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Qin Y, Wei Q, Chen R, Jiang Z, Qiu Y, Jiang Y, Li L. Roles of red mud-based biochar carriers in the recovery of anammox activity: characteristics and mechanisms. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:20488-20498. [PMID: 38376779 DOI: 10.1007/s11356-024-32263-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 01/26/2024] [Indexed: 02/21/2024]
Abstract
Anaerobic ammonium oxidation (anammox) sludge is easily deactivated in the process of treating ammonia-laden wastewater. To investigate an effective recovery method, red mud-based biochar carriers (RMBC) were prepared and added to a deactivated anammox reactor; the operation of this reactor had been interrupted for 6 months with starvation and low temperature. The deactivated sludge with added RMBC was recovered rapidly after 31 days, with the specific anammox activity rapidly increasing to 0.84 g N/(g VSS∙day), and the recovery efficiency of nitrogen removal rate increased by four times compared to the unadded control. The granulation degree and extracellular polymeric substances secretion of the anammox sludge with the added RMBC were significantly higher than that of the control group. In addition, a large number of spherical anammox bacteria were observed moored at the porous channels of RMBC, and the copy numbers of functional genes of anammox bacteria were approximately twice that of the control group. Hence, RMBC is a potential sludge activator, and it can provide a "house" to protect anammox bacteria, enhance the metabolic activity and the agglomerative growth of anammox bacteria, and synergistically achieve rapid recovery of deactivated anammox sludge.
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Affiliation(s)
- Yongli Qin
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, China
| | - Qiaoyan Wei
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, China
| | - Ruihong Chen
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, China
| | - Zhicheng Jiang
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, China
| | - Yuchen Qiu
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, China
| | - Yongrong Jiang
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, China.
| | - Li Li
- School of Electronic Engineering and Automation, Guilin University of Electronic Technology, Guilin, 541004, China
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2
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Yan Y, Li X, Ren S, Zhang Q, Wu D, Zhou J, Peng Y. Efficient nitrogen removal and robustness enhancement of a two-stage partial nitrification-anammox (PN/A) process with low sludge concentration for mature landfill leachate. BIORESOURCE TECHNOLOGY 2023; 387:129573. [PMID: 37506937 DOI: 10.1016/j.biortech.2023.129573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/17/2023] [Accepted: 07/25/2023] [Indexed: 07/30/2023]
Abstract
The biological treatment system for high-strength wastewater, particularly landfill leachate, typically requires high sludge concentration to maintain nitrogen removal performance. However, it frequently causes an excessive accumulation of toxins in microbial metabolism, resulting in unstable performance during long-term operation. An efficient two-stage partial nitrification/anammox (PN/A) mature landfill leachate process with low sludge concentration was constructed by settling time reduction and Ca2+ addition. The ammonia removal rate reached 46.7 mg N/(L·h) in PN-SBR. Nitrosomonas (2.0%) was the sole genus responsible for partial nitrification. The influent NO2--N/NH4+-N of A-SBR was kept at 1.39, leading to a dynamic equilibrium of anammox and denitrification. Ca. Brocadia recovered fastest (0.32% → 1.8%) among the detected AnAOB genera. The process achieved NRE of 95.0% with effluent TIN of 37.6 mg/L (<40 mg/L). This research offered recommendations for the favorable operation of the two-stage PN/A mature landfill leachate treatment system with low sludge concentration.
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Affiliation(s)
- Ying Yan
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, 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, China
| | - Shang Ren
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, China
| | - Qiong Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, China
| | - Di Wu
- Qingdao SPRING Water Treatment Co. Ltd., Qingdao 266510, China
| | - Jiazhong Zhou
- Qingdao SPRING Water Treatment Co. Ltd., Qingdao 266510, 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, China.
