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Li C, Liu C, Shan Y, Lan T. Effects of low frequency ultrasound treatment on dissolved organic nitrogen removal by biological activated carbon: Critical insights into molecular characteristics, microbial traits, and metabolism. WATER RESEARCH 2024; 260:121924. [PMID: 38896885 DOI: 10.1016/j.watres.2024.121924] [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: 12/18/2023] [Revised: 05/22/2024] [Accepted: 06/10/2024] [Indexed: 06/21/2024]
Abstract
Drinking water treatment plants (DWTPs) in China that pioneered the biological activated carbon (BAC) process have reached 10 years of operation. There has been a renewed focus on biofiltration and the performance of old BAC filters for dissolved organic nitrogen (DON) has been poor, requiring replacement and regeneration of the BAC. Therefore, it is necessary to explore a cost-effective way to improve the water quality of the old BAC filters. To address this, low frequency ultrasound is proposed to enhance DON removal efficiency by BAC. In this study, bench and pilot tests were conducted to investigate the effect of low frequency ultrasound on DON removal by 10-year BAC. The results indicated that low frequency ultrasound significantly improved the DON removal rate increased from 15.83 % to 85.87 % and considerably inhibited the nitrogenous disinfection by-products (N-DBPs) formation potential, which was attributed to a decrease in the production of lipid-like, carbohydrate-like, and protein/amino sugar-like DON. The biomass on the BAC was significantly reduced after ultrasound treatment, and it decreased from 349.56∼388.98 nmol P/gBAC to 310.12∼377.63 nmol P/gBAC, enabling the biofilm thickness to decrease and the surface to become sparse and porous, which was conducive to oxygen and nutrients transfer. The Rhizobials associated with microbe-derived DON were stripped away during ultrasound treatment, which reduced microbe-derived DON associated with amino acids. Additionally, ultrasound regulated metabolic pathways, including amino acids, tricarboxylic acid (TCA) cycle, and nucleotide metabolism, to improve the osmotic pressure of the biofilm. In short, low frequency ultrasound treatment can enhance BAC biological properties and effectively remove DON and N-DBPs formation potentials, which provides a viable and promising strategy for improving the safety of drinking water in practice.
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Affiliation(s)
- Congcong Li
- College of Environment, Hohai University, Nanjing 210098, PR China; School of Water Conservancy and Environment, University of Jinan, Jinan 250022, Shandong, PR China
| | - Cheng Liu
- College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Yiwen Shan
- College of Environment, Hohai University, Nanjing 210098, PR China
| | - Tong Lan
- College of Environment, Hohai University, Nanjing 210098, PR China
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2
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Zhou W, Hao J, Guo Y, Zhao C, Zhang M, Zhang S, Han F. Revealing bioresponses of biofilm and flocs to salinity gradient in halophilic biofilm reactor. BIORESOURCE TECHNOLOGY 2024; 401:130727. [PMID: 38643952 DOI: 10.1016/j.biortech.2024.130727] [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: 03/01/2024] [Revised: 04/09/2024] [Accepted: 04/18/2024] [Indexed: 04/23/2024]
Abstract
Understanding the different biological responses to salinity gradient between coexisting biofilm and flocs is crucial for regulating the ecological function of biofilm system. This study investigated performance, dynamics, and community assembly of biofilm system under 3 %-7% salinity gradient. The removal efficiency of NH4+-N remained stable and exceeded 93 % at 3 %-6% salinity, but decreased to below 80 % at 7 % salinity. The elevated salinity promoted the synthesis of extracellular polymer substrates, inhibited microbial respiration, and significantly regulated the microbial community structure. Compared to flocs, biofilm exhibited greater species diversity and richer Nitrosomonas. It was found diffusion limitations dominated the microbial community assembly under the salinity gradient. And microbial network revealed positive interactions predominated the microbial relationships, designating norank Spirochaetaceae, unclassified Micrococcales, Corynebacterium, and Pusillimonas as keystone species. Moreover, distinct salinity preferences in nitrogen transformation-related genes were observed. This study can improve the understanding to the regulation of biofilm systems to salt stresses.
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Affiliation(s)
- Weizhi Zhou
- School of Civil Engineering, Shandong University, Jinan, Shandong 250002, China; School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, China
| | - Jie Hao
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266000, China; School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, China
| | - Yiting Guo
- School of Civil Engineering, Shandong University, Jinan, Shandong 250002, China; School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, China
| | - Chuanfu Zhao
- School of Civil Engineering, Shandong University, Jinan, Shandong 250002, China; School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, China
| | - Mengru Zhang
- School of Civil Engineering, Shandong University, Jinan, Shandong 250002, China; School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, China
| | - Shuhui Zhang
- School of Civil Engineering, Shandong University, Jinan, Shandong 250002, China; School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, China
| | - Fei Han
- School of Civil Engineering, Shandong University, Jinan, Shandong 250002, China; School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, China.
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Jiao T, Zhao C, Zhang M, Han F, Liu Z, Zhang S, Zhou W. Recovery mechanism of heterotrophic ammonia assimilation system under chromium hexavalent stress. BIORESOURCE TECHNOLOGY 2024; 399:130615. [PMID: 38513926 DOI: 10.1016/j.biortech.2024.130615] [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: 01/10/2024] [Revised: 03/16/2024] [Accepted: 03/18/2024] [Indexed: 03/23/2024]
Abstract
Heterotrophic ammonia assimilation (HAA), an innovative technology for high-salinity wastewater treatment, demonstrates self-recovery capability following Cr (VI) stress. This study investigated the inhibitory effects and self-restoration mechanisms of Cr (VI) at various stress levels. The removal efficiencies of NH4+-N and Cr (VI) in the HAA gradually decreased with increasing influent Cr (VI) concentration. Exposure to Cr (VI) increased the amounts of high-molecular-weight proteins in soluble microbial products and stimulated the generation of extracellular polymeric substances. Heterotrophic functional microorganisms with Cr (VI) tolerance, such as Marinobacter and Planktosalinus, were enriched. An assimilation pathway gene (glnA) and a Cr (VI)-related gene (atoB) were also upregulated. After ceasing Cr (VI) addition, the HAA system demonstrated a 17.1 % increase in the removal efficiency of NH4+-N, which was attributable to its self-recovery ability. This study provides a scientific and theoretical foundation for the HAA process in resisting the impact of heavy-metal-containing wastewater and self-recovery.
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Affiliation(s)
- Tong Jiao
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of Water-sediment Regulation and Eco-decontamination, Jinan, Shandong, PR China
| | - Chuanfu Zhao
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of Water-sediment Regulation and Eco-decontamination, Jinan, Shandong, PR China
| | - Mengru Zhang
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of Water-sediment Regulation and Eco-decontamination, Jinan, Shandong, PR China
| | - Fei Han
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of Water-sediment Regulation and Eco-decontamination, Jinan, Shandong, PR China
| | - Zhe Liu
- Laboratory of Water-sediment Regulation and Eco-decontamination, Jinan, Shandong, PR China; School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, PR China
| | - Shuhui Zhang
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of Water-sediment Regulation and Eco-decontamination, Jinan, Shandong, PR China
| | - Weizhi Zhou
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of Water-sediment Regulation and Eco-decontamination, Jinan, Shandong, PR China.
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Huang YP, Wang X, Wang RL, He JT, Huang Y, Hang ZY, Chen X, Li ZH. Managing stability of aerobic granules by coordinating diameter and denitrification. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167795. [PMID: 37838046 DOI: 10.1016/j.scitotenv.2023.167795] [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: 08/08/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/16/2023]
Abstract
Aerobic Granular Sludge (AGS) technology is a promising solution for wastewater treatment due to its structure and high biomass retention capacity. However, the stability of AGS is still a challenge for widespread use. This study investigated the relationships among granule stability, granule diameter, biomass retention capacity, and denitrification efficiency. The results showed that granule diameter did not necessarily indicate granule stability, nor was it associated with biomass retention capacity. For mature granules, promoting simultaneous nitrification and denitrification rather than anoxic denitrification was found to improve granule stability. The deterioration of clarification capacity caused by increased anoxic denitrification at high nitrate concentration was not indicated by diameters or the commonly used SVI5/SVI30. Therefore, ensuring coordination between diameter and denitrification control is crucial for the stability of AGS. These results provide a basis for further research and development of efficient and user-friendly methods for monitoring granular stability.
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Affiliation(s)
- Yong-Peng Huang
- Key Laboratory of Northwest Water Resource, Environment, and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Xi'an Key Laboratory of Intelligent Equipment Technology for Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Xin Wang
- Key Laboratory of Northwest Water Resource, Environment, and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Xi'an Key Laboratory of Intelligent Equipment Technology for Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Ruo-Lan Wang
- Key Laboratory of Northwest Water Resource, Environment, and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Xi'an Key Laboratory of Intelligent Equipment Technology for Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Jin-Tao He
- Key Laboratory of Northwest Water Resource, Environment, and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Xi'an Key Laboratory of Intelligent Equipment Technology for Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Yuan Huang
- Key Laboratory of Northwest Water Resource, Environment, and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Xi'an Key Laboratory of Intelligent Equipment Technology for Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Zhen-Yu Hang
- Key Laboratory of Northwest Water Resource, Environment, and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Xi'an Key Laboratory of Intelligent Equipment Technology for Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Xi Chen
- School of Urban Planning and Municipal Engineering, Xi'an Polytechnic University, Xi'an 710048, China
| | - Zhi-Hua Li
- Key Laboratory of Northwest Water Resource, Environment, and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Xi'an Key Laboratory of Intelligent Equipment Technology for Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
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5
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Zeng Y, Zeng M, Cheng Y, Long B, Wu J. Cultivation of autotrophic nitrifying granular sludge for simultaneous removal of ammonia nitrogen and Tl(I). ENVIRONMENTAL TECHNOLOGY 2023; 44:4017-4032. [PMID: 35574708 DOI: 10.1080/09593330.2022.2077659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
Autotrophic nitrifying granular sludge (ANGS) was cultivated for the simultaneous removal of ammonia nitrogen and Tl(I) from inorganic wastewater. The chemical oxygen demand (COD) in the influent gradually decreased to approximately zero in four parallel sequencing batch reactors (B1: blank controller, B2: 10 mL of added nitrifying bacteria concentrate in each cycle, B3: 1 mg/L Tl(I) added in each cycle and B4: 10 mL of added nitrifying bacteria concentrate and 1 mg/L Tl(I) in each cycle) within 15 days. The main properties, such as the granulation rate and specific oxygen uptake rate (SOUR) of the ANGS in B1, B2, B3 and B4 tended to be stable within 40, 33, 30 and 33 days, the removal efficiencies of Tl(I) were 59.5%-82.9% and 57.1%-88.6% in B3 and B4 after Day 30, the removal efficiencies of ammonia nitrogen in B1, B2, B3 and B4 were usually above 90% after Day 33, and the total inorganic nitrogen (TIN) in the effluent of B1, B2, B3 and B4 gradually stabilized after Day 36, 32, 32 and 36, indicating that mature ANGS was successfully cultivated in B1, B2, B3 and B4 within 40, 33, 33 and 36 days. The nitrogen degradation kinetic parameters of ANGS indicated that B3 had the strongest ability to remove ammonia and nitrite, suggesting that Tl(I) stress was beneficial to ammonia nitrogen removal and nitrite oxidation. The adsorption of Tl(I) can be described by the Freundlich equation, and the addition of external nitrifying bacteria improved the adsorption ability of ANGS.
