101
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Zhang S, Li B, Yu Z, Meng F. Aggregate size-dependence of bacterial community separation in a full-scale membrane bioreactor plant. FEMS Microbiol Ecol 2020; 96:5818762. [PMID: 32275301 DOI: 10.1093/femsec/fiaa060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 04/02/2020] [Indexed: 11/13/2022] Open
Abstract
The size of bacterial aggregates can determine both nutrient removal and sludge/water separation in activated sludge processes. In this study, the bacterial community structures and network associations of different sized aggregates obtained from a full-scale membrane bioreactor plant over a one-year period were investigated. Our results showed that biodiversity of larger sized aggregates was significantly higher than that of smaller ones and that the bacterial compositions of different sized aggregates differed significantly from each other. Bacteria related to nutrient removal (e.g. denitrification, hydrolysis and fermentation) were found to be significantly more abundant in larger aggregates than smaller ones. Network analysis revealed significant difference in species-species interactions, topological roles of individual OTU and keystone populations among different sized aggregates. Moreover, the occurrence of keystone OTUs affiliated with denitrifiers (Thermomonas) in networks of large and medium aggregates may suggest that denitrification influences bacterial interactions in large and medium aggregates. Overall, our results indicate the aggregates size-dependence of bacterial community separation in activated sludge. The current findings not only can provide guidance for process design and operation optimization, but also highlight the necessity for paying more attentions to the aggregate-based community, metabolic function and gene expression of activated sludge in future studies.
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Affiliation(s)
- Shaoqing Zhang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China.,Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, PR China
| | - Bing Li
- Division of Energy and Environment, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China
| | - Zhong Yu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China.,Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, PR China
| | - Fangang Meng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China.,Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, PR China
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102
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Xu J, Pang H, He J, Nan J. The effect of supporting matrix on sludge granulation under low hydraulic shear force: Performance, microbial community dynamics and microorganisms migration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 712:136562. [PMID: 32050387 DOI: 10.1016/j.scitotenv.2020.136562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/12/2019] [Accepted: 01/04/2020] [Indexed: 06/10/2023]
Abstract
Granular sludge usually takes extracellular polymers (EPS) as matrices for colonizing microorganisms and maintaining structural stability. However, the low strength of EPS threatens the disintegration of granules, especially under low hydraulic shear force. To accelerate the formation and enhance the stability of granules, micro-sized melamine (ME) sponges (RA) and polyurethane (PU) sponges (RB) were screened out as matrix substitutes for developing aerobic granular biofilm (AGB) in this study. The superficial gas velocity was 0.8 cm s-1. Both reactors achieved over 95% ammonium nitrogen removal efficiency within 10 days. During stabilization period, the chemical oxygen demand, total nitrogen and total phosphorus removal efficiencies were 90.5%, 70% and 95% in RA and 87.8%, 83% and 88% in RB, respectively. Confocal laser scanning microscopy (CLSM) detection revealed that β-polysaccharide was more concentrated in the outer layer in PU-AGB but uniformly dispersed in ME-AGB. The denitrifying phosphorus accumulating organisms (Flavobacterium) was dominant in RA, while the denitrifying glycogen accumulating organisms (Candidatus_Competibacter) was dominant in RB. Fluorescence in situ hybridization (FISH) analysis indicated that the microbial distribution in ME-AGB was relatively uniform, while there was a significant migration of functional microorganisms in PU-AGB. The super-hydrophilicity of ME and the high hydrophobicity of PU may be the main reasons for these differences. Overall, this study indicated that ME sponge is a more suitable material for supporting AGB than PU sponge.
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Affiliation(s)
- Jie Xu
- School of Environment, Harbin Institute of Technology (HIT), Harbin 150090, China
| | - Heliang Pang
- School of Environment, Harbin Institute of Technology (HIT), Harbin 150090, China.
| | - Junguo He
- Guangzhou University, Guangzhou 510006, China
| | - Jun Nan
- School of Environment, Harbin Institute of Technology (HIT), Harbin 150090, China
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103
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Wu J, de Los Reyes FL, Ducoste JJ. Modeling cell aggregate morphology during aerobic granulation in activated sludge processes reveals the combined effect of substrate and shear. WATER RESEARCH 2020; 170:115384. [PMID: 31838364 DOI: 10.1016/j.watres.2019.115384] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/05/2019] [Accepted: 12/08/2019] [Indexed: 06/10/2023]
Abstract
Past research on AGS (aerobic granular sludge technology) has mainly focused on macro-environment factors, such as settling time, feeding pattern, OLR (organic loading rate), SRT (sludge retention time), among others, and their effects on the granulation process. The biomass granulation process, however, is significantly affected by the micro-environment surrounding these biomass aggregates. In this research, an in silico computational approach was adopted to study the impact of the micro-environment on the biomass granulation process. A 2-D biofilm model based on the cellular automata algorithm and computational fluid dynamics was used to simulate the development of an individual biomass aggregate under specific hydrodynamic and substrate availability conditions. The simulation results indicated that shear and bulk substrate concentration combined to create the optimal conditions for aerobic granule formation. This process can be characterized by the RT (reversed Thiele) modulus value, which is the ratio of the maximum substrate transport over the maximum substrate reaction rate and an indicator of substrate availability. For AGS formation, the RT value should be greater than 0.1. Many common strategies, such as the application of batch reactors, selection for slow-growing microorganism, F/M (food/mass) ratio adjustment, feast and famine condition, and short settling time, for biomass granulation production can be explained by the RT value. The results suggest that rethinking unit process configurations in wastewater treatment facilities will be required to achieve reliable AGS formation.
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Affiliation(s)
- Jun Wu
- School of Environmental Engineering and Science, Yangzhou University, 196 West Huayang Road, Yangzhou, Jiangsu, 225127, China.
| | - Francis L de Los Reyes
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC, 27695-7908, United States
| | - Joel J Ducoste
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC, 27695-7908, United States
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104
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He Q, Wang H, Chen L, Gao S, Zhang W, Song J, Yu J. Robustness of an aerobic granular sludge sequencing batch reactor for low strength and salinity wastewater treatment at ambient to winter temperatures. JOURNAL OF HAZARDOUS MATERIALS 2020; 384:121454. [PMID: 31668764 DOI: 10.1016/j.jhazmat.2019.121454] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/09/2019] [Accepted: 10/09/2019] [Indexed: 06/10/2023]
Abstract
Acclimation performances and characteristics of aerobic granular sludge to salt and temperature were investigated in a sequencing batch reactor (SBR) performing simultaneous nitrification, denitrification and phosphorus removal (SNDPR). The aerobic granular SNDPR system was firstly subjected to low salinity (0.5%, w/v) at moderate temperature (> 15 ℃) and subsequent low temperature (< 15 ℃). The shock loading of salinity temporarily deteriorated biological phosphorus removal, while dual stresses of salinity and low temperature induced temporary inhibition on both nitrogen and phosphorus removal. Both salinity and low temperature stimulated the settleability of aerobic granules, accompanied with decreased ratios of protein to polysaccharide (PN/PS). Illumina MiSeq sequencing revealed that salinity rarely affected bacterial richness, but significantly decreased the diversity. Whereas low temperature strengthened both bacterial richness and diversity. Phyla Proteobacteria, Chloroflexi and their sub-groups acted as the main halophilic bacteria while Proteobacteria was also psychrophilic. The functional bacteria such as nitrifiers, denitrifiers, and phosphorus removal bacteria exhibited greater tolerance to salt and low temperature than glycogen accumulating organisms (GAOs). Overall, the present study demonstrated the resilience and robustness of aerobic granular sludge toward salinity and low temperature, which could aid the knowledge of saline wastewater treatment by aerobic granular sludge.