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Masood JAIS, Chakravarthy NSK, Abd-Elkader OH, Ahamed A, Mohaideen AMK, Sugumaran V. A microbiological identification and recovery actions of critical symptoms of anammox image bacteria. Prev Med 2023; 174:107620. [PMID: 37451554 DOI: 10.1016/j.ypmed.2023.107620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 07/01/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Currently, the risks posed by bacteria are becoming increasingly important. It now appears that the cell wall of Anammox image bacteria is very different from what has been generally considered for many years. Not every textbook contains the peptidoglycan on the cell wall of Anammox image bacteria - the sugar-protein chain that strengthens the cells of most bacteria. Most researchers in this Anammox image bacteria diseased identification wanted to find out what gave the Anammox image cell its stability. It used powerful cryo-electron microscopes to examine the bacterial cell wall and find the exact structure of the peptidoglycan. A new algorithm is proposed to discover that Anammox image bacteria contain peptidoglycan, which completes a theory in microbiology. The identification of different diseases is listed, and the proposed model compares the exact results while comparing the parameters like accuracy, precision, recall, and F1-Score. Keywords: Anammox image bacteria, cell wall, cell stability, cryo-electron, microscope images, accuracy, precision, recall, F1-score.
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Affiliation(s)
- Jafar Ali Ibrahim Syed Masood
- Department of Internet of Things, School of Computer Science and Engineering, Vellore Institute of Technology, Vellore 632 014, Tamilnadu, India.
| | - N S Kalyan Chakravarthy
- Center for Data Science, School of Computer Science and Engineering, QIS College of Engineering and Technology, Ongole 523272, Andhra Pradesh, India.
| | - Omar H Abd-Elkader
- Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
| | - Anis Ahamed
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
| | | | - Vijayan Sugumaran
- Department of Decision and Information Sciences, School of Business Administration, Oakland University, Rochester, MI 48309, USA..
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4
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Li B, Godfrey BJ, RedCorn R, Wang Z, Goel R, Winkler MKH. Simultaneous anaerobic carbon and nitrogen removal from primary municipal wastewater with hydrogel encapsulated anaerobic digestion sludge and AOA-anammox coated hollow fiber membrane. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 883:163696. [PMID: 37100124 DOI: 10.1016/j.scitotenv.2023.163696] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/04/2023] [Accepted: 04/19/2023] [Indexed: 06/03/2023]
Abstract
In this study, a one-stage continuous-flow membrane-hydrogel reactor integrating both partial nitritation-anammox (PN-anammox) and anaerobic digestion (AD) was designed and operated for simultaneous autotrophic nitrogen (N) and anaerobic carbon (C) removal from mainstream municipal wastewater. In the reactor, a synthetic biofilm consisting of anammox biomass and pure culture ammonia oxidizing archaea (AOA) were coated onto and maintained on a counter-diffusion hollow fiber membrane to autotrophically remove nitrogen. Anaerobic digestion sludge was encapsulated in hydrogel beads and placed in the reactor to anaerobically remove COD. During the pilot operation at three operating temperature (25, 16 and 10 °C), the membrane-hydrogel reactor demonstrated stable anaerobic COD removal (76.2 ± 15.5 %) and membrane fouling was successfully suppressed allowing a relatively stable PN-anammox process. The reactor demonstrated good nitrogen removal efficiency, with an overall removal efficiency of 95.8 ± 5.0 % for NH4+-N and 78.9 ± 13.2 % for total inorganic nitrogen (TIN) during the entire pilot operation. Reducing the temperature to 10 °C caused a temporary reduction in nitrogen removal performance and abundances of AOA and anammox. However, the reactor and microbes demonstrated the ability to adapt to the low temperature spontaneously with recovered nitrogen removal performance and microbial abundances. Methanogens in hydrogel beads and AOA and anammox on the membrane were observed in the reactor by qPCR and 16S sequencing across all operational temperatures.
