Removal and Transformation of Pollutants in a Two-Line Denitrifying Phosphorus Removal Process Treating Low C/N Municipal Wastewater: Influence of Hydraulic Retention Time
- 131 Downloads
A two-line denitrifying phosphorus removal process (2L-DPR) was established treating low C/N municipal wastewater efficiently in our previous studies, while hydraulic retention time (HRT) is one of the most important factors determining the substrate loading, contact time for biomass, and pollutants and further affect performance of the whole system. Removal and transformation mechanism of organic carbon (C), nitrogen (N), and phosphorus (P) were investigated together with mass balance under various HRTs (6, 9, and 18 h) in the established 2L-DPR process. The results showed that in anaerobic units, the concentration of the main storage products in activated sludge such as poly-hydroxyvalerate (PHV) and poly-hydroxybutyrate (PHB) at HRT of 9 h was higher than that under other HRTs. The highest TN and TP removal efficiency was also achieved under the HRT of 9 h with removal rates of 55.9% and 84.6% respectively. Increasing HRT from 6 to 9 h greatly enhanced TN removal in anoxic and aerobic units; however, HRTs had little influence on COD removal with effluent concentration of 48.6, 49.1, and 48.9 mg/L, respectively. HRT affected phosphorus up-taken in anoxic and aerobic units rather than on the release of phosphorus processes in anaerobic units.
KeywordsMunicipal wastewater Biological nutrient removal (BNR) Denitrifying phosphorus removal Hydraulic retention time (HRT) Low C/N ratio
This study was financially supported by the Natural Science Foundation of China (NSFC No. 21206092) and the RTTC-China 2014 project.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
- Abyar, H., Younesi, H., Bahramifar, N., Zinatizadeh, A.A., Amini, M. 2017. Kinetic evaluation and process analysis of COD and nitrogen removal in UAASB bioreactor. Journal of the Taiwan Institute of Chemical Engineers.Google Scholar
- APHP, AWWA, WPCF, WEF. (1915). Standard methods for the examination of water and wastewater. APHP.Google Scholar
- Mannina, G., Capodici, M., Cosenza, A., Trapani, D.D., Ekama, G.A., Mannina, G., Capodici, M., Cosenza, A., Trapani, D.D., Ekama, G.A. 2017. The effect of the solids and hydraulic retention time on moving bed membrane bioreactor performance. Journal of Cleaner Production.Google Scholar
- Rizvi, H., Ahmad, N., Abbas, F., Bukhari, I. H., Yasar, A., Ali, S., Yasmeen, T., & Riaz, M. (2013). Start-up of UASB reactors treating municipal wastewater and effect of temperature/sludge age and hydraulic retention time (HRT) on its performance. Arabian Journal of Chemistry, 8(6), 780–786.CrossRefGoogle Scholar
- Wang, Z. C., Gao, M. C., Ren, Y., Wang, Z., She, Z. L., Jin, C. J., Chang, Q. B., Sun, C. Q., Zhang, J., & Yang, N. (2015). Effect of hydraulic retention time on performance of an anoxic–aerobic sequencing batch reactor treating saline wastewater. International Journal of Environmental Science & Technology, 12(6), 2043–2054.CrossRefGoogle Scholar