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Affiliation(s)
- Qiulai He
- Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha, 410082, China.
| | - Hongyu Wang
- School of Civil Engineering, Wuhan University, Wuhan, 430072, China
| | - Li Chen
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Shuxian Gao
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Wei Zhang
- School of Civil Engineering, Wuhan University, Wuhan, 430072, China
| | - Jianyang Song
- School of Civil Engineering, Wuhan University, Wuhan, 430072, China
| | - Jian Yu
- Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha, 410082, China
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105
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Du R, Cao S, Zhang H, Peng Y. Formation of partial-denitrification (PD) granular sludge from low-strength nitrate wastewater: The influence of loading rates. JOURNAL OF HAZARDOUS MATERIALS 2020; 384:121273. [PMID: 31585283 DOI: 10.1016/j.jhazmat.2019.121273] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 09/18/2019] [Accepted: 09/20/2019] [Indexed: 06/10/2023]
Abstract
Granular sludge has been believed to be a promising technology in wastewater biological treatment. However, the formation of granules at low substrate concentration is a difficult task that has seldom been achieved. This study aimed at forming the granules in the recently developed partial-denitrification (PD, NO3--N→NO2--N) for nitrite production. Two sequencing batch reactors (SBRs) were operated at a low nitrate of 30 mg N/L with nitrate loading rate (NLR) of 0.12 (R1) and 0.24 kg N/m3/d (R2). Results showed that the granulation of PD sludge experienced a developing and matured process with the progressive increase in size followed by maintaining a stable value. Higher NLR resulted in a more rapid granulation with the larger and looser structure. While the granules under lower NLR appeared to be denser and more compact with better settling ability. Microbial communities of two SBRs were revealed to show little difference, with the PD functional bacteria of Thauera (50.7% in R1 and 55.4% in R2) dominated during the granulation process. The Flavobacterium, likely to be closely related with sludge granulation, accounted for a higher proportion in R2 (10.16%) than R1 (5.91%), which might result in a larger granule formed in R2. This study clearly confirmed the feasibility of granulation of PD sludge under low nitrogen loads, shedding new light on the low-strength nitrate wastewater treatment with an efficient and economical way.
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Affiliation(s)
- Rui Du
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Shenbin Cao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore, 637141, Singapore
| | - Hanyu Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, 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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106
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Rollemberg SLDS, Ferreira TJT, Firmino PIM, Dos Santos AB. Impact of cycle type on aerobic granular sludge formation, stability, removal mechanisms and system performance. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 256:109970. [PMID: 31989985 DOI: 10.1016/j.jenvman.2019.109970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/11/2019] [Accepted: 12/06/2019] [Indexed: 06/10/2023]
Abstract
This paper aimed to assess the impact of the cycle type on aerobic granular sludge (AGS) formation, stability and system performance. Six AGS reactors were operated either on A/O cycles (anaerobic followed by oxic phase) or A/O/A cycles (anaerobic, followed by oxic and anoxic phases), changing only the phase time distribution. Reactors with high percentage of aerobic phase (65% of the total cycle time) generated granules with better settleability and resistance, however denitrification was impaired. On the other hand, reactors with long anaerobic or anoxic phases presented excellent nutrients removals, but the granules were fluffy and unstable. The best results in terms of performance and stability were achieved in an A/O/A reactor with short anoxic phase (10% of the total cycle) and medium aerobic phase (55% of the total cycle). Therefore, in AGS reactors, it is indispensable to optimize the cycle, aiming at fast biomass formation, long-term granule stability and high-rate pollutants removal.
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Affiliation(s)
| | | | - Paulo Igor Milen Firmino
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - André Bezerra Dos Santos
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil.
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107
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Jiang Y, Shang Y, Gong T, Hu Z, Yang K, Shao S. High concentration of Mn 2+ has multiple influences on aerobic granular sludge for aniline wastewater treatment. CHEMOSPHERE 2020; 240:124945. [PMID: 31726594 DOI: 10.1016/j.chemosphere.2019.124945] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/08/2019] [Accepted: 09/22/2019] [Indexed: 06/10/2023]
Abstract
In this study, the effect of high concentration of Mn2+ on the aerobic granular sludge (AGS) systems for aniline wastewater treatment was systematically investigated in terms of AGS formation and pollutant removal efficiency. Two parallel sequencing batch reactors were operated to treat the aniline-rich wastewater with and without 20 mg L-1 of Mn2+. In the presence of Mn2+, the time to granulation was prolonged from 23 d to 30 d due to the toxicity of the high concentration of Mn2+. However, the mature granules with Mn2+ produced more protein and polysaccharides, and had a larger size (870 μm) than that without Mn2+ (740 μm). The extracellular polymeric substances of the granules in the two reactors had similar protein compositions, but some functional groups increased with Mn2+. The reactors showed high overall removal efficiency of chemical oxygen demand, NH4+-N, and total nitrogen with average concentrations below 40, 1.0, and 19 mg L-1, respectively, in the effluents. In one typical operating cycle, however, Mn2+ retarded nitrification and the degradation of aniline, while promoted denitrification. The microbial community analysis revealed that the growth of Terrisporobacter, Pseudomonas, and many other bacteria responsible for aniline degradation was inhibited by Mn2+, and so were the strains involved in nitrification. In contrast, Mn2+ facilitated the growth of denitrifying bacteria.
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Affiliation(s)
- Yu Jiang
- School of Civil Engineering, Wuhan University, Wuhan, 430072, China
| | - Yu Shang
- School of Civil Engineering, Wuhan University, Wuhan, 430072, China
| | - Tengjing Gong
- School of Civil Engineering, Wuhan University, Wuhan, 430072, China
| | - Zixin Hu
- School of Civil Engineering, Wuhan University, Wuhan, 430072, China
| | - Kai Yang
- School of Civil Engineering, Wuhan University, Wuhan, 430072, China
| | - Senlin Shao
- School of Civil Engineering, Wuhan University, Wuhan, 430072, China.
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108
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Zhang B, Li W, Guo Y, Zhang Z, Shi W, Cui F, Lens PNL, Tay JH. A sustainable strategy for effective regulation of aerobic granulation: Augmentation of the signaling molecule content by cultivating AHL-producing strains. WATER RESEARCH 2020; 169:115193. [PMID: 31670083 DOI: 10.1016/j.watres.2019.115193] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 10/05/2019] [Accepted: 10/13/2019] [Indexed: 06/10/2023]
Abstract
The positive roles of N-acyl homoserine lactone (AHL)-mediated quorum sensing (QS) in aerobic granular sludge (AGS) have been widely acknowledged. However, it is not feasible to manipulate granulation via direct addition of AHL chemicals or AHL-producing strains. Here, several strains with high AHL-producing capacity were successfully isolated from AGS. These QS strains were cultivated, mixed as a consortium, and then divided into two groups: AHLs supernatant and bacterial cells encapsulated in sodium alginate (CEBs). The potential of QS regulation, via doses of AHLs supernatant and CEBs, in accelerating granulation was evaluated. Results clearly indicated that short-term (days 21-70) addition of AHLs supernatant led to a rapid specific growth rate (0.08 d-1), compact structure without filamentous bacteria overgrowth, excellent settlement performance (SVI10 37.2 mL/g), and a high integrity coefficient (4.4%) of the granules. Sustainable release of AHLs (mainly C6- and C8-HSL) was induced by exogenous AHLs, possibly attributed to the enrichment of the genera Aeromonas and Pseudomonas. Further, tryptophan and aromatic protein substances were produced to maintain structural stability, suggesting that short-term QS regulation had long-term positive effects on the characteristics of AGS. By comparison, the addition of CEBs posed negligible or negative impact on the granulation, as evidenced by the rupture of smaller aggregates and poor characteristics of AGS. Overall, augmentation of the signaling content via addition of AHLs supernatant from QS strains is an economical and feasible regulation strategy to accelerate granulation and sustain long-term structural stability.
