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Fu M, Qiu S, Wang J, Zhu Y, Yuan M, Wang L. Tourmaline mediated enhanced autotrophic denitrification: The mechanisms of electron transfer and Paracoccus enrichment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 915:169847. [PMID: 38185169 DOI: 10.1016/j.scitotenv.2023.169847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/19/2023] [Accepted: 12/30/2023] [Indexed: 01/09/2024]
Abstract
Autotrophic denitrification (AD) without carbon source is an inevitable choice for denitrification of municipal wastewater under the carbon peaking and carbon neutrality goals. This study first employed sulfur-tourmaline-AD (STAD) as an innovative nitrate removal trial technique in wastewater. STAD demonstrated a 2.23-fold increase in nitrate‑nitrogen (NO3--N) removal rate with reduced nitrite‑nitrogen (NO2--N) accumulation, effectively removing 99 % of nitrogen pollutants compared to sulfur denitrification. Some denitrifiers microorganisms that could secrete tyrosine, tryptophan, and aromatic protein (extracellular polymeric substances (EPS)). Moreover, according to the EPS composition and characteristics analysis, the secretion of loosely bound extracellular polymeric substances (LB-EPS) that bound to the bacterial endogenous respiration and enriched microbial abundance, was produced more in the STAD system, further improving the system stability. Furthermore, the addition of tourmaline (Tm) facilitated the discovery of a new genus (Paracoccus) that enhanced nitrate decomposition. Applying optimal electron donors through metabolic pathways and the microbial community helps to strengthen the AD process and treat low carbon/nitrogen ratio wastewater efficiently.
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Affiliation(s)
- Mengqi Fu
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150090, China
| | - Shan Qiu
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150090, China.
| | - Jue Wang
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150090, China
| | - Yingshi Zhu
- Zhejiang Environment Technology Co., Ltd, Hangzhou 311100, China; Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, China
| | - Mu Yuan
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150090, China
| | - Liang Wang
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150090, China
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2
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Chang JY, Syauqi TA, Sudesh K, Ng SL. Insights into biofilm development on polyhydroxyalkanoate biofilm carrier for anoxic azo dye decolourization of acid orange 7. BIORESOURCE TECHNOLOGY 2024; 393:130054. [PMID: 37995876 DOI: 10.1016/j.biortech.2023.130054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/16/2023] [Accepted: 11/16/2023] [Indexed: 11/25/2023]
Abstract
Polyhydroxyalkanoates (PHAs) are promising alternatives to non-degradable polymers in various applications. This study explored the use of biologically recovered PHA as a biofilm carrier in a moving bed biofilm reactor for acid orange 7 treatment. The PHA was comprised of 86 ± 1 mol% of 3-hydroxybutyrate and 14 ± 1 mol% of 3-hydroxyhexanoate and was melt-fused at 140 °C into pellets. The net positive surface charge of the PHA biocarrier facilitated attachment of negatively charged activated sludge, promoting biofilm formation. A 236-µm mature biofilm developed after 26 days. The high polysaccharides-to-protein ratio (>1) in the biofilm's extracellular polymeric substances indicated a stable biofilm structure. Four main microbial strains in the biofilm were identified as Leclercia adecarboxylata, Leuconostoc citreum, Bacillus cereus, and Rhodotorula mucilaginosa, all of which exhibited decolourization abilities. In conclusion, PHA holds promise as an effective biocarrier for biofilm development, offering a sustainable alternative in wastewater treatment applications.
