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Chen R, Xu D, Zhao J, Tang X, Yang H, Liang H. Effects of cations on biofilms in gravity-driven membrane system: Filtration performance and mechanism investigation. WATER RESEARCH 2024; 254:121383. [PMID: 38432002 DOI: 10.1016/j.watres.2024.121383] [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: 10/19/2023] [Revised: 02/15/2024] [Accepted: 02/25/2024] [Indexed: 03/05/2024]
Abstract
The gravity-driven membrane (GDM) system is desirable for energy-efficient water treatment. However, little is known about the influence of cations on biofilm properties and GDM performance. In this study, typical cations (Ca2+ and Na+) were used to reveal the combined fouling behavior and mechanisms. Results showed that Ca2+ improved the stable flux and pollutant removal efficiency, while Na+ adversely affected the flux. Compared with GDM control, the concentration of pollutants was lower in Ca-GDM, as indicated by the low biomass, proteins, and polysaccharides. A heterogeneous and loose biofilm was observed in the Ca-GDM system, with roughness and porosity increasing by 43.06 % and 32.60 %, respectively. However, Na+ induced a homogeneous and dense biofilm, with porosity and roughness respectively reduced by 17.48 % and 22.04 %. The richness of bacterial communities increased in Ca-GDM systems, while it decreased in Na-GDM systems. High adenosine triphosphate (ATP) concentration in Ca-GDM system was consistent with the abundant bacteria and their high biological activity, which was helpful for the efficient removal of pollutants. The abundance of Apicomplexa, Platyhelminthes, Annelida and Nematoda increased after adding Ca2+, which was related to the formation of loose biofilms. Computational simulations indicated that the free volumes of the biofilms in Ca-GDM and Na-GDM were 13.7 and 13.2 nm3, respectively. The addition of cations changed intermolecular forces, Ca2+ induced bridging effects led to large and loose floc particles, while the significant dehydration of hydrated molecules in the Na-GDM caused obvious aggregation. Overall, microbiological characteristics and contaminant molecular interactions were the main reasons for differences in GDM systems.
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Affiliation(s)
- Rui Chen
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, PR China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China
| | - Daliang Xu
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Jing Zhao
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Xiaobin Tang
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Haiyang Yang
- School of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China
| | - Heng Liang
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.
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Chen Y, Guo G, Li YY. Kinetic and elemental characterization of HAP-based high-rate partial nitritation/anammox system orienting stability and inorganic elemental requirements. WATER RESEARCH 2024; 251:121169. [PMID: 38281335 DOI: 10.1016/j.watres.2024.121169] [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: 11/20/2023] [Revised: 12/29/2023] [Accepted: 01/17/2024] [Indexed: 01/30/2024]
Abstract
Anammox-based processes are attractive for biological nitrogen removal, and the combination of anammox and hydroxyapatite (HAP) is promising for the simultaneous removal of nitrogen and phosphorus from wastewater. However, the kinetics of one-stage partial nitritation/anammox (PNA) in which ammonia-oxidizing bacteria (AOB) and anammox bacteria (AnAOB) exist in a reactor are poorly understood. Moreover, inorganic elements are required to promote microbial cell synthesis and growth; therefore, monitoring of elements to prevent the limitation and inhibition of the process is critical. The minimum amounts of inorganic elements required for a one-stage PNA process and the elemental flow remain unknown. Therefore, in this study, kinetics, stoichiometry, and element flow in the long-term, high-rate, continuous, one-stage HAP-PNA process with microaerobic granular sludge at 25 °C were determined using process modeling, parameter estimation, and mass balance. The biomass elemental composition was determined to be CH2.2O0.89N0.18S0.0091, and the biomass yield (Yobs) was calculated to be 0.0805 g/g NH4+-N. Therefore, a stoichiometric reaction equation for the one-stage HAP-PNA system was also proposed. The maximum specific growth rate (μm) of AnAOB and AOB were 0.0360 and 0.0982 d-1 with doubling times of 19 and 7.1 d, respectively. Finally, the elemental requirements for stable and high-rate performance were determined using element flow analysis. These findings are essential for developing the anammox-based process in a stable and resource-efficient manner and determining engineering applicability.
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Affiliation(s)
- Yujie Chen
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aoba, Aramaki-Aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Guangze Guo
- Department of Frontier Sciences for Advanced Environment, Graduate School of Environmental Studies, Tohoku University, 6-6-06 Aoba, Aramaki-Aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Yu-You Li
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aoba, Aramaki-Aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan; Department of Frontier Sciences for Advanced Environment, Graduate School of Environmental Studies, Tohoku University, 6-6-06 Aoba, Aramaki-Aza, Aoba-ku, Sendai, Miyagi 980-8579, Japan.
