Stephanie H. Ayotte , Kristen O. Brush , Christopher R. Allen , Otto R. Stein , Ellen G. Lauchnor
{"title":"亚高山带处理湿地的温室气体排放和氮去除:传质效应和剂量的含义","authors":"Stephanie H. Ayotte , Kristen O. Brush , Christopher R. Allen , Otto R. Stein , Ellen G. Lauchnor","doi":"10.1016/j.ecoleng.2025.107746","DOIUrl":null,"url":null,"abstract":"<div><div>Today, there is increased focus on greenhouse gas emissions (GHGs) from wastewater treatment, as industrialization and global population growth threaten to exponentiate current emission trends. This study focuses on the effects of intermittent dosing on nitrous oxide (N<sub>2</sub>O), methane (CH<sub>4</sub>) and carbon dioxide (CO<sub>2</sub>) emissions from a two-stage, low temperature vertical flow treatment wetland (VFTW) treating 3 °C ski resort wastewater. The system has a partially saturated first stage and unsaturated second stage with recycle to optimize for total nitrogen removal. Following two automated closed-loop GHG sampling campaigns across 16 locations in the TW, emission profiles were found to vary significantly by location. Smaller influent wastewater doses resulted in higher proportion of dissolved N<sub>2</sub>O and indications of carbon limitations across the first stage of the system due to incomplete denitrification. Small and large doses resulted in spikes of CH<sub>4</sub> and N<sub>2</sub>O emissions, suggesting mass transfer effects temporarily increased emissions. CH<sub>4</sub> was generated almost entirely in the primary sedimentation tank, with an observed 70 % drop in emissions from hours 1 to 8 of the dosing schedule. Additionally, heavy snowpack and ice lens formations resulted in preferential gas flow in the first stage. These results suggest that estimates of GHG emissions from TWs may be falsely elevated due to mass transfer and environmental conditions that hinder transport. The results indicate a need to continually inventory GHGs due to the complexity of wastewater systems, and that specific wastewater application methods may help to mitigate emissions.</div></div>","PeriodicalId":11490,"journal":{"name":"Ecological Engineering","volume":"220 ","pages":"Article 107746"},"PeriodicalIF":4.1000,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Greenhouse gas emissions and nitrogen removal from a subalpine zone treatment wetland: Implications of mass transfer effects and dosing\",\"authors\":\"Stephanie H. Ayotte , Kristen O. Brush , Christopher R. Allen , Otto R. Stein , Ellen G. Lauchnor\",\"doi\":\"10.1016/j.ecoleng.2025.107746\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Today, there is increased focus on greenhouse gas emissions (GHGs) from wastewater treatment, as industrialization and global population growth threaten to exponentiate current emission trends. This study focuses on the effects of intermittent dosing on nitrous oxide (N<sub>2</sub>O), methane (CH<sub>4</sub>) and carbon dioxide (CO<sub>2</sub>) emissions from a two-stage, low temperature vertical flow treatment wetland (VFTW) treating 3 °C ski resort wastewater. The system has a partially saturated first stage and unsaturated second stage with recycle to optimize for total nitrogen removal. Following two automated closed-loop GHG sampling campaigns across 16 locations in the TW, emission profiles were found to vary significantly by location. Smaller influent wastewater doses resulted in higher proportion of dissolved N<sub>2</sub>O and indications of carbon limitations across the first stage of the system due to incomplete denitrification. Small and large doses resulted in spikes of CH<sub>4</sub> and N<sub>2</sub>O emissions, suggesting mass transfer effects temporarily increased emissions. CH<sub>4</sub> was generated almost entirely in the primary sedimentation tank, with an observed 70 % drop in emissions from hours 1 to 8 of the dosing schedule. Additionally, heavy snowpack and ice lens formations resulted in preferential gas flow in the first stage. These results suggest that estimates of GHG emissions from TWs may be falsely elevated due to mass transfer and environmental conditions that hinder transport. The results indicate a need to continually inventory GHGs due to the complexity of wastewater systems, and that specific wastewater application methods may help to mitigate emissions.</div></div>\",\"PeriodicalId\":11490,\"journal\":{\"name\":\"Ecological Engineering\",\"volume\":\"220 \",\"pages\":\"Article 107746\"},\"PeriodicalIF\":4.1000,\"publicationDate\":\"2025-07-28\",\"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/S0925857425002368\",\"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/S0925857425002368","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}
Greenhouse gas emissions and nitrogen removal from a subalpine zone treatment wetland: Implications of mass transfer effects and dosing
Today, there is increased focus on greenhouse gas emissions (GHGs) from wastewater treatment, as industrialization and global population growth threaten to exponentiate current emission trends. This study focuses on the effects of intermittent dosing on nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) emissions from a two-stage, low temperature vertical flow treatment wetland (VFTW) treating 3 °C ski resort wastewater. The system has a partially saturated first stage and unsaturated second stage with recycle to optimize for total nitrogen removal. Following two automated closed-loop GHG sampling campaigns across 16 locations in the TW, emission profiles were found to vary significantly by location. Smaller influent wastewater doses resulted in higher proportion of dissolved N2O and indications of carbon limitations across the first stage of the system due to incomplete denitrification. Small and large doses resulted in spikes of CH4 and N2O emissions, suggesting mass transfer effects temporarily increased emissions. CH4 was generated almost entirely in the primary sedimentation tank, with an observed 70 % drop in emissions from hours 1 to 8 of the dosing schedule. Additionally, heavy snowpack and ice lens formations resulted in preferential gas flow in the first stage. These results suggest that estimates of GHG emissions from TWs may be falsely elevated due to mass transfer and environmental conditions that hinder transport. The results indicate a need to continually inventory GHGs due to the complexity of wastewater systems, and that specific wastewater application methods may help to mitigate emissions.
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.