1
|
Zhang C, Zeng X, Xu X, Nie W, Dubey BK, Ding W. PDA-Fe 3O 4 decorated carbon felt anode enhancing electrochemical performance of microbial fuel cells: Effect of electrode materials on electroactive biofilm. CHEMOSPHERE 2024; 355:141764. [PMID: 38521108 DOI: 10.1016/j.chemosphere.2024.141764] [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: 11/16/2023] [Revised: 03/14/2024] [Accepted: 03/19/2024] [Indexed: 03/25/2024]
Abstract
Anode modification is an effective strategy for enhancing the electrochemical performance of microbial fuel cell (MFC). However, the impacts of the modified materials on anode biofilm development during MFC operation have been less studied. We prepared a novel PDA-Fe3O4-CF composite anode by coating original carbon felt anode (CF) with polydopamine (PDA) and Fe3O4 nanoparticles. The composite anode material was characterized by excellent hydrophilicity and electrical conductivity, and the anodic biofilm exhibited fast start-up, higher biomass, and more uniform biofilm layer after MFC operation. The MFC reactor assembled with the composite anode achieved a maximum power density of 608 mW m-2 and an output voltage of 586 mV, which were 316.4% and 72.4% higher than the MFC with the original CF anode, respectively. Microbial community analysis indicated that the modified anode biofilm had a higher relative abundance of exoelectrogen species in comparison to the unmodified anode. The PICRUSt data revealed that the anodic materials may affect the bioelectrochemical performance of the biofilm by influencing the expression levels of key enzyme genes involved in biofilm extracellular polymer (EPS) secretion and extracellular electron transfer (EET). The growth of the anodic biofilm would exert positive or negative influences on the efficiency of electricity production and electron transfer of the MFCs at different operating stages. This work expands the knowledge of the role that anodic materials play in the development and electrochemical performance of anodic biofilm in MFCs.
Collapse
Affiliation(s)
- Cunkuan Zhang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400044, China
| | - Xiaolan Zeng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400044, China.
| | - Xiaotang Xu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400044, China
| | - Wenbo Nie
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400044, China
| | - Brajesh Kumar Dubey
- Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West India
| | - Wenchuan Ding
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400044, China; College of Environment and Ecology, Chongqing University, Chongqing 400044, China.
| |
Collapse
|
2
|
Maghrawy HH, El Kareem HA, Gomaa OM. Enhanced exopolysaccharide production in gamma irradiated Bacillus subtilis: A biofilm-mediated strategy for ZnO nanoparticles removal. Int J Biol Macromol 2024; 258:128884. [PMID: 38141708 DOI: 10.1016/j.ijbiomac.2023.128884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 12/05/2023] [Accepted: 12/17/2023] [Indexed: 12/25/2023]
Abstract
Biofilm-mediated strategy was studied for ZnO nanoparticle removal from aqueous media. Bacillus subtilis isolated from the soil rhizosphere was selected based on its high viscosity (133 Pa/s) of the cultivated culture and biofilm formation. The bacterium was exposed to gamma-irradiation to enhance EPS production along with its cultivation in EPS-producing media. The results show an increase in viscosity that reached 160 Pa/s at 2 kGy. EPS production increased from 4.45 to 7.95 mg/mL and the protein/carbohydrate ratio increased from 3 to 4.4 which reflects the stickiness of EPS. Thermal Gravimetric Analysis (TGA) showed 2 phase weight loss for gamma irradiated EPS and defined protein peaks when characterized using Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF). Native and gamma-irradiated Bacillus subtilis cells with their enhanced EPS were grown as a biofilm on sterile waste gauze fabric, Scanning Electron Microscopy (SEM) showed an increased biofilm attachment in gamma-irradiated samples. The latter was used for the removal of ZnO NP from aqueous media. Energy dispersive X-ray (EDX) mapping confirms that ZnO NPs were entrapped within the carbon and oxygen elements forming the biofilm with net intensities of 14.04, 1713, and 1190, respectively. The results confirm that biofilm-mediated strategy is effective in nanoparticles removal.
