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Dai Z, Zhang N, Wang F, Li Y, Peng J, Xiang T, Zhao X, Yang S, Cao W. Loss of microbial functional diversity following Spartina alterniflora invasion reduces the potential of carbon sequestration and nitrogen removal in mangrove sediments-from a gene perspective. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121569. [PMID: 38914045 DOI: 10.1016/j.jenvman.2024.121569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 06/26/2024]
Abstract
Mangrove ecosystems play an important role in carbon (C) sequestration and nitrogen (N) removal. Although Spartina alterniflora has successively invaded native mangrove habitats during the preceding two decades, the effects of this invasion on the microbial functional potential involved in nutrient cycling remain unclear. In this study, metagenomic sequencing was used to investigate microbial C and N cycling in sediments derived from S. alterniflora and three native mangrove species (Kandelia obovata, Avicennia marina, and Aegiceras corniculatum). Greater differences in functional profiles of C and N cycling-related genes were observed between S. alterniflora and mangrove sediments than between different mangrove sediments. Functional diversity was lower in S. alterniflora sediments than in native mangrove sediments. The growth of Thaumarchaeota and Proteobacteria, was enhanced due to their resilience to diversity loss, while the growth of oligotrophs, such as Chloroflexi and Firmicutes, was inhibited in S. alterniflora sediments. Compared to mangrove sediments, the abundance of genes involved in C fixation and methane production was lower in S. alterniflora sediments. However, S. alterniflora significantly increased the gene abundance of pmo which controlled the oxidation process of CH4 to carbon dioxide. Additionally, genes involved in nitrification were enriched, whereas genes involved in N reduction processes, such as denitrification and dissimilatory nitrate reduction to ammonium, N immobilization, and N mineralization, were depleted in S. alterniflora sediments compared to mangrove sediments. Partial least squares regression models demonstrated that the decrease in soil organic C and increase in pH after S. alterniflora invasion induced the loss of microbial functional diversity, which was the main driver of changes in the abundances of genes involved in C and N cycling. Overall, our findings indicate that S. alterniflora invasion modifies the microbial functional profile of nutrient cycling in native mangrove ecosystems and potentially weakens the capacity of mangroves to sequester carbon and remove nitrogen.
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Affiliation(s)
- Zetao Dai
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
| | - Ning Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
| | - Feifei Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
| | - Yujie Li
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
| | - Jiarui Peng
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
| | - Tao Xiang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
| | - Xiaoyu Zhao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
| | - Shengchang Yang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
| | - Wenzhi Cao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China.
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Zhao L, Fu G, Zeng A, Cheng B, Song Z, Hu Z. Effects of different aeration strategies and ammonia-nitrogen loads on nitrification performance and microbial community succession of mangrove constructed wetlands for saline wastewater treatment. CHEMOSPHERE 2023; 339:139685. [PMID: 37532202 DOI: 10.1016/j.chemosphere.2023.139685] [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: 02/18/2023] [Revised: 07/25/2023] [Accepted: 07/29/2023] [Indexed: 08/04/2023]
Abstract
In highly salinized environments, nitrification is the process that limits the rate of nitrogen transformation and removal. Therefore, this study concentrated on the impacts of different aeration strategies and NH4+-N loads on the nitrification performance of mangrove constructed wetlands (CWs), as well as investigating the succession mechanism of ammonia-oxidizing microorganisms (AOMs). The results showed that both the CW with continuous aeration (CA-CW) and intermittent aeration (IA-CW) achieved a nitrification efficiency of more than 98% under an NH4+-N loading of 1.25-4.7 g/(m2·d). However, the total nitrogen removal rates of IA-CW under low and high ammonia-nitrogen loads (LAL, 20.09 ± 4.4% and HAL, 8.77 ± 1.35%, respectively) were higher than those of CA-CW (16.11 ± 4.7% and 3.32 ± 2.3%, respectively), especially under HAL (p < 0.05). Pearson correlation analysis showed that under different operating conditions, the differential secretion of Kandelia candel rhizosphere organic matter had a certain regulatory effect on nitrification and denitrification groups such as Candidatus Nitrocosmicus, Nitrancea, Truepera, Pontibacter, Halomonas, and Sulfurovum in the wetland root layer. The quantitative polymerase chain reaction revealed that the NH4+-N load rate was the primary factor driving the succession of the AOMs, with different aeration strategies exacerbating this process. Overall, this study revealed that the dominant AOMs in mangrove CWs could be significantly altered by regulating the aeration modes and pollution loads to adjust the rhizosphere organic matter in situ, thereby resulting in more efficient nitrification.
