1
|
Yang P, Li J, Hou R, Yuan R, Chen Y, Liu W, Yu G, Wang W, Zhou B, Chen Z, Chen H. Mitigating N 2O emissions in land treatment systems: Mechanisms, influences, and future directions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175638. [PMID: 39168319 DOI: 10.1016/j.scitotenv.2024.175638] [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: 04/18/2024] [Revised: 08/17/2024] [Accepted: 08/17/2024] [Indexed: 08/23/2024]
Abstract
Land treatment systems (LTS) are widely used in decentralized domestic wastewater treatment due to low energy requirements and effective treatment outcomes. However, LTS operations are also a significant source of N2O emissions, a potent greenhouse gas threatening the ozone layer and posing risks to human health. Despite the importance of understanding and controlling N2O emissions, existing literature lacks comprehensive analyses of the mechanisms driving N2O generation and effective control strategies within LTS. This study addresses this gap by reviewing current research and identifying key factors influencing N2O emissions in LTS. This review reveals that in addition to traditional nitrification and denitrification processes, co-denitrification and complete ammonia oxidation are crucial for microbial nitrogen removal in LTS. Plant selection is primarily based on their nitrogen absorption capacity while using materials such as biochar and iron can provide carbon sources or electrons to support microbial activities. Optimizing operational parameters is essential for reducing N2O emissions and enhancing nitrogen removal efficiency in LTS. Specifically, the carbon-to‑nitrogen ratio should be maintained between 5 and 12, and the hydraulic loading rate should be kept within 0.08-0.2 m3/(m2·d). Dissolved oxygen and oxidation-reduction potential should be adjusted to meet the aerobic or anaerobic conditions the microorganisms require. Additionally, maintaining a pH range of 6.5-7.5 by adding alkaline substances is crucial for sustaining nitrous oxide reductase activity. The operating temperature should be maintained between 20 and 30 °C to support optimal microbial activity. This review further explores the relationship between environmental factors and microbial enzyme activity, community structure changes, and functional gene expression related to N2O production. Future research directions are proposed to refine N2O flux control strategies. By consolidating current knowledge and identifying research gaps, this review advances LTS management strategies that improve wastewater treatment efficiency while mitigating the environmental and health impacts of N2O emissions.
Collapse
Affiliation(s)
- Peng Yang
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China
| | - Junhong Li
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China
| | - Rongrong Hou
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China
| | - Rongfang Yuan
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China
| | - Yuefang Chen
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China.
| | - Weiqing Liu
- Beijing Institute of Geology for Mineral Resources, Yuanlin East Road, Mi Yun, Beijing 101500, China
| | - Guoqing Yu
- Beijing Geo-Exploration and Water Environment Engineering Institute Co., Ltd., Tiancun Road, Beijing 100142, China
| | - Weiqiang Wang
- Beijing Geo-Exploration and Water Environment Engineering Institute Co., Ltd., Tiancun Road, Beijing 100142, China
| | - Beihai Zhou
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhongbing Chen
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16500 Praha-Suchdol, Czech Republic.
| | - Huilun Chen
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China.
| |
Collapse
|
2
|
Wu H, Hao B, You Y, Zou C, Cai X, Li J, Qin H. Aquatic macrophytes mitigate the conflict between nitrogen removal and nitrous oxide emissions during tailwater treatments. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 370:122671. [PMID: 39357443 DOI: 10.1016/j.jenvman.2024.122671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 09/20/2024] [Accepted: 09/24/2024] [Indexed: 10/04/2024]
Abstract
Tailwater from wastewater treatment plants (WWTP) usually reduces the nitrogen (N) removal efficiency while simultaneously elevates nitrous oxide (N2O) emissions due to the low carbon-nitrogen (C/N) ratio. Conflicts between N removal and N2O emissions require mitigation by selecting appropriate aquatic plants for tailwater treatment. In this study, a simulated tailwater mesocosm was established using three aquatic plants including Eichhornia crassipes, Myriophyllum aquaticum and Pistia stratiotes. Results of the 15N isotope mass balance analysis revealed the considerable contributions from plant uptake and benthic retention to overall N removal. It was demonstrated that the N assimilation efficiency of aquatic plants depended more on the root-shoot ratio rather than on growth rate. Furthermore, aquatic plants indirectly influence microbial N removal and N2O emissions by altering the water quality parameters. Additionally, aquatic plants could regulate the N transformation through affecting the structure of bacterial community, including microbial abundance, diversity and association networks. Overall, the study underlined the enormous capacities of E. crassipes and P. stratiotes for N uptake and N2O mitigation in tailwater treatment. Utilizing these two aquatic plants for phytoremediation may help mitigate the conflict between tailwater purification and N2O production.