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Affiliation(s)
- Yu Zeng
- School of Civil and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou, People's Republic of China
| | - Mingjing Zeng
- School of Civil and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou, People's Republic of China
| | - Yuanyuan Cheng
- School of Civil and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou, People's Republic of China
| | - Bei Long
- School of Civil and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou, People's Republic of China
| | - Junfeng Wu
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Pingdingshan, People's Republic of China
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6
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Cheng L, Wei M, Hu Q, Li B, Li B, Wang W, Abudi ZN, Hu Z. Aerobic granular sludge formation and stability in enhanced biological phosphorus removal system under antibiotics pressure: Performance, granulation mechanism, and microbial successions. JOURNAL OF HAZARDOUS MATERIALS 2023; 454:131472. [PMID: 37099906 DOI: 10.1016/j.jhazmat.2023.131472] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 04/04/2023] [Accepted: 04/21/2023] [Indexed: 05/19/2023]
Abstract
Wastewater containing antibiotics can pose a significant threat to biological wastewater treatment processes. This study investigated the establishment and stable operation of enhanced biological phosphorus removal (EBPR) by aerobic granular sludge (AGS) under mixed stress conditions induced by tetracycline (TC), sulfamethoxazole (SMX), ofloxacin (OFL), and roxithromycin (ROX). The results show that the AGS system was efficient in removing TP (98.0%), COD (96.1%), and NH4+-N (99.6%). The average removal efficiencies of the four antibiotics were 79.17% (TC), 70.86% (SMX), 25.73% (OFL), and 88.93% (ROX), respectively. The microorganisms in the AGS system secreted more polysaccharides, which contributed to the reactor's tolerance to antibiotics and facilitated granulation by enhancing the production of protein, particularly loosely bound protein. Illumina MiSeq sequencing revealed that putative phosphate accumulating organisms (PAOs)-related genera (Pseudomonas and Flavobacterium) were enormously beneficial to the mature AGS for TP removal. Based on the analysis of extracellular polymeric substances, extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, and microbial community, a three-stage granulation mechanism was proposed including adaption to the stress environment, formation of early aggregates and maturation of PAOs enriched microbial granules. Overall, the study demonstrated the stability of EBPR-AGS under mixed antibiotics pressure, providing insight into the granulation mechanism and the potential use of AGS for wastewater treatment containing antibiotics.
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Affiliation(s)
- Long Cheng
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Mingyu Wei
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Qixing Hu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Bingtang Li
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Bo Li
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wenjia Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zaidun Naji Abudi
- Environmental Engineering Department, College of Engineering, Mustansiriyah University, Baghdad 999048, Iraq
| | - Zhiquan Hu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
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7
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An Z, Wang J, Zhang X, Bott CB, Angelotti B, Brooks M, Wang ZW. Coupling physical selection with biological selection for the startup of a pilot-scale, continuous flow, aerobic granular sludge reactor without treatment interruption. WATER RESEARCH X 2023; 19:100186. [PMID: 37332326 PMCID: PMC10276156 DOI: 10.1016/j.wroa.2023.100186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/29/2023] [Accepted: 05/31/2023] [Indexed: 06/20/2023]
Abstract
This study removes two technical constraints for transitioning full-scale activated sludge infrastructure to continuous flow, aerobic granular sludge (AGS) facilities. The first of these is the loss of treatment capacity as a result of the rapid washout of flocculent sludge inventory and in turn the potential loss of nitrification during initial AGS reactor startup. The second is the physical selector design which currently is limited to either the complex sequencing batch reactor selection or sidestream hydrocyclones. Briefly, real wastewater data collected from this study suggested that by increasing the surface overflow rate (SOR) of an upflow clarifier to 10 m h - 1, the clarifier can be taken advantage of as a physical selector to separate flocculant sludge from AGS. Redirecting the physical selector underflow and overflow sludge to the feast and famine zones of a treatment train, respectively, can create a biological selection that not only promotes AGS formation but also safeguards the effluent quality throughout the AGS reactor startup period. This study provides a novel concept for economically implementing continuous flow AGS within existing full-scale, continuous flow treatment trains.
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Affiliation(s)
- Zhaohui An
- Department of Biological Systems Engineering, Virginia Tech, 1230 Washington St. SW, Blacksburg, VA 24061, USA
| | - Jiefu Wang
- Department of Biological Systems Engineering, Virginia Tech, 1230 Washington St. SW, Blacksburg, VA 24061, USA
| | - Xueyao Zhang
- Department of Biological Systems Engineering, Virginia Tech, 1230 Washington St. SW, Blacksburg, VA 24061, USA
| | - Charles B. Bott
- Hampton Roads Sanitation District, 1434 Air Rail Avenue, Virginia Beach, VA 23455, USA
| | - Bob Angelotti
- Upper Occoquan Service Authority, 14631 Compton Rd, Centreville, VA 20121, USA
| | - Matt Brooks
- Upper Occoquan Service Authority, 14631 Compton Rd, Centreville, VA 20121, USA
| | - Zhi-Wu Wang
- Department of Biological Systems Engineering, Virginia Tech, 1230 Washington St. SW, Blacksburg, VA 24061, USA
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Liu W, Song J, Wang J, Ji X, Shen Y, Yang D. Achieving robust nitritation in a modified continuous-flow reactor: From micro-granule cultivation to nitrite-oxidizing bacteria elimination. J Environ Sci (China) 2023; 124:117-129. [PMID: 36182122 DOI: 10.1016/j.jes.2021.11.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 11/03/2021] [Accepted: 11/03/2021] [Indexed: 06/16/2023]
Abstract
In this study, a modified continuous-flow nitrifying reactor was successfully operated for rapid cultivation of micro-granules and achieving robust nitritation. Results showed that sludge granulation with mean size of ca. 100 µm was achieved within three weeks by gradually increasing settling velocity-based selection pressure from 0.48 to 0.9 m/hr. Though Nitrospira like nitrite-oxidizing bacteria (NOB) were enriched in the micro-granules with a ratio between ammonia-oxidizing bacteria (AOB) and NOB of 5.7%/6.5% on day 21, fast nitritation was achieved within one-week by gradually increasing of influent ammonium concentration (from 50 to 200 mg/L). Maintaining ammonium in-excess was the key for repressing NOB in the micro-granules. Interestingly, when the influent ammonium concentration switched back to 50 mg/L still with the residual ammonium of 15-25 mg/L, the nitrite accumulation efficiency increased from 90% to 98%. Experimental results suggested that the NOB repression was intensified by both oxygen and nitrite unavailability in the inner layers of micro-granules. Unexpectedly, continuous operation with ammonium in excess resulted in overproduction of extracellular polysaccharides and overgrowth of some bacteria (e.g., Nitrosomonas, Arenimonas, and Flavobacterium), which deteriorated the micro-granule stability and drove the micro-granules aggregation into larger ones with irregular morphology. However, efficient nitritation was stably maintained with extremely high ammonium oxidation potential (> 50 mg/g VSS/hr) and nearly complete washout of NOB was obtained. This suggested that smooth and spherical granule was not a prerequisite for achieving NOB wash-out and maintaining effective nitritation in the granular reactor. Overall, the micro-granules exhibited a great practical potential for high-rate nitritation.
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Affiliation(s)
- Wenru Liu
- National & Local Joint Engineering Laboratory for Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China; School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
| | - Jiajun Song
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Jianfang Wang
- National & Local Joint Engineering Laboratory for Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China; School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Xiaoming Ji
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yaoliang Shen
- National & Local Joint Engineering Laboratory for Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China; School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Dianhai Yang
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China
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Wan C, Fu L, Li Z, Liu X, Lin L, Wu C. Formation, application, and storage-reactivation of aerobic granular sludge: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 323:116302. [PMID: 36150350 DOI: 10.1016/j.jenvman.2022.116302] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/31/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
It was an important discovery in wastewater treatment that the microorganisms in the traditional activated sludge can form aerobic granular sludge (AGS) by self-aggregation under appropriate water quality and operation conditions. With a typical three-dimensional spherical structure, AGS has high sludge-water separation efficiency, great treatment capacity, and strong tolerance to toxic and harmful substances, so it has been considered to be one of the most promising wastewater treatment technologies. This paper comprehensively reviewed AGS from multiple perspectives over the past two decades, including the culture conditions, granulation mechanisms, metabolic and structural stability, storage, and its diverse applications. Some important issues, such as the reproducibility of culture conditions and the structural and functional stability during application and storage, were also summarized, and the research prospects were put forward. The aggregation behavior of microorganisms in AGS was explained from the perspectives of physiology and ecology of complex populations. The storage of AGS is considered to have large commercial potential value with the increase of large-scale applications. The purpose of this paper is to provide a reference for the systematic and in-depth study on the sludge aerobic granulation process.
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Affiliation(s)
- Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China
| | - Liya Fu
- Research Center of Environmental Pollution Control Engineering Technology, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Zhengwen Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China.
| | - Lin Lin
- Environmental Science and New Energy Technology Research Center, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, 518055, China
| | - Changyong Wu
- Research Center of Environmental Pollution Control Engineering Technology, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
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Phosphorus Removal from Aerobic Granular Sludge: Proliferation of Polyphosphate-Accumulating Organisms (PAOs) under Different Feeding Strategies. Processes (Basel) 2022. [DOI: 10.3390/pr10071399] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Aerobic granular sludge (AGS) is known for high phosphorus removal from wastewaters, and phosphorus can be recovered from high phosphorus-containing waste sludge granules. This study aimed at determining the feeding strategy that provides the best performance in terms of the proliferation of polyphosphate-accumulating organisms (PAOs) and phosphorus removal. Using three AGS bioreactors, this study compared phosphorus removal and the proliferation dynamics of PAOs under three different feeding strategies: anaerobic slow feeding (R1), pulse feeding + anaerobic mixing (R2), and pulse feeding (R3). Results indicate that R1 and R2 achieved significantly higher phosphorus removal (97.6 ± 3% for R1 and 98.3 ± 1% for R2) than R3 (55 ± 11%). The anaerobic slow feeding procedure (R1) achieved the highest specific phosphorus release rate (SPRR) and specific phosphorus uptake rate (SPUR) as compared to the other two feeding conditions. 16S ribosomal ribonucleic acid (rRNA) gene sequencing assay of the microbial community for the three feeding strategies indicated that although the feeding strategy impacted reactor performance, it did not significantly alter the microbial community. The bacteria community composition maintained a similar degree of diversity. Proteobacteria, Bacteroidetes, and Verrucomicrobia were the dominant bacterial phyla in the system. Dominant PAOs were from the class Betaproteobacteria and the genera Paracoccus and Thauera. Glycogen-accumulating organisms were significantly inhibited while other less-known bacteria such as Wandonia and Hyphomonas were observed in all three reactors.
