{"title":"多电子供体自养反硝化(MEDAD)底物在人工湿地处理低碳氮比废水中的应用:一个可行的框架","authors":"Lin Zhao, Yifan Zhang, Jun Tang","doi":"10.1016/j.ecoleng.2025.107648","DOIUrl":null,"url":null,"abstract":"<div><div>Constructed wetlands (CWs) offer a sustainable solution for treating low carbon-to‑nitrogen (C/N) ratio wastewater, yet their nitrogen removal efficiency is often constrained by insufficient organic electron donors. This review systematically evaluates the mechanisms, efficacy, and challenges of autotrophic denitrification in CWs using inorganic electron donors, including sulfur-, iron-, hydrogen-, and manganese-based systems. Sulfur-based systems (e.g., S<sup>0</sup>, pyrite) achieve nitrate removal rates exceeding 90 % but risk sulfate accumulation and acidification, while iron-based substrates (e.g., siderite, steel slag) enhance simultaneous nitrogen (71 % TN removal) and phosphorus removal (93 % TP removal) via Fe<sup>2+</sup>/Fe<sup>3+</sup> redox reactions. Hydrogenotrophic denitrification exhibits high efficiency (>97 % NO<sub>3</sub><sup>−</sup>-N removal) but faces practical hurdles in H<sub>2</sub> utilization. Crucially, multi-electron donor autotrophic denitrification (MEDAD) systems, integrating substrates like pyrite-steel slag composites, demonstrate synergistic benefits: TN and TP removal efficiencies improve by 40–54 % and 19 %, respectively, while stabilizing pH and mitigating phytotoxicity. The interplay between wetland vegetation and MEDAD substrates is highlighted, with root exudates (e.g., organic acids, sugars) potentially regulating microbial denitrification pathways. However, challenges persist, including byproduct management (e.g., sulfates, Fe (OH)<sub>3</sub> passivation), substrate longevity, and scalability. This study proposes a feasibility framework for MEDAD-CW integration, emphasizing substrate optimization, microbial community control, and system engineering. By addressing these factors, MEDAD-CWs can achieve efficient, stable treatment of low C/N ratio wastewater, advancing their application in eutrophication mitigation and water quality restoration.</div></div>","PeriodicalId":11490,"journal":{"name":"Ecological Engineering","volume":"217 ","pages":"Article 107648"},"PeriodicalIF":3.9000,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Application of multi-electron donor autotrophic denitrification (MEDAD) substrate in constructed wetlands for treating low carbon-to‑nitrogen ratio wastewater: A feasible framework\",\"authors\":\"Lin Zhao, Yifan Zhang, Jun Tang\",\"doi\":\"10.1016/j.ecoleng.2025.107648\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Constructed wetlands (CWs) offer a sustainable solution for treating low carbon-to‑nitrogen (C/N) ratio wastewater, yet their nitrogen removal efficiency is often constrained by insufficient organic electron donors. This review systematically evaluates the mechanisms, efficacy, and challenges of autotrophic denitrification in CWs using inorganic electron donors, including sulfur-, iron-, hydrogen-, and manganese-based systems. Sulfur-based systems (e.g., S<sup>0</sup>, pyrite) achieve nitrate removal rates exceeding 90 % but risk sulfate accumulation and acidification, while iron-based substrates (e.g., siderite, steel slag) enhance simultaneous nitrogen (71 % TN removal) and phosphorus removal (93 % TP removal) via Fe<sup>2+</sup>/Fe<sup>3+</sup> redox reactions. Hydrogenotrophic denitrification exhibits high efficiency (>97 % NO<sub>3</sub><sup>−</sup>-N removal) but faces practical hurdles in H<sub>2</sub> utilization. Crucially, multi-electron donor autotrophic denitrification (MEDAD) systems, integrating substrates like pyrite-steel slag composites, demonstrate synergistic benefits: TN and TP removal efficiencies improve by 40–54 % and 19 %, respectively, while stabilizing pH and mitigating phytotoxicity. The interplay between wetland vegetation and MEDAD substrates is highlighted, with root exudates (e.g., organic acids, sugars) potentially regulating microbial denitrification pathways. However, challenges persist, including byproduct management (e.g., sulfates, Fe (OH)<sub>3</sub> passivation), substrate longevity, and scalability. This study proposes a feasibility framework for MEDAD-CW integration, emphasizing substrate optimization, microbial community control, and system engineering. By addressing these factors, MEDAD-CWs can achieve efficient, stable treatment of low C/N ratio wastewater, advancing their application in eutrophication mitigation and water quality restoration.