved 69–86% of soluble chemical oxygen demand (COD_solu) removal and 56–80% of total nitrogen (TN) removal. Biogas production was between 25 and 76 L/m³ wastewater (50–75% methane content) for the treatment of high-strength municipal wastewater. As the anaerobic process combined with a shortcut nitrogen removal step can achieve reduction of footprint, lower greenhouse gas emission and a potential for bioenergy recovery, the integrated UASB-MBR system could be a better choice for municipal wastewater treatment than the conventional activated sludge treatment process in warm climatic conditions.