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Affiliation(s)
- Jia Yun Chang
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
| | - Taufiq Ahmad Syauqi
- School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
| | - Kumar Sudesh
- School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
| | - Si Ling Ng
- School of Chemical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
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3
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Wang Z, Liang H, Yan Y, Li X, Zhang Q, Peng Y. Stimulating extracellular polymeric substances production in integrated fixed-film activated sludge reactor for advanced nitrogen removal from mature landfill leachate via one-stage double anammox. BIORESOURCE TECHNOLOGY 2024; 391:129968. [PMID: 37925083 DOI: 10.1016/j.biortech.2023.129968] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 10/26/2023] [Accepted: 10/31/2023] [Indexed: 11/06/2023]
Abstract
Introducing carbon sources to achieve nitrogen removal from mature landfill leachate not only increases the costs and carbon emissions but also inhibits the activity of autotrophic bacteria. Thus, this study constructed a double anammox system that combines partial nitrification-anammox (PNA) and endogenous partial denitrification-anammox (EPDA) within an integrated fixed-film activated sludge (IFAS) reactor. In this system, PNA primarily contributes to nitrogen removal pathways, achieving a nitrite accumulation rate of 98.23%. The production of extracellular polymer substances (EPS) in the IFAS reactor is stimulated by introducing co-fermentation liquid. Through the utilization of EPS, the system effectively achieves EPDA with the nitrite transformation rate of 97.20%. Under the intermittent aeration operation strategy, EPDA combined with PNA and anammox in the oxic and anoxic stages enhanced the nitrogen removal efficiency of the system to 99.70 ± 0.12%. The functional genus Candidatus kuenenia became enriched in biofilm sludge, while Thauera and Nitrosomonas predominated in floc sludge.
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Affiliation(s)
- Zhaozhi Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Haoran Liang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Ying Yan
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Xiyao Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Qiong Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
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4
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Wei S, Zeng F, Zhou Y, Zhao J, Wang H, Gao R, Liang W. Phototransformation of extracellular polymeric substances in activated sludge and their interaction with microplastics. RSC Adv 2023; 13:26574-26580. [PMID: 37674486 PMCID: PMC10478482 DOI: 10.1039/d3ra04027e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/01/2023] [Indexed: 09/08/2023] Open
Abstract
Substantial amounts of extracellular polymeric substances (EPS) are present in sludge from wastewater treatment plants (WWTP), and EPS can significantly affect the fate, bioavailability, and toxicity of microplastics (MPs) that coexist in the effluent, however, the mechanism of action between EPS and microplastics remains unclear. In addition, ultraviolet (UV) disinfection is indispensable in the wastewater treatment process in WWTP, which can significantly affect the characteristics of EPS. Therefore, it is of great significance to study the photochemical characteristics of EPS and the effect on binding MPs. In this study, using multispectral technology and two-dimensional correlation spectroscopy analysis, indicates that the molecular weight and aromaticity of EPS after phototransformation were reduced. The results showed that the adsorption of EPS on PSMPs was in the order of TB-EPS > LB-EPS > S-EPS, which was positively correlated with the SUVA254, but negatively correlated with O/C of EPS. This indicates that the main adsorption mechanisms of PSMPs on EPS were π-π and hydrophobicity. The adsorption capacity of S-EPS, LB-EPS and TB-EPS to PSMPs decreased with the increasing of illumination time. After phototransformation, the adsorption sensitivity and reaction sequence of EPS and PSMPs did not change much. This research provides a theoretical basis for understanding the photochemical transformation of extracellular polymers and the morphology and migration of microplastics in sewage treatment, and evaluating the impact of microplastics on ecosystems.
