1
|
Rui D, Liu K, Ma Y, Huang K, Chen M, Wu F, Zhang X, Ye L. Pilot-scale investigation of performance and microbial community in a novel system combining fixed and suspended activated sludge. ENVIRONMENTAL RESEARCH 2024; 246:118141. [PMID: 38191046 DOI: 10.1016/j.envres.2024.118141] [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: 12/20/2023] [Accepted: 01/05/2024] [Indexed: 01/10/2024]
Abstract
The conventional activated sludge (CAS) process is a widely used method for wastewater treatment due to its effectiveness and affordability. However, it can be prone to sludge abnormalities such as sludge bulking/foaming and sludge loss, which can lead to a decrease in treatment efficiency. To address these issues, a novel bag-based fixed activated sludge (BBFAS) system utilizing mesh bags to contain the sludge was developed for low carbon/nitrogen ratio wastewater treatment. Pilot-scale experiments demonstrated that the BBFAS system could successfully avoid the sludge abnormalities. Moreover, it was not affected by mass transfer resistance and exhibited significantly higher nitrogen removal efficiency, surpassing that of the CAS system by up to 78%. Additionally, the BBFAS system demonstrated comparable organic matter removal efficiency to CAS system. 16S rRNA gene high-throughput sequencing revealed that the bacterial community structure within the BBFAS system was significantly different from that of the CAS system. The bacteria associated with ammonium removal were more abundant in the BBFAS system than in the CAS system. The abundance of Nitrospira in the BBFAS could reach up to 6% and significantly higher than that in the CAS system, and they were likely responsible for both ammonia-oxidizing and nitrite-oxidizing functions. Clear stratification of microbial communities was observed from the outer to inner layers of the bag components due to the gradients of dissolved oxygen and other substrates. Overall, this study presents a promising approach for avoiding activated sludge abnormalities while maintaining high pollutant removal performance.
Collapse
Affiliation(s)
- Dongni Rui
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Kunlong Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Yanyan Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Kailong Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China; Nanjing Jiangdao Institute of Environmental Research, Nanjing, 210019, China
| | - Mengxue Chen
- Nanjing Gaoke Environmental Technology Co., Ltd., Nanjing, 210038, China
| | - Fei Wu
- Nanjing Gaoke Environmental Technology Co., Ltd., Nanjing, 210038, China
| | - Xuxiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Lin Ye
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China.
| |
Collapse
|
2
|
Liu S, Zhou M, Daigger GT, Huang J, Song G. Granule formation mechanism, key influencing factors, and resource recycling in aerobic granular sludge (AGS) wastewater treatment: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 338:117771. [PMID: 37004484 DOI: 10.1016/j.jenvman.2023.117771] [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: 01/02/2023] [Revised: 03/14/2023] [Accepted: 03/18/2023] [Indexed: 06/19/2023]
Abstract
The high-efficiency and additionally economic benefits generated from aerobic granular sludge (AGS) wastewater treatment have led to its increasing popularity among academics and industrial players. The AGS process can recycle high value-added biomaterials including extracellular polymeric substances (EPS), sodium alginate-like external polymer (ALE), polyhydroxyfatty acid (PHA), and phosphorus (P), etc., which can serve various fields including agriculture, construction, and chemical while removing pollutants from wastewaters. The effects of various key operation parameters on formation and structural stability of AGS are comprehensively summarized. The degradable metabolism of typical pollutants and corresponding microbial diversity and succession in the AGS wastewater treatment system are also discussed, especially with a focus on emerging contaminants removal. In addition, recent attempts for potentially effective production of high value-added biomaterials from AGS are proposed, particularly concerning improving the yield, quality, and application of these biomaterials. This review aims to provide a reference for in-depth research on the AGS process, suggesting a new alternative for wastewater treatment recycling.
