Stable nitrite accumulation and phosphorous removal from nitrate and municipal wastewaters in a combined process of endogenous partial denitrification and denitrifying phosphorus removal (EPDPR)
| Autor: | Jianyuang Zhen, Ji Zhao, Meng-Fei Yuan, Xiaoxia Wang, Shi-Ming Du, Deshuang Yu, Chen Guanghui |
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| Rok vydání: | 2019 |
| Předmět: |
Denitrification
General Chemical Engineering Phosphorus chemistry.chemical_element Sequencing batch reactor 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Anoxic waters Industrial and Manufacturing Engineering 0104 chemical sciences Denitrifying bacteria chemistry.chemical_compound Nitrate chemistry Anammox Environmental chemistry Environmental Chemistry Nitrite 0210 nano-technology |
| Zdroj: | Chemical Engineering Journal. 355:560-571 |
| ISSN: | 1385-8947 |
| DOI: | 10.1016/j.cej.2018.08.165 |
| Popis: | In this study, a novel process was developed by combining endogenous partial denitrification (EPD, NO3−-N → NO2−-N) with denitrifying phosphorus removal (DPR) in an anaerobic/anoxic/aerobic sequencing batch reactor (SBR) to achieve a stable nitrite accumulation and phosphorus removal from high-strength nitrate (NO3−-N: 186.5 mg/L) and municipal wastewater (NH4+-N: 52.6 mg/L, chemical oxygen demand (COD): 242.7 mg/L). After 138-day, high nitrate-to-nitrite transformation ratio (NTR) of 75.3% and PO43−-P removal efficiency of 92.3% were achieved by controlling the anaerobic drainage ratio and anoxic/aerobic durations. During the anaerobic stage (2.5 h), carbon source in raw municipal wastewater was efficiently utilized by phosphorus-and-glycogen accumulating organisms (PAOs and GAOs) to enhance intracellular carbon storage (69.9% in anaerobic COD consumption), providing sufficient carbons for subsequent anoxic EPD and DPR. During the anoxic stage (2.5 h), high activity of DGAONO3-NO2 (denitrifying GAOs conducting NO3−-N → NO2−-N) over DPAONO3 and DGAONO3 (DPAOs and DGAOs conducting NO3−-N → N2) in nitrate denitrification (77.7% > 8.2% and 5.7%) facilitated the nitrite accumulation and phosphorus uptake. In the last short aerobic stage (10 min), further phosphorus was removed by aerobic PAOs without initiating ammonia/nitrite oxidation. Thus, effluent NO2−-N/NH4+-N ratio of 1.02:1 (close to the theoretical value of 1.32:1 for anammox process) with limited NO3−-N, PO43−-P and COD (1.8, 0.4 and 23.5 mg/L, respectively) were obtained. This provides the potential for advanced nutrient removal from nitrate and municipal wastewaters by combining EPDPR with anammox. Microbial community analysis revealed that Cluster I of Defluviicoccus-GAO group (∼7%) dominated the high nitrite accumulation performance, while Accumulibacter-PAO group (15 ± 3%) was responsible for the P removal performance. |
| Databáze: | OpenAIRE |
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