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Affiliation(s)
- Bing Zhang
- School of Environment, Harbin Institute of Technology, Harbin, 150090, China; Department of Civil Engineering, University of Calgary, Calgary, T2N 1N4, Canada
| | - Wei Li
- School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Yuan Guo
- School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Zhiqiang Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Wenxin Shi
- School of Environment and Ecology, Chongqing University, Chongqing, 400030, China.
| | - Fuyi Cui
- School of Environment and Ecology, Chongqing University, Chongqing, 400030, China.
| | - Piet N L Lens
- UNESCO-IHE Institute for Water Education, Westvest 7, 2601 DA, Delft, the Netherlands
| | - Joo Hwa Tay
- Department of Civil Engineering, University of Calgary, Calgary, T2N 1N4, Canada
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109
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Xu X, Ma B, Lu W, Feng D, Wei Y, Ge C, Peng Y. Effective nitrogen removal in a granule-based partial-denitrification/anammox reactor treating low C/N sewage. BIORESOURCE TECHNOLOGY 2020; 297:122467. [PMID: 31796378 DOI: 10.1016/j.biortech.2019.122467] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/13/2019] [Accepted: 11/17/2019] [Indexed: 06/10/2023]
Abstract
The partial-denitrification/anammox (PDA) process is a promising method to achieve mainstream anammox in wastewater treatment plants (WWTPs). To investigate the feasibility of developing a granule-based process for effective nitrogen removal via PDA, an upflow anaerobic sludge bed reactor was used as a PDA reactor treating low C/N sewage for over 200 days. Granules were formed with an average particle size of 1.92 mm. Metagenomic analysis revealed that the two most abundant genera in granules were Thauera (17.46%) and Candidatus Brocadia (6.24%) which played important roles in achieving partial-denitrification and anammox, respectively. Effective nitrogen removal was achieved with an average effluent TN concentration of 8.74 mg/L when influent TN concentration and COD/TN ratio were 42.56 mg/L and 1.52, respectively. Nitrogen removal via anammox accounted for 90% of dinitrogen production in the PDA reactor. Finally, a granule-based combined process of PDA with nitrification was proposed for achieving anammox in mainstream WWTPs.
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Affiliation(s)
- Xinxin Xu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
| | - Bin Ma
- School of Ecology and Environment, Hainan University, Haikou 570228, China; National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China.
| | - Wenkang Lu
- School of Ecology and Environment, Hainan University, Haikou 570228, China
| | - Dianbao Feng
- School of Ecology and Environment, Hainan University, Haikou 570228, China
| | - Yan Wei
- School of Ecology and Environment, Hainan University, Haikou 570228, China
| | - Chengjun Ge
- School of Ecology and Environment, Hainan University, Haikou 570228, China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
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110
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Czarnota J, Masłoń A, Zdeb M, Łagód G. The Impact of Different Powdered Mineral Materials on Selected Properties of Aerobic Granular Sludge. Molecules 2020; 25:molecules25020386. [PMID: 31963466 PMCID: PMC7024291 DOI: 10.3390/molecules25020386] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/09/2020] [Accepted: 01/15/2020] [Indexed: 12/05/2022] Open
Abstract
This study aimed to evaluate and compare the physical, chemical and biological properties of aerobic granular sludge from reactors with the addition of different powdered mineral materials. These properties have a significant impact on the efficiency of systems in which the biomass in granular form is used. Four identical granular sequencing batch reactors (GSBRs) were adopted for the research performed on a laboratory scale (R1—control reactor; R2, R3 and R4—with materials, PK, PG and PL respectively). The results indicate that the addition of powdered mineral materials improved the properties of biomass in reactors. The SVI5/SVI30 ratio values were significantly lower in the reactors with added materials (approx. 1.3 ± 0.3). The mean values of the sludge volume index at 30 min were the lowest in the R2 (39.8 ± 8.6 mL/g) and R4 (32.8 ± 10.7 mL/g) reactors. The settling velocity of biomass was the highest in the R2 reactor (15.4 ± 6.1 m/h). In the early days of the study, the highest extracellular polymeric substances (EPS) content was found in the biomass from the reactors to which the materials with higher Ca and Mg content were added (380.18–598.30 mg/g MLVSS). The rate of specific oxygen uptake (SOUR) by biomass indicated an insufficient biomass content in the R1 reactor—to 7.85 mg O2/(g MLVSS∙h)—while in the reactors with materials, the SOUR values were at the higher levels.
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Affiliation(s)
- Joanna Czarnota
- Department of Environmental Engineering and Chemistry, Rzeszow University of Technology, 6 Powstańców Warszawy Av, 35-959 Rzeszów, Poland;
- Correspondence: (J.C.); (G.Ł.); Tel.: +48-17-865-1278 (J.C.); +48-81-538-4322 (G.Ł.)
| | - Adam Masłoń
- Department of Environmental Engineering and Chemistry, Rzeszow University of Technology, 6 Powstańców Warszawy Av, 35-959 Rzeszów, Poland;
| | - Monika Zdeb
- Department of Water Purification and Protection, Rzeszow University of Technology, 6 Powstańców Warszawy Av, 35-959 Rzeszów, Poland;
| | - Grzegorz Łagód
- Faculty of Environmental Engineering, Lublin University of Technology, Nadbystrzycka 40B, 20-618 Lublin, Poland
- Correspondence: (J.C.); (G.Ł.); Tel.: +48-17-865-1278 (J.C.); +48-81-538-4322 (G.Ł.)
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111
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Xu J, Pang H, He J, Nan J, Wang M, Li L. Start-up of aerobic granular biofilm at low temperature: Performance and microbial community dynamics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 698:134311. [PMID: 31783455 DOI: 10.1016/j.scitotenv.2019.134311] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 09/04/2019] [Accepted: 09/04/2019] [Indexed: 06/10/2023]
Abstract
Low temperature is a great challenge for the biological treatment of wastewater. In this study, the rapid start-up of aerobic granular biofilm (AGF) reactor was realized by adding micro-sized polyurethane (PU) sponges as matrices at 10 °C. The results showed that the granulation process of AGF was different from that of traditional aerobic granular sludge and biofilms, which was formed by using the sludge intercepted in PU matrix instead of sponge skeletons as granulation carriers. During the 5-month operation period, stable pollutants removal performance was achieved within 70 days, besides, the corresponding ammonium, total nitrogen, and total phosphorus removal efficiencies were 98%, 70%, and 95%, respectively. The addition of PU matrices inhibited the growth of filamentous bacteria and provided support for high structural stability of AGF. With the operation of the reactor, the relative abundance of traditional denitrifying bacteria (genera Thauera and Acidovorax, etc.) decreased gradually, and the putative denitrifying phosphorus accumulating genus, Dechloromonas, occupied a dominant position in the system. This experiment showed that AGF system could be successfully started-up and operated with efficient pollutants removal performance under low temperature when using micro-sized PU sponges as matrices.