Collapse
Affiliation(s)
- Shuli Liu
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450000, China; Zhongzhou Water Holding Co., Ltd., Zhengzhou, 450046, China; Civil and Environmental Engineering, University of Michigan, 2350 Hayward St, G.G. Brown Building, Ann Arbor, MI, 48109, USA.
| | - Miao Zhou
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450000, China.
| | - Glen T Daigger
- Civil and Environmental Engineering, University of Michigan, 2350 Hayward St, G.G. Brown Building, Ann Arbor, MI, 48109, USA.
| | - Jianping Huang
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450000, China.
| | - Gangfu Song
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450000, China; Zhongzhou Water Holding Co., Ltd., Zhengzhou, 450046, China.
| |
Collapse
|
3
|
Chen D, Li H, Xue X, Zhang L, Hou Y, Chen H, Zhang Y, Song Y, Zhao S, Guo J. Enhanced simultaneous partial nitrification and denitrification performance of aerobic granular sludge via tapered aeration in sequencing batch reactor for treating low strength and low COD/TN ratio municipal wastewater. ENVIRONMENTAL RESEARCH 2022; 209:112743. [PMID: 35065929 DOI: 10.1016/j.envres.2022.112743] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/06/2022] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
The aerobic granular sludge simultaneous partial nitrification, denitrification and phosphorus removal (AGS-SPNDPR) process was carried out via tapered aeration in sequencing batch reactor (SBR) for treating low strength and low COD/TN ratio municipal wastewater. The results showed that aerobic granular sludge was successfully cultivated with good sedimentation performance when treating the municipal wastewater. Meanwhile, the median granule size increased to 270 (R1) and 257 (R2) μm on day 80. The excellent removal performance of COD (92%) and NH4+-N (95%) were achieved under different aeration modes, while the higher TN removal efficiency (76%) was achieved by tapered aeration. The accumulation of NO2--N in R2 indicated that the tapered aeration was beneficial to achieve simultaneously partial nitrification and denitrification. Meanwhile, the high-efficiency phosphorus (95%) removal was realized via additional carbon source, and SPNDPR process was formed under tapered aeration. The bacterial community analysis indicated denitrifying glycogen-accumulating organisms (DGAOs) Candidatus_Competibacter and ammonia-oxidizing bacteria (AOB) Nitrosomonas were more effectively enriched via tapered aeration, while phosphorus-accumulating organisms (PAOs) Candidatus_Accumulibacter were effectively enriched under additional organic carbon. AOB, denitrifying bacteria and PAOs were simultaneously enriched by tapered aeration and additional carbon source, which was beneficial to nutrients removal. This study might be conducive to the application of AGS-SPNDPR system for treating low strength and low COD/TN ratio municipal wastewater under tapered aeration.
Collapse
Affiliation(s)
- Denghui Chen
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road #26, Tianjin, 300384, PR China; Beijing Enterprises Water Group (China) Investment Limited, BEWG Building, Poly International Plaza T3, Zone 7, Wangjingdongyuan, Chaoyang District, Beijing, 100102, PR China
| | - Haibo Li
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road #26, Tianjin, 300384, PR China.
| | - Xiaofei Xue
- Beijing Enterprises Water Group (China) Investment Limited, BEWG Building, Poly International Plaza T3, Zone 7, Wangjingdongyuan, Chaoyang District, Beijing, 100102, PR China
| | - Lili Zhang
- Beijing Enterprises Water Group (China) Investment Limited, BEWG Building, Poly International Plaza T3, Zone 7, Wangjingdongyuan, Chaoyang District, Beijing, 100102, PR China.