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Affiliation(s)
- Lin Zhao
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China; Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, Shenzhen University, Shenzhen, 518055, China; Anhui Province Key Laboratory of Environmental Hormone and Reproduction, College of Biology and Food engineering, Fuyang Normal University, Fuyang, 236037, China.
| | - Guiping Fu
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China.
| | - Anzu Zeng
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Bingzhen Cheng
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Zihao Song
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Zhangli Hu
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China; Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, Shenzhen University, Shenzhen, 518055, China.
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3
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Zhang L, Hong W, Pan Z, Fang W, Shen Z, Cai H. Wastewater treatment effectiveness is facilitated by crucial bacterial communities in the wetland ecosystem. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159375. [PMID: 36240933 DOI: 10.1016/j.scitotenv.2022.159375] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Microorganisms play essential roles in nutrient removal and biogeochemical cycling during wastewater treatment. However, little is known about the main roles of key functional bacterial communities in wastewater treatment processes. We collected 18 water samples and 15 sediment samples from the six operational subsystems of the constructed wetland, among which the contact oxidation pond, enhanced hybrid biofilm reactor, and central stabilization pond are the main wastewater treatment units in the constructed wetland, and then investigated the bacterial communities using 16S rRNA gene targeting and sequencing to address this knowledge gap. The results indicated that the composition of the bacterial community is closely related to the efficiency of pollutant removal. The abundant carbon metabolism function increased the removal of nitrate‑nitrogen (NO3--N) and total nitrogen (TN) by the contact oxidation pond by 89.84 % and 38.91 %, respectively. The overlap of ecological niches and the presence of pathogenic bacteria substantially affect effluent wastewater treatment. Second, NO3--N (p < 0.001) was the most important factor driving the bacterial community composition in water and sediments. Furthermore, the positive structure was prevalent in the cooccurrence network of water samples (87.24 %) and sediments (76.53 %) of the wetland, and this positive structure with keystone species was critical for the adaptation of the bacterial community to environmental filtration. In summary, this study reveals the distribution patterns of bacterial communities in different wastewater treatment processes and their driving factors and provides new perspectives on the link between the bacterial community composition and wastewater treatment.
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Affiliation(s)
- Lei Zhang
- School of Civil Engineering and Architecture, Chuzhou University, Chuzhou 239000, China.