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Si G, Liu B, Liu Y, Yan T, Wei D. Light-introduced partial nitrification in an algal-bacterial granular sludge bioreactor: Performance evolution and microbial community shift. BIORESOURCE TECHNOLOGY 2022; 354:127226. [PMID: 35477103 DOI: 10.1016/j.biortech.2022.127226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
This objective of study was to evaluate the influence of light on the achievement of partial nitrification algal-bacterial granular bioreactor and its related nitrite accumulation mechanism. After 150-days operation, partial nitrification algal-bacterial granulation bioreactor was achieved under the 200 μmol/(m2·s) illuminance condition. The effluent NH4+-N, NO2--N, NO3--N concentrations were average at 1.1, 61.7 and 8.0 mg/L (n = 21), respectively. The average sphericity of algal-bacterial aerobic granular sludge (AB-AGS) increased from 82.7% to 91.1%, accompanied by the significantly increased diameter. Additionally, extracellular protein increased by 1.5 times and 0.5 times higher in LB-EPS and TB-EPS of AB-AGS, respectively. According to typical cycles, N2O emission amount reactor accounted for 2.4% of the removed nitrogen. Under the combined inhibition of light and free ammonia (FA), Nitrosomonas-related AOB (0.2% to 2.1%) were the predominant functional bacteria, whereas Nitrospira-related NOB (0.07% to below 0.01%) was fully inhibited.
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Affiliation(s)
- Guangchao Si
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, PR China
| | - Bing Liu
- Resources and Environment Innovation Research Institute, School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250101, PR China
| | - Yingrui Liu
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, PR China
| | - Tao Yan
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, PR China
| | - Dong Wei
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, PR China; CECEP Guozhen Environmental Protection Technology Co., Ltd, Hefei 230088, PR China.
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12
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Han F, Zhang M, Liu Z, Han Y, Li Q, Zhou W. Enhancing robustness of halophilic aerobic granule sludge by granular activated carbon at decreasing temperature. CHEMOSPHERE 2022; 292:133507. [PMID: 34979206 DOI: 10.1016/j.chemosphere.2021.133507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/30/2021] [Accepted: 12/30/2021] [Indexed: 06/14/2023]
Abstract
High salinity seriously inhibits the growth and metabolism of microorganisms, resulting in poor settleability, excessive biomass loss and low treatment efficiency of biological wastewater treatment systems. The development of halophilic aerobic granular sludge (HAGS) is a feasible strategy for addressing this challenge. However, there are problems with the granulation of HAGS and the stability of granules at decreasing temperatures. In this study, granular activated carbon (GAC) with a large specific surface area and good biocompatibility was used to enhance the robustness of HAGS. The results showed that the addition of GAC shortened the granulation time from 60 d (control system) to 35 d (GAC-addition system). The proteins contents of extracellular polymeric substances (EPS) in the GAC-addition system was significantly higher (p < 0.05) than that in the control system during granulation. Satisfactory NH4+-N and chemical oxygen demand (COD) removal efficiencies reached more than 96% in both systems at 18-26 °C. When the operating temperature was lower than 15 °C, the GAC-addition system exhibited better NH4+-N removal performance (>80%) than the control system (<60%). Moreover, the abundance of almost all nitrogen metabolism-related genes in the GAC-addition system was higher than that in the control system. During the granulation process, the enrichment of functional microorganisms, including family Flavobacteriaceae, Rhodobacteraceae, and Cryomorphaceae, may promote the production of EPS by significantly upregulating (p < 0.05) the metabolic pathway "Signaling Molecules and Interaction" in the GAC-addition system. The overexpression of the nitrogen assimilation gene glnA in heterotrophic bacteria (Halomonas and Marinobacterium) may promote the conversion of inorganic nitrogen to extracellular proteins to adapt to the decreased operational temperature. Our findings confirm that GAC addition is a simple but effective strategy to accelerate granulation and enhance the robustness of HAGS in saline wastewater treatment.
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Affiliation(s)
- Fei Han
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266000, China
| | - Mengru Zhang
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266000, China
| | - Zhe Liu
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266000, China
| | - Yufei Han
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266000, China
| | - Qian Li
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266000, China
| | - Weizhi Zhou
- School of Civil Engineering, Shandong University, Jinan, Shandong, 250002, China.
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13
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Heo S, Liu YQ. Dependence of poly-β-hydroxybutyrate accumulation in sludge on biomass concentration in SBRs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 797:149138. [PMID: 34346384 DOI: 10.1016/j.scitotenv.2021.149138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/07/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
The combination of wastewater treatment with polyhydroxyalkanoate production has attracted increasing interest in the context of the circular economy. Recent studies have thus attempted to optimize the conditions for polyhydroxyalkanoate accumulation in sludge when treating wastewater. The effects of biomass concentration and sludge morphologies in reactors on PHB storage, however, were neglected in the literature. Therefore, in this study settling time and organic loading rate were manipulated to adjust sludge morphology and biomass concentration in sequential batch reactors (SBRs) to investigate their influence on PHB storage in the feast phase. Our study shows that reducing settling times in SBRs from 10 to 0 min under organic loading rate of 3 g L-1 d-1 resulted in the decrease in biomass concentration at steady states from 4.2 to 1.0 g L-1 and the change of sludge morphology from well-settled granules to poorly settled pinpoint flocs, but PHB content in sludge at the end of feast phase increased from 7.7 to 26.7%. The well-fitted regression lines between PHB content, SRT, feast/famine and food/microorganisms ratios and biomass concentration under different settling times suggest that PHB was highly dependent on biomass concentration but independent on sludge morphology. Under settling time of 0 min, the increase in OLR from 3 to 7.5 g L-1 d-1 resulted in an increased biomass concentration from 1.0 to 2.1 g L-1 and an increase in PHB content from 26.7 to 33.8%. The batch and fed-batch experiments with different biomass concentrations also showed the influence of biomass concentration on PHB accumulation in sludge. The conclusion of the dependence of PHB content on biomass concentration under a fixed OLR and varied OLRs drawn from this study enables sludge PHB content as high as possible by adjusting biomass concentration in SBRs apart from the selective enriching strategies for PHB accumulating organisms when treating VFA-rich wastewater.
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Affiliation(s)
- Seongbong Heo
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Yong-Qiang Liu
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom.
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14
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Liu YQ, Cinquepalmi S. Exploration of mechanisms for calcium phosphate precipitation and accumulation in nitrifying granules by investigating the size effects of granules. WATER RESEARCH 2021; 206:117753. [PMID: 34688097 DOI: 10.1016/j.watres.2021.117753] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Calcium phosphate could be accumulated in aerobic granules, which attracts attention recently for phosphorus removal and recovery from wastewater. In this study, partial nitrifying granules with high calcium precipitate content were sorted into different size groups for characterization and evaluation to reveal the dynamic balance of granules at stead state and relevant calcium phosphate precipitation and accumulation mechanism. It was found that light yellow small granules without calcium precipitates but high microbial activity co-existed with deep brown granules with calcium precipitate of around 91% and low microbial activity. Characterization with specific oxygen uptake rates, specific ammonium oxidation rates, calcium and phosphate removal rates from solution, EPS contents, elemental compositions by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and scanning electron microscopy (SEM) for different size groups of granules enabled a proposal of a new hypothesized mechanism for calcium precipitation and accumulation. With this proposed mechanism, it is believed that sufficient granule retention time in reactors was critical for the accumulation of calcium precipitates followed by a slow microbial growth rate of biomass due to mass transfer resistance. The co-precipitation of calcium carbonate and calcium phosphate mainly occurred in granules with a size less than 710 µm while calcium phosphate dominant minerals were accumulated in granules larger than 710 µm. The results and conclusions in this study shed light on the mechanisms of calcium phosphate accumulation in granules, which could be used to better operate and control aerobic granular sludge with calcium phosphates for phosphorus removal and recovery.
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Affiliation(s)
- Yong-Qiang Liu
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom.
| | - Simone Cinquepalmi
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
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15
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Wan C, Li Z, Shen Y, Liu X. Alternating nitrogen feeding strategy induced aerobic granulation: Influencing conditions and mechanism. J Environ Sci (China) 2021; 109:135-147. [PMID: 34607662 DOI: 10.1016/j.jes.2021.03.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/30/2021] [Accepted: 03/30/2021] [Indexed: 06/13/2023]
Abstract
Effective cultivation of stable aerobic granular sludge (AGS) is a crucial step in the successful application of this technology, and the formation of AGS could be facilitated by some environmental stress conditions. Four identical sequencing batch reactors (SBRs) were established to investigate the aerobic granulation process under the same alternating ammonia nitrogen feeding strategy superimposed with different environmental conditions (inorganic carbon source, temperature, N/COD). Although various superimposed conditions induced a significant difference in the size, settling velocity, mechanic strength of AGS, mature aerobic granules could be successfully obtained in all four reactors after 70 days' operation, indicating the alternating ammonia nitrogen feeding strategy was the most critical factor for AGS formation. Based on the results of redundancy analysis, the presence of an inorganic carbon source could facilitate the cultivation of AGS with nitrification function, while the moderate temperature and fluctuant N/COD might benefit the cultivation of more stable AGS. In addition, superimposed stress conditions could result in the difference in the microbial population between four reactors, but the population diversity and abundance of microorganisms were not the determinants of AGS formation. This study provided an effective method for the cultivation of AGS by using alternating ammonia nitrogen feeding strategy.
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Affiliation(s)
- Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Zhengwen Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Yanggui Shen
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
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16
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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.
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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
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17
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Hang Z, Li Z, Zhu Y, Zhang J, Yang F, Zhang T. A new approach to evaluate and improve the stability of aerobic sludge systems based on maintenance coefficient. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 296:113192. [PMID: 34252857 DOI: 10.1016/j.jenvman.2021.113192] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/31/2021] [Accepted: 06/28/2021] [Indexed: 06/13/2023]
Abstract
Stability is a key issue of wastewater treatment plants using either aerobic granular (AGS) or conventional activated sludge (CAS). The two forms of aerobic sludge were cultivated under different conditions to study the main factors affecting their stability. It was found that maintenance coefficient (m) describing the fraction of non-growth energy of granules increased significantly when the system became more stable during processes with the enhancement of granulation and the periodic short-term shock load. The yield coefficient (YH) was the main factor affecting the m value, and the inhibition in YH value was able to promote the maintenance potential according to the kinetic equation. Therefore, strategies that promote the maintenance coefficient could be applied to improve the stability of sludge systems, including inhibiting the yield rate and taking periodic short-term shock. Evaluation of stability based on the maintenance coefficient is a promising tool for ensuring the stable operation of wastewater treatment processes.
