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Xu L, Zhao J, Wang J, Gu R, Qu Y, Yin J, Yu D, Yu Z, Feng J, Wang X. Elucidating performance failure in the use of an Anaerobic-Oxic-Anoxic (AOA) plug-flow system for biological nutrient removal. Sci Total Environ 2023; 880:163320. [PMID: 37028655 DOI: 10.1016/j.scitotenv.2023.163320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/30/2023] [Accepted: 04/02/2023] [Indexed: 04/14/2023]
Abstract
The Anaerobic-oxic-anoxic (AOA) process is a carbon-saving and high-efficiency way to treat municipal wastewater and gets more attention. Recent reports suggest that in the AOA process, well-performed endogenous denitrification (ED), conducted by glycogen accumulating organisms (GAOs), is crucial to advanced nutrient removal. However, the consensuses about starting up and optimizing AOA, and in-situ enriching GAOs, are still lacking. Hence, this study tried to verify whether AOA could be established in an ongoing anaerobic-oxic (AO) system. For this aim, a lab-scale plug-flow reactor (working volume of 40 L) previously operated under AO mode for 150 days, during that 97.87 % of ammonium was oxidized to nitrate and 44.4 % of orthophosphate was absorbed. Contrary to expectations, under AOA mode, little nitrate reduction (only 6.3 mg/L within 5.33 h) indicated the failure of ED. According to high-throughput sequencing analysis, GAOs (Candidatus_Competibacter and Defluviicoccus) were enriched within the AO period (14.27 % and 3 %) and then still dominated during the AOA period (13.9 % and 10.07 %) but contributed little to ED. Although apparent alternate orthophosphate variations existed in this reactor, no typical phosphorus accumulating organisms were abundant (< 2 %). More than that, within the long-term AOA operation (109 days), the nitrification weakened (merely 40.11 % of ammonium been oxidized) since the dual effects of low dissolved oxygen and long unaerated duration. This work reveals the necessity of developing practical strategies for starting and optimizing AOA, and then three aspects in future studying are pointed out.
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Affiliation(s)
- Lingna Xu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Ji Zhao
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Jimiao Wang
- Qingdao Water Group Co. Ltd., Qingdao 266100, China
| | - Ruihuan Gu
- Qingdao Water Group Co. Ltd., Qingdao 266100, China
| | - Yong Qu
- Qingdao Shuangyuan Water Co. Ltd., Qingdao 266109, China
| | - Jianhui Yin
- Qingdao Shuangyuan Water Co. Ltd., Qingdao 266109, China
| | - Deshuang Yu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Zhengda Yu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Juan Feng
- Science and Technology Department, Qingdao University, Qingdao 266071, China.
| | - Xiaoxia Wang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China.
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Long XY, Tang R, Wang T, Tao GJ, Wang JY, Zhou HW, Xue M, Yu YP. Characteristics of enhanced biological phosphorus removal (EBPR) process under the combined actions of intracellular and extracellular polyphosphate. Chemosphere 2021; 279:130912. [PMID: 34134440 DOI: 10.1016/j.chemosphere.2021.130912] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/23/2021] [Accepted: 05/13/2021] [Indexed: 06/12/2023]
Abstract
The characteristics of enhanced biological phosphorus removal (EBPR) process under the combined actions of intracellular and extracellular polyphosphate (polyP) were investigated with the 31P Nuclear Magnetic Resonance (NMR) and the fractionation extracting the loosely-bound and tightly-bound extracellular polymer substances (i.e., LB-EPS and TB-EPS) and bacterial cells in EBPR sludge. The hydrolysis/synthesis of extracellular and intracellular polyP was a key step of the phosphate migration and transformation in EBPR sludge. The orthophosphate (orthoP) produced from the intracellular and extracellular polyP anaerobic-hydrolysis was partially accumulated in the bacterial cells and TB-EPS, and then the accumulated orthoP was main composition for these polyP aerobic-synthesis. Importantly, the anaerobic-hydrolysis enhancement of intracellular and extracellular ployP could promote EBPR sludge to absorb volatile fatty acids (VFAs) followed by being transformed into intracellular poly-hydroxy-alkanoates (PHAs). The mechanism for VFAs passing through the LB-EPS and TB-EPS should be an anion-exchange action between orthoP and VFAs. The orthoP accumulation in the TB-EPS kept an orthoP concentration gradient among the TB-EPS, LB-EPS and bulk solution, driving orthoP and VFAs migrations. The orthoP accumulation in the bacterial cells could keep an orthoP concentration difference between the cell-membrane two sides of phosphorus accumulating organisms (PAOs) to promote VFAs passing through the cell membrane considered as an anion exchange membrane. The intracellular PHAs continuously hydrolyzed accompanied with the average chain-length increases of the extracellular and intracellular polyP during the whole aerobic stage. Additionally, the energy of the extracellular polyP synthesized in situ should came from the intracellular PHAs hydrolysis.