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Affiliation(s)
- Shuyin Wei
- School of Chemistry, Sun Yat-sen University Guangzhou 510275 China +8620-84114133
| | - Feng Zeng
- School of Chemistry, Sun Yat-sen University Guangzhou 510275 China +8620-84114133
| | - Yingyue Zhou
- School of Chemistry, Sun Yat-sen University Guangzhou 510275 China +8620-84114133
| | - Jiawei Zhao
- School of Chemistry, Sun Yat-sen University Guangzhou 510275 China +8620-84114133
| | - Hao Wang
- School of Chemistry, Sun Yat-sen University Guangzhou 510275 China +8620-84114133
| | - Rui Gao
- School of Chemistry, Sun Yat-sen University Guangzhou 510275 China +8620-84114133
| | - Weiqian Liang
- School of Chemistry, Sun Yat-sen University Guangzhou 510275 China +8620-84114133
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Ma Y, Li TY, Meng H, Wang GX, Zhang LM, Jia GZ, Ma J, Xiao Y, Li WH, Xie WM. The contradictory roles of tightly bound and loosely bound extracellular polymeric substances of activated sludge in trimethoprim adsorption process. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 336:117661. [PMID: 36913857 DOI: 10.1016/j.jenvman.2023.117661] [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: 01/12/2023] [Revised: 02/12/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
Extracellular polymeric substances (EPS) of activated sludge are a mixture of high molecular weight polymers secreted by microorganisms, which have the double structure of tightly-bound EPS (TB-EPS) in inner layer and loosely-bound EPS (LB-EPS) in outer layer. The characteristic of LB- and TB-EPS were different, which would affect their adsorption of antibiotics. However, the adsorption process of antibiotics on LB- and TB-EPS was still unclear yet. Therefore, in this work, the roles of LB-EPS and TB-EPS in adsorption of a typical antibiotic-trimethoprim (TMP) at environmentally relevant concentration (25.0 μg/L) were investigated. The results showed the content of TB-EPS was higher than that of LB-EPS, which was 17.08 and 10.36 mg/g VSS, respectively. The adsorption capacity of raw, LB-EPS extracted and both LB- and TB-EPS extracted activated sludges for TMP were 5.31, 4.65 and 9.51 μg/g VSS, respectively, which indicated LB-EPS had positive effect on TMP removal, while TB-EPS had negative effect. The adsorption process can be well described by a pseudo-second-order kinetic model (R2 > 0.980). The ratio of different functional groups was calculated and the CO and C-O bond might be responsible for the adsorption capacity difference between LB- and TB-EPS. The fluorescence quenching results indicated that tryptophan protein-like substances in LB-EPS provided more binding sites (n = 0.36) than that of tryptophan amino acid in TB-EPS (n = 0.1). Furthermore, the extend DLVO results also demonstrated that LB-EPS promoted the adsorption of TMP, while TB-EPS inhibited the process. We hope the results of this study were helpful for understanding the fate of antibiotics in wastewater treatment systems.
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Affiliation(s)
- You Ma
- Jiangsu Engineering Lab of Water and Soil Eco-remediation, School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Tian-Yu Li
- Jiangsu Engineering Lab of Water and Soil Eco-remediation, School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Han Meng
- Jiangsu Engineering Lab of Water and Soil Eco-remediation, School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Guo-Xiang Wang
- Jiangsu Engineering Lab of Water and Soil Eco-remediation, School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Li-Min Zhang
- Jiangsu Engineering Lab of Water and Soil Eco-remediation, School of Environment, Nanjing Normal University, Nanjing, 210023, China; Green Economy Development Institute, Nanjing University of Finance and Economic, Nanjing, 210023, China
| | - Guo-Zheng Jia
- Jiangsu Engineering Lab of Water and Soil Eco-remediation, School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Jie Ma
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, China
| | - Yan Xiao
- Hangzhou Environmental Protection Research Institute of China Coal Technology & Engineering Group, Hangzhou, 311201, China
| | - Wei-Hua Li
- School of Environment and Energy Engineering, Anhui Jianzhu University, Hefei, 230061, China
| | - Wen-Ming Xie
- Jiangsu Engineering Lab of Water and Soil Eco-remediation, School of Environment, Nanjing Normal University, Nanjing, 210023, China.