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Affiliation(s)
- Zhenyu Hang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Zhihua Li
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China.
| | - Yuanmo Zhu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Jing Zhang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Fan Yang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Tianyu Zhang
- Department of Mathematical Sciences, Montana State University, Bozeman, MT, 59717-2400, USA
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18
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Gao W, Hu Y, Jiao X, Gao M, Wang X. Recovery of structure and activity of disintegrated aerobic granular sludge after long-term storage: Effect of exogenous N-acyl-homoserine lactones. CHEMOSPHERE 2021; 281:130894. [PMID: 34289603 DOI: 10.1016/j.chemosphere.2021.130894] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/16/2021] [Accepted: 05/13/2021] [Indexed: 06/13/2023]
Abstract
Long-term storage of aerobic granular sludge (AGS) may lead to granule inactivation and disintegration. Granule recovery in both structure and activity is important for scale-up and stability of AGS, but information about the structure recovery of stored AGS is limited. In addition, whether short-term exogenous N-acyl-homoserine lactones (AHLs) regulations could accelerate the granule recovery and sustain positive effects on AGS is unknown. Herein, the recovery of 33-month stored AGS was performed in three reactors for 38 days (phase I) at different exogenous AHLs concentrations (0, 50 and 500 nM of AHL-mixtures in R0, R1 and R2, respectively) and for an extended 45 days without exogenous AHLs (phase II). Results demonstrated successful recovery of disintegrated AGS in all reactors, although it was relatively time-consuming in R0. The treatment performance was similar among the reactors and steady-state removal of COD (90%) and NH4+-N (94%) could be recovered within 7 and 21 days, respectively. However, exogenous AHLs regulation (especially in R1) obviously accelerated bioactivity recovery of heterotrophs and nitrifiers and improved granule characteristics, including biomass, density, hydrophobicity and extracellular polymeric substance (EPS). During phase II, sustainable positive effects remained in R1, but granule characteristics deteriorated in R2. The abundance of functional genera Thauera, Nitrosomonas and Candidatus_Nitrotoga, contributed to the rapid recovery and helped maintain the structure and activity of AGS. The predictive functional profiling of bacterial communities also demonstrated sustainably higher activities of metabolism, growth and signal sensing under exogenous AHLs regulation at an appropriate content.
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Affiliation(s)
- Wei Gao
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266237, China
| | - Yuanchao Hu
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266237, China
| | - Xianhui Jiao
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266237, China
| | - Mingming Gao
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266237, China
| | - Xinhua Wang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266237, China.
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19
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Li D, Yang J, Li Y, Zhang J. Research on rapid cultivation of aerobic granular sludge (AGS) with different feast-famine strategies in continuous flow reactor and achieving high-level denitrification via utilization of soluble microbial product (SMP). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 786:147237. [PMID: 33964764 DOI: 10.1016/j.scitotenv.2021.147237] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 06/12/2023]
Abstract
The mixture of partial AGS and flocculent sludge in continuous flow reactors were operated with periodic famine (PF) strategy and continuous feast (CF) strategy to reveal the impact of the feast-famine strategies on cultivation of AGS and the dynamics of microbial communities. The experimental results showed that the mature AGS were cultivated with PF and CF strategy on the 31st and the 71st days respectively, which was the result of good extracellular polymeric substance (EPS) secretion with PF strategy. It could accelerate the formation of microbial aggregates due to the conditions of periodic famine. High-level denitrification with PF strategy via utilization of SMP was examined by EEM-PARAFAC on cycle test. The high-throughput pyrosequencing showed that the dominant bacteria with PF strategy involved functional bacteria of nutrient removal and EPS secreting bacteria, while the dominant bacteria were fast-growing heterotrophic organisms with CF strategy.
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Affiliation(s)
- Dong Li
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100123, China.
| | - Jingwei Yang
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100123, China.
| | - Yue Li
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100123, China
| | - Jie Zhang
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100123, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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20
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Fluctuation and Re-Establishment of Aerobic Granules Properties during the Long-Term Operation Period with Low-Strength and Low C/N Ratio Wastewater. Processes (Basel) 2021. [DOI: 10.3390/pr9081290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Long-term structure stability of aerobic granules is critical to maintaining stable wastewater treatment performance. In this study, granulation and long-term stability of sludge-treating synthetic wastewater with a low chemical oxygen demand to nitrogen (COD/N) ratio of 4:1 and COD concentration of 400 mg/L in anoxic-oxic conditions were investigated for over 300 days. Inoculated suspended sludge gradually transformed into granules-dominant sludge on day 80. Due to the improved sludge volume index after 30 min settling (SVI30), mixed liquor suspended solids (MLSS) reached 5.2 g/L on day 140. Without any external intervention or disturbance, aerobic granules started to disintegrate from day 140, causing the increase in SVI and the decrease in biomass concentration until day 210, with the average sludge size reduced to 243 µm. From day 210, granular sludge started to be re-established by re-granulation, and the average granule size increased to 500 µm on day 302. During these disintegration and re-granulation periods, there was no obvious difference in terms of COD removal and nitrification, but microbial species were found more diverse after the re-granulation, with Thauera and Sphingomonas dominant. Although there was no external intervention, the food to microorganisms ratio (F/M) varied significantly due to the changes in biomass concentration caused by strong selective pressure and the change of sludge-settling ability in the reactor. F/M ratios should be controlled between 0.3 and 1.0 gCOD/gSS·d to maintain the stable structure of granules to minimize the fluctuation of sludge properties under the conditions used in this study. Although aerobic granular sludge is able to re-establish itself after disintegration, controlling F/M ratios in a certain range would benefit long-term stability. The findings in this study are significant to deepen the understanding of granule stability with low-strength and low COD ratio wastewater and, thus, provide guidance for maintaining the long-term stability of granules.
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21
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Amorim de Carvalho CD, Ferreira Dos Santos A, Tavares Ferreira TJ, Sousa Aguiar Lira VN, Mendes Barros AR, Bezerra Dos Santos A. Resource recovery in aerobic granular sludge systems: is it feasible or still a long way to go? CHEMOSPHERE 2021; 274:129881. [PMID: 33582539 DOI: 10.1016/j.chemosphere.2021.129881] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 01/26/2021] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
Lately, wastewater treatment plants are much often being designed as wastewater-resource factories inserted in circular cities. Among biological treatment technologies, aerobic granular sludge (AGS), considered an evolution of activated sludge (AS), has received great attention regarding its resource recovery potential. This review presents the state-of-the-art concerning the influence of operational parameters on the recovery of alginate-like exopolysaccharides (ALE), tryptophan, phosphorus, and polyhydroxyalkanoates (PHA) from AGS systems. The carbon to nitrogen ratio was identified as a parameter that plays an important role for the optimal production of ALE, tryptophan, and PHA. The sludge retention time effect is more pronounced for the production of ALE and tryptophan. Additionally, salinity levels in the bioreactors can potentially be manipulated to increase ALE and phosphorus yields simultaneously. Some existing knowledge gaps in the scientific literature concerning the recovery of these resources from AGS were also identified. Regarding industrial applications, tryptophan has the longest way to go. On the other hand, ALE production/recovery could be considered the most mature process if we take into account that existing alternatives for phosphorus and PHA production/recovery are optimized for activated sludge rather than granular sludge. Consequently, to maintain the same effectiveness, these processes likely could not be applied to AGS without undergoing some modification. Therefore, investigating to what extent these adaptations are necessary and designing alternatives is essential.
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Affiliation(s)
- Clara de Amorim de Carvalho
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Amanda Ferreira Dos Santos
- 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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22
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Zheng Z, Li J, Wang C. Rapid cultivation of the aerobic granules for simultaneous phenol degradation and ammonium oxidation in a sequencing batch reactor. BIORESOURCE TECHNOLOGY 2021; 325:124414. [PMID: 33493744 DOI: 10.1016/j.biortech.2020.124414] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/08/2020] [Accepted: 11/11/2020] [Indexed: 06/12/2023]
Abstract
The rapid cultivation strategy of aerobic granular sludge (AGS) for simultaneous phenol degradation and ammonium oxidation was studied in a sequence batch reactor (SBR). The short-term inhibitory kinetics of phenol was studied through batch experiments. For the sodium acetate fed AGS, the phenol inhibition constants (Ki) of specific oxygen utilization rate by heterotrophic bacteria (SOURh) was 508.6 mg/L. The Ki of specific ammonium utilization rate (SAUR) was 232.3 mg/L. After 28 days' acclimatization, the phenol and NH4+-N removal rates of the SBR reached 94.0% and 96.4% when the influent phenol and NH4+-N concentrations were 1000 and 33.5 mg/L, respectively. The phenol removal loading rate was 1.69 kg/(m3·d). For the mature phenol&ammonium degrading AGS, the polysaccharide (PS) and protein (PN) concentrations were 247.4 ± 10.3 and 68.6 ± 6.5 mg/g VSS, respectively. The functional groups analysis showed that the amount of OH, NH, CO and CC groups remained unchanged in the mature phenol&ammonium degrading AGS.
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Affiliation(s)
- Zhaoming Zheng
- National Engineering Laboratory for Wastewater Treatment Technology, Beijing University of Technology, Beijing 100124, China
| | - Jun Li
- National Engineering Laboratory for Wastewater Treatment Technology, Beijing University of Technology, Beijing 100124, China.
| | - Changwen Wang
- National Engineering Laboratory for Wastewater Treatment Technology, Beijing University of Technology, Beijing 100124, China
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23
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An Z, Kent TR, Sun Y, Bott CB, Wang ZW. Free ammonia resistance of nitrite-oxidizing bacteria developed in aerobic granular sludge cultivated in continuous upflow airlift reactors performing partial nitritation. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2021; 93:421-432. [PMID: 32816336 DOI: 10.1002/wer.1440] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/18/2020] [Accepted: 08/14/2020] [Indexed: 06/11/2023]
Abstract
Free ammonia (FA) inhibition has been taken advantage as a strategy to suppress the growth of nitrite-oxidizing bacteria (NOB) in aerobic granules stabilized in a continuous upflow airlift reactor to achieve partial nitritation. However, after nearly 18 months of continuous exposure of aerobic granules to FA in the reactor, the FA inhibition of NOB was proven ineffective, and the partial nitritation gradually shifted to partial nitrification even though the long-term granule structural stability remained excellent under the continuous-flow mode. The extent of NOB resistance to FA inhibition was quantified based on the kinetic response of NOB to various FA concentrations in the form of an uncompetitive inhibition coefficient. It was confirmed that the NOB immobilized in larger granules under longer term exposure to FA tend to become more resistant to FA. Thereby, it was concluded that NOB can develop strong resistance to FA after continuous exposure, and thus, FA inhibition is not a reliable strategy to achieve partial nitritation in mainstream wastewater treatment. PRACTITIONER POINTS: Nitrifying aerobic granules can remain structurally stable in continuous-flow bioreactors. NOB developed free ammonia resistance after 6-month continuous exposure. Larger aerobic granules tended to develop stronger free ammonia resistance. Free ammonia inhibition is not a reliable strategy for mainstream anammox.