| | - Wenqing Hong
- School of Civil Engineering and Architecture, Chuzhou University, Chuzhou 239000, China
| | - Zhongling Pan
- School of Civil Engineering and Architecture, Chuzhou University, Chuzhou 239000, China
| | - Wangkai Fang
- School of Earth and Environment, Anhui University of Science & Technology, Huainan 232000, China
| | - Zhen Shen
- Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Hua Cai
- School of Civil Engineering and Architecture, Chuzhou University, Chuzhou 239000, China
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4
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He L, Lin Z, Zhu K, Wang Y, He X, Zhou J. Mesophilic condition favors simultaneous partial nitrification and denitrification (SPND) and anammox for carbon and nitrogen removal from anaerobic digestate food waste effluent. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 816:151498. [PMID: 34752875 DOI: 10.1016/j.scitotenv.2021.151498] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/16/2021] [Accepted: 11/03/2021] [Indexed: 06/13/2023]
Abstract
Three simultaneous partial nitrification and denitrification (SPND) bioreactors were established on ambient (30 °C), mesophilic (40 °C) and thermophilic condition (50 °C) at high dissolved oxygen levels (2-7 mg L-1) to remove nitrogen and carbon from anaerobic digestate food waste effluent (ADFE). The bioreactor performed best under mesophilic condition, with TN and COD removal efficiency of 96.3 ± 0.1% and 91.7 ± 0.1%, respectively. Free ammonia (FA) and free nitrous acid (FNA) alternately ensured selective inhibition of nitrite-oxidizing bacteria (NOB) in long-term operation of SPND systems. Candidatus Brocadia, known as anammox bacteria, was observed unexpectedly in the bioreactors. The analysis of microbial community and metabolic pathways revealed that mesophilic strategy stimulated SPND and anammox process. Mesophilic condition helped autotropic microbes resist the competitive pressure from heterotrophic bacteria, improving the balance between nitrifiers, anammox bacteria and other co-existing heterotrophs. Overall, this study offers new insights into the linkage among temperature, pollutant removals (carbon and nitrogen) and metabolic potential in the SPND bioreactors.
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Affiliation(s)
- Lei He
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Ziyuan Lin
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Kun Zhu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Yingmu Wang
- College of Civil Engineering, Fuzhou University, Fujian 350116, China
| | - Xuejie He
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Jian Zhou
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
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5
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Zhang J, Zhang Z, Liu W, Li L, Han L, Xu L, Zhao Y. Transcriptome Analysis Revealed a Positive Role of Ethephon on Chlorophyll Metabolism of Zoysia japonica under Cold Stress. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11030442. [PMID: 35161421 PMCID: PMC8839986 DOI: 10.3390/plants11030442] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/30/2022] [Accepted: 02/03/2022] [Indexed: 05/18/2023]
Abstract
Zoysia japonica is a warm-season turfgrass with a good tolerance and minimal maintenance requirements. However, its use in Northern China is limited due to massive chlorophyll loss in early fall, which is the main factor affecting its distribution and utilization. Although ethephon treatment at specific concentrations has reportedly improved stress tolerance and extended the green period in turfgrass, the potential mechanisms underlying this effect are not clear. In this study, we evaluated and analyzed chlorophyll changes in the physiology and transcriptome of Z. japonica plants in response to cold stress (4 °C) with and without ethephon pretreatment. Based on the transcriptome and chlorophyll content analysis, ethephon pretreatment increased the leaf chlorophyll content under cold stress by affecting two processes: the stimulation of chlorophyll synthesis by upregulating ZjMgCH2 and ZjMgCH3 expression; and the suppression of chlorophyll degradation by downregulating ZjPAO, ZjRCCR, and ZjSGR expression. Furthermore, ethephon pretreatment increased the ratio of chlorophyll a to chlorophyll b in the leaves under cold stress, most likely by suppressing the conversion of chlorophyll a to chlorophyll b due to decreased chlorophyll b synthesis via downregulation of ZjCAO. Additionally, the inhibition of chlorophyll b synthesis may result in energy redistribution between photosystem II and photosystem I.
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Affiliation(s)
- Jiahang Zhang
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
| | - Zhiwei Zhang
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
- CCTEG Ecological Environment Technology Co., Ltd., Beijing 100013, China
| | - Wen Liu
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
| | - Lijing Li
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
| | - Liebao Han
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
| | - Lixin Xu
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
- Correspondence: (L.X.); (Y.Z.)
| | - Yuhong Zhao
- Animal Science College, Tibet Agriculture & Animal Husbandry University, Nyingchi 860000, China
- Correspondence: (L.X.); (Y.Z.)