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Affiliation(s)
- Bo Li
- University of Washington, Department of Civil & Environmental Engineering, Seattle, WA 98105, USA.
| | - Bruce J Godfrey
- University of Washington, Department of Civil & Environmental Engineering, Seattle, WA 98105, USA
| | - Raymond RedCorn
- University of Washington, Department of Civil & Environmental Engineering, Seattle, WA 98105, USA
| | - Zhiwu Wang
- Virginia Polytechnic Institute and State University, Department of Biological Systems Engineering, 1230 Washington St. SW, VA 24061, Blacksburg, VA 20147, USA
| | - Ramesh Goel
- The University of Utah, Department of Civil & Environmental Engineering, 110 S. Central Campus Drive, 2000MCE, Salt Lake City, UT 84112, USA
| | - Mari-K H Winkler
- University of Washington, Department of Civil & Environmental Engineering, Seattle, WA 98105, USA
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Jiang M, Ji S, Wu R, Yang H, Li YY, Liu J. Exploiting refractory organic matter for advanced nitrogen removal from mature landfill leachate via anammox in an expanded granular sludge bed reactor. BIORESOURCE TECHNOLOGY 2023; 371:128594. [PMID: 36634882 DOI: 10.1016/j.biortech.2023.128594] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/31/2022] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
Anammox is an efficient low-carbon nitrogen removal technology for mature landfill leachate (MLL). However, it produces 11 % nitrate theoretically, which needs further removal. In this study, the mechanisms of exploiting refractory organic matter (ROM) from an MLL as an inner carbon source for advanced nitrogen removal via anammox were systematically analyzed, and the effects of hydraulic retention time on nitrogen and ROM removal/utilization were investigated. Without any external carbon source, a total nitrogen and organic carbon removal efficiency of 94.50 % and 27.12 %, respectively, were achieved, with a nitrogen loading rate of 2.4 kg N/(m3·d). The abundances of norank_f_norank_o_SBR1031, OLB13, and norank_f_A4b, which had the capacity to degrade ROM, increased from 21.63 % to 49.21 %. This study reveals that the ROM in an MLL can be exploited for synchronous advanced nitrogen and organic matter removal.
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Affiliation(s)
- Mengting Jiang
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Shenghao Ji
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Ruixin Wu
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Huan Yang
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Yu-You Li
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Jianyong Liu
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China.
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6
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Flow cytometry: a tool for understanding the behaviour of polyhydroxyalkanoate accumulators. Appl Microbiol Biotechnol 2023; 107:581-590. [PMID: 36525042 DOI: 10.1007/s00253-022-12318-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 11/24/2022] [Accepted: 11/26/2022] [Indexed: 12/23/2022]
Abstract
The use of mixed microbial cultures (MMCs) is seen as an attractive strategy for polyhydroxyalkanoate (PHA) production. In order to optimize the MMC-PHA production process, tools are required to improve our understanding of the physiological state of the PHA-storing microorganisms within the MMC. In the present study, we explored the use of flow cytometry to analyse the metabolic state and polyhydroxybutyrate (PHB) content of the microorganisms from an MMC-PHA production process. A sequencing batch reactor under a feast and famine regime was used to enrich an MMC with PHB-storing microorganisms. Interestingly, once the PHB-storing microorganisms are selected, the level of PHB accumulation depends largely on the metabolic state of these microorganisms and not exclusively on the consortium composition. These results demonstrate that flow cytometry is a powerful tool to help to understand the PHA storage response of an MMC-PHA production process. KEY POINTS: • Flow cytometry allows to measure PHB content and metabolic activity over time. • Microorganisms showing high PHB content also have high metabolic activity. • PHB producers with low metabolic activity show low PHB content.