| | - Yanan Hou
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road #26, Tianjin, 300384, PR China
| | - Han Chen
- Beijing Enterprises Water Group (China) Investment Limited, BEWG Building, Poly International Plaza T3, Zone 7, Wangjingdongyuan, Chaoyang District, Beijing, 100102, PR China
| | - Yousuo Zhang
- CCCC-TDC Harbour Construction Engineering Co., Ltd., Huanggu Dongheng Street #8, Tianjin, 300450, China
| | - Yunda Song
- Beijing Enterprises Water Group (China) Investment Limited, BEWG Building, Poly International Plaza T3, Zone 7, Wangjingdongyuan, Chaoyang District, Beijing, 100102, PR China
| | - Shiqi Zhao
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road #26, Tianjin, 300384, PR China
| | - Jianbo Guo
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road #26, Tianjin, 300384, PR China
| |
Collapse
|
4
|
Zhang X, Lei Z, Liu Y. Microalgal-bacterial granular sludge for municipal wastewater treatment: From concept to practice. BIORESOURCE TECHNOLOGY 2022; 354:127201. [PMID: 35460841 DOI: 10.1016/j.biortech.2022.127201] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/17/2022] [Accepted: 04/18/2022] [Indexed: 06/14/2023]
Abstract
Recently, increasing interest has been placed in microalgal-bacterial granular sludge (MBGS) in the journey towards the energy and carbon neutrality of municipal wastewater treatment. Different from aerobic granular sludge, the performance of MBGS is mainly determined by the mutualism and symbiosis between coexisting microalgae and bacteria. It appears from the literature that most of studies on MBGS were conducted at small benchtop scales under controlled conditions with synthetic wastewater. Therefore, this article attempts to look into the major engineering gaps between the knowledge generated from numerous laboratory research works and the large-scale application of MBGS, including massive production of MBGS, type of bioreactor, effect of alternate photo and dark metabolisms on effluent quality, resource recovery from waste MBGS, etc. It is clearly demonstrated that MBGS is still at its infant stage, and more effort is strongly needed to identify the technological bottlenecks of full-scale applications, while providing corresponding engineering solutions.
Collapse
Affiliation(s)
- Xiaoyuan Zhang
- Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore.
| | - Zhongfang Lei
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Yu Liu
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
| |
Collapse
|
5
|
Dong Y, Chen F, Li L, Yin Z, Zhang X. Enhanced aerobic granular sludge formation by applying Phanerochaete chrysosporium pellets as induced nucleus. Bioprocess Biosyst Eng 2022; 45:815-828. [PMID: 35318496 DOI: 10.1007/s00449-022-02698-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 01/18/2022] [Indexed: 11/02/2022]
Abstract
The long start-up period is a major challenging issue for the widespread application of aerobic granular sludge (AGS). In this study, a novel rapid start-up strategy was developed by inoculating Phanerochaete chrysosporium (P. chrysosporium) pellets as the induced nucleus in a sequencing batch airlift reactor (SBAR) to enhance activated sludge granulation. The results demonstrated that P. chrysosporium pellets could effectively shorten the aerobic granulation time from 32 to 20 days. The AGS promoted by P. chrysosporium pellets had a larger average diameter (2.60-2.74 mm) than that without P. chrysosporium pellets (1.78-1.88 mm) and had better biomass retention capacity and sedimentation properties; its mixed liquor suspended solids (MLSS) and sludge volume index (SVI30) reached approximately 5.2 g/L and 45 mL/g, respectively. The addition of P. chrysosporium pellets promoted the secretion of extracellular polymeric substances (EPS), especially protein (PN). The removal efficiencies of chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), total nitrogen (TN), and total phosphorus (TP) in P. chrysosporium pellets reactor were 98.91%, 89.17%, 64.73%, and 94.42%, respectively, which were higher than those in the reactor without P. chrysosporium pellets (88.73%, 82.09%, 55.75%, and 88.92%). High throughput sequencing analysis indicated that several functional genera that were responsible for the formation of aerobic granules and the removal of pollutants, such as Acinetobacter, Pseudomonas, Janthinobacterium, and Enterobacter, were found to be predominant in the mature sludge granules promoted by P. chrysosporium pellets.