Collapse
Affiliation(s)
- Heba Hamed Maghrawy
- Radiation Microbiology Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt
| | - Hussein Abd El Kareem
- Radiation Microbiology Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt
| | - Ola M Gomaa
- Radiation Microbiology Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt.
| |
Collapse
|
3
|
Zhao S, Li H, Guo J, Zhang Y, Zhao J, Song Y, Lu C, Han Y, Zhang D, Hou Y. Formation of anaerobic granular sludge (AnGS) to treat high-strength perchlorate wastewater via anaerobic baffled reactor (ABR) system: Electron transfer characteristic, bacterial community and positive feedback mechanism. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 828:154531. [PMID: 35292321 DOI: 10.1016/j.scitotenv.2022.154531] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/08/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Anaerobic granular sludge (AnGS) was cultured to treat high-strength perchlorate (reaching to 4800 mg/L) wastewater by an anaerobic baffled reactor (ABR) system with five equal-volume compartments (C1-C5 compartments). Inoculated sludge completely granulated on day 104 with granule size of 0.50-0.75 mm and perchlorate removal efficiency reaching to 97% (influent perchlorate of 2000-4800 mg/L). The Cyclic voltammetry (CV) capacitance increased from 487.5, 465.8 and 407.8 μF to 576.5, 552.4, 549.6 μF in C1, C3 and C5 compartments of ABR system, respectively, suggesting the electron transfer capacity was enhanced under high-strength perchlorate stress. Meanwhile, adenosine triphosphate (ATP) value and electron transport system activity (ETSA) increased to 25.05, 22.87, 20.43 and 6.22, 4.87, 3.95 of C1, C3 and C5 compartments, respectively. The results suggested that high-strength perchlorate stress improved the microbial metabolic activity, which promoted secretion of extracellular polymeric substances (EPS). The more EPS could facilitate the formation and stability of AnGS under high-strength perchlorate stress. In addition, more reasonable metabolic division of labor in functional bacterial (Thauera and Comamonas) was beneficial to AnGS formation, which achieved high-strength perchlorate efficient removal. Finally, a positive feedback mechanism between AnGS formation and high-strength perchlorate removal was established through EPS, microbial metabolic activity and electron transfer characteristic in ABR system. However, excessive perchlorate (5800 mg/L) would exceed the treatment capacity of AnGS, which resulted in the deterioration of removal performance. This work provided an effective information for AnGS application to treat high-strength perchlorate wastewater.
Collapse
Affiliation(s)
- Shiqi Zhao
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Haibo Li
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China.
| | - Jianbo Guo
- School of Civil Engineering and Architecture, Taizhou University, Taizhou 318000, China
| | - Yuxiang Zhang
- Jinzhou Electromechanical Engineering School, Tianshan Road 17, Jinzhou 121007, Liaoning, China
| | - Jianhai Zhao
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Yuanyuan Song
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Caicai Lu
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Yi Han
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Daohong Zhang
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Yanan Hou
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| |
Collapse
|
4
|
Structural Characteristics of Aerobic Granular Sludge and Factors That Influence Its Stability: A Mini Review. WATER 2021. [DOI: 10.3390/w13192726] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Current extensive research on aerobic granular sludge (AGS) largely focuses on improving its microbial biodiversity, settlement behavior, nitrogen and phosphorus removal efficiency, and shock load resistance. Great challenges that have to be faced are the bottleneck of slow-speed granulation and easy disintegration after granulation, which are key to the extended application of AGS technology. In the present review, the typical morphological structures of AGS are firstly summarized as well as the granulation model hypotheses, and then, we analyze the dominant microflora and their spatial distribution features. The influencing factors on particle structure stability are discussed thereafter on a macro and micro scale. Prospects and future research trends are also discussed based on the current study results for AGS technology.
Collapse
|
5
|
Zhao T, Qiao K, Wang L, Zhang W, Meng W, Liu F, Gao X, Zhu J. Isolation and characterization of a strain with high microbial attachment in aerobic granular sludge. J Environ Sci (China) 2021; 106:194-203. [PMID: 34210435 DOI: 10.1016/j.jes.2021.01.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 01/17/2021] [Accepted: 01/18/2021] [Indexed: 06/13/2023]
Abstract
Aerobic granule is a special microbial aggregate associated with biofilm structure. The formation of aerobic granular sludge is primarily depending on its bacterial community and relevant microbiological properties. In this experiment, a strain with high microbial attachment was isolated from aerobic granular sludge, and the detailed characteristics were examined. Its high attachment ability could reach 2.34 (OD600nm), while other low attachment values were only around 0.06-0.32, which indicated a big variation among the different bacteria. The strain exhibited a very special morphology with many fibric fingers under SEM observation. A distinctive behaviour was to form a spherical particle by themselves, which would be very beneficial for the formation and development of granular sludge. The EPS measurement showed that its PN content was higher than low attachment bacteria, and 3D-EEM confirmed that there were some different components. Based on the 16S rRNA analysis, it was identified to mostly belong to Stenotrophomonas. Its augmentation to particle sludge cultivation demonstrated that the strain could significantly promote the formation of aerobic granule. Conclusively, it was strongly suggested that it might be used as a good and potential model strain or chassis organism for the aerobic granular sludge formation and development.