Collapse
Affiliation(s)
- Haoping Wu
- Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China; Key Laboratory of Modern Agricultural Intelligent Equipment in South China, Ministry of Agriculture and Rural Affairs, Guangdong, 510630, China; Key Laboratory of Urban Agriculture in South China, Ministry of Agriculture and Rural Affairs, Guangzhou, 510640, China
| | - Beibei Hao
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, China
| | - Yi You
- Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China; Key Laboratory of Urban Agriculture in South China, Ministry of Agriculture and Rural Affairs, Guangzhou, 510640, China
| | - Chunping Zou
- Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China; Key Laboratory of Urban Agriculture in South China, Ministry of Agriculture and Rural Affairs, Guangzhou, 510640, China
| | - Xixi Cai
- Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China; Key Laboratory of Urban Agriculture in South China, Ministry of Agriculture and Rural Affairs, Guangzhou, 510640, China
| | - Jianying Li
- Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China; Key Laboratory of Urban Agriculture in South China, Ministry of Agriculture and Rural Affairs, Guangzhou, 510640, China
| | - Hongjie Qin
- Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China; Key Laboratory of Urban Agriculture in South China, Ministry of Agriculture and Rural Affairs, Guangzhou, 510640, China.
| |
Collapse
|
3
|
Zuo J, Xu L, Guo J, Xu S, Ma S, Jiang C, Yang D, Wang D, Zhuang X. Microbial community structure analyses and cultivable denitrifier isolation of Myriophyllum aquaticum constructed wetland under low C/N ratio. J Environ Sci (China) 2023; 127:30-41. [PMID: 36522062 DOI: 10.1016/j.jes.2022.04.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/01/2022] [Accepted: 04/02/2022] [Indexed: 06/17/2023]
Abstract
With the rapid expansion of livestock production, the amount of livestock wastewater accumulated rapidly. Lack of biodegradable organic matter makes denitrification of livestock wastewater after anaerobic digestion more difficult. In this study, Myriophyllum aquaticum constructed wetlands (CWs) with efficient nitrogen removal performance were established under different carbon/nitrogen (C/N) ratios. Analysis of community composition reveals the change of M. aquaticum CWs in microbial community structure with C/N ratios. The proportion of Proteobacteria which is one of the dominant phyla among denitrifier communities increased significantly under low C/N ratio conditions. Besides, to obtain cultivable denitrifier that could be added into CWs in situ, 33 strains belonging to phylum Proteobacteria were isolated from efficient M. aquaticum CWs, while the best-performing denitrification strain M3-1 was identified as Bacillus velezensis JT3-1 (GenBank No. CP032506.1). Redundancy analysis and quadratic models showed that C/N ratio had significant effects on disposal of nitrate (NO3--N) and the strains isolated could perform well in denitrification when C/N ratio is relatively low. In addition, they have relatively wide ranges of carbon sources, temperature and a high NO3- removal rate of 9.12 mg/(L·hr) at elevated concentrations of 800 mg/L nitrate. Thus, strains isolated from M. aquaticum CWs with low C/N ratio have a practical application value in the treatment of nitrate-containing wastewater. These denitrifying bacteria could be added to CWs to enhance nitrogen removal efficiency of CWs for livestock wastewater with low C/N ratio in the future.
Collapse
Affiliation(s)
- Jialiang Zuo
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Sino-Danish Center, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Lina Xu
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jianlin Guo
- Ningxia Zhongke Jingke Testing Technology Company, Yinchuan 750000, China
| | - Shengjun Xu
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Shuanglong Ma
- College of Resources and Environmental Sciences, Henan Agricultural University, Zhengzhou 450002, China
| | - Cancan Jiang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Dongmin Yang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Danhua Wang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xuliang Zhuang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.
| |
Collapse
|
4
|
Tang H, Ma Z, Qin Y, Wu H, Xu X, Xin L, Wu W. Pilot-scale study of step-feed anaerobic coupled four-stage micro-oxygen gradient aeration process for treating digested swine wastewater with low carbon/nitrogen ratios. BIORESOURCE TECHNOLOGY 2023; 380:129087. [PMID: 37094619 DOI: 10.1016/j.biortech.2023.129087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 04/18/2023] [Accepted: 04/21/2023] [Indexed: 05/03/2023]
Abstract
This study developed an innovative step-feed anaerobic coupled four-stage micro-oxygen gradient aeration process to treat digested swine wastewater. An anaerobic zone was used for prepositive denitrification; four micro-oxygen reactors (zones O1-O4) were used for simultaneous partial nitrification and denitrification through low-dissolved oxygen gradient control, step-feed, and swine wastewater-digested swine wastewater distribution. The nitrogen-removal efficiency was satisfactory (93 ± 3 %; effluent total nitrogen, 53 ± 19 mg/L). Mass balance coupled with quantitative polymerase chain reaction analysis revealed that simultaneous partial nitrification and denitrification was achieved in four micro-oxygen zones. Zones O1 were the major denitrification zones for nitrogen removal; nitrification was primary happened in zones O2 and O3. Correlation analysis confirmed that low-dissolved oxygen gradient control was the key to achieving efficient nitrogen removal. This study provides a low oxygen energy consumption method to treat digested swine wastewater with a low carbon/nitrogen ratio (<3).