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Affiliation(s)
- Jie Xu
- School of Environment, Harbin Institute of Technology (HIT), Harbin 150090, China.
| | - Heliang Pang
- School of Environment, Harbin Institute of Technology (HIT), Harbin 150090, China
| | - Junguo He
- School of Civil Engineering, Guangzhou University, Guangzhou 510006, China
| | - Jun Nan
- School of Environment, Harbin Institute of Technology (HIT), Harbin 150090, China
| | - Mengfei Wang
- School of Environment, Harbin Institute of Technology (HIT), Harbin 150090, China
| | - Lin Li
- School of Environment, Harbin Institute of Technology (HIT), Harbin 150090, China
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112
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Zhang L, Long B, Wu J, Cheng Y, Zhang B, Zeng Y, Huang S, Zeng M. Evolution of microbial community during dry storage and recovery of aerobic granular sludge. Heliyon 2019; 5:e03023. [PMID: 31890963 PMCID: PMC6926229 DOI: 10.1016/j.heliyon.2019.e03023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/18/2019] [Accepted: 12/06/2019] [Indexed: 12/15/2022] Open
Abstract
Aerobic granular sludge (AGS) was imbedded in agar and stored at 4 °C for 30 days, and then the stored granules were recovered in a sequencing batch reactor fed real wastewater within 11 days. Variations in microbial community compositions were investigated during dry storage and recovery of AGS, aiming to elucidate the mechanism of granular stability loss and recovery. The storage and recovery of AGS involved microbial community evolution. The dominant bacterial genera of the mature AGS were Zoogloea (relative abundance of 22.39%), Thauera (16.03%) and Clostridium_sensu_stricto (11.17%), and those of the stored granules were Acidovorax (26.79%), Macellibacteroides (12.83%) and Pseudoxanthomonas (5.69%), respectively. However, the dominant genera were Streptococcus (43.64%), Clostridium_sensu_stricto (12.3.6%) and Lactococcus (11.47%) in the recovered AGS. Methanogens were always the dominant archaeal species in mature AGS (93.01%), stored granules (99.99%) and the recovered AGS (94.84%). Facultative anaerobes and anaerobes proliferated and dominated in the stored granules, and their metabolic activities gradually led to granular structure destruction and property deterioration. However, the stored granules served as carriers for the microbes originated from the real septic tank wastewater during recovery. They proliferated rapidly and secreted a large number of extracellular polymeric substances which helped to recover the granular structure in 11 days.
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Affiliation(s)
- Linan Zhang
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave. 86, Ganzhou, 341000, Jiangxi, China
| | - Bei Long
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave. 86, Ganzhou, 341000, Jiangxi, China
| | - Junfeng Wu
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Mingyue Road, Pingdingshan, 467036, Henan, China
| | - Yuanyuan Cheng
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave. 86, Ganzhou, 341000, Jiangxi, China
| | - Binchao Zhang
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave. 86, Ganzhou, 341000, Jiangxi, China
| | - Yu Zeng
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave. 86, Ganzhou, 341000, Jiangxi, China
| | - Sinong Huang
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave. 86, Ganzhou, 341000, Jiangxi, China
| | - Mingjing Zeng
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave. 86, Ganzhou, 341000, Jiangxi, China
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113
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He Q, Zhang J, Gao S, Chen L, Lyu W, Zhang W, Song J, Hu X, Chen R, Wang H, Yu J. A comprehensive comparison between non-bulking and bulking aerobic granular sludge in microbial communities. BIORESOURCE TECHNOLOGY 2019; 294:122151. [PMID: 31557652 DOI: 10.1016/j.biortech.2019.122151] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/08/2019] [Accepted: 09/12/2019] [Indexed: 06/10/2023]
Abstract
Filamentous sludge bulking poses great threats to operational stability of aerobic granular sludge. Exploration of the microbial community aids knowledge of the causative factors to sludge bulking and guides directions for corresponding actions for prevention and controlling. Detailed changes of bacterial community within the non-bulking and bulking were performed and compared with a non-specific method through 1‰ (v/v) hydrogen peroxide (H2O2) addition. Results revealed that non-bulking/bulking granules maintained effective carbon and nitrogen removal, while bulking completely deteriorated enhanced biological phosphorus removal (EBPR). Excess extracellular polymeric substances (EPS) especially polysaccharide (PS) were directly linked with sludge bulking and abundant PS contributed to subsequent granular re-stability. Filamentous bulking dramatically altered the bacterial populations and 1‰ H2O2 effectively controlled bulking by eliminating causative filaments Singulisphaera and Thiothrix. Together, this study provides new insights into the non-bulking/bulking granules and could direct the prevention and control of filamentous bulking in aerobic granules.
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Affiliation(s)
- Qiulai He
- Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha 410082, China.
| | - Jing Zhang
- School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430072, China
| | - Shuxian Gao
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Li Chen
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Wanlin Lyu
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Wei Zhang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Jianyang Song
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Xiaoling Hu
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Rongfan Chen
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Hongyu Wang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Jian Yu
- Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha 410082, China
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114
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Lee YJ, Lei Z. Microalgal-bacterial aggregates for wastewater treatment: A mini-review. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.biteb.2019.100199] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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115
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Strengthening of aerobic sludge granulation by the endogenous acylated homoserine lactones-secreting strain Aeromonas sp. A-L3. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.107329] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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116
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Zhang C, Li L, Wang Y, Hu X. Enhancement of the ANAMMOX bacteria activity and granule stability through pulsed electric field at a lower temperature (16 ± 1 °C). BIORESOURCE TECHNOLOGY 2019; 292:121960. [PMID: 31437798 DOI: 10.1016/j.biortech.2019.121960] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/01/2019] [Accepted: 08/04/2019] [Indexed: 06/10/2023]
Abstract
The effects of different frequencies of pulsed electric field (PEF) on the ANAMMOX process were investigated. The results showed that the intermediate frequency could dramatically enhance both the ANAMMOX bacterial activity and granule sludge stability at 16 ± 1 °C The nitrogen removal efficiency of R1 (intermediate frequency) was significantly enhanced by 62.24% and 79.51% compared to R2 (lower frequency) and R3 (higher frequency), with a nitrogen loading rate of 6.84 kg Nm-3 d-1. In addition, the intermediate frequency could stimulate cells to secrete more extracellular polymeric substances (EPS) to sustain the granule sludge stability. The granule sludge disintegrated on days 55 and 35 in R2 and R3. The protein (PN)/polysaccharide (PS) ratios of R1 were 28.46% and 54.20% higher than R2 and R3, which was beneficial to granule sludge stability. This study showed that PEF could solve the problem of decreased ANAMMOX bacterial activity and granule stability at lower temperatures.
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Affiliation(s)
- Chi Zhang
- School of Resources & Civil Engineering, Northeastern University, Shenyang 110819, PR China; Key Lab of Eco-restoration of Regional Contaminated Environment (Shenyang University) Ministry of Education, PR China
| | - Liang Li
- School of Resources & Civil Engineering, Northeastern University, Shenyang 110819, PR China; Key Lab of Eco-restoration of Regional Contaminated Environment (Shenyang University) Ministry of Education, PR China
| | - Yujia Wang
- Shenyang JianZhu Univ, Sch Municipal & Environm Engn, Shenyang 110168, PR China
| | - Xiaomin Hu
- School of Resources & Civil Engineering, Northeastern University, Shenyang 110819, PR China.