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7
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Cao Q, Li X, Chen Y, Li X, Xie Z, Li D. Nitrification resistance and functional redundancy maintain the system stability of partial nitrification in high-strength ammonium wastewater system. BIORESOURCE TECHNOLOGY 2022; 365:128157. [PMID: 36272680 DOI: 10.1016/j.biortech.2022.128157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/11/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
The sudden change of ammonia loading in high-strength ammonium wastewater treatment can directly affect the system stability by altering microbial community dynamics. To maintain the system stability, the effects of ammonia shock loading on microbial community dynamics must be studied. Two sets of sequencing batch reactors were operated with 6 shock cycles (maximum volumetric loading rate of 1928 mg N/(L·d)). CN system contained both organic carbon and ammonia and N system contained only ammonia. Comparing with N system, CN system operated more stably and had higher nitrite accumulation rate. Free ammonia (FA) was the select stress for the turnover of CN microbial communities, while the N communities didn t shift much. The increase of Nitrosomonas and the appearance of heterotrophic nitrification-aerobic denitrification bacteria in CN system presented its resistance and redundancy against FA impact, while the increase of functional genes exhibited functional genes redundancy which maintained the system stability.
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Affiliation(s)
- Qin Cao
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiangzhen Li
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Yichao Chen
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Xin Li
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhijie Xie
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Dong Li
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
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8
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Han F, Li Z, Li Q, Liu Z, Han Y, Li Q, Zhou W. Cooperation of heterotrophic bacteria enables stronger resilience of halophilic assimilation biosystem than nitrification system under long-term stagnation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 848:157806. [PMID: 35932852 DOI: 10.1016/j.scitotenv.2022.157806] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 07/30/2022] [Accepted: 07/30/2022] [Indexed: 06/15/2023]
Abstract
Long-term stagnation of biosystems (with no or very little wastewater) owing to seasonal downtime or failure maintenance brings great challenges to the performance recovery after system restart. In particular, the reduction of microbial activity and change of dissolved organic matter (DOM) affect the effluent quality and subsequent treatment procedures. Monitoring the dynamics and resilience of biosystems after long-term stagnation is important to formulate targeted countermeasures for system stability. However, the influence of long-term stagnation on autotrophic nitrification (AN) and heterotrophic assimilation (HA) biosystems has not been systematically explored. Here, we used halophilic AN and HA systems to study the stability and resilience of two nitrogen removal consortia after long-term stagnation. The results showed that 97.5 % and 93 % of ammonium and 47.0 % and 90.1 % of total nitrogen were removed using the halophilic AN and HA systems, respectively, in the stable period. After four weeks of stagnation, the HA system showed stronger resilience than AN system, in terms of faster recovery of treatment performance, and less fluctuations in sludge settleability and extracellular polymeric substances. In addition, after the stagnation period, the DOM of AN system was rich in low-molecular refractory humic acid, whereas that of HA system was rich in high-molecular proteins. The stagnation period led to the replacement of the dominant heterotrophic functional microorganisms, Paracoccus and Halomonas, with Muricauda and Marinobacterium in the HA system. The microbial network results revealed that the cooperation of heterotrophic bacteria enables stronger resilience of the HA system from prolonged stagnation than the AN system. In addition, the nitrogen removal efficiency, protein to polysaccharide ratio of EPS and fluorescence intensity of DOM were significantly correlated with the microbial community composition. These results suggest that AN system has greater risks in terms of treatment performance and sludge stability than the system after long-term stagnation.
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Affiliation(s)
- Fei Han
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266000, China
| | - Zhe Li
- School of Civil Engineering, Shandong University, Jinan, Shandong 250002, China
| | - Qinyang Li
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266000, China
| | - Zhe Liu
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266000, China
| | - Yufei Han
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266000, China
| | - Qian Li
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266000, China
| | - Weizhi Zhou
- School of Civil Engineering, Shandong University, Jinan, Shandong 250002, China.