Collapse
Affiliation(s)
- Tingting Zhao
- School of Environment, Beijing Normal University, Beijing 100875, China; R & D Centre of Aerobic Granule Technology, Beijing 100875, China
| | - Kai Qiao
- School of Environment, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Water Simulation, Beijing 100875, China
| | - Lei Wang
- School of Environment, Beijing Normal University, Beijing 100875, China; R & D Centre of Aerobic Granule Technology, Beijing 100875, China
| | - Wei Zhang
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Wei Meng
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Fan Liu
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Xu Gao
- School of Environment, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Water Simulation, Beijing 100875, China
| | - Jianrong Zhu
- School of Environment, Beijing Normal University, Beijing 100875, China; R & D Centre of Aerobic Granule Technology, Beijing 100875, China.
| |
Collapse
|
6
|
Peng H, Guo J, Li H, Song Y, Lu C, Han Y, Hou Y. Granulation and response of anaerobic granular sludge to allicin stress while treating allicin-containing wastewater. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.107971] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
7
|
Guo D, Zhang X, Shi Y, Cui B, Fan J, Ji B, Yuan J. Microalgal-bacterial granular sludge process outperformed aerobic granular sludge process in municipal wastewater treatment with less carbon dioxide emissions. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:13616-13623. [PMID: 33188629 DOI: 10.1007/s11356-020-11565-7] [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: 08/27/2020] [Accepted: 11/05/2020] [Indexed: 06/11/2023]
Abstract
The aerobic granular sludge (AGS) process and microalgal-bacterial granular sludge (MBGS) process were comparably applied for municipal wastewater treatment in sequencing batch reactors with a height to diameter ratio of eight. For morphological appearances, the yellow aerobic granules were strip-shaped (4.0 mm × 0.62 mm) while the green microalgal-bacterial granules were elliptical-shaped (2.0 mm × 0.75 mm). The dominated rod-shaped bacteria (e.g., Acidobacteria and Bacteroidetes) and the slender configuration might be associated with the strip shape of aerobic granules under weak acid conditions. The nutrients removal performances by MBGS process were generally slightly better than AGS process. In addition, nutrients removal mechanisms were identified to elucidate how organics, ammonia, and phosphorus were removed by AGS process and MBGS process, respectively. Mass balance calculation estimated that MBGS process appeared to achieve much less CO2 emission (5.8%) compared with AGS process (44.4%). Overall, it proved that MBGS process, with the merits of potentially low energy cost, limited CO2 emission, and excellent performance, showed more prospects in municipal wastewater treatment than AGS process.
Collapse
Affiliation(s)
- Dabin Guo
- Department of Water and Wastewater Engineering, Wuhan University of Science and Technology, Wuhan, 430065, China
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore
| | - Xuechun Zhang
- Department of Water and Wastewater Engineering, Wuhan University of Science and Technology, Wuhan, 430065, China
| | - Yuting Shi
- Department of Water and Wastewater Engineering, Wuhan University of Science and Technology, Wuhan, 430065, China
| | - Baihui Cui
- Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore
| | - Jie Fan
- Department of Water and Wastewater Engineering, Wuhan University of Science and Technology, Wuhan, 430065, China
| | - Bin Ji
- Department of Water and Wastewater Engineering, Wuhan University of Science and Technology, Wuhan, 430065, China.
| | - Julin Yuan
- Agriculture Ministry Key Laboratory of Healthy Freshwater Aquaculture, Key Laboratory of Fish Health and Nutrition of Zhejiang Province, Zhejiang Institute of Freshwater Fisheries, Huzhou, 313001, China.
| |
Collapse
|
8
|
Wang X, Li J, Zhang X, Chen Z, Shen J, Kang J. Impact of hydraulic retention time on swine wastewater treatment by aerobic granular sludge sequencing batch reactor. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:5927-5937. [PMID: 32981014 DOI: 10.1007/s11356-020-10922-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
In this study, the effect of hydraulic retention time (HRT) on the performance of aerobic granular sludge (AGS) treating swine wastewater (SW) in sequencing batch reactor (SBR) was investigated. The HRT was set at 4.8, 6, 8, 12, and 16 h and performed in five parallel aerobic granular sludge sequence batch reactors (AGSBRs), respectively. The results showed that sedimentation performance and biomass concentration were improved by decreasing the HRT from 16 to 8 h. However, when further decreasing HRT from 8 to 4.8 h, the AGS performance became worse. The AGS process with HRT of 8 h exhibited high pollutant removal efficiency, and an abundant microbial community and a stable microbial community structure were observed. High-throughput 16S rRNA analysis revealed that there were significant differences between the microorganisms in AGS samples with HRT of 8 h at the phylum level and that the dominant microbes changed as the process proceeded. At the genus level, the species and relative abundance of microorganisms gradually evolved for AGS stability in all cases.