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Izadi P, Izadi P, Eldyasti A. Evaluation of PAO adaptability to oxygen concentration change: Development of stable EBPR under stepwise low-aeration adaptation. CHEMOSPHERE 2022; 286:131778. [PMID: 34426132 DOI: 10.1016/j.chemosphere.2021.131778] [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: 05/10/2021] [Revised: 07/13/2021] [Accepted: 08/01/2021] [Indexed: 06/13/2023]
Abstract
Recent research has shown the adaptability of Biological Nutrient Removal (BNR) systems to very low level dissolved oxygen (DO) concentration, mainly focusing in the nitrification ability that maintains the nitrogen oxidation process even at very low DO levels. Although step-wise aeration decrease on Enhanced Biological Phosphorus Removal (EBPR) is not fully comprehended. This study investigated the effect of reaching micro-aeration with adaptation strategies on EBPR performance. A step-wise oxygen concentration decrease, arriving at an average aeration level of 0.4 mgO2/L was evaluated, with an outcome of approximately 90 % phosphorus removal efficiency. Compared with different aeration modes, the highest phosphorus (P)-removal efficiency, P-release and lowest effluent phosphorus was achieved in gradual DO decrease strategy. On the other hand, an instant decrease in aeration from stable EBPR process from 2 mgO2/L to 0.4 mgO2/L adversely impacted P-removal by decreasing the efficiency to average 60 % and deteriorating the phosphorus removing microbial consortium. Comparison of results between instant and gradual DO-decrease, indicated the sensitivity of microorganisms to aeration. Microbial adaptation to decreased oxygen availability is crucial to reach high process performance. This study proposes, a potential aeration mode, which contributes in reduction of energy consumption in BNR systems through wastewater treatment.
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Affiliation(s)
- Parnian Izadi
- Civil Engineering, York University, 4700 Keele St, Toronto, M3J 1P3, ON, Canada.
| | - Parin Izadi
- Civil Engineering, York University, 4700 Keele St, Toronto, M3J 1P3, ON, Canada.
| | - Ahmed Eldyasti
- Civil Engineering, York University, 4700 Keele St, Toronto, M3J 1P3, ON, Canada.
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Wang H, Li Z, Peng L, Tang X, Lin Y, Yang D, Geng J, Ren H, Xu K. Performance evaluation and mechanism of nitrogen removal in a packed bed reactor using micromagnetic carriers at different carbon to nitrogen ratios. BIORESOURCE TECHNOLOGY 2021; 341:125747. [PMID: 34461406 DOI: 10.1016/j.biortech.2021.125747] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/05/2021] [Accepted: 08/07/2021] [Indexed: 06/13/2023]
Abstract
Advanced nitrogen removal of effluent discharged from secondary treatment systems can avoid eutrophication. However, the lack of biodegradable organics limits biodenitrification. Packed bed reactors filled with carriers with different micromagnetic field (MMF) strengths were used to perform tertiary denitrification. The results showed that MMF significantly improved the denitrification performance, especially at low C/N ratios. Total nitrogen (TN) removal was increased by 4.12% with 0.6 mT MMF when C/N = 4 and increased by 7.06% and 8.06% with 0.3 mT and 0.9 mT MMFs when C/N = 3, respectively. Zooglea, Flavobacterium, and Denitratisoma contributed to the advanced denitrification performance under MMF. In addition, 0.6 mT MMF enhanced nitrogen metabolism and ABC transporter protein and two-component system activities of microorganisms under C/N = 4; 0.3 mT and 0.9 mT MMFs increased nitrogen, carbohydrate, and amino acid metabolism and ABC transporter protein activities under C/N = 3. These findings indicate that MMF has great potential for advanced denitrification from secondary effluent.