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Shi X, Ling Q, Jiang Z, Pei F, Xin M, Tan W, Chen X, Liu K, Ma J, Yu F, Li Y. Insight into the roles of soluble, loosely bound and tightly bound extracellular polymeric substances produced by Enterobacter sp. in the Cd 2+ and Pb 2+ biosorption process: Characterization and mechanism. Colloids Surf B Biointerfaces 2023; 227:113348. [PMID: 37201449 DOI: 10.1016/j.colsurfb.2023.113348] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/29/2022] [Accepted: 05/12/2023] [Indexed: 05/20/2023]
Abstract
Extracellular polymeric substances (EPSs) are macromolecular polymers formed by metabolic secretion, and they have great potential for removing heavy metal (HM) ions from the aquatic phase. In this study, the contributions of soluble EPSs (S-EPSs), loosely bound EPSs (LB-EPSs) and tightly bound EPSs (TB-EPSs) secreted by Enterobacter sp. to Cd2+ and Pb2+ adsorption were analyzed. The results indicated that in a solution containing both Cd2+ and Pb2+, pH= 6.0 was best suited for the adsorption process, and adsorption equilibrium was reached in approximately 120 min. Moreover, the mechanism for adsorption of Cd2+ and Pb2+ by the different layers of EPSs involved spontaneous chemical processes. However, Cd2+ adsorption by the three layers of the EPSs was an exothermic process (∆H0 <0), but Pb2+ adsorption by the three layers of the EPSs was an endothermic process (∆H0 >0). The variations in zeta potentials indicated that ion exchange occurred during Cd2+ and Pb2+ adsorption. FT-IR, XPS and 3D-EEM analyses indicated that the functional groups of the EPSs involved in adsorption were mainly the CO, C-O and C-O-C groups of the polysaccharides; furthermore, fulvic acid-like substances, humic-like substances and tyrosine-like proteins played important roles in the adsorption of Cd2+ and Pb2+ by the different EPS layers.
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Affiliation(s)
- Xinwei Shi
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Qiujie Ling
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Zhiling Jiang
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Fengmei Pei
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Meifen Xin
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Weilan Tan
- College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Xuan Chen
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China
| | - Kehui Liu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, 541004 Guilin, China; College of Life Science, Guangxi Normal University, 541004 Guilin, China
| | - Jiangming Ma
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, 541004 Guilin, China; College of Life Science, Guangxi Normal University, 541004 Guilin, China
| | - Fangming Yu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China.
| | - Yi Li
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004 Guilin, China.
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7
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Wu KK, Zhao L, Sun ZF, Wang ZH, Chen C, Ren HY, Yang SS, Ren NQ. Synergistic effect of hydrogen and nanoscale zero-valent iron on ex-situ biogas upgrading and acetate recovery. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159100. [PMID: 36174700 DOI: 10.1016/j.scitotenv.2022.159100] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/16/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
Hydrogen (H2) assisted ex-situ biogas upgrading and liquid chemicals production can augment the fossil fuel-dominated energy market, and alleviate CO2-induced global warming. Recent investigations confirmed that nanoscale zero-valent iron (nZVI) enabled the enhancement of anaerobic digestion for biogas production. However, little is known about the effect of nZVI on the downstream ex-situ biogas upgrading. Herein, different levels (0 mg L-1, 100 mg L-1, 200 mg L-1, 500 mg L-1, 1000 mg L-1, 2000 mg L-1) of nZVI were added for H2-assisted ex-situ biogas upgrading, to study whether nZVI could impact the biomethane purity and acetate yield for the first time. Results showed that all tested nZVI levels were favorable for biogas upgrading in the presence of H2, the highest biomethane content (94.1 %, v/v), the CO2 utilization ratio (95.9 %), and acetate yield (19.4 mmol L-1) were achieved at 500 mg L-1 nZVI, respectively. Further analysis indicated that increased biogas upgrading efficiency was related to an increase in extracellular polymeric substances, which ensures the microbial activity and stability of the ex-situ biogas upgrading. Microbial community characterization showed that the Petrimonas, Romboutsia, Acidaminococcus, and Clostridium predominated the microbiome during biogas upgrading at 500 mg L-1 nZVI with H2 supply. These results suggested that nZVI and H2 contributed jointly to promoting the bioconversion of CO2 in biogas to acetate. The findings could be helpful for paving a new way for efficient simultaneous ex-situ biogas upgrading and liquid chemicals recovery.