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Affiliation(s)
- Xiang-Yu Long
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Ran Tang
- College of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, University Town, Shapingba District, Chongqing, 401331, China.
| | - Tao Wang
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Guang-Jian Tao
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Jia-Yue Wang
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Hai-Wei Zhou
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Ming Xue
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Yong-Ping Yu
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
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Sun S, Gao M, Wang Y, Qiu Q, Han J, Qiu L, Feng Y. Phosphate removal via biological process coupling with hydroxyapatite crystallization in alternating anaerobic/aerobic biofilter reactor. Bioresour Technol 2021; 326:124728. [PMID: 33508642 DOI: 10.1016/j.biortech.2021.124728] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/09/2021] [Accepted: 01/12/2021] [Indexed: 05/25/2023]
Abstract
In this work, a laboratory-scale alternating anaerobic/aerobic biofilter (A/O BF) filled with self-made steel slag media was constructed, where the integrated biological and crystalline phosphorus removal process was realized to remove phosphorus and achieve phosphorus recovery from wastewater. Phosphorus accumulating organisms (PAOs) were successfully enriched within 30 days operation, the maximum phosphate removal efficiency was close to 80% under the optimal conditions with the anaerobic time of 34 h, HRT of 4 h and influent COD of 300 mg/L. The analysis of SEM-EDS and XRD indicated that hydroxyapatite (HAP) crystals were formed inside biofilms without addition of chemical reagents. The high phosphate environment created by PAOs and the release of Ca2+ from the steel slag media might be responsible for the generation of HAP. These findings have crucial implications for the application BF technology to remove and recover phosphorus from wastewater.
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Affiliation(s)
- Shaofang Sun
- School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, China; Research Center for Functional Material & Water Purification Engineering of Shandong Province, Jinan 250022, China
| | - Mingchang Gao
- School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, China
| | - Yue Wang
- School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, China
| | - Qi Qiu
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Junli Han
- School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, China
| | - Liping Qiu
- School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, China; Research Center for Functional Material & Water Purification Engineering of Shandong Province, Jinan 250022, China.
| | - Yan Feng
- School of Civil Engineering and Architecture, University of Jinan, Jinan 250022, China; Research Center for Functional Material & Water Purification Engineering of Shandong Province, Jinan 250022, China
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Zhao J, Wang X, Li X, Jia S, Peng Y. Combining partial nitrification and post endogenous denitrification in an EBPR system for deep-level nutrient removal from low carbon/nitrogen (C/N) domestic wastewater. Chemosphere 2018; 210:19-28. [PMID: 29986220 DOI: 10.1016/j.chemosphere.2018.06.135] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/16/2018] [Accepted: 06/19/2018] [Indexed: 05/25/2023]
Abstract
In this study, partial nitrification and post endogenous denitrification (PED) were combined with enhancing bacterial phosphorus removal (EBPR) in an anaerobic/aerobic/anoxic operated sequencing batch reactor (SBR) for deep-level nutrient removal from low carbon/nitrogen (C/N, chemical oxygen demand (COD)/total nitrogen (TN)) domestic wastewater. At anaerobic stage, abundant organic matters (96.6% of COD consumption) in raw wastewater were stored as poly-hydroxyalkanoates (PHAs) by phosphorus and glycogen accumulating organisms with enhanced activities, which provided sufficient intracellular carbons for subsequent aerobic phosphorus uptake and anoxic PED. By controlling suitable aeration rate and duration, high nitrite accumulation rate (97.2%) was obtained at aerobic stage, which saved intracellular carbons consumption of PED. Moreover, the subsequent utilization of glycogen after PHAs via PED ensured the deep-level TN removal (94.9%) without external carbon addition. After 160-day operation, the average effluent PO43--P and TN concentrations were 0.4 and 3.0 mg/L, respectively, at C/N of 3.1.