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Zhang Q, Lin L, Chen Y, Wang Y, Li X, Li L, Cao W, Zhang Y. Dual-edged effects and mechanisms of hydroxylamine in partial denitrification-anaerobic ammonium oxidation system. ENVIRONMENTAL RESEARCH 2023; 235:116664. [PMID: 37451572 DOI: 10.1016/j.envres.2023.116664] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
The combination of partial denitrification (PD) and anaerobic ammonium oxidation (anammox) is a novel and promising nitrogen removal process. Regulating the synergistic reaction between denitrifiers and anammox bacteria (AnAOB) is the key to achieving stable and efficient PD-anammox performance. In this study, 10 mg/L of hydroxylamine (NH2OH) was considered to efficiently promote the bacterial activity, microbial energy flow, and the synergy of functional microflora. As a result, the nitrogen removal rate (NRR) significantly increased from 0.05 to 0.30 g N/L/d in parallel with an increase in the nitrogen loading rate (NLR) from 0.10 to 0.40 g N/L/d. However, the dual-edged effect of NH2OH was also confirmed. The long-term presence of NH2OH caused overgrowth of complete-denitrifying bacteria and decreased the NRR to 0.11 g N/L/d. Additionally, NH2OH enhanced nitrous oxide (N2O) emissions via chemical pathways as well as enhanced denitrification Fortunately, the inhibition caused by NH2OH was reversible by stopping the dosing, the reactor restored to stable operation with an NRR of 0.27 g N/L/d. Analysis of metabolic intensity and pathways revealed the effecting process and mechanism of NH2OH on the PD-anammox system. This study verified the dual-edged effects and mechanisms of NH2OH, therefore proving a theoretical basis and technical reference for the application of PD-anammox.
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Affiliation(s)
- Qi Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China
| | - Lan Lin
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China
| | - Yuqi Chen
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China
| | - Yuzheng Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China
| | - Xiao Li
- Xiamen Junhong Environmental Solid Waste Disposal Co., Ltd., Xiamen, Fujian, 361102, China
| | - Linxi Li
- Xiamen Junhong Environmental Solid Waste Disposal Co., Ltd., Xiamen, Fujian, 361102, China
| | - Wenzhi Cao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China
| | - Yanlong Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen, Fujian, 361102, China; Fujian Key Laboratory of Coastal Pollution Prevention and Control (CPPC), College of Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China.
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Li H, Cai T, Gao Y, Dai Q, Liu X, Chen X, Lu X, Zhen G. Long-term performance, microbial evolution and spatial microstructural characteristics of anammox granules in an upflow blanket filter (UBF) treating high-strength nitrogen wastewater. BIORESOURCE TECHNOLOGY 2023; 367:128206. [PMID: 36323371 DOI: 10.1016/j.biortech.2022.128206] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/19/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
Granule formation, microstructure and microbial spatial distribution are crucial to granule stability and nitrogen removal. Here, an upflow blanket filter (UBF) reactor with porous fixed cylinder carriers was fabricated and operated for 234 days to investigate overall performance and the formation mechanism of anammox granules. Results showed that the UBF performed the highest nitrogen removal efficiency of 93.19 ± 3.39% under nitrogen loading rate of 3.6 kg-N/m3/d and HRT of 2 h. The tryptophan-like proteins as the key component in EPS were vital for granules formation. Further 16 s rRNA analysis indicated that SBR1031 with a relative abundance of 40.5% played an important role in cell aggregation. Thus, anammox granules were developed successfully with a two-layered spatial structure where outer-layer was ammonia oxidizing bacteria and inner-core was anaerobic ammonia oxidizing bacteria. Together, introduction of porous fixed cylinder carriers is a valid method to avoid biomass loss and floatation.
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Affiliation(s)
- Huan Li
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Teng Cai
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Yijing Gao
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Qicai Dai
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Xinyu Liu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Xue Chen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Xueqin Lu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China; Institute of Eco-Chongming (IEC), 3663 N Zhongshan Rd, Shanghai 200062, PR China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, PR China.
| | - Guangyin Zhen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, PR China; Shanghai Institute of Pollution Control and Ecological Security, 1515 North Zhongshan Rd. (No. 2), Shanghai 200092, PR China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N Zhongshan Road, Shanghai 200062, PR China
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