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Affiliation(s)
- Kai-Kai Wu
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Lei Zhao
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Zhong-Fang Sun
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Zi-Han Wang
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Chuan Chen
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Hong-Yu Ren
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Shan-Shan Yang
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Nan-Qi Ren
- School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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8
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Xing L, Yang J, Zhang Y, Ni BJ, Yang C, Yuan C, Li A. Model-based evaluation of the impacts of aeration on tightly bound and loosely bound extracellular polymeric substance production under non-steady-state conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 852:158566. [PMID: 36075439 DOI: 10.1016/j.scitotenv.2022.158566] [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: 02/21/2022] [Revised: 08/15/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
Tightly bound extracellular polymeric substances (TB-EPS) and loosely bound extracellular polymeric substances (LB-EPS) affect the flocculability and settleability of sludge and the transfer of oxygen, which are highly related to aeration. In this study, we systemically evaluated the expanded unified model-TL2.1 for its long-term simulation of TB-EPS and LB-EPS. Two different aeration conditions and three different influent carbon sources were used to evaluate the model, and the simulation results fit well with the experimental data. TB-EPS and LB-EPS production increased with aeration intensity. The influence of aeration parameters on TB-EPS and LB-EPS production in a short-term batch system and long-term sequencing batch reactor (SBR) system was compared. The aeration parameters included the total transfer coefficient (kLa) and the concentration of dissolved oxygen at the interface (CS). To ensure a high removal rate of substrates and ammonia nitrogen and achieve a stable active biomass concentration, the following aeration parameters can be adopted to reduce energy wastage during aeration: when CS is 2 mg/L, kLa can be set above 30 h-1 and below 50 h-1; when kLa is 50 h-1, CS can be set above 1 mg/L and below 1.5 mg/L. This study systematically revealed the influence of aeration on TB-EPS and LB-EPS formation in an SBR system through a mathematical model, and it provides a theoretical basis for better understanding aeration.
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Affiliation(s)
- Lulu Xing
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - Jixian Yang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - Yueyan Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - Bing-Jie Ni
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Chao Yang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - Chunyan Yuan
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - Ang Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
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9
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Yu Z, Chen J, Tan Y, Shen Y, Zhu L, Yu P. Phage Predation Promotes Filamentous Bacterium Piscinibacter Colonization and Improves Structural and Hydraulic Stability of Microbial Aggregates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:16230-16239. [PMID: 36173693 DOI: 10.1021/acs.est.2c04745] [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: 06/16/2023]
Abstract
Although bacteria-phage interactions have broad environmental applications and ecological implications, the influence of phage predation on bacterial aggregation and structural stability remains largely unexplored. Herein, we demonstrate that inefficient lytic phage predation can promote host filamentous bacterium Piscinibacter colonization onto non-host Thauera aggregates, improving the structural and hydraulic stability of the dual-species aggregates. Specifically, phage predation at 103-104 PFU/mL (i.e., multiplication of infection at 0.01-0.1) promoted initial Piscinibacter colonization by 10-15 folds and resulted in 29-31% higher abundance of Piscinibacter in the stabilized aggregates than that in the control aggregates without phage predation. Transcriptomic analysis revealed upregulated genes related to quorum sensing (by 15-92 folds) and polysaccharide secretion (by 10-90 folds) within the treated aggregates, which was consistent with 120-172% higher content of polysaccharides for the treated dual-species aggregates. Confocal laser scanning microscopic images further confirmed the increase of filamentous bacteria and polysaccharides (both with wider distribution) within the dual-species aggregates. Accordlingly, the aggregates' structural strength (via atomic force microscopes) and shear resistance (via hydraulic stress tests) increased by 77 and 42%, respectively, relative to the control group. In the long-term experiments, the enhanced hydraulic stability of the treated aggregates could facilitate dwelling bacteria propagation in flow-through conditions. Overall, our study demonstrates that phage predation can promote bacterial aggregation and enhance aggregate structural stability, revealing the beneficial role of lytic phage predation on bacterial symbiosis and environmental adaptivity.