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Affiliation(s)
- Ji Zhao
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Xiaoxia Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Xiyao Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Shuyuan Jia
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, PR China.
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Wang X, Wang S, Zhao J, Dai X, Peng Y. Combining simultaneous nitrification-endogenous denitrification and phosphorus removal with post-denitrification for low carbon/nitrogen wastewater treatment. Bioresour Technol 2016; 220:17-25. [PMID: 27552719 DOI: 10.1016/j.biortech.2016.06.132] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 06/28/2016] [Accepted: 06/30/2016] [Indexed: 06/06/2023]
Abstract
Due to the limited nutrient removal from low carbon/nitrogen (⩽4) wastewater, a process combined simultaneous nitrification-endogenous denitrification and phosphorus removal (SNDPR) with post-denitrification (PD) in a SBR was proposed for deep-level nutrient removal without external carbon addition. SNDPR driven by PAOs and GAOs reduced PO4(3-)-P (98.3%) and partial TN (59.0%) at low DO conditions (0.5±0.1mg/L), and post-dentrification achieved further NOX(-) (produced by SNDPR) removal (24.0%) anoxically by utilizing the residual intracellular polymers in GAOs. Combined control of anaerobic/aerobic/anoxic durations and low DO inhibition to aerobic GAOs and NOB conducted partial nitrification-endogenous denitrification (PNED) (66%), which saved 44.3% intracellular polymers to further reduce 64% TN in effluent. After 115-day operation, the average effluent PO4(3-)-P and TN concentrations were 0.4 and 3.9mg/L, respectively, with 92.1% of TN removal. Highly enriched PAOs (36%±2%), GAOs (22%±2%) and AOB (15%±3%) over NOB (3%±1%) facilitated P uptake, PNED and post-denitrification in the SNDPR-PD system.
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Affiliation(s)
- Xiaoxia Wang
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Shuying Wang
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China.
| | - Ji Zhao
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Xian Dai
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Yongzhen Peng
- Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
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Zhang HL, Sheng GP, Fang W, Wang YP, Fang CY, Shao LM, Yu HQ. Calcium effect on the metabolic pathway of phosphorus accumulating organisms in enhanced biological phosphorus removal systems. Water Res 2015; 84:171-180. [PMID: 26233656 DOI: 10.1016/j.watres.2015.07.042] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 07/20/2015] [Accepted: 07/24/2015] [Indexed: 06/04/2023]
Abstract
Phosphorus accumulating organisms (PAOs) have been found to act as glycogen-accumulating organisms (GAOs) under certain conditions, thus, the deterioration in the performance of enhanced biological phosphorus removal systems is not always attributed to the proliferation of GAOs. In this work, the effects of calcium on the metabolic pathway of PAOs were explored. It was found that when the influent Ca(2+) concentration was elevated, the tendency and extent of extracellular calcium phosphate precipitation increased, and the intracellular inert Ca-bound polyphosphate was synthesized, while the microbial population remained almost unchanged. The changes in the ratios of phosphorus released/acetate uptaken, the glycogen degraded/acetate uptaken and the poly-β-hydroxyalkanoates synthesized/acetate uptaken during the anaerobic period confirm that, as the influent Ca(2+) concentration was increased, the polyphosphate-accumulating metabolism was partially shifted to the glycogen-accumulating metabolism. At an influent Ca(2+) around 50 mg/L, in addition to the extracellular calcium phosphate precipitation, the intracellular inert Ca-bound polyphosphate synthesis might also be involved in the metabolic change of PAOs. The results of the present work would be beneficial to better understand the biochemical metabolism of PAOs in enhanced biological phosphorus removal systems.
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Affiliation(s)
- Hai-Ling Zhang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China; Institute of Materials, China Academy of Engineering Physics, Mianyang, Sichuan, 621907, China
| | - Guo-Ping Sheng
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China.
| | - Wei Fang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Yong-Peng Wang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China; Institute of Materials, China Academy of Engineering Physics, Mianyang, Sichuan, 621907, China
| | - Cai-Yun Fang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Li-Min Shao
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China.
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