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Affiliation(s)
- Zhaohui An
- Occoquan Laboratory, Department of Civil and Environmental Engineering, Virginia Tech, Manassas, VA, USA
| | | | - Yewei Sun
- Occoquan Laboratory, Department of Civil and Environmental Engineering, Virginia Tech, Manassas, VA, USA
- Hazen and Sawyer, Fairfax, VA, USA
| | - Charles B Bott
- Hampton Roads Sanitation District, Virginia Beach, VA, USA
| | - Zhi-Wu Wang
- Occoquan Laboratory, Department of Civil and Environmental Engineering, Virginia Tech, Manassas, VA, USA
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Sivasubramanian R, Chen GH, Mackey HR. Shock effects of monovalent cationic salts on seawater cultivated granular sludge. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123646. [PMID: 32846259 DOI: 10.1016/j.jhazmat.2020.123646] [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: 05/23/2020] [Revised: 07/15/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
Saline wastewater is commonly encountered in various industries, posing challenges to biological treatments. The application of seawater as a seed source provides a media of diverse halophilic organisms for rapid startup. However, effects of transitioning from a mixed salt source to monovalent salt solutions prevalent in industry remains unexplored. Hence, seed sludge was cultivated using seawater and later granulated under a mixed-salt synthetic medium comprising a mixture of NaCl, KCl and Na2SO4 at a combined concentration of 0.8 M (0.27 M each). The stable, acclimated granules were then tested against single salt media of 0.8 M NaCl, KCl, or Na2SO4. Shift to single salt media resulted in granule disaggregation, poor settling, sludge washout and development of fluffy or slimy flocs. Changes in exopolysaccharides composition after the single salt shift was the predominant reason for the large changes in sludge morphology. The impacts of KCl and Na2SO4 were more significant than the shift to NaCl. The resulting impacts also had a major influence on the treatment performance. A complex mechanism involving monovalent cation stimulation of proteins; ionic strength impacts on exopolysaccharides and morphology; solution density influence on sludge density and settling; and tonicity impacts on cell viability and treatment is described.
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Affiliation(s)
| | - Guang-Hao Chen
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Hamish Robert Mackey
- Division of Sustainable Development, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar.
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Sun Y, Angelotti B, Brooks M, Wang ZW. Feast/famine ratio determined continuous flow aerobic granulation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 750:141467. [PMID: 32853933 DOI: 10.1016/j.scitotenv.2020.141467] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/01/2020] [Accepted: 08/02/2020] [Indexed: 06/11/2023]
Abstract
Plug flow reactors (PFRs) made of multiple completely stirred tank reactors (CSTRs) in series were used to cultivate aerobic granules in real domestic wastewater. Theoretically, changing the number of CSTR chambers in series will change the nature of plug flow, and thus alter the pattern of the feast/famine condition and impact the aerobic granulation progress. Therefore, PFRs were operated in 4-, 6-, and 8-chamber mode under the same gravity selection pressure (a critical settling velocity of 9.75 m h-1) and hydraulic retention time (6.5 h) until steady states were reached to evaluate the effect of the feast/famine condition on continuous flow aerobic granulation. The sludge particle size, circularity, settleability, specific gravity, zone settling velocity, and extracellular polymeric substance contents were analyzed to evaluate the role that a feast/famine regime plays in aerobic granulation. It was found that aerobic granulation failed whenever the feast/famine ratio was greater than 0.5. The results support a conclusion that the feast/famine condition is likely a prerequisite for continuous flow aerobic granulation.
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Affiliation(s)
- Yewei Sun
- Occoquan Laboratory, Department of Civil and Environmental Engineering, Virginia Tech, 9408 Prince William Street, Manassas, VA 20110, USA; Hazen and Sawyer, 4035 Ridge Top Road, Suite 500, Farfax, VA 22030, USA
| | - Bob Angelotti
- Upper Occoquan Service Authority, 14631 Compton Rd, Centreville, VA 20121, USA
| | - Matt Brooks
- Upper Occoquan Service Authority, 14631 Compton Rd, Centreville, VA 20121, USA
| | - Zhi-Wu Wang
- Occoquan Laboratory, Department of Civil and Environmental Engineering, Virginia Tech, 9408 Prince William Street, Manassas, VA 20110, USA.
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Effect of Aeration Mode on Microbial Structure and Efficiency of Treatment of TSS-Rich Wastewater from Meat Processing. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10217414] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The present study investigated the effect of aeration mode on microbial structure and efficiency of treatment of wastewater with a high concentration of suspended solids (TSS) from meat processing in sequencing batch reactors (R). R1 was constantly aerated, while in R2 intermittent aeration was applied. DNA was isolated from biomass and analyzed using next-generation sequencing (NGS) and real-time PCR. As a result, in R1 aerobic granular sludge was cultivated (SVI30 = 44 mL g−1 MLSS), while in R2 a very well-settling mixture of aerobic granules and activated sludge was obtained (SVI30 = 65 mL g−1 MLSS). Intermittent aeration significantly increased denitrification and phosphorus removal efficiencies (68% vs. 43%, 73% vs. 65%, respectively) but resulted in decomposition of extracellular polymeric substances and worse-settling properties of biomass. In both reactors, microbial structure significantly changed in time; an increase in relative abundances of Arenimonas sp., Rhodobacterace, Thauera sp., and Dokdonella sp. characterized the biomass of stable treatment of meat-processing wastewater. Constant aeration in R1 cycle favored growth of glycogen-accumulating Amaricoccus tamworthensis (10.9%) and resulted in 2.4 times and 1.4 times greater number of ammonia-oxidizing bacteria and full-denitrifiers genes in biomass, respectively, compared to the R2.
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Aqeel H, Liss SN. Autotrophic Fixed-Film Systems Treating High Strength Ammonia Wastewater. Front Microbiol 2020; 11:551925. [PMID: 33013783 PMCID: PMC7506033 DOI: 10.3389/fmicb.2020.551925] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 08/12/2020] [Indexed: 01/04/2023] Open
Abstract
The aim of the study was enrichment of nitrifying bacteria and to investigate the potential of autotrophic fixed-film and hybrid bioreactors to treat high strength ammonia wastewater (up to 1,000 mg N/L). Two types of fixed-film systems [moving bed biofilm reactor (MBBR) and BioCordTM] in two different configurations [sequencing batch reactor (SBR) and a continuous stirred tank reactor (CSTR)] were operated for 306 days. The laboratory-scale bioreactors were seeded with activated sludge from a municipal wastewater treatment plant and fed synthetic wastewater with no organics. Strategies for acclimation included biomass reseeding (during bioreactor start-up), and gradual increase in the influent ammonia concentration [from 130 to 1,000 mg N/L (10% every 5 days)]. Stable ammonia removal was observed up to 750 mg N/L from 45 to 145 days in the MBBR SBR (94-100%) and CSTR (72-100%), and BioCordTM SBR (96-100%) and CSTR (92-100%). Ammonia removal declined to 87% ± 6, in all bioreactors treating 1,000 mg N/L (on day 185). Following long-term operation at 1,000 mg N/L (on day 306), ammonia removal was 93-94% in both the MBBR SBR and BioCordTM CSTR; whereas, ammonia removal was relatively lower in MBBR CSTR (20-35%) and BioCordTM SBR (45-54%). Acclimation to increasing concentrations of ammonia led to the enrichment of nitrifying (Nitrosomonas, Nitrospira, and Nitrobacter) and denitrifying (Comamonas, OLB8, and Rhodanobacter) bacteria [16S rRNA gene sequencing (Illumina)] in all bioreactors. In the hybrid bioreactor, the nitrifying and denitrifying bacteria were relatively more abundant in flocs and biofilms, respectively. The presence of dead cells (in biofilms) suggests that in the absence of an organic substrate, endogenous decay is a likely contributor of nutrients for denitrifying bacteria. The nitrite accumulation and abundance of denitrifying bacteria indicate partial denitrification in fixed-film bioreactors operated under limited carbon conditions. Further studies are required to assess the contribution of organic material produced in autotrophic biofilms (by endogenous decay and soluble microbial products) to the overall treatment process. Furthermore, the possibility of sustaining autotrophic nitrogen in high strength waste-streams in the presence of organic substrates warrants further investigation.
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Affiliation(s)
- Hussain Aqeel
- School of Environmental Studies, Queen's University, Kingston, ON, Canada
| | - Steven N Liss
- School of Environmental Studies, Queen's University, Kingston, ON, Canada.,Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada.,Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
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Nitrogen Removal Efficiency and Microbial Community Analysis of a High-Efficiency Honeycomb Fixed-Bed Bioreactor. WATER 2020. [DOI: 10.3390/w12061832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Based on the concept of microbial community multi-processing in integrated spatial bacterial succession (ISBS), this study constructs a highly efficient cellular fixed-bed bioreactor that follows the growth of biological flora in the wastewater treatment process. The reactor is organically partitioned based on synergistic laws and in accordance with environmental and microbial metabolic changes, and sewage is subjected to unitized and specialized biological treatment under direct current conditions. The results show that the ISBS reactor exhibits stable nitrogen removal performance under a low-carbon source. Compared with traditional sewage biochemical treatment technology, the microbial concentration is increased by 2–3 times and even up to 12 times, and the ammonia nitrogen removal rate is maintained at 99%. The removal rate reaches 90% (hydraulic retention time of 14 h). High-throughput sequencing analysis based on 16S rDNA reveals the microbial community structure succession at different depths of the same section of the reactor. The microbial community is rich under the influence of environmental factors and exhibits different responses. The intervals vary. An analysis of the microbial community function explains why the ISBS reactor has high nitrogen removal efficiency.
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Peng B, Liang H, Wang S, Gao D. Effects of DO on N 2O emission during biological nitrogen removal using aerobic granular sludge via shortcut simultaneous nitrification and denitrification. ENVIRONMENTAL TECHNOLOGY 2020; 41:251-259. [PMID: 29962291 DOI: 10.1080/09593330.2018.1494757] [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: 04/28/2018] [Accepted: 06/23/2018] [Indexed: 06/08/2023]
Abstract
Dissolved oxygen (DO) is an important factor influencing biological nitrogen removal. This study investigated the effects of different DO concentrations (4, 2, 1 mg/L) on nitrous oxide (N2O) production and nitrogen removal via shortcut simultaneous nitrification and denitrification by aerobic granular sludge (SNDAG) using a sequencing bath reactor. The results showed that N2O production was highest (127.6 mg/m3) at a DO concentration of 2 mg/L; this was 24.17 and 2.90 times the production at DO concentrations of 4 and 12 mg/L, respectively. The removal efficiency of total nitrogen also was the highest (61.68%) when the DO concentration was 2 mg/L, compared to 35.22% and 50.65% at DO concentrations of 4 and 1 mg/L, respectively. The efficiency of the SNDAG process reached 53.86% at a DO concentration of 2 mg/L, which was 1.33 and 1.67 times the efficiencies at DO concentrations of 4 and 1 mg/L, respectively. Therefore, reducing the DO concentration benefited the SNDAG process, but increased the emission of N2O.