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117
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Yin Y, Liu F, Wang L, Sun J. Overcoming the instability of aerobic granular sludge under nitrogen deficiency through shortening settling time. BIORESOURCE TECHNOLOGY 2019; 289:121620. [PMID: 31229861 DOI: 10.1016/j.biortech.2019.121620] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/02/2019] [Accepted: 06/05/2019] [Indexed: 06/09/2023]
Abstract
This study investigated the short settling time strategy to overcome the instability of aerobic granular sludge (AGS) under nitrogen deficiency. AGS variations in its physical and chemical characteristics and microbial community were investigated. Results showed that nitrogen deficiency led to the instability of AGS, while short settling time strategy could overcome the instability of AGS under nitrogen deficiency. Extracellular polymeric substances (EPS), especially, the increased secretion of polysaccharide and proteins with amide III groups at the short settling time enhanced the stability of the granules under nitrogen deficiency. Unclassified_f_Microbacteriaceae shifted to be the major bacteria group at short settling time, along with the decrease of Meganema and Rhodobacter and the increase of Lysobacter, which may play an important role in enhancing AGS stability. Therefore, shortening settling time supports an effective strategy for applications of AGS under nitrogen deficiency.
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Affiliation(s)
- Yunjun Yin
- School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, China.
| | - Fengyuan Liu
- School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, China
| | - Lu Wang
- Development Research Center of the Ministry of Water Resources of P.R. China, Beijing 100038, China
| | - Jian Sun
- School of Civil and Architecture Engineering, Xi'an Technological University, Xi'an 710021, China
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118
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Ouyang J, Li C, Zhang G, Wei D, Wei L, Chang CC. Activated sludge and other aerobic suspended culture processes. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2019; 91:992-1000. [PMID: 31220385 DOI: 10.1002/wer.1164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 06/12/2019] [Indexed: 06/09/2023]
Abstract
The fields in the process model of activated sludge, the characteristics and species of microbial communities, dynamics and mechanism in the process, the influence of different xenobiotics on activated sludge, anaerobic digestion on waste activated sludge, and design and operation for activated sludge are reviewed in 2018. Contrast with the past reviews, several new highlights such as waste activated sludge treatment, antibiotic and heavy-metal xenobiotic, and pretreatment for anaerobic digestion are mentioned in 2018, which indicated that the research tendency of activated sludge from wastewater treatment to waste sludge treatment in the retrieved literature is developing. PRACTITIONER POINTS: None.
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Affiliation(s)
- Jia Ouyang
- Guangzhou HKUST Fok Ying Tung Research Institute, Guangzhou, China
| | - Chunying Li
- School of Energy and Civil Engineering, Harbin University of Commerce, Harbin, China
| | - Guocai Zhang
- College of Forestry, Northeast Forestry University, Harbin, China
| | - Dong Wei
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, China
| | - Li Wei
- Guangzhou HKUST Fok Ying Tung Research Institute, Guangzhou, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, China
| | - Chein-Chi Chang
- Department of Engineering and Technical Services, DC Water and Sewer Authority, Washington, District of Columbia, USA
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119
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Khan MF, Yu L, Tay JH, Achari G. Coaggregation of bacterial communities in aerobic granulation and its application on the biodegradation of sulfolane. JOURNAL OF HAZARDOUS MATERIALS 2019; 377:206-214. [PMID: 31163349 DOI: 10.1016/j.jhazmat.2019.05.076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/09/2019] [Accepted: 05/26/2019] [Indexed: 06/09/2023]
Abstract
Aerobic granulation is regarded as the future technology for wastewater treatment that can replace conventional activated sludge. In this study, two approaches of forming sulfolane degrading aerobic granules (SDAG) were successfully developed and evaluated. These include adaptation of pre-grown granules to sulfolane environment and coaggregation of pre-grown granules with bacterial culture native to sulfolane contaminated site. The adaption method required a longer period to form robust SDAG compared to coaggregation method where degradation of sulfolane was observed within 24 h. Electronic images revealed dominant filamentous bacteria on the surface of granules while DNA analysis unveiled the complexity of the dynamic change of microbial community during aerobic granule formation. The rate of sulfolane degradation by coaggregated granules reduced as the concentration of carbon source increased, nevertheless, the rate increased with increased biomass. In addition, the presence of co-contaminants can slightly impact the ability of newly cultivated granules to degrade sulfolane. Finally, the stability and settleability of the new aerobic granules was investigated under different environmental conditions. About 30% of the aerobic granules were lost after 14 d of operation without any continuous supply of carbon sources. The surviving SDAGs continued to display an intact structure coupled with good settleability.
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Affiliation(s)
- Muhammad Faizan Khan
- Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Linlong Yu
- Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Joo Hwa Tay
- Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Gopal Achari
- Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
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120
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Sharaf A, Guo B, Liu Y. Impact of the filamentous fungi overgrowth on the aerobic granular sludge process. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.biteb.2019.100272] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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121
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Cao S, Peng Y, Du R, Zhang H. Characterization of partial-denitrification (PD) granular sludge producing nitrite: Effect of loading rates and particle size. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 671:510-518. [PMID: 30933806 DOI: 10.1016/j.scitotenv.2019.03.380] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/09/2019] [Accepted: 03/24/2019] [Indexed: 06/09/2023]
Abstract
The granule-based partial-denitrification (PD) reactor can achieve an efficient nitrite production for anammox process. In this study, the PD granules were successfully cultivated in a sequencing batch reactor (SBR), the physicochemical properties and microbial activities were characterized at increasing nitrate loading rate (NLR). Results indicated that high NLR benefited the PD for nitrite production, and a more dense and compact granule can be developed at the NLR of 0.24-0.48 Kg N/m3/d. Whereas the settling ability decreased when the NLR increased to 0.96 Kg N/m3/d, which was likely caused by the decrease of proteins (PN) in extracellular polymeric substances (EPS) content and the increase of loosely bound EPS (L-EPS) fraction. Besides, the characterization of size-fractionated PD granules revealed that a better settling ability was generally obtained with larger granules except for the size of d > 3.35 mm, which the settling velocity was reduced, likely attributed to the excess L-EPS fraction (56.3%) and presence of empty capsule inside granules. The smaller granules exhibited higher microbial activities due to the favorable mass transfer, the nitrate reduction rate was as high as 152.6 mg N/h/g VSS with granules of d < 1.0 mm. Results obtained in this study provided a better understanding of the properties of PD granules and would be helpful for the future development of granule-based PD reactor in achieving an efficient and stable nitrite production.