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Affiliation(s)
- Zhuodong Yu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Juhong Chen
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Yixiao Tan
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yun Shen
- Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Liang Zhu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Pingfeng Yu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
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10
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Pan M, Li H, Han X, Ma W, Li X, Guo Q, Yang B, Ding C, Ma Y. Effects of hydrodynamic conditions on the composition, spatiotemporal distribution of different extracellular polymeric substances and the architecture of biofilms. CHEMOSPHERE 2022; 307:135965. [PMID: 35963380 DOI: 10.1016/j.chemosphere.2022.135965] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 07/12/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Microbial biofilms are common on abiotic and biotic surfaces, especially in rivers, which drive crucial ecosystem processes. The microorganisms of biofilms are surrounded by a self-produced extracellular polymeric substance (EPS). In this study, we investigated the effects of different hydrodynamic conditions on the composition, spatiotemporal distribution of different extracellular polymeric substances, and the architecture of biofilms. Multidisciplinary methods offer complementary insights into complex architecture correlations in biofilms. The biofilms formed in turbulent flow with high shear force were thin but dense. However, the biofilms formed under laminar flow conditions were thick but relatively loose. The thickness and compactness of the biofilms formed in the transitional flow were different from those of the other biofilms. The compact structure of the biofilm helped to resist shear forces to minimize detachment. Under the turbulent flow condition, bacteria, exopolysaccharides, and extracellular proteins permeated through the biofilm, and more extracellular polysaccharides enveloped bacteria and extracellular proteins. However, under the transitional flow condition, the extracellular polysaccharides and proteins were fewer than those under the turbulent flow condition; bacteria and algae were seen more prominently in the upper layer of the biofilm. Under the laminar flow condition, the distribution of extracellular polysaccharides, extracellular proteins, and bacteria was relatively uniform throughout the biofilm. The number of extracellular polysaccharides was greater than that of extracellular proteins. The total number of EPS in the biofilm was the largest under turbulent flow condition, followed by that under transitional flow condition and then under laminar flow condition. This study also observed that soluble EPS (S-EPS) were secreted first, followed by loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS). In particular, the adhesion of LB-EPS and flocculation capability of TB-EPS play some role in regulating biofilm formation. This study would help to perfect the five-stages theory of biofilm formation.
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Affiliation(s)
- Mei Pan
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng, 224003, Jiangsu Province, PR China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, PR China
| | - Haizong Li
- Yancheng Environmental Monitoring Center, Yancheng, 224002, PR China
| | - Xiangyun Han
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng, 224003, Jiangsu Province, PR China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, PR China
| | - Weixing Ma
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng, 224003, Jiangsu Province, PR China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, PR China
| | - Xuan Li
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng, 224003, Jiangsu Province, PR China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, PR China
| | - Qingyuan Guo
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng, 224003, Jiangsu Province, PR China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, PR China
| | - Bairen Yang
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng, 224003, Jiangsu Province, PR China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, PR China.
| | - Cheng Ding
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng, 224003, Jiangsu Province, PR China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, PR China.