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Affiliation(s)
- Bo Peng
- Center for Ecological Research, Northeast Forestry University, Harbin, People's Republic of China
| | - Hong Liang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, People's Republic of China
| | - Shanshan Wang
- Center for Ecological Research, Northeast Forestry University, Harbin, People's Republic of China
| | - Dawen Gao
- Center for Ecological Research, Northeast Forestry University, Harbin, People's Republic of China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, People's Republic of China
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30
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Omar AH, Muda K, Majid ZA, Affam AC, Ezechi EH. Effect of magnetic activated carbon on the surface hydrophobicity for initial biogranulation via response surface methodology. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2020; 92:73-83. [PMID: 31276251 DOI: 10.1002/wer.1177] [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: 03/27/2019] [Revised: 06/20/2019] [Accepted: 06/29/2019] [Indexed: 06/09/2023]
Abstract
Biogranulation is an effective biological technology suitable for the treatment of various wastewaters. However, the major drawback of this technique is the long start-up period for biogranule development. Hence, the primary focus of this study was on cell surface hydrophobicity which is the main parameter that indicates cell agglomeration during the initial self-immobilization process of aerobic granulation. The effects of sludge concentration and magnetic activated carbon on cell surface hydrophobicity were investigated in this study. Response surface methodology (RSM) was applied to design, analyze, and optimize the outcome of the study. Experiments were performed at sludge concentration of 1,000-3,000 mg/L and magnetic activated carbon mass of 1-5 g/L with 24 hr of aeration time. The results show that both variables yielded a positive significant effect on the initial development of aerobic granulation with 56% surface hydrophobicity. Interaction effects between variables on the responses were significant with positive estimated interaction effect at all different measured aeration time. The magnetic activated carbon acted as nuclei to induce bacterial attachment and further enhanced the initial process of biogranule development under optimal condition of 1:1.1 (sludge concentration: magnetic activated carbon). PRACTITIONER POINTS: Cell surface hydrophobicity was evaluated Magnetic activated carbon enhanced cell surface hydrophobicity Response surface methodology was employed for analyses Magnetic activate carbon mass and biomass concentration was significant Magnetic activated carbon acted as nuclei to improve biogranulation.
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Affiliation(s)
- Ahmad Hanis Omar
- Water and Environmental Engineering, School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
| | - Khalida Muda
- Water and Environmental Engineering, School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
| | - Zaiton Abdul Majid
- Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
| | - Augustine Chioma Affam
- Civil Engineering Department, University College of Technology Sarawak, Sibu, Sarawak, Malaysia
| | - Ezerie Henry Ezechi
- Water and Environmental Engineering, School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
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31
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Li X, Feng H, Li Z, Shi Y, Tian J, Zhao C, Yu M, Liu Z, Li H, Shi B, Wang Q, Li L, Wang D, Zhu L, Liu R, Li Z. High-Throughput Identification and Screening of Single Microbial Cells by Nanobowl Array. ACS APPLIED MATERIALS & INTERFACES 2019; 11:44933-44940. [PMID: 31675212 DOI: 10.1021/acsami.9b08662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
High-throughput screening and fast identification of single bacterial cells are crucial for clinical diagnosis, bioengineering, and fermentation engineering. Although single-cell technologies have been developed extensively in recent years, the single-cell technologies for bacteria still need further exploration. In this study, we demonstrate an identification and screening technology for single bacterial cells based on a large-scale nanobowl array, which is well-ordered and size-adjustable for use with different kinds of bacteria. When the culture medium with monodispersed bacteria was placed on the nanobowl array, it successfully enabled loading of single bacterium into a single nanobowl. Because of the limitative size and depth of the nanobowls, mixture of different bacteria species could be screened according to their sizes. In addition, with the help of a low electrical current, the bacteria can be further screened according to their intrinsic surface charges. If combined with micromanipulation technology, high-throughput single bacterial selection can be achieved in future.
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Affiliation(s)
- Xiuyan Li
- Beijing Institute of Graphic Communication , Beijing 102600 , P. R. China
| | - Hongqing Feng
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083 , P. R. China
- School of Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Zhe Li
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083 , P. R. China
- School of Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Yue Shi
- Beijing Institute of Graphic Communication , Beijing 102600 , P. R. China
| | - Jingjing Tian
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083 , P. R. China
- School of Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Chaochao Zhao
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083 , P. R. China
- School of Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Min Yu
- School of Stomatology and Medicine , Foshan University , Foshan 528000 , P. R. China
| | - Zhuo Liu
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083 , P. R. China
| | - Hu Li
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083 , P. R. China
| | - Bojing Shi
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083 , P. R. China
| | - Qian Wang
- Beijing Institute of Graphic Communication , Beijing 102600 , P. R. China
| | - Luhai Li
- Beijing Institute of Graphic Communication , Beijing 102600 , P. R. China
| | - Dongshu Wang
- State Key Laboratory of Pathogen and Biosecurity , Beijing Institute of Biotechnology , Beijing 100071 , P. R. China
| | - Li Zhu
- State Key Laboratory of Pathogen and Biosecurity , Beijing Institute of Biotechnology , Beijing 100071 , P. R. China
| | - Ruping Liu
- Beijing Institute of Graphic Communication , Beijing 102600 , P. R. China
| | - Zhou Li
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083 , P. R. China
- School of Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
- Center on Nanoenergy Research, School of Physical Science and Technology , Guangxi University , Nanning 530004 , P. R. China
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32
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Pishgar R, Dominic JA, Sheng Z, Tay JH. Influence of operation mode and wastewater strength on aerobic granulation at pilot scale: Startup period, granular sludge characteristics, and effluent quality. WATER RESEARCH 2019; 160:81-96. [PMID: 31132565 DOI: 10.1016/j.watres.2019.05.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/07/2019] [Accepted: 05/08/2019] [Indexed: 06/09/2023]
Abstract
This study attempted to investigate the influence of operation mode and wastewater strength on startup period, aerobic granular sludge (AGS) characteristics, and system effluent quality at pilot scale. Granulation was monitored in three pilot-scale granular sequencing batch reactors (GSBRs). Comparative evaluation of AN/O/AX/O_SBR and O_SBR, fed with wastewater of the same composition but run with completely different SBR reaction phase arrangements (alternating vs. purely aerobic), revealed the effect of SBR operation mode. Comparative study of the GSBRs operated with alternating SBR reaction phases (AN/O/AX/O_SBR and AN/O_SBR) and fed with wastewater of different strength (high- vs. medium-strength) determined the effect of wastewater composition. Granulation time and granule size were regulated by wastewater strength and the resulting organic and sludge loading conditions. Whereas, AGS morphology, granule structure, and floccular proportion of AGS were attributed to SBR operation mode. Effluent clarity in terms of suspended solid concentration depended on wastewater strength. Subtle but distinct microbial selection strategies were in effect during granulation which were also imposed by wastewater strength. Due to strong correlation between the effluent and AGS microbial structures, demonstrated by biodiversity analysis, differences in the microbial composition of effluent biomass and washout patterns of the GSBRs could be explained by wastewater strength as well. Limited nutrient removal efficiencies, restricted by organic matter concentration, could be due to involvement of unorthodox nutrient removal pathways which warrants further investigation.
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Affiliation(s)
- Roya Pishgar
- Department of Civil Engineering, University of Calgary, Calgary, Canada.
| | | | - Zhiya Sheng
- Department of Civil Engineering, University of Calgary, Calgary, Canada
| | - Joo Hwa Tay
- Department of Civil Engineering, University of Calgary, Calgary, Canada
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33
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Farhat NM, Javier L, Van Loosdrecht MCM, Kruithof JC, Vrouwenvelder JS. Role of feed water biodegradable substrate concentration on biofouling: Biofilm characteristics, membrane performance and cleanability. WATER RESEARCH 2019; 150:1-11. [PMID: 30508707 DOI: 10.1016/j.watres.2018.11.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 10/25/2018] [Accepted: 11/19/2018] [Indexed: 06/09/2023]
Abstract
Biofouling severely impacts operational performance of membrane systems increasing the cost of water production. Understanding the effect of critical parameters of feed water such as biodegradable substrate concentration on the developed biofilm characteristics enables development of more effective biofouling control strategies. In this study, the effect of substrate concentration on the biofilm characteristics was examined using membrane fouling simulators (MFSs). A feed channel pressure drop (PD) increase of 200 mbar was used as a benchmark to study the developed biofilm. The amount and characteristics of the formed biofilm were analysed in relation to membrane performance indicators: feed channel pressure drop and permeate flux. The effect of the characteristics of the biofilm developed at three substrate concentrations on the removal efficiency of the different biofilms was evaluated applying acid/base cleaning. Results showed that a higher feed water substrate concentration caused a higher biomass amount, a faster PD increase, but a lower permeate flux decline. The permeate flux decline was affected by the spatial location and the physical characteristics of the biofilm rather than the total amount of biofilm. The slower growing biofilm developed at the lowest substrate concentration was harder to remove by NaOH/HCl cleanings than the biofilm developed at the higher substrate concentrations. Effective biofilm removal is essential to prevent a fast biofilm regrowth after cleaning. While substrate limitation is a generally accepted biofouling control strategy delaying biofouling, development of advanced cleaning methods to remove biofilms formed under substrate limited conditions is of paramount importance.
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Affiliation(s)
- N M Farhat
- King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia.
| | - L Javier
- King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia
| | - M C M Van Loosdrecht
- Delft University of Technology, Faculty of Applied Sciences, Department of Biotechnology, Van der Maasweg 9, 2629, HZ, Delft, the Netherlands
| | - J C Kruithof
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911, MA, Leeuwarden, the Netherlands
| | - J S Vrouwenvelder
- King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia; Delft University of Technology, Faculty of Applied Sciences, Department of Biotechnology, Van der Maasweg 9, 2629, HZ, Delft, the Netherlands
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34
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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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35
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Li D, Zhang S, Li S, Zeng H, Zhang J. The nitrogen removal of autotrophic and heterotrophic bacteria in aerobic granular reactors with different feast/famine ratio. BIORESOURCE TECHNOLOGY 2019; 272:370-378. [PMID: 30384212 DOI: 10.1016/j.biortech.2018.10.046] [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: 09/12/2018] [Revised: 10/17/2018] [Accepted: 10/19/2018] [Indexed: 05/21/2023]
Abstract
Aerobic granular sludge was cultivated in three column reactors, which had been operated for 120 days under different feast/famine ratio (1:7, 1:11, 1:15). The composition of total bacteria was analyzed by testing oxygen uptake rates of mixed liquor samples taken from the reactors and calculating according to activated sludge model. The results revealed that long famine phase favored the growth of heterotrophic bacteria. The heterotrophic bacteria accounts for 49.80, 53.37, 91.39% of total bacteria respectively in R1, R2 and R3. The heterotrophic nitrification was also observed in all the reactors, which accounts for 58.62, 58.33, 61.54% of total nitrification respectively in R1, R2 and R3. A novel nitrogen-removal pathway involving simultaneous nitrification-denitrification by heterotrophic nitrification bacteria was proposed. The results revealed that microbial system consisted of heterotrophic ammonia oxidizing bacteria showed stronger capacity of simultaneous nitrification-denitrification.