Collapse
Affiliation(s)
- Xiaochun Wang
- Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Department of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), 518055, Shenzhen, China
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Ji Li
- Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Department of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), 518055, Shenzhen, China
| | - Xiaolei Zhang
- Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Department of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), 518055, Shenzhen, China.
| | - Zhonglin Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jimin Shen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jing Kang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| |
Collapse
|
9
|
Wang T, Liu Y, Guo J, Song Y, Gu J, Lian J, Lu C, Han Y, Li H, Hou Y. Rapid start up anammox process through a new strategy with inoculating perchlorate reduction sludge and a small amount of anammox sludge. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107784] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
10
|
Sha L, Yu X, Zhang Y, Jiang Q, Liu X, Wu Z, Zhang S. Investigation on the variations of sludge water holding capacity of electro-dewatering process. ENVIRONMENTAL RESEARCH 2020; 190:110011. [PMID: 32763282 DOI: 10.1016/j.envres.2020.110011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/31/2020] [Accepted: 07/25/2020] [Indexed: 06/11/2023]
Abstract
Since the effect of electro-dewatering (EDW) on sludge water holding capacity was unknown, tests were conducted in this study to investigate the water holding capacity of EDW sludge and the potential mechanism related to the sludge physicochemical characteristics, EPS properties and sludge structure. Sludge was dewatered to the average moisture content (AMC) of 80%, 70% and 60% with different applied voltages at 20, 30 and 40V in EDW, respectively. Then the dewatered sludge near the anode and cathode were rewatered. The variation of sludge water holding capacity in EDW process was evaluated in terms of filterability and saturated moisture content (SMC), and the filterability was assessed by the specific resistance to filtration (SRF) of rewatered sludge. The results indicated that SRF of rewatered sludge near the cathode increased greatly. The proteins/polysaccharides (PN/PS) of loosely bound extracellular polymeric substances (LB-EPS) was significantly positively correlated with SRF (r = 0.891, p < 0.01). Moreover, the exposure of hydrophobic sites or groups in PN near the cathode improved the surface hydrophobicity of sludge, which reduced the filterability. In addition, higher voltage could destroy the sludge structure near the anode at the later stage of EDW process, leading to the decrease of SRF and SMC. These results expanded the knowledge about changes in sludge properties and water holding capacity during EDW process.
Collapse
Affiliation(s)
- Li Sha
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300354, China
| | - Xiaoyan Yu
- School of Environmental and Safety Engineering, Taiyuan Institute of Technology, Taiyuan, 030008, China
| | - Yuxin Zhang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300354, China
| | - Qingqing Jiang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300354, China
| | - Xingxin Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300354, China
| | - Zhangxiang Wu
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300354, China
| | - Shuting Zhang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300354, China.
| |
Collapse
|
11
|
Sun H, Cai C, Chen J, Liu C, Wang G, Li X, Zhao H. Effect of temperatures and alternating anoxic/oxic sequencing batch reactor (SBR) operating modes on extracellular polymeric substances in activated sludge. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2020; 82:120-130. [PMID: 32910797 DOI: 10.2166/wst.2020.336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In order to investigate the effect of temperatures and operating modes on extracellular polymeric substances (EPS) contents, three sequencing batch reactors (SBRs) were operated at temperatures of 15, 25, and 35 °C (R15 °C, R25 °C, and R35 °C, respectively), with two SBRs operated under alternating anoxic/oxic conditions (RA/O and RO/A, respectively). Results showed that higher contents of tightly bound EPS (TB-EPS) and total EPS appeared in R15 °C, while loosely bound EPS (LB-EPS) dominated in R35 °C. In all three kinds of EPS (LB-EPS, TB-EPS and total EPS) assessed, protein was the main component in R15 °C and R25 °C, while polysaccharides dominated in R35 °C. Moreover, compared with RO/A, RA/O was favorable for the production of the three kinds of EPS. Furthermore, three kinds of EPS and their components were augmented during the nitrification process, while they declined during the denitrification process under all conditions except for R35 °C.
Collapse
Affiliation(s)
- Hongwei Sun
- School of Environmental and Material Engineering, Yantai University, Yantai 264005, China E-mail:
| | - Chenjian Cai
- School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Jixue Chen
- School of Environmental and Material Engineering, Yantai University, Yantai 264005, China E-mail:
| | - Chunyu Liu
- School of Environmental and Material Engineering, Yantai University, Yantai 264005, China E-mail:
| | - Guangjie Wang
- Shandong Tongji Testing Technology Co., Ltd, Yantai 264005, China
| | - Xiaoqiang Li
- School of Environmental and Material Engineering, Yantai University, Yantai 264005, China E-mail:
| | - Huanan Zhao
- School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
| |
Collapse
|