Collapse
Affiliation(s)
- Yihua Dong
- Key Laboratory of the Ministry of Education for Eco-Restoration of Regional Contaminated Environment, Shenyang University, Shenyang, 110044, Liaoning, China
| | - Feng Chen
- Key Laboratory of the Ministry of Education for Eco-Restoration of Regional Contaminated Environment, Shenyang University, Shenyang, 110044, Liaoning, China
| | - Liang Li
- School of Resources and Civil Engineering, Northeastern University, Shenyang, 110819, Liaoning, China.
| | - Zhiwen Yin
- Key Laboratory of the Ministry of Education for Eco-Restoration of Regional Contaminated Environment, Shenyang University, Shenyang, 110044, Liaoning, China
| | - Xueying Zhang
- Key Laboratory of the Ministry of Education for Eco-Restoration of Regional Contaminated Environment, Shenyang University, Shenyang, 110044, Liaoning, China
| |
Collapse
|
6
|
Zhou L, Dong N, Ye B, Zhuang WQ, Xia S. Assessing effects of Ca 2+ addition on membrane bioreactor performance and macro-floc sludge characteristics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 798:149223. [PMID: 34375270 DOI: 10.1016/j.scitotenv.2021.149223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/15/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
Calcium ions (Ca2+) can trigger coagulation-flocculation process to form macro-flocculated sludge (MFS). Thus, dosing Ca2+-containing reagents into membrane bioreactors (MBRs) is considered as a promising approach to mitigate membrane biofouling. However, a mechanistic understanding of Ca2+ addition to MBR performance remains elucidated, such as physicochemical characteristics of MFS and their functionality variations. Consequently, this study was sought to understand the interplays of Ca2+ addition and MBR performance with a focus on characterizing MFS in detail. Three parallel MBRs were amended with 82, 208 and 410 mg-Ca2+/L final concentrations. Particle size analyses revealed that MFS formation was overall enhanced by the Ca2+ addition and granular sludge with diameters of up to 900 μm was formed in the 410 mg-Ca2+/L scenario. We believed that cationic bridges facilitated by elevated Ca2+ concentrations in conjunction with coagulation-flocculation were primary mechanisms of the formation of large flocs. Moreover, significant portions of soluble proteins and polysaccharides were flocculated and precipitated by Ca2+, which demonstrated a negative correlation between extracellular polymeric substances (EPS) concentrations and the formation of MFS. Furthermore, the population abundancies of Thiotrichaceae, Sphingomonadales and Hyphomicrobiaceae decreased in the sludge with Ca2+ addition resulted in profound changes of the microbial communities in the MBRs. But MBR performance, such as chemical oxygen demand removal (over 90%), showed no variation during the MBR operation. On the contrary, total nitrogen removal was inhibited in the MBRs. It was because the enlarging MFS formed diffusion barriers to prevent organic component from entering into the sludge flocs to be consumed.
Collapse
Affiliation(s)
- Lijie Zhou
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China.
| | - Nan Dong
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Biao Ye
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, PR China
| | - Wei-Qin Zhuang
- Department of Civil and Environmental Engineering, University of Auckland, Auckland 1142, New Zealand
| | - Siqing Xia
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, PR China.
| |
Collapse
|
7
|
Hamiruddin NA, Awang NA, Mohd Shahpudin SN, Zaidi NS, Said MAM, Chaplot B, Azamathulla HM. Effects of wastewater type on stability and operating conditions control strategy in relation to the formation of aerobic granular sludge - a review. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 84:2113-2130. [PMID: 34810301 DOI: 10.2166/wst.2021.415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Currently, research trends on aerobic granular sludge (AGS) have integrated the operating conditions of extracellular polymeric substances (EPS) towards the stability of AGS systems in various types of wastewater with different physical and biochemical characteristics. More attention is given to the stability of the AGS system for real site applications. Although recent studies have reported comprehensively the mechanism of AGS formation and stability in relation to other intermolecular interactions such as microbial distribution, shock loading and toxicity, standard operating condition control strategies for different types of wastewater have not yet been discussed. Thus, the dimensional multi-layer structural model of AGS is discussed comprehensively in the first part of this review paper, focusing on diameter size, thickness variability of each layer and diffusion factor. This can assist in facilitating the interrelation between disposition and stability of AGS structure to correspond to the changes in wastewater types, which is the main objective and novelty of this review.