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Affiliation(s)
- Dong Li
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100123, China.
| | - Shirui Zhang
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100123, China
| | - Shuai Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Huiping Zeng
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100123, China
| | - Jie Zhang
- Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100123, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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de Sousa Rollemberg SL, Mendes Barros AR, Milen Firmino PI, Bezerra Dos Santos A. Aerobic granular sludge: Cultivation parameters and removal mechanisms. BIORESOURCE TECHNOLOGY 2018; 270:678-688. [PMID: 30201322 DOI: 10.1016/j.biortech.2018.08.130] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 06/08/2023]
Abstract
Aerobic granular sludge (AGS) has been the focus of many investigations, and the main parameters responsible for AGS formation are hydrodynamic shear force, short periods and feast-famine cycles. However, some other parameters are associated with AGS maintenance after long periods of operation. This review evaluates the parameters responsible for AGS formation and maintenance and some reference values are proposed. In addition, some discussions are addressed about the main metabolic pathways that AGS uses for the removal of some compounds, such as nutrients, organic matter, dyes, recalcitrant compounds, among others. Finally, the main microbial groups present in the AGS and their respective functions are discussed. It is also highlighted that many parameters that are taken as reference currently for AGS cultivation and maintenance can be optimized for energy savings, implementation costs, among others, as well as a greater recovery of resources during wastewater treatment, within the scope of the biorefinery concept.
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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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Wei D, Ngo HH, Guo W, Xu W, Du B, Wei Q. Partial nitrification granular sludge reactor as a pretreatment for anaerobic ammonium oxidation (Anammox): Achievement, performance and microbial community. BIORESOURCE TECHNOLOGY 2018; 269:25-31. [PMID: 30149251 DOI: 10.1016/j.biortech.2018.08.088] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 08/17/2018] [Accepted: 08/20/2018] [Indexed: 06/08/2023]
Abstract
Partial nitrification granular sludge was successfully cultivated in a sequencing batch reactor as a pretreatment for anaerobic ammonium oxidation (Anammox) through shortening settling time. After 250-days operation, the effluent NH4+-N and NO2--N concentrations were average at 277.5 and 280.5 mg/L with nitrite accumulation rate of 87.8%, making it as an ideal influent for Anammox. Simultaneous free ammonia (FA) and free nitrous acid (FNA) played major inhibitory roles on the activity of nitrite oxidizing bacteria (NOB). The MLSS and SVI30 of partial nitrification reactor were 14.6 g/L and 25.0 mL/g, respectively. Polysaccharide (PS) and protein (PN) amounts in extracellular polymeric substances (EPS) from granular sludge were about 1.3 and 2.8 times higher than from seed sludge. High-throughput pyrosequencing results indicated that Nitrosomonas affiliated to the ammonia oxidizing bacteria (AOB) was the predominant group with a proportion of 24.1% in the partial nitrification system.
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Affiliation(s)
- Dong Wei
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China
| | - Huu Hao Ngo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Wenshan Guo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Weiying Xu
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China
| | - Bin Du
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China.
| | - Qin Wei
- Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China
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Han F, Ye W, Wei D, Xu W, Du B, Wei Q. Simultaneous nitrification-denitrification and membrane fouling alleviation in a submerged biofilm membrane bioreactor with coupling of sponge and biodegradable PBS carrier. BIORESOURCE TECHNOLOGY 2018; 270:156-165. [PMID: 30218931 DOI: 10.1016/j.biortech.2018.09.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 09/04/2018] [Accepted: 09/05/2018] [Indexed: 06/08/2023]
Abstract
Simultaneous nitrification-denitrification (SND) was achieved in submerged biofilm membrane bioreactor (SBF-MBR) treating low carbon/nitrogen (C/N) ratio wastewater. A novel bio-carrier coupling of sponge and biodegradable poly(butanediol succinate) (PBS) was applied as external carbon source and biofilm carrier. Result represented that NH4+-N and total nitrogen removal efficiencies were high of 99.1% and 94.3% in the SBF-MBR. Protein (PN) contents from SND-biofilm were reduced by 10.5% and 44.3% in TB-EPS and LB-EPS, while polysaccharides (PS) were reduced by 45.8% and 34.8%, respectively. 3D-EEM spectra indicated that protein-like, humic acid-like and fulvic acid-like substances were the main components in EPS and their peak intensities were reduced. Additionally, membrane fouling of SBF-MBR was improved after the achievement of biofilm. Microbial community analysis showed that Simplicispira, Thauera, Desulfovibrio, Dechlorobacter and Acinetobacter were dominant genus, which indicated co-existence of nitrifying bacteria, heterotrophic denitrifiers and aerobic denitrifiers in the SBF-MBR.
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Affiliation(s)
- Fei Han
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China
| | - Wei Ye
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China
| | - Dong Wei
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China.
| | - Weiying Xu
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China
| | - Bin Du
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China
| | - Qin Wei
- Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China
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Li J, Ye W, Wei D, Ngo HH, Guo W, Qiao Y, Xu W, Du B, Wei Q. System performance and microbial community succession in a partial nitrification biofilm reactor in response to salinity stress. BIORESOURCE TECHNOLOGY 2018; 270:512-518. [PMID: 30248650 DOI: 10.1016/j.biortech.2018.09.068] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/11/2018] [Accepted: 09/12/2018] [Indexed: 06/08/2023]
Abstract
The system performance and microbial community succession in a partial nitrification biofilm reactor in response to salinity stress was conducted. It was found that the NH4+-N removal efficiency decreased from 98.4% to 42.0% after salinity stress increased to 20 g/L. Specific oxygen uptake rates suggested that AOB activity was more sensitive to the stress of salinity than that of NOB. Protein and polysaccharides contents showed an increasing tendency in both LB-EPS and TB-EPS after the salinity exposure. Moreover, EEM results indicated that protein-like substances were the main component in LB-EPS and TB-EPS as self-protection in response to salinity stress. Additionally, humic acid-like substances were identified as the main component in the effluent organic matter (EfOM) of partial nitrification biofilm, whereas fulvic acid-like substances were detected at 20 g/L salinity stress. Microbial community analysis found that Nitrosomonas as representative species of AOB were significantly inhibited under high salinity condition.
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Affiliation(s)
- Jibin Li
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, PR China
| | - Wei Ye
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, PR China
| | - Dong Wei
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, PR China.
| | - Huu Hao Ngo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Wenshan Guo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Yiming Qiao
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, PR China
| | - Weiying Xu
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, PR China
| | - Bin Du
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, PR China
| | - Qin Wei
- Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China
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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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Kent TR, Bott CB, Wang ZW. State of the art of aerobic granulation in continuous flow bioreactors. Biotechnol Adv 2018; 36:1139-1166. [PMID: 29597030 DOI: 10.1016/j.biotechadv.2018.03.015] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 03/21/2018] [Accepted: 03/21/2018] [Indexed: 10/17/2022]
Abstract
In the wake of the success of aerobic granulation in sequential batch reactors (SBRs) for treating wastewater, attention is beginning to turn to continuous flow applications. This is a necessary step given the advantages of continuous flow treatment processes and the fact that the majority of full-scale wastewater treatment plants across the world are operated with aeration tanks and clarifiers in a continuous flow mode. As in SBRs, applying a selection pressure, based on differences in either settling velocity or the size of the biomass, is essential for successful granulation in continuous flow reactors (CFRs). CFRs employed for aerobic granulation come in multiple configurations, each with their own means of achieving such a selection pressure. Other factors, such as bioaugmentation and hydraulic shear force, also contribute to aerobic granulation to some extent. Besides the formation of aerobic granules, long-term stability of aerobic granules is also a critical issue to be addressed. Inorganic precipitation, special inocula, and various operational optimization strategies have been used to improve granule long-term structural integrity. Accumulated studies reviewed in this work demonstrate that aerobic granulation in CFRs is capable of removing a wide spectrum of contaminants and achieving properties generally comparable to those in SBRs. Despite the notable research progress made toward successful aerobic granulation in lab-scale CFRs, to the best of our knowledge, there are only three full-scale tests of the technique, two being seeded with anammox-supported aerobic granules and the other with conventional aerobic granules; two other process alternatives are currently in development. Application of settling- or size-based selection pressures and feast/famine conditions are especially difficult to implement to these and similar mainstream systems. Future research efforts needs to be focused on the optimization of the granule-to-floc ratio, enhancement of granule activity, improvement of long-term granule stability, and a better understanding of aerobic granulation mechanisms in CFRs, especially in full-scale applications.
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Affiliation(s)
- Timothy R Kent
- Occoquan Laboratory, Department of Civil and Environmental Engineering, Virginia Tech, United States
| | | | - Zhi-Wu Wang
- Occoquan Laboratory, Department of Civil and Environmental Engineering, Virginia Tech, United States.
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42
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Cetin E, Karakas E, Dulekgurgen E, Ovez S, Kolukirik M, Yilmaz G. Effects of high-concentration influent suspended solids on aerobic granulation in pilot-scale sequencing batch reactors treating real domestic wastewater. WATER RESEARCH 2018; 131:74-89. [PMID: 29275102 DOI: 10.1016/j.watres.2017.12.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 12/08/2017] [Accepted: 12/09/2017] [Indexed: 06/07/2023]
Abstract
The aim of this study was to investigate the effect of high-influent-concentration suspended solids (SS) on the cultivation, structure and long-term stability of aerobic granular sludge (AGS). Cultivation and long-term stability of AGS were monitored in two pilot-scale sequencing batch reactors fed with raw (R1) and settled (R2) domestic wastewater, representing high and medium SS content, respectively. The real domestic wastewater had high chemical oxygen demand (COD) content (1100 ± 270 mg COD L-1). Aerobic granular sludge was cultivated in 44 days (R1) and 25 days (R2) under the conditions of high settling velocity (18 m h-1) and high organic loading rate (OLR) (2.1-2.4 kg COD m3 day). The AGS in both reactors had similar structural properties during long-term operation and remained structurally and functionally stable during the last five months of operation. Comparative evaluation of the results indicated that the high influent SS content of the real domestic wastewater had a positive influence on maintaining significantly lower SVI30 and relatively lower effluent SS concentration. Moreover, a higher influent SS content resulted in smaller mature granules during the stable period. Microbial community analyses helped to understand the aerobic granular sludge structure and showed that the sludge retention time and OLR affected the granular sludge population. The high influent SS increased biomass detachment from the granular sludge surface and caused wash-out of some bacteria colonizing the exterior of the granular sludge.