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Wang H, Chen C, Yang E, Tu Z, Liang J, Dai X, Chen H. Revealing the effect of biofilm formation in partial nitritation-anammox systems: Start-up, performance stability, and recovery. BIORESOURCE TECHNOLOGY 2022; 357:127379. [PMID: 35642853 DOI: 10.1016/j.biortech.2022.127379] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/20/2022] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
Successful application of partial nitritation-anammox (PNA) processes is currently and primarily associated with biofilm systems. Biofilm characteristics significantly influence start-up, performance stability, and recovery. Here, two PNA systems with and without carriers were implemented simultaneously for treating wastewater containing 50 mg-NH4/L. The performance characteristics of these two PNA systems were compared. Stable nitrogen removal efficiencies of 76.3 ± 2.8% and 72.9 ± 1.6% were obtained for suspended sludge and biofilm systems, respectively. The slow process of biofilm colonization resulted in a long start-up time in the biofilm system. Biofilm enrichment and protection conferred stable performance when exposed to aeration shock. The suspended sludge system displayed good elasticity during performance recovery after shock compared to the slow recovery in the biofilm system. Moreover, suitable control of dissolved oxygen could improve the activity and abundance of the functional microbes. This study provides new insights into the operation and control of PNA systems for treating mainstream wastewater.
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Affiliation(s)
- Hong Wang
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha 410114, China; State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Chen Chen
- Changsha Social Work College, Changsha 410004, China
| | - Enzhe Yang
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha 410114, China
| | - Zhi Tu
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha 410114, China
| | - Jie Liang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Hong Chen
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha 410114, China.
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Bian H, Zhu Z, Sui Q, Wang S. The Pilot Study of the Influence of Free Ammonia on Membrane Fouling during the Partial Nitrosation of Pig Farm Anaerobic Digestion Liquid. MEMBRANES 2021; 11:894. [PMID: 34832123 PMCID: PMC8620214 DOI: 10.3390/membranes11110894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/04/2021] [Accepted: 11/04/2021] [Indexed: 11/16/2022]
Abstract
The problem of membrane fouling is a key factor restricting the application of the membrane bioreactor (MBR) in the partial nitrosation (PN) and anaerobic ammonia oxidation (anammox) processes. In this study, the pilot-scale continuous flow MBR was used to start up the partial nitrosation process in order to investigate the change trend of mid-transmembrane pressure (TMP) in the process of start-up, which was further explored to clarify the membrane fouling mechanism in the pilot-scale reactor. The results showed that the MBR system was in a stable operating condition during the partial nitrosation operation and that the online automatic backwash operation mode is beneficial in alleviating membrane fouling and reducing the cost of membrane washing. Particular attention was paid to the influence trend of free ammonia (FA)on membrane fouling, and it was found that the increase in FA concentration plays the most critical role in membrane fouling. The increase in FA concentration led to an increase in the extracellular polymer (EPS), dissolved microorganism product (SMP) and soluble chemical oxygen demand (SCOD) concentration. FA was extremely significantly correlated with EPS and SCOD, and the FA concentration was approximately 20.7 mg/L. The SCODeff (effluent SCOD concentration) concentration was approximately 147 mg/L higher than the SCODinf (influent SCOD concentration) concentration. FA mainly affects membrane fouling by affecting the concentration of EPS and SCOD.
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Affiliation(s)
- Hanxiao Bian
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (H.B.); (S.W.)
- Key Laboratory of Energy Conservation and Waste Management in Agricultural Structures, Ministry of Agriculture and Rural Affairs, Beijing 100081, China
| | - Zhiping Zhu
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (H.B.); (S.W.)
- Key Laboratory of Energy Conservation and Waste Management in Agricultural Structures, Ministry of Agriculture and Rural Affairs, Beijing 100081, China
| | - Qianwen Sui
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China;
- Laboratory of Water Pollution Control Technology, Chinese Academy of Sciences, Beijing 100085, China
| | - Shunli Wang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (H.B.); (S.W.)
- Key Laboratory of Energy Conservation and Waste Management in Agricultural Structures, Ministry of Agriculture and Rural Affairs, Beijing 100081, China
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