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Affiliation(s)
- Shenbin Cao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore, 637141, Singapore
| | - Yongzhen Peng
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering and Technology Research Center of Beijing, Beijing University of Technology, Beijing 100124, China.
| | - Rui Du
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering and Technology Research Center of Beijing, Beijing University of Technology, Beijing 100124, China
| | - Hanyu Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering and Technology Research Center of Beijing, Beijing University of Technology, Beijing 100124, China
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122
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Long B, Xuan X, Yang C, Zhang L, Cheng Y, Wang J. Stability of aerobic granular sludge in a pilot scale sequencing batch reactor enhanced by granular particle size control. CHEMOSPHERE 2019; 225:460-469. [PMID: 30889409 DOI: 10.1016/j.chemosphere.2019.03.048] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 02/22/2019] [Accepted: 03/09/2019] [Indexed: 06/09/2023]
Abstract
Aerobic granulation was successfully achieved in a pilot scale sequencing batch reactor within 40 days. Then, stability of different particle size granules was explored according to their activity and resistance to ultrasonic crushing. Different particle size granules (0.3-0.6 mm, 0.6-1 mm, 1-1.43 mm, 1.43-2 mm, 2-3 mm and 3-4 mm) were exposed under different ultrasonic power separately. It was found that the granules with 2-3 mm always had the maximum granulation rates after ultrasonic crushing. Meanwhile, activity data showed that the 2-3 mm granules had the lowest specific oxygen utilization rates, which indicated that they were easier to maintain stability as the increase of their particle sizes was the slowest. So, 500 mL mixed liquid of the reactor were taken out and sieved to obtain the 2-3 mm granules, which were subsequently returned to the reactor to increase their proportion. Through the manual regulation, the proportion of 2-3 mm granules kept increasing which gradually became dominant in the reactor. Under the strategy of 86 days of operation, the aerobic granules were regular and compact, which had good removal effects of the real wastewater. The results indicated that the stability of the system could be greatly enhanced by the method, which provided a new strategy to maintain the granular stability.
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Affiliation(s)
- Bei Long
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave.86, Ganzhou, 341000, Jiangxi, China
| | - Xinpeng Xuan
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave.86, Ganzhou, 341000, Jiangxi, China
| | - Changzhu Yang
- College of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074, Wuhan, China.
| | - Linan Zhang
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave.86, Ganzhou, 341000, Jiangxi, China
| | - Yuanyuan Cheng
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave.86, Ganzhou, 341000, Jiangxi, China
| | - Jianqi Wang
- School of Architectural and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Hongqi Ave.86, Ganzhou, 341000, Jiangxi, China
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123
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Cai W, Huang W, Lei Z, Zhang Z, Lee DJ, Adachi Y. Granulation of activated sludge using butyrate and valerate as additional carbon source and granular phosphorus removal capacity during wastewater treatment. BIORESOURCE TECHNOLOGY 2019; 282:269-274. [PMID: 30875594 DOI: 10.1016/j.biortech.2019.03.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 03/03/2019] [Accepted: 03/04/2019] [Indexed: 06/09/2023]
Abstract
As an efficient and low-cost phosphorus (P) removal method from wastewater, enhanced biological phosphorus removal process always faces the insufficient carbon source issue. In this study, two identical sequencing batch reactors were used to cultivate aerobic granular sludge, in which butyrate (Rb) and valerate (Rv), two major volatile fatty acids that can be produced from anaerobic fermentation of waste biomass, were respectively applied as additional carbon source. Both reactors exhibited almost same excellent organics and total nitrogen removals during 120 days' operation, about 95.2-95.7% and 67.9-68.0% respectively with noticeable difference in P removal. Compared to the granules in Rv (24.3 mg P/g-total solids), bigger and more stable ones with higher P removal capacity (11.5 mg P/g-volatile solids∙d) were finally achieved in Rb, containing higher P content (36.0 mg P/g-total solids) with more orthophosphate and polyphosphate accumulated. Microbial community analysis reflected more polyphosphate-accumulating organisms (Rhodocyclus-related bacteria and Actinobacteria) in the granules from Rb.
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Affiliation(s)
- Wei Cai
- College of Biological and Agricultural Engineering, Jilin University, Changchun 130022, China; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Wenli Huang
- MOE Key Laboratory of Pollution Process and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
| | - Zhongfang Lei
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
| | - Zhenya Zhang
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Yasuhisa Adachi
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
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124
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Zhang S, He Z, Meng F. Floc-size effects of the pathogenic bacteria in a membrane bioreactor plant. ENVIRONMENT INTERNATIONAL 2019; 127:645-652. [PMID: 30991220 DOI: 10.1016/j.envint.2019.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 03/29/2019] [Accepted: 04/01/2019] [Indexed: 06/09/2023]
Abstract
The size nature of sludge flocs could affect the occurrence and distribution of bacterial pathogens in wastewater treatment plants (WWTPs). In this study, the floc-size dependence of bacterial pathogens in the activated sludge of a WWTP was investigated using high-throughput metagenomic sequencing approaches. The results showed that a total of 423 pathogenic species belonging to 123 genera were identified in the three size-fractionated flocs. Also, we found that all the pathogens on the WHO's global priority pathogens list were detected in the size-fractionated flocs, with relative abundance of 0.4%, 0.3% and 0.3% for large-size, medium-size and small-size flocs, respectively, indicating the severe human and environmental health risks of activated sludge. Importantly, our results revealed that the pathogenic species showed a clear floc-size dependent distribution manner, leading to significant differences (P < 0.05) of pathogenic communities among the size-fractionated flocs. Additionally, by partitioning pathogens based on the occurrence and significant difference in abundances, we suggested the following distribution features: 1) large flocs-associated pathogens, such as Borrelia recurrentis, Actinobacillus ureae and Campylobacter gracilis; 2) medium flocs-associated pathogens, such as Mycobacterium szulgai and Ureaplasma urealyticum; and 3) small flocs-associated pathogens, such as Rickettsia akari, Staphylococcus anginosus and Helicobacter cinaedi. Overall, this study provides a comprehensive understanding of pathogens in activated sludge, which is expected to aid in assessment and management of pathogen risks.
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Affiliation(s)
- Shaoqing Zhang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Zhili He
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, PR China; College of Agronomy, Hunan Agricultural University, Changsha 410128, PR China
| | - Fangang Meng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, PR China.
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125
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Kang D, Xu D, Yu T, Feng C, Li Y, Zhang M, Zheng P. Texture of anammox sludge bed: Composition feature, visual characterization and formation mechanism. WATER RESEARCH 2019; 154:180-188. [PMID: 30797126 DOI: 10.1016/j.watres.2019.01.052] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 12/17/2018] [Accepted: 01/20/2019] [Indexed: 06/09/2023]
Abstract
Anammox granular sludge biotechnology has been successfully applied in the environmental engineering for nitrogen removal from wastewater. However, the startup and control of anammox process was difficult and lacks an easy-recognized indicator. In this work, the texture of anammox sludge bed in a long-term (>15 months) stable-operated and high-rate anammox reactor was investigated for the first time. The results showed that the anammox sludge bed took on the unique texture which was closely related to the biological loading rates of sludge bed at different heights of the reactor. The texture was ascribed to the pattern created by granule gradation (granules size distribution) and granule number density (spaces between granules). The sludge bed texture displayed the distinctive vision and could be characterized by the reflected light of sludge bed. The lightness indicator was found to have an excellent linear relationship with the height of anammox sludge bed. The texture of anammox sludge bed was revealed to originate from the periodic cycle of gas-driven segregation and density-based aggregation of granules. The results hint at a convenient and efficient strategy for operators to assess and control the working state of anammox system.
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Affiliation(s)
- Da Kang
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Dongdong Xu
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Tao Yu
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Chengdong Feng
- State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai, China
| | - Yiyu Li
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Meng Zhang
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China; Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, Singapore
| | - Ping Zheng
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China.
