%A Xiao Quan, Kai Huang, Mei Li, Meichao Lan, Baoan Li %T Nitrogen removal performance of municipal reverse osmosis concentrate with low C/N ratio by membrane-aerated biofilm reactor %0 Journal Article %D 2018 %J Front. Environ. Sci. Eng. %J Frontiers of Environmental Science & Engineering %@ 2095-2201 %R 10.1007/s11783-018-1047-6 %P 5- %V 12 %N 6 %U {https://journal.hep.com.cn/fese/EN/10.1007/s11783-018-1047-6 %8 2018-08-19 %X

MABR exhibits excellent TN removal performance for treating ROC with low C/N ratio.

Operating conditions should be properly controlled to achieve optimal TN removal.

Denitrifying bacteria and NOB are proved notably inhibited by high salinity stress.

The TN removal rate remains over 70% when the NaCl addition amount is below 20 g/L.

A membrane-aerated biofilm reactor was employed to investigate the nitrogen removal of one typical municipal reverse osmosis(RO) concentrate with a high total nitrogen (TN) concentration and a low C/N ratio. The effects of operational conditions, including the aeration pressure, the hydraulic retention time and the C/N ratio, on the systematic performance were evaluated. The nitrogen removal mechanism was evaluated by monitoring the effluent concentrations of nitrogen contents. Furthermore, the microbial tolerance with elevated salinity was identified. The results indicated that the optimal TN removal efficiency of 79.2% was achieved of the aeration pressure of 0.02 MPa, hydraulic retention time of 24 h, and the C/N ratio of 5.8, respectively. It is essential to supplement the carbon source for the targeted RO concentrate to promote the denitrification process. The inhibitory effect of salinity on denitrifying bacteria and nitrite oxidizing bacteria was significant, revealing the limited TN removal capacity of the conditions in this work. The TN removal efficiency remained more than 70% with the addition of salt (NaCl) amount below 20 g/L. This work preliminarily demonstrated the MABR feasibility for the nitrogen removal of municipal RO concentrate with low C/N ratio and provided technical guidance for further scale-up application.