Collapse
Affiliation(s)
- N A Hamiruddin
- School of Civil Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia E-mail:
| | - N A Awang
- School of Civil Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia E-mail:
| | - S N Mohd Shahpudin
- Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200 Kepala Batas, Penang, Malaysia
| | - N S Zaidi
- School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Malaysia
| | - M A M Said
- School of Civil Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia E-mail:
| | - B Chaplot
- Department of Geography, M.J.K College, Bettiah, a constituent unit of B.R.A., Bihar University, Bettiah, Muzaffarpur, India
| | - H M Azamathulla
- Faculty of Engineering, The University of the West Indies, St. Augustine, Trinidad
| |
Collapse
|
8
|
Yu C, Wang K, Tian C, Yuan Q. Aerobic granular sludge treating low-strength municipal wastewater: Efficient carbon, nitrogen and phosphorus removal with hydrolysis-acidification pretreatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 792:148297. [PMID: 34153768 DOI: 10.1016/j.scitotenv.2021.148297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 06/13/2023]
Abstract
Low organic load while high fraction of particulates still challenging the application of aerobic granular sludge process in low-strength municipal wastewater treatment. The feasibility of adopting short cycle length to increase organic load and hydrolysis-acidification pretreatment to enhance anaerobic COD uptake was evaluated. As the cycle length decreased from 4 h to 2 h, the organic loading rate increased from 0.98 to 1.3 g L-1 d-1 and granulation appeared after two weeks. Moreover, with the hydrolysis-acidification pretreatment, the average effluent TN and TP concentrations decreased respectively from 17.8 to 13.7 mg L-1 and 0.76 to 0.41 mg L-1, meeting the Grade IA of the effluent standards in China. Furthermore, cycle tests were conducted to reveal the underlying mechanism of the pretreatment effects. The results showed that the hydrolysis-acidification pretreatment enhanced the COD storage and phosphorus release in anaerobic phase, and improved the simultaneous nitrification-denitrification process, as well as the phosphorus uptake in aeration phase.
Collapse
Affiliation(s)
- Cheng Yu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Kaijun Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
| | - Chen Tian
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Quan Yuan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| |
Collapse
|
9
|
Structural Characteristics of Aerobic Granular Sludge and Factors That Influence Its Stability: A Mini Review. WATER 2021. [DOI: 10.3390/w13192726] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Current extensive research on aerobic granular sludge (AGS) largely focuses on improving its microbial biodiversity, settlement behavior, nitrogen and phosphorus removal efficiency, and shock load resistance. Great challenges that have to be faced are the bottleneck of slow-speed granulation and easy disintegration after granulation, which are key to the extended application of AGS technology. In the present review, the typical morphological structures of AGS are firstly summarized as well as the granulation model hypotheses, and then, we analyze the dominant microflora and their spatial distribution features. The influencing factors on particle structure stability are discussed thereafter on a macro and micro scale. Prospects and future research trends are also discussed based on the current study results for AGS technology.
Collapse
|
10
|
Sun H, Narihiro T, Ma X, Zhang XX, Ren H, Ye L. Diverse aromatic-degrading bacteria present in a highly enriched autotrophic nitrifying sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 666:245-251. [PMID: 30798235 DOI: 10.1016/j.scitotenv.2019.02.172] [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: 01/01/2019] [Revised: 02/10/2019] [Accepted: 02/11/2019] [Indexed: 06/09/2023]
Abstract
Biotransformation of refractory organics by ammonia-oxidizing microorganisms in nitrifying sludge have been widely reported, while the contribution of heterotrophic bacteria in nitrifying sludge in the biotransformation and degradation process might be overlooked. Here, we provide metagenomic and metatranscriptomic evidences showing that heterotrophic bacteria in a highly enriched autotrophic nitrifying sludge could significantly contribute to the aromatic biotransformation and biodegradation. Diverse genes encoding enzymes for aromatic degradation were observed in an enriched autotrophic nitrifying sludge. These genes are involved in the degradation of at least 15 complex aromatics. Genome binning results showed that these genes were mainly carried by species in Bacteroidetes (Flavobacteriaceae and Sphingobacteriales), Alphaproteobacteria (Rhodobacter) and Betaproteobacteria (Bordetella, Acidovorax, Ramlibacter and Pusillimonas). According to the metatranscriptomic analysis, the overall expression of the potential aromatic-degrading genes was significantly upregulated, and almost all genes involved in phenol degradation were over expressed after the nitrifying sludge was exposed to phenol. Overall, our results suggest that certain heterotrophs in nitrifying sludge are involved aromatic biotransformation and biodegradation and advance our knowledge of the underlying properties and metabolic mechanisms of the nitrifying sludge.