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Affiliation(s)
- Ender Cetin
- Istanbul University, Faculty of Engineering, Environmental Engineering Department, Avcilar 34320, Istanbul, Turkey
| | - Emre Karakas
- Istanbul University, Faculty of Engineering, Environmental Engineering Department, Avcilar 34320, Istanbul, Turkey
| | - Ebru Dulekgurgen
- Istanbul Technical University, Faculty of Civil Engineering, Environmental Engineering Department, Maslak 34469, Istanbul, Turkey
| | - Suleyman Ovez
- Istanbul Technical University, Faculty of Civil Engineering, Environmental Engineering Department, Maslak 34469, Istanbul, Turkey
| | | | - Gulsum Yilmaz
- Istanbul University, Faculty of Engineering, Environmental Engineering Department, Avcilar 34320, Istanbul, Turkey.
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43
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Franca RD, Pinheiro HM, van Loosdrecht MC, Lourenço ND. Stability of aerobic granules during long-term bioreactor operation. Biotechnol Adv 2018; 36:228-246. [DOI: 10.1016/j.biotechadv.2017.11.005] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/30/2017] [Accepted: 11/14/2017] [Indexed: 10/18/2022]
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He Q, Zhang W, Zhang S, Zou Z, Wang H. Performance and microbial population dynamics during stable operation and reactivation after extended idle conditions in an aerobic granular sequencing batch reactor. BIORESOURCE TECHNOLOGY 2017; 238:116-121. [PMID: 28433898 DOI: 10.1016/j.biortech.2017.03.181] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 06/07/2023]
Abstract
The evolution of removal performance and bacterial population dynamics of an aerobic granular sequencing batch reactor were investigated during stable operation and reactivation after prolonged storage. The system was run for a period of 130days including the stable condition phase, storage period and the subsequent reactivation process. Excellent removal performance was obtained during the stable operation period, which was decayed by the extended idle conditions. The removal efficiencies for both carbon and nitrogen decayed while phosphorus removal remained unaffected. Both granules structure and physical properties could be fully restored. Microbial populations shifted sharply and the storage perturbations irreversibly altered the microbial communities at different levels. Extracellular polymeric substances (especially protein) and key groups were identified as contributors for storage and re-startup of the aerobic granular system.
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Affiliation(s)
- Qiulai He
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Wei Zhang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Shilu Zhang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Zhuocheng Zou
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Hongyu Wang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China.
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Tao J, Qin L, Liu X, Li B, Chen J, You J, Shen Y, Chen X. Effect of granular activated carbon on the aerobic granulation of sludge and its mechanism. BIORESOURCE TECHNOLOGY 2017; 236:60-67. [PMID: 28390278 DOI: 10.1016/j.biortech.2017.03.106] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/12/2017] [Accepted: 03/17/2017] [Indexed: 06/07/2023]
Abstract
The granulation of activated sludge and effect of granular activated carbon (GAC) was investigated under the alternative anaerobic and aerobic conditions. The results showed that GAC accelerated the granulation, but had no obvious effect on the bacterial community structure of granules. The whole granulation process could be categorized into three phases, i.e. lag, granulation and granule maturation phase. During lag period GAC provided nuclei for sludge to attach, and thus enhanced the morphological regularization of sludge. During granulation period the granule size increased significantly due to the growth of bacteria in granules. GAC reduced the compression caused by the inter-particle collisions and thus accelerate the granulation. GAC has no negative effect on the performance of SBR, and thus efficient simultaneous removal of COD, nitrogen and phosphorus were obtained during most of the operating time.
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Affiliation(s)
- Jia Tao
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Lian Qin
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Xiaoying Liu
- School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, China
| | - Bolin Li
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Junnan Chen
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Juan You
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Yitian Shen
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Xiaoguo Chen
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China; Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan 430070, China.
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Hu Y, Wang XC, Sun Q, Ngo HH, Yu Z, Tang J, Zhang Q. Characterization of a hybrid powdered activated carbon-dynamic membrane bioreactor (PAC-DMBR) process with high flux by gravity flow: Operational performance and sludge properties. BIORESOURCE TECHNOLOGY 2017; 223:65-73. [PMID: 27780093 DOI: 10.1016/j.biortech.2016.10.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/12/2016] [Accepted: 10/13/2016] [Indexed: 06/06/2023]
Abstract
Three PAC-DMBRs were developed for wastewater treatment under different PAC dosages with biomass concentrations averaged at 2.5, 3.5 and 5.0g/L. The DMBRs could be continuously operated at 40-100L/m2h, while higher fluxes were obtained within the PAC-DMBRs with hydraulic retention times varying in 4-10h. A dose of 1g/L PAC brought about obvious improvement in the sludge particle size distribution, settling, flocculating and dewatering properties due to the formation of biological PAC, and the sludge properties were further improved at a higher PAC dose (3g/L). The addition of PAC notably shortened the DM formation time after air backwashing and enhanced pollutant removal. Moreover, under a long solid retention time (approximately 150d), the concentrations of both soluble and bound extracellular polymeric substances (EPS) decreased substantially because of the adsorption and biodegradation effects of the biological PAC. No obvious impact on biomass activity was observed with PAC addition.
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Affiliation(s)
- Yisong Hu
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, PR China; International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an 710055, PR China
| | - Xiaochang C Wang
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, PR China; Key Lab of Environmental Engineering, Xi'an, Shaanxi Province 710055, PR China; International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an 710055, PR China.
| | - Qiyuan Sun
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, PR China
| | - Huu Hao Ngo
- International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an 710055, PR China; Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Zhenzhen Yu
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, PR China
| | - Jialing Tang
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, PR China
| | - Qionghua Zhang
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, PR China; International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an 710055, PR China
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47
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Li K, Wei D, Yan T, Du B, Wei Q. Responses of soluble microbial products and extracellular polymeric substances to the presence of toxic 2,6-dichlorophenol in aerobic granular sludge system. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2016; 183:594-600. [PMID: 27623368 DOI: 10.1016/j.jenvman.2016.09.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/04/2016] [Accepted: 09/03/2016] [Indexed: 06/06/2023]
Abstract
The objective of this study was to evaluate the responses of soluble microbial products (SMP) and extracellular polymeric substances (EPS) to the presence of toxic 2,6-dichlorophenol (2,6-DCP) in aerobic granular sludge (AGS) system. Batch experiment showed that NH4+-N removal efficiency significantly decreased from 99.6% to 47.2% in the toxic 2,6-DCP of 20 mg/L. Moreover, the inhibition degrees of 2,6-DCP on (SOUR)H, [Formula: see text] and [Formula: see text] were 7.8%, 32.1% and 9.5%, respectively. The main components of SMP, including protein (PN) and polysaccharide (PS) increased from 2.3 ± 0.74 and 16.8 ± 0.12 mg/L to 66.4 ± 0.56 and 18.0 ± 0.19 mg/L in the presence of 2,6-DCP. Three-dimensional excitation-emission matrix (3D-EEM) spectroscopy identified tryptophan PN-like, humic acid-like and fulvic acid-like substances in the control SMP, and their fluorescence intensities increased after exposure to 2,6-DCP. Synchronous fluorescence spectra suggested that the fluorescence quenching between EPS and 2,6-DCP was a static quenching process. The obtained results could provide insightful information on the responses of microbial products to AGS in the presence of toxic chlorophenols.
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Affiliation(s)
- Kai Li
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China
| | - Dong Wei
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China
| | - Tao Yan
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China
| | - Bin Du
- School of Resources and Environment, University of Jinan, Jinan 250022, PR China.
| | - Qin Wei
- Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China
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Wu N, Wei D, Zhang Y, Xu W, Yan T, Du B, Wei Q. Comparison of soluble microbial products released from activated sludge and aerobic granular sludge systems in the presence of toxic 2,4-dichlorophenol. Bioprocess Biosyst Eng 2016; 40:309-318. [DOI: 10.1007/s00449-016-1698-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/20/2016] [Indexed: 10/20/2022]
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Zhang Z, Gao P, Li M, Cheng J, Liu W, Feng Y. Influence of Silver nanoparticles on nutrient removal and microbial communities in SBR process after long-term exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 569-570:234-243. [PMID: 27343942 DOI: 10.1016/j.scitotenv.2016.06.115] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/13/2016] [Accepted: 06/15/2016] [Indexed: 06/06/2023]
Abstract
The widespread utilization of silver nanoparticles (AgNPs) in industrial and commercial products inevitably raises the release into wastewater that might cause potential negative impacts on sewage treatment system. In this paper, long-term exposure experiments at four levels were conducted to determine whether AgNPs caused adverse impacts on nutrient removals in sequencing batch reactors (SBRs) and changes of microbial community structure. Compared with the control reactor (without AgNPs), carbon, nitrogen and phosphorus removal in presence of 0.1mg/L AgNPs was no difference. However, presence of 1.0 and 10mg/L AgNPs decreased the average removal efficiencies of COD from 95.4% to 85.2% and 68.3%, ammonia nitrogen from 98.8% to 71.2% and 49%, SOP from 97.6% to 75.5% and 54.1%, respectively. It was found that AgNPs could accumulate in sludge with the distribution coefficients of 39.2-114L/g, inhibit the protein and polysaccharide production in EPS, reduce the SOUR of sludge, and greatly increase LDH release from microbial cells. The illumina high-throughput sequencing results indicated that AgNPs concentration changed the structures of bacterial communities, associating with the effects of AgNPs on reactor performance. Sequence analyses showed that Proteobacteria, Bacteroidetes and Acidobacteria were the dominant phyla. It was notable that AgNPs addition reduced the contents of several nitrifying bacteria at genera level in sludge, leading to the lower removal of nitrogen.
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Affiliation(s)
- Zhaohan Zhang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No73, Huanghe Road, Nangang District, Harbin 150090, China; Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No 43, Songfa Street, Daoli District, Harbin 150001, China
| | - Peng Gao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No73, Huanghe Road, Nangang District, Harbin 150090, China.
| | - Moqing Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No73, Huanghe Road, Nangang District, Harbin 150090, China
| | - Jiaqi Cheng
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No73, Huanghe Road, Nangang District, Harbin 150090, China
| | - Wei Liu
- Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No 43, Songfa Street, Daoli District, Harbin 150001, China
| | - Yujie Feng
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No73, Huanghe Road, Nangang District, Harbin 150090, China.
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Yilmaz G, Bozkurt U, Magden KA. Effect of iron ions (Fe2+, Fe3+) on the formation and structure of aerobic granular sludge. Biodegradation 2016; 28:53-68. [DOI: 10.1007/s10532-016-9777-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 10/18/2016] [Indexed: 11/25/2022]
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