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126
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Jiang Y, Yang K, Shang Y, Zhang H, Wei L, Wang H. Response and recovery of aerobic granular sludge to pH shock for simultaneous removal of aniline and nitrogen. CHEMOSPHERE 2019; 221:366-374. [PMID: 30641378 DOI: 10.1016/j.chemosphere.2018.12.207] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 11/22/2018] [Accepted: 12/31/2018] [Indexed: 06/09/2023]
Abstract
Considering the pH fluctuation in industrial wastewater, the response and resilience to pH shock should be investigated during aerobic granular sludge (AGS) system operation. In this work, three AGS reactors, namely R1, R2, and R3 for simultaneous removal of aniline and nitrogen were exposed to neutral, acidic, and alkaline conditions, respectively. The removal efficiency of aniline and chemical oxygen demand with pH variation was over 99.9% and 91.0%, respectively after stable in the three reactors. The aniline removal rate modestly decreased in R2 and R3 after pH varied and denitrification was slightly improved in acidic environment with average removal efficiency of 61.2%. The mature AGS could maintain settleability in R1 and R2 with 30 min sludge volume index below 35 mL g-1 but was unstable under alkaline condition. Correspondingly, the secretion of extracellular polymeric substances especially protein decreased notably in R3. The bacterial groups varied with pH shock, but some could recover after adjustment to original pH value. Proteobacteria was the predominant phylum in the three reactors and Bacteroidetes was enriched in alkaline conditions. In addition, the main functional genera such as Achromobacter, Defluviimonas, Enterobacter, Pseudomonas, and Pseudoxanthomonas, were detected in the system and were found to be responsible for reduction of aniline and nitrogen.
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Affiliation(s)
- Yu Jiang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Kai Yang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Yu Shang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Huining Zhang
- School of Civil Engineering, Lanzhou University of Technology, Lanzhou 730000, China
| | - Li Wei
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Hongyu Wang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China.
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127
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Wang XC, Chen ZL, Kang J, Zhao X, Shen JM, Yang L. The key role of inoculated sludge in fast start-up of sequencing batch reactor for the domestication of aerobic granular sludge. J Environ Sci (China) 2019; 78:127-136. [PMID: 30665631 DOI: 10.1016/j.jes.2018.08.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/28/2018] [Accepted: 08/29/2018] [Indexed: 06/09/2023]
Abstract
Two types of inoculated sludges, granular sludge that had been stored at -20°C and activated sludge, were investigated for the domestication of aerobic granular sludges (AGSs) in sequencing batch reactors (SBRs). The results showed that using the stored granular sludge as inoculation sludge could effectively shorten the domestication time of AGS and yielded mature granular sludge after 22 days of operation. The AGS domesticated by stored granular sludge had better biomass and sedimentation properties; its MLSS and SVI reached 8.55 g/L and 35.27 mL/g, respectively. The removal efficiencies for chemical oxygen demand (COD), ammonium nitrogen (NH4+-N) and total phosphorus (TP) reached 90.76%, 97.39% and 96.40%, respectively. By contrast, 54 days were needed to obtain mature granules using activated sludge. The microbial community structure was probed by using scanning electron microscopy (SEM) and high-throughput sequencing. The results showed that the diversity of the microbial community in mature granules was reduced when stored granular sludge rather than activated sludge was employed as inoculation sludge, and the dominant microbes were changed. The dominant species in mature granules domesticated using stored granular sludge were Zoogloea, Acidovorax and Tolumonas at the genus classification level, while the dominant species were Zoogloea and TM7-genera in granules developed from activated sludge.
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Affiliation(s)
- Xiao-Chun Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Zhong-Lin Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jing Kang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Xia Zhao
- College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050, China
| | - Ji-Min Shen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Liu Yang
- College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050, China
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128
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Rollemberg SLDS, de Oliveira LQ, Barros ARM, Melo VMM, Firmino PIM, Dos Santos AB. Effects of carbon source on the formation, stability, bioactivity and biodiversity of the aerobic granule sludge. BIORESOURCE TECHNOLOGY 2019; 278:195-204. [PMID: 30703637 DOI: 10.1016/j.biortech.2019.01.071] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/14/2019] [Accepted: 01/18/2019] [Indexed: 06/09/2023]
Abstract
Three aerobic granular sludge systems were operated as sequencing batch reactors (SBR) with acetate, ethanol and glucose as carbon source. The SBR cycle was 6 h, with an anaerobic phase followed by an aerobic phase. The acetate granules (>1.5 mm) had the greatest microbial diversity and better results in terms of removal efficiency for carbon and nutrients (TN ≈ 72% and TP ≈ 42%) and also in the resistance tests. However, partial disintegration was observed. On the other hand, when ethanol was the substrate, the granules were stable, good nitrogen removal was achieved (TN ≈ 53%), but phosphorus removal was not favored (TP ≈ 31%). Glucose presented the lowest efficiency values for nitrogen (TN ≈ 44%) and phosphorous removal (TP ≈ 21%), and the granules formed (<1 mm) had the lowest microbial diversity. Therefore, the carbon source had a high impact on the characteristics of the granules.
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Affiliation(s)
| | - Lorayne Queiroz de Oliveira
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | | | | | - Paulo Igor Milen Firmino
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - André Bezerra Dos Santos
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil.
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129
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Yin Y, Sun J, Liu F, Wang L. Effect of nitrogen deficiency on the stability of aerobic granular sludge. BIORESOURCE TECHNOLOGY 2019; 275:307-313. [PMID: 30594841 DOI: 10.1016/j.biortech.2018.12.069] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/16/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
To assess the stability of aerobic granular sludge (AGS) under nitrogen deficiency conditions, three sequence batch reactors were operated with chemical oxygen demand (COD) to nitrogen (N) ratios of 100/5, 100/2.5, and 100/2, while COD concentration was kept consistent. AGS variations in its physicochemical characteristics, microbial community, and treatment performance were investigated. The results indicated that good treatment performance and stable AGS were achieved under nitrogen deficiency. Extracellular polymeric substances (EPS) regulating mechanism preserved AGS stability under nitrogen deficiency, especially through increased secretion of polysaccharide. In addition, members of the Anaerolineaceae were the major filamentous bacteria, which are strictly anaerobic organism, providing a possible explanation to the lack of filamentous bacteria outgrowth under N deficient condition. Insights from this study could help lower chemical costs in AGS applications for specific industrial wastewater treatments.
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Affiliation(s)
- Yunjun Yin
- School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, China.
| | - Jian Sun
- School of Civil and Architecture Engineering, Xi'an Technological University, Xi'an 710021, China
| | - Fengyuan Liu
- School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, China
| | - Lu Wang
- Development Research Center of the Ministry of Water Resources of P.R. China, Beijing 100038, China
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130
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Guo Y, Zhang B, Zhang Z, Shi W, Zhang R, Cheng J, Li W, Cui F. Enhanced aerobic granulation by applying the low-intensity direct current electric field via reactive iron anode. WATER RESEARCH 2019; 149:159-168. [PMID: 30439579 DOI: 10.1016/j.watres.2018.10.095] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 10/12/2018] [Accepted: 10/31/2018] [Indexed: 06/09/2023]
Abstract
A novel granulation strategy by applying the low-intensity direct current (DC) electric field via reactive iron anode into the aerobic granular sludge (AGS) system was systematically investigated in this study. Three identical sequencing batch reactors (SBRs, namely R1, R2, and R3) were operated for 100 days. Comparatively, the R1 and R3 were continuously subjected to the 1.0 V DC electric field via a reactive Fe anode and an inert Ti-Ir/Rh anode, respectively, while the R2 without DC exposure. The results showed that the sludge granulation processes were accelerated in order as follows: R2<R3<R1, and the properties of mature granules were improved in order as follows: R3<R2<R1. Interestingly, at the end of experiment, total phosphorus (TP) removal efficiency in R1 dramatically increased to 80.52%, which was 2.15 and 1.96 folds than that in R2 and R3, respectively. Further investigations revealed that this novel strategy could simultaneously improve the secretion of EPS and the release of iron ions in R1, which cooperatively enhanced the granulation process. Moreover, in R1, mineral precipitation of phosphate remarkably improved the capability of phosphorus removal. The observed effective and stable performance highlights the feasibility and potential of this novel strategy for the rapid start-up and stable operation of AGS system.