</div></div>\",\"PeriodicalId\":11490,\"journal\":{\"name\":\"Ecological Engineering\",\"volume\":\"217 \",\"pages\":\"Article 107648\"},\"PeriodicalIF\":3.9000,\"publicationDate\":\"2025-04-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Ecological Engineering\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0925857425001363\",\"RegionNum\":2,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ECOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ecological Engineering","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0925857425001363","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ECOLOGY","Score":null,"Total":0}
Application of multi-electron donor autotrophic denitrification (MEDAD) substrate in constructed wetlands for treating low carbon-to‑nitrogen ratio wastewater: A feasible framework
Constructed wetlands (CWs) offer a sustainable solution for treating low carbon-to‑nitrogen (C/N) ratio wastewater, yet their nitrogen removal efficiency is often constrained by insufficient organic electron donors. This review systematically evaluates the mechanisms, efficacy, and challenges of autotrophic denitrification in CWs using inorganic electron donors, including sulfur-, iron-, hydrogen-, and manganese-based systems. Sulfur-based systems (e.g., S0, pyrite) achieve nitrate removal rates exceeding 90 % but risk sulfate accumulation and acidification, while iron-based substrates (e.g., siderite, steel slag) enhance simultaneous nitrogen (71 % TN removal) and phosphorus removal (93 % TP removal) via Fe2+/Fe3+ redox reactions. Hydrogenotrophic denitrification exhibits high efficiency (>97 % NO3−-N removal) but faces practical hurdles in H2 utilization. Crucially, multi-electron donor autotrophic denitrification (MEDAD) systems, integrating substrates like pyrite-steel slag composites, demonstrate synergistic benefits: TN and TP removal efficiencies improve by 40–54 % and 19 %, respectively, while stabilizing pH and mitigating phytotoxicity. The interplay between wetland vegetation and MEDAD substrates is highlighted, with root exudates (e.g., organic acids, sugars) potentially regulating microbial denitrification pathways. However, challenges persist, including byproduct management (e.g., sulfates, Fe (OH)3 passivation), substrate longevity, and scalability. This study proposes a feasibility framework for MEDAD-CW integration, emphasizing substrate optimization, microbial community control, and system engineering. By addressing these factors, MEDAD-CWs can achieve efficient, stable treatment of low C/N ratio wastewater, advancing their application in eutrophication mitigation and water quality restoration.
期刊介绍:
Ecological engineering has been defined as the design of ecosystems for the mutual benefit of humans and nature. The journal is meant for ecologists who, because of their research interests or occupation, are involved in designing, monitoring, or restoring ecosystems, and can serve as a bridge between ecologists and engineers.
Specific topics covered in the journal include: habitat reconstruction; ecotechnology; synthetic ecology; bioengineering; restoration ecology; ecology conservation; ecosystem rehabilitation; stream and river restoration; reclamation ecology; non-renewable resource conservation. Descriptions of specific applications of ecological engineering are acceptable only when situated within context of adding novelty to current research and emphasizing ecosystem restoration. We do not accept purely descriptive reports on ecosystem structures (such as vegetation surveys), purely physical assessment of materials that can be used for ecological restoration, small-model studies carried out in the laboratory or greenhouse with artificial (waste)water or crop studies, or case studies on conventional wastewater treatment and eutrophication that do not offer an ecosystem restoration approach within the paper.