Collapse
Affiliation(s)
- Haohao Sun
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China
| | - Takashi Narihiro
- Bioproduction Research Institute, Nrational Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Xueyan Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China
| | - Lin Ye
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China.
| |
Collapse
|
11
|
Xia J, Ye L, Ren H, Zhang XX. Microbial community structure and function in aerobic granular sludge. Appl Microbiol Biotechnol 2018; 102:3967-3979. [PMID: 29550989 DOI: 10.1007/s00253-018-8905-9] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 02/22/2018] [Accepted: 02/26/2018] [Indexed: 12/28/2022]
Abstract
Aerobic granular sludge (AGS), a self-immobilized microbial consortium containing different functional microorganisms, is receiving growing attention, since it has shown great technological and economical potentials in the field of wastewater treatment. Microbial community is crucial for the formation, stability, and pollutant removal efficiency of aerobic granules. This mini-review systematically summarizes the recent findings of the microbial community structure and function of AGS and discusses the new research progress in the microbial community dynamics during the granulation process and spatial distribution patterns of the microbiota in AGS. The presented information may be helpful for the in-depth theoretical study and practical application of AGS technology in the future.
Collapse
Affiliation(s)
- Juntao Xia
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China
| | - Lin Ye
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China.
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China.
| |
Collapse
|
12
|
State of the art on granular sludge by using bibliometric analysis. Appl Microbiol Biotechnol 2018; 102:3453-3473. [PMID: 29497798 DOI: 10.1007/s00253-018-8844-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 02/02/2018] [Accepted: 02/05/2018] [Indexed: 02/07/2023]
Abstract
With rapid industrialization and urbanization in the nineteenth century, the activated sludge process (ASP) has experienced significant steps forward in the face of greater awareness of and sensitivity toward water-related environmental problems. Compared with conventional flocculent ASP, the major advantages of granular sludge are characterized by space saving and resource recovery, where the methane and hydrogen recovery in anaerobic granular and 50% more space saving, 30-50% of energy consumption reduction, 75% of footprint cutting, and even alginate recovery in aerobic granular. Numerous engineers and scientists have made great efforts to explore the superiority over the last 40 years. Therefore, a bibliometric analysis was desired to trace the global trends of granular sludge research from 1992 to 2016 indexed in the SCI-EXPANDED. Articles were published in 276 journals across 44 subject categories spanning 1420 institutes across 68 countries. Bioresource Technology (293, 11.9%), Water Research (235, 9.6%), and Applied Microbiology and Biotechnology (127, 5.2%) dominated in top three journals. The Engineering (991, 40.3%), China (906, 36.9%), and Harbin Inst Technol, China (114, 4.6%) were the most productive subject category, country, and institution, respectively. The hotspot is the emerging techniques depended on granular reactors in response to the desired removal requirements and bio-energy production (primarily in anaerobic granular sludge). In view of advanced and novel bio-analytical methods, the characteristics, functions, and mechanisms for microbial granular were further revealed in improving and innovating the granulation techniques. Therefore, a promising technique armed with strengthened treatment efficiency and efficient resource and bio-energy recovery can be achieved.
Collapse
|