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Affiliation(s)
- Haiyue Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Zhihao Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Ling Peng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Xi Tang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yuan Lin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Dongli Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Jinju Geng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Ke Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
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Zhu YM, Xu D, Ren H, Geng J, Xu K. Metagenomic insights into the "window" effect of static magnetic field on nitrous oxide emission from biological nitrogen removal process at low temperature. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 298:113377. [PMID: 34375917 DOI: 10.1016/j.jenvman.2021.113377] [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: 04/14/2021] [Revised: 07/11/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
This study aimed to explore whether the "window" effect of static magnetic field (SMF) on nitrous oxide (N2O) emission from the biological nitrogen removal process at low temperature existed and reveal its biological mechanism at the gene level. Four sequencing batch reactors (SBRs) with SMFs of 0, 10, 45, and 75 mT were operated continuously for 110 days at 10 °C and the lowest N2O-Gas cumulative emission (5.50 mg N/day) and N2O conversion rate (4.28 %) in 45 mT SMF-SBR verified the existence of the "window" effect. In 45 mT SMF-SBR, nearly all enzymatic activities related to N2O reduction and corresponding functional gene abundances improved significantly. Metagenomic high-throughput sequencing analysis revealed that Alicycliphilus denitricans, Paracoccus denitrificans, Rhodopseudomonas palustris, Pseudomonas stutzeri, and Dechloromonas aromatica, as species related to N2O reduction, could be separately enriched by applying suitable SMF intensity. Gene functions annotation based on KEGG and CAZy databases indicated that SMF not only accelerated the rate of free ammonia into ammonia-oxidizing bacteria and electrons delivered to the corresponding denitrification reductases, but also enhanced the degradation of complex organic matter into smaller molecules, and thus reducing the production of N2O via nitrifier denitrification and incomplete denitrification pathways at 10 °C. These findings provided a guideline and presented a blueprint of ecophysiology for the future application of magnetic field to the reduction of N2O emission in wastewater treatment plants in the cold region.
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Affiliation(s)
- Yuan-Mo Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, China; Nanjing University Yixing Environmental Protection Research Institute, Yixing, 214200, Jiangsu, China
| | - Dan Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, China; Nanjing University Yixing Environmental Protection Research Institute, Yixing, 214200, Jiangsu, China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, China; Nanjing University Yixing Environmental Protection Research Institute, Yixing, 214200, Jiangsu, China
| | - Jinju Geng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, China; Nanjing University Yixing Environmental Protection Research Institute, Yixing, 214200, Jiangsu, China
| | - Ke Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, China; Nanjing University Yixing Environmental Protection Research Institute, Yixing, 214200, Jiangsu, China.
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9
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Ren T, Chi Y, Wang Y, Shi X, Jin X, Jin P. Diversified metabolism makes novel Thauera strain highly competitive in low carbon wastewater treatment. WATER RESEARCH 2021; 206:117742. [PMID: 34653797 DOI: 10.1016/j.watres.2021.117742] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 08/01/2021] [Accepted: 10/04/2021] [Indexed: 06/13/2023]
Abstract
Thauera, as one of the core members of wastewater biological treatment systems, plays an important role in the process of nitrogen and phosphorus removal from low-carbon source sewage. However, there is a lack of systematic understanding of Thauera's metabolic pathway and genomics. Here we report on the newly isolated Thauera sp. RT1901, which is capable of denitrification using variety carbon sources including aromatic compounds. By comparing the denitrification processes under the conditions of insufficient, adequate and surplus carbon sources, it was found that strain RT1901 could simultaneously use soluble microbial products (SMP) and extracellular polymeric substances (EPS) as electron donors for denitrification. Strain RT1901 was also found to be a denitrifying phosphate accumulating bacterium, able to use nitrate, nitrite, or oxygen as electron acceptors during poly-β-hydroxybutyrate (PHB) catabolism. The annotated genome was used to reconstruct the complete nitrogen and phosphorus metabolism pathways of RT1901. In the process of denitrifying phosphorus accumulation, glycolysis was the only pathway for glycogen metabolism, and the glyoxylic acid cycle replaced the tricarboxylic acid cycle (TCA) to supplement the reduced energy. In addition, the abundance of conventional phosphorus accumulating bacteria decreased significantly and the removal rates of total nitrogen (TN) and chemical oxygen demand (COD) increased after the addition of RT1901 in the low carbon/nitrogen (C/N) ratio of anaerobic aerobic anoxic-sequencing batch reactor (AOA-SBR). This research indicated that the diverse metabolic capabilities of Thauera made it more competitive than other bacteria in the wastewater treatment system.