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Affiliation(s)
- Yuan Guo
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Bing Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Zhiqiang Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Wenxin Shi
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China; College of Urban Construction and Environmental Engineering, Chongqing University, Chongqing, 400044, China.
| | - Ruijun Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jun Cheng
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Weiguang Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Fuyi Cui
- College of Urban Construction and Environmental Engineering, Chongqing University, Chongqing, 400044, China.
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131
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Zhou JH, Zhou YC, Yu HC, Zhao YQ, Ye KQ, Fang JY, Wang HY. Determining the effects of aeration intensity and reactor height to diameter (H/D) ratio on granule stability based on bubble behavior analysis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:784-796. [PMID: 30415362 DOI: 10.1007/s11356-018-3666-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
Aerobic granular sludge was considered as a leading wastewater technology in the next century. However, the loss of granule stability limited the application of this promising biotechnology. Increasing aeration intensity and height to diameter (H/D) ratio were conventional strategies to enhance granule stability. In this study, hydraulic effects of aeration intensity and H/D ratio were explored basing on bubble behavior analysis. However, results revealed that due to viscous resistance, increasing aeration intensity and H/D ratio had limited effects on enhancing hydraulic shear stress, not to mention the extra operation and construction cost. A deflector component was further applied to regulate hydraulic shear stress on large granules under low aeration intensity and H/D ratio. Hydraulic shear stress of large granules was constantly around 3.0 times higher than that in the conventional reactor, resulting in higher percentage of granules within optimal size range (81.95 ± 5.13%). A high abundance of denitrifying bacteria was observed in reactors, which led to high TN removal efficiency of 88.6 ± 3.8%.
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Affiliation(s)
- Jia Heng Zhou
- College of Civil Engineering and Architecture, Zhejiang University of Technology, No. 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| | - Yun Cheng Zhou
- College of Civil Engineering and Architecture, Zhejiang University of Technology, No. 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| | - Hao Cheng Yu
- College of Civil Engineering and Architecture, Zhejiang University of Technology, No. 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| | - Yi Qun Zhao
- College of Civil Engineering and Architecture, Zhejiang University of Technology, No. 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| | - Kai Qiang Ye
- College of Civil Engineering and Architecture, Zhejiang University of Technology, No. 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| | - Jing Yuan Fang
- College of Civil Engineering and Architecture, Zhejiang University of Technology, No. 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| | - Hong Yu Wang
- College of Civil Engineering and Architecture, Zhejiang University of Technology, No. 18 Chaowang Road, Hangzhou, 310014, People's Republic of China.
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132
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Zaghloul MS, Hamza RA, Iorhemen OT, Tay JH. Performance prediction of an aerobic granular SBR using modular multilayer artificial neural networks. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 645:449-459. [PMID: 30025244 DOI: 10.1016/j.scitotenv.2018.07.140] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/10/2018] [Accepted: 07/11/2018] [Indexed: 06/08/2023]
Abstract
Aerobic granulation is a complex process that, while proven to be more effective than conventional treatment methods, has been a challenge to control and maintain stable operation. This work presents a static data-driven model to predict the key performance indicators of the aerobic granulation process. The first sub-model receives influent characteristics and granular sludge properties. These predicted parameters then become the input for the second sub-model, predicting the effluent characteristics. The model was developed with a dataset of 2600 observations and evaluated with an unseen dataset of 286 observations. The prediction R2 and RMSE were >99% and <5% respectively for all predicted parameters. The results of this paper show the effectiveness of data-driven models for simulating the complex aerobic granulation process, providing a great tool to help in predicting the behaviour, and anticipating failures in aerobic granular reactors.
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Affiliation(s)
- Mohamed Sherif Zaghloul
- Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB., Canada. T2N 1N4.
| | - Rania Ahmed Hamza
- Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB., Canada. T2N 1N4.
| | - Oliver Terna Iorhemen
- Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB., Canada. T2N 1N4.
| | - Joo Hwa Tay
- Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB., Canada. T2N 1N4.
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133
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Liu S, Zhan H, Xie Y, Shi W, Wang S. Rapid cultivation of aerobic granular sludge by xanthan gum in SBR reactors. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2018; 2017:360-369. [PMID: 29851388 DOI: 10.2166/wst.2018.151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This study focuses on the effect of xanthan gum on aerobic sludge granulation, through close monitoring of the physical and chemical changes of the aerobic granular sludge, and treatment performance. Two sequencing batch reactors (SBRs), R1 and R2, were seeded with activated sludge only (R1) and with a mixture of activated sludge and 40 mg/L of xanthan gum (R2). The results showed that granulation finished on the 20th day in R2, far faster than the granulation time of 30 days in R1. Meanwhile, there was a reliably higher sludge concentration, better settling properties and better particle mechanical strength in R2, and better removal performance of total nitrogen (TN) and chemical oxygen demand (COD). The results demonstrated that seeding xanthan gum enhanced the aerobic sludge granulation in the SBR. Maybe its anionic and hydrophilic surface characteristics facilitate interactions with cations and other polysaccharides, inducing stronger gelation, which promoted the formation of particles or increased the internal relationship between particles, thereby increasing the cohesion within the sludge, so that the granular sludge was not easily broken.
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Affiliation(s)
- Sha Liu
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, China E-mail:
| | - Hanhui Zhan
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, China E-mail:
| | - Yaqi Xie
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, China E-mail:
| | - Weijiang Shi
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, China E-mail:
| | - Siming Wang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, China E-mail:
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134
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Wilén BM, Liébana R, Persson F, Modin O, Hermansson M. The mechanisms of granulation of activated sludge in wastewater treatment, its optimization, and impact on effluent quality. Appl Microbiol Biotechnol 2018; 102:5005-5020. [PMID: 29705957 PMCID: PMC5960003 DOI: 10.1007/s00253-018-8990-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 12/14/2022]
Abstract
Granular activated sludge has gained increasing interest due to its potential in treating wastewater in a compact and efficient way. It is well-established that activated sludge can form granules under certain environmental conditions such as batch-wise operation with feast-famine feeding, high hydrodynamic shear forces, and short settling time which select for dense microbial aggregates. Aerobic granules with stable structure and functionality have been obtained with a range of different wastewaters seeded with different sources of sludge at different operational conditions, but the microbial communities developed differed substantially. In spite of this, granule instability occurs. In this review, the available literature on the mechanisms involved in granulation and how it affects the effluent quality is assessed with special attention given to the microbial interactions involved. To be able to optimize the process further, more knowledge is needed regarding the influence of microbial communities and their metabolism on granule stability and functionality. Studies performed at conditions similar to full-scale such as fluctuation in organic loading rate, hydrodynamic conditions, temperature, incoming particles, and feed water microorganisms need further investigations.
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Affiliation(s)
- Britt-Marie Wilén
- Division of Water Environment Technology, Department of Architecture and Civil and Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
| | - Raquel Liébana
- Division of Water Environment Technology, Department of Architecture and Civil and Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Frank Persson
- Division of Water Environment Technology, Department of Architecture and Civil and Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Oskar Modin
- Division of Water Environment Technology, Department of Architecture and Civil and Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Malte Hermansson
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden
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