| | - Yuwen Ma
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng, 224003, Jiangsu Province, PR China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, PR China
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11
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Huang L, Jin Y, Zhou D, Liu L, Huang S, Zhao Y, Chen Y. A Review of the Role of Extracellular Polymeric Substances (EPS) in Wastewater Treatment Systems. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:12191. [PMID: 36231490 PMCID: PMC9566195 DOI: 10.3390/ijerph191912191] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 09/18/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
A review of the characterization and functions of extracellular polymeric substances (EPS) of microbial aggregates in biological wastewater treatment systems is presented in this paper. EPS represent the complex high-molecular-weight mixture of polymers excreted by microorganisms generated from cell lysis as well as adsorbed inorganic and organic matter from wastewater. EPS exhibit a three-dimensional, gel-like, highly hydrated matrix that facilitates microbial attachment, embedding, and immobilization. EPS play multiple roles in containments removal, and the main components of EPS crucially influence the properties of microbial aggregates, such as adsorption ability, stability, and formation capacity. Moreover, EPS are important to sludge bioflocculation, settleability, and dewatering properties and could be used as carbon and energy sources in wastewater treatment. However, due to the complex structure of EPS, related knowledge is incomplete, and further research is necessary to understand fully the precise roles in biological treatment processes.
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Affiliation(s)
- Lei Huang
- Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing 400716, China
| | - Yinie Jin
- Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Danheng Zhou
- Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Linxin Liu
- Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Shikun Huang
- Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Yaqi Zhao
- Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Yucheng Chen
- Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing 400716, China
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Zhao P, Zhao S, Wang HG, Lu M, Li ZH. Encapsulation of bacteria in different stratified extracellular polymeric substances and its implications for performance enhancement and resource recovery. WATER RESEARCH 2022; 220:118684. [PMID: 35661510 DOI: 10.1016/j.watres.2022.118684] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/24/2022] [Accepted: 05/27/2022] [Indexed: 05/06/2023]
Abstract
Simultaneous recovery of biopolymers and enhanced bio-reactor performance are promising options for sustainable wastewater treatment, and the bioactivity of sludge after biopolymer extraction is thus critical for the performance of the system. To this end, stratified extracellular polymeric substances (EPS), including slime, loosely bound EPS (LB-EPS), and tightly bound EPS (TB-EPS), were extracted, and the bioactivities of the consequent extraction residues were assessed using aerobic respirogram, kinetic, and flow cytometry (FCM). After the initial weak extraction of slime, the particle size distribution of the sludge significantly decreased, and subsequent extractions of LB-EPS and TB-EPS produced an equivalent size distribution. In contrast, the fractal dimension decreased after each extraction, suggesting that LB-EPS and TB-EPS affected the compactness of flocs rather than the size. The aerobic bacteria distribution estimated using respirogram shows that slime mainly encapsulated heterotrophs while LB-EPS mainly encapsulated nitrifiers. In addition, the ammonia-nitrogen affinity coefficient decreased from 1.79 to 0.28 mg/L when slime was removed, thereby encouraging the activities of autotrophic nitrifiers. Further removal of LB-EPS induced high energy dispersion as the maintenance coefficient m and the metabolic dispersion index μ/m increased from 0.11 to 0.22 and 0.44 to 0.63, respectively. Meanwhile, the yield rate decreased from 0.77 to 0.66. Although pellets that resulted from TB-EPS extraction were not aerobically active as described by respirogram and growth curves, they were still metabolically active as measured by live/dead cell counting and redox sensor green signal. These pellets used more energy for maintenance as indicated by the high maintenance coefficient than those residual after either slime or LB-EPS extraction. In addition, the variation in bacteria community distribution across flocs was related to the variation in temperatures, suggesting that the inner part of a floc might be hotter than the outer side. Therefore, compared to bacteria in the raw sludge, the viable bacteria bounded in LB-EPS and TB-EPS convert more energy to heat rather than growth. These results indicate that energy was dispersed as metabolic heat for the LB-EPS extracted sludge, and removal of LB-EPS favored thermogenesis and sludge reduction. Based on the above findings, a simultaneously EPS-recovery and performance enhancement configuration is thus proposed, which holds great promise for the integration of next-generation wastewater treatment plants.
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Affiliation(s)
- Pian Zhao
- 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; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Song Zhao
- 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; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Hai-Guang 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; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Meng Lu
- 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; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, 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; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
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