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Affiliation(s)
- Tong Ren
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China
| | - Yulei Chi
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China
| | - Yu Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China
| | - Xuan Shi
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China
| | - Xin Jin
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China
| | - Pengkang Jin
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China; School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China.
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Shao Q, Wan F, Du W, He J. Enhancing biological nitrogen removal for a retrofit project using wastewater with a low C/N ratio-a model-based study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:53074-53086. [PMID: 34023998 PMCID: PMC8140755 DOI: 10.1007/s11356-021-14396-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/10/2021] [Indexed: 05/12/2023]
Abstract
Anaerobic ammonium oxidation (anammox) has the merit of saving the carbon source and aeration energy for nitrogen (N) removal, but it is normally a challenge to achieve mainstream anammox. In this study, the potential to enhance the N-removal capability of an existing University of Cape Town membrane bioreactor system (UCT-MBR) system is evaluated through process modeling. In addition to external carbon addition, the UCT-MBR system is proposed to be converted into an anoxic-oxic (AO) configuration with two operation plans: one is single-sludge (suspended sludge) and the other is double-sludge (suspended sludge and biofilm). The choice between pushing anammox and enhancing conventional heterotrophic denitrification is assessed. The simulation result indicates it is feasible to strategically adjust the spatial-temporal balance between electron donors and electron acceptors to achieve enhanced N-removal by utilizing the influent organic carbon other than adding external carbon. Although anammox can be promoted in the double-sludge-based AO under low-DO conditions, pushing anammox will weaken the system's resilience to influent fluctuations and carries no economic advantage over the single-sludge-based AO. Overall, this study concurs with the United Nations Sustainable Development Goal that the wastewater industry should seek more energy-efficient measures for wastewater treatment.
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Affiliation(s)
- Qian Shao
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Fan Wan
- Wuhan Planning and Design Co., Ltd., Wuhan, 430014, China
| | - Weiwei Du
- Sichuan Wentao Engineering and Technologies Co., Ltd., Chengdu, 610000, China
| | - Jiajie He
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
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Zhao L, Fu G, Wu J, Pang W, Hu Z. Bioaugmented constructed wetlands for efficient saline wastewater treatment with multiple denitrification pathways. BIORESOURCE TECHNOLOGY 2021; 335:125236. [PMID: 33991883 DOI: 10.1016/j.biortech.2021.125236] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/19/2021] [Accepted: 04/23/2021] [Indexed: 06/12/2023]
Abstract
Six laboratory-scale constructed wetlands (CWs) were used to quantify the nitrogen removal (NR) capacity in the treatment of saline wastewater at high (6:1) and low (2:1) carbon-nitrogen ratios (C/N), with and without bioaugmentation of aerobic-denitrifying bacterium. Sustained high-efficiency nitrification was observed throughout the operation. However, under different C/N ratios, although the bioaugmentation of aerobic-denitrifying bacterium promoted the removal of NO3--N and TN, there were still great differences in denitrification. Molecular biology experiments revealed ammonia-oxidizing archaea, together with the Nitrosomonas and Nitrospira, led to highly efficient nitrification. Furthermore, aerobic-denitrifying bacterium and sulfur-driven denitrifiers were the core denitrification groups in CWs. By performing these combined experiments, it was possible to determine the optimal CW design and the most relevant NR processes for the treatment of salty wastewater. The results suggest that the bioaugmentation of salt-tolerant functional bacteria with multiple NR pathways are crucial for the removal of salty wastewater pollutants.
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Affiliation(s)
- Lin Zhao
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Guiping Fu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
| | - Jinfa Wu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Weicheng Pang
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
| | - Zhangli Hu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China
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