Collapse
Affiliation(s)
- Hang Tang
- Institute of Environment Science and Technology, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety Technology, Zhejiang 310058, PR China
| | - Zhuang Ma
- Zhejiang Transper Environmental Protection Technology Co., Ltd., Hangzhou 310058, PR China
| | - Yong Qin
- Institute of Environment Science and Technology, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety Technology, Zhejiang 310058, PR China.
| | - Hanghang Wu
- Guangdong Provincial Academy of Environmental Science, Guangdong 510045, PR China
| | - Xingkun Xu
- Institute of Environment Science and Technology, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety Technology, Zhejiang 310058, PR China
| | - Liqing Xin
- Institute of Environment Science and Technology, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety Technology, Zhejiang 310058, PR China
| | - Weixiang Wu
- Institute of Environment Science and Technology, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety Technology, Zhejiang 310058, PR China
| |
Collapse
|
5
|
Qian Z, Zhuang S, Gao J, Tang L, Harindintwali JD, Wang F. Aeration increases soil bacterial diversity and nutrient transformation under mulching-induced hypoxic conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 817:153017. [PMID: 35026241 DOI: 10.1016/j.scitotenv.2022.153017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 05/22/2023]
Abstract
Soil oxygen (O2) deficiency induced by organic mulching is easy to overlook. Aeration has been shown to potentially alleviate soil hypoxia stress. However, the responses of soil bacterial communities to such mulching-induced hypoxic conditions and aeration remain elusive. Therefore, a three-year field experiment, consisting of mulching (T1), mulching with aeration (TA1, poor aeration; TA2, strong aeration), and no-mulching (CK) treatments, was conducted in bamboo (Phyllostachys praecox) plantations. According to our results, the strong aeration treatment (TA2) alleviated soil acidification, increased soil nutrient availability, and significantly increased soil O2 content by 18.44% (P < 0.05) when compared with T1. In addition, TA2 significantly increased soil β-glucosidase, invertase, urease, and acid phosphatase activities compared with CK and T1 (P < 0.05). The alpha diversity indices with TA2 treatment were the highest, indicating that aeration increased the species richness and diversity of bacteria. The changes in bacterial community composition associated with TA2 treatment (i.e., an increase in Firmicutes, Verrucomicrobia, and Faecalibacterium abundance and a decrease in Chloroflexi and Bradyrhizobium abundance) were mainly related to nutrient and O2 content. Mantel Test results suggested that soil O2 content and temperature were the key factors shaping bacterial community composition. Structural equation modeling revealed that soil O2 content had a positive and direct influence on bacterial community diversity. Functional annotation of prokaryotic taxa predicted that TA2 significantly increased the relative abundance of bacterial communities associated with nitrification, nitrogen fixation, and ureolysis. Our results demonstrated that optimal soil aeration conditions (17.60% of O2 content) could enhance the diversity and function of soil bacterial communities. Overall, the findings of this study could serve as a benchmark for alleviating soil hypoxia caused by organic mulches, which is important for increasing the functionality of nutrient cycling bacterial communities in the soil.
Collapse
Affiliation(s)
- Zhuangzhuang Qian
- State Key Lab of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, PR China
| | - Shunyao Zhuang
- State Key Lab of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Jianshuang Gao
- State Key Lab of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Luozhong Tang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, PR China
| | - Jean Damascene Harindintwali
- University of Chinese Academy of Sciences, Beijing 100049, PR China; CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Fang Wang
- University of Chinese Academy of Sciences, Beijing 100049, PR China; CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| |
Collapse
|
6
|
Zhang Z, Zhong M, Sun Y, Liang Y, Liu M, Li J, Cui H, Meng F, Huang Z, Cui L. Efficient treatment of digested piggery wastewater via an improved anoxic/aerobic process with Myriophyllum spicatum and bionic aquatic weed. BIORESOURCE TECHNOLOGY 2021; 341:125825. [PMID: 34481299 DOI: 10.1016/j.biortech.2021.125825] [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: 07/17/2021] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
The traditional anoxic/aerobic process (A/O) process is widely used for treating digested piggery wastewater, but the lack of carbon sources leads to poor efficiency. Therefore, the process needs optimization to achieve high-efficiency and low-cost operation mode. In this study, an improved A/O system with bionic aquatic weed and Myriophyllum sp. was established to decontaminate digested piggery wastewater. The average removal efficiencies of chemical oxygen demand (COD), NH4+-N, and total nitrogen (TN) by the improved A/O system was satisfactory. The average removal efficiencies of COD, NH4+-N, and TN were 62.1%, 87.5%, and 61.9%, respectively. High-throughput sequencing identified a number of dominant microorganisms. The relative abundance of Nitrosomonas (ammonia-oxidizing bacteria) and Nitrospira (nitrite-oxidizing bacteria) was 0.07%-3.52% and 0.32%-1.30%, respectively. Combining bionic aquatic weed and Myriophyllum sp. altered the microbial community structure and metabolic pathways. The results demonstrate a cost-effective method for treating digested piggery wastewater.
Collapse
Affiliation(s)
- Ze Zhang
- Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Mingjun Zhong
- Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Yaping Sun
- Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Yuhai Liang
- Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Mengxue Liu
- Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Jing Li
- Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Hongcan Cui
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Fangang Meng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Zhujian Huang
- Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan 410125, China
| | - Lihua Cui
- Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan 410125, China.
| |
Collapse
|