Pub Date : 2023-06-20DOI: 10.1021/acsenvironau.3c00002
Zhuo Liu, Biyang Xu, Yu-Jing Jiang, Yang Zhou, Xiaolian Sun, Yuanyuan Wang and Wenlei Zhu*,
With 28–34 times the greenhouse effect of CO2 over a 100-year period, methane is regarded as the second largest contributor to global warming. Reducing methane emissions is a necessary measure to limit global warming to below 1.5 °C. Photocatalytic conversion of methane is a promising approach to alleviate the atmospheric methane concentrations due to its low energy consumption and environmentally friendly characteristics. Meanwhile, this conversion process can produce valuable chemicals and liquid fuels such as CH3OH, CH3CH2OH, C2H6, and C2H4, cutting down the dependence of chemical production on crude oil. However, the development of photocatalysts with a high methane conversion efficiency and product selectivity remains challenging. In this review, we overview recent advances in semiconductor-based photocatalysts for methane conversion and present catalyst design strategies, including morphology control, heteroatom doping, facet engineering, and cocatalysts modification. To gain a comprehensive understanding of photocatalytic methane conversion, the conversion pathways and mechanisms in these systems are analyzed in detail. Moreover, the role of electron scavengers in methane conversion performance is briefly discussed. Subsequently, we summarize the anthropogenic methane emission scenarios on earth and discuss the application potential of photocatalytic methane conversion. Finally, challenges and future directions for photocatalytic methane conversion are presented.
{"title":"Photocatalytic Conversion of Methane: Current State of the Art, Challenges, and Future Perspectives","authors":"Zhuo Liu, Biyang Xu, Yu-Jing Jiang, Yang Zhou, Xiaolian Sun, Yuanyuan Wang and Wenlei Zhu*, ","doi":"10.1021/acsenvironau.3c00002","DOIUrl":"10.1021/acsenvironau.3c00002","url":null,"abstract":"<p >With 28–34 times the greenhouse effect of CO<sub>2</sub> over a 100-year period, methane is regarded as the second largest contributor to global warming. Reducing methane emissions is a necessary measure to limit global warming to below 1.5 °C. Photocatalytic conversion of methane is a promising approach to alleviate the atmospheric methane concentrations due to its low energy consumption and environmentally friendly characteristics. Meanwhile, this conversion process can produce valuable chemicals and liquid fuels such as CH<sub>3</sub>OH, CH<sub>3</sub>CH<sub>2</sub>OH, C<sub>2</sub>H<sub>6</sub>, and C<sub>2</sub>H<sub>4</sub>, cutting down the dependence of chemical production on crude oil. However, the development of photocatalysts with a high methane conversion efficiency and product selectivity remains challenging. In this review, we overview recent advances in semiconductor-based photocatalysts for methane conversion and present catalyst design strategies, including morphology control, heteroatom doping, facet engineering, and cocatalysts modification. To gain a comprehensive understanding of photocatalytic methane conversion, the conversion pathways and mechanisms in these systems are analyzed in detail. Moreover, the role of electron scavengers in methane conversion performance is briefly discussed. Subsequently, we summarize the anthropogenic methane emission scenarios on earth and discuss the application potential of photocatalytic methane conversion. Finally, challenges and future directions for photocatalytic methane conversion are presented.</p>","PeriodicalId":29801,"journal":{"name":"ACS Environmental Au","volume":"3 5","pages":"252–276"},"PeriodicalIF":0.0,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/9a/65/vg3c00002.PMC10515711.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41136826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-14DOI: 10.1021/acsenvironau.2c00071
Jacob S. Shedd, Jonghwa Oh, Evan L. Floyd and Claudiu T. Lungu*,
Products and starting materials containing volatile organic compounds (VOCs) can easily be found in a variety of businesses, making them a common source of occupational exposure. To prevent negative impacts on employee health, field industrial hygienists must conduct regular sampling to ensure exposures remain below the regulatory limits set by governmental and professional associations. As such, the need for sensitive and reliable exposure assessment techniques becomes evident. Over the preceding decade, the industrial hygiene research group at the University of Alabama at Birmingham (UAB) has been working on the development of an emerging, preanalytical technique known as photothermal desorption (PTD) to improve upon the analytical sensitivity of currently employed methods. PTD’s novel design uses pulses of high-energy light to desorb analytes from thermally conductive, carbonaceous sorbents, to be delivered to downstream analytical detectors. Since PTD’s conception, the theoretical framework and advances in sorbent fabrication have been investigated; however, further work is needed to produce a field-ready sampling device for use with PTD. As such, objectives of the present work were to design a PTD-compatible diffusive sampler prototype and characterize the prototype’s sampling efficiencies for toluene, n-hexane, trichloroethylene, and isopropyl alcohol. In pursuit of these objectives, the study empirically quantified the sampled masses of toluene, n-hexane, trichloroethylene, and isopropyl alcohol, at occupationally relevant air concentrations, to be 12.17 ± 0.06, 8.2 ± 0.1, 3.97 ± 0.06, and 8.0 ± 0.1 mg, respectively. Moreover, the analyte sampling efficiencies were found to be 2.2 ± 0.1, 1.7 ± 0.1, 1.2 ± 0.1, and 0.51 ± 0.05 (unitless) when comparing empirically (i.e., laboratory observed) sample mass values to theoretically predicted values. The sampling efficiencies and collected sample masses reported herein demonstrate the promising design of PTD-compatible diffusive samplers. When used in conjunction with the PTD method, the prototype samplers present strong evidence for improving analytical sensitivity in exposure assessments of VOCs in the workplace.
{"title":"Characterization of Photothermal Desorption-Compatible Diffusive Samplers for Volatile Organic Compounds","authors":"Jacob S. Shedd, Jonghwa Oh, Evan L. Floyd and Claudiu T. Lungu*, ","doi":"10.1021/acsenvironau.2c00071","DOIUrl":"10.1021/acsenvironau.2c00071","url":null,"abstract":"<p >Products and starting materials containing volatile organic compounds (VOCs) can easily be found in a variety of businesses, making them a common source of occupational exposure. To prevent negative impacts on employee health, field industrial hygienists must conduct regular sampling to ensure exposures remain below the regulatory limits set by governmental and professional associations. As such, the need for sensitive and reliable exposure assessment techniques becomes evident. Over the preceding decade, the industrial hygiene research group at the University of Alabama at Birmingham (UAB) has been working on the development of an emerging, preanalytical technique known as photothermal desorption (PTD) to improve upon the analytical sensitivity of currently employed methods. PTD’s novel design uses pulses of high-energy light to desorb analytes from thermally conductive, carbonaceous sorbents, to be delivered to downstream analytical detectors. Since PTD’s conception, the theoretical framework and advances in sorbent fabrication have been investigated; however, further work is needed to produce a field-ready sampling device for use with PTD. As such, objectives of the present work were to design a PTD-compatible diffusive sampler prototype and characterize the prototype’s sampling efficiencies for toluene, <i>n</i>-hexane, trichloroethylene, and isopropyl alcohol. In pursuit of these objectives, the study empirically quantified the sampled masses of toluene, <i>n</i>-hexane, trichloroethylene, and isopropyl alcohol, at occupationally relevant air concentrations, to be 12.17 ± 0.06, 8.2 ± 0.1, 3.97 ± 0.06, and 8.0 ± 0.1 mg, respectively. Moreover, the analyte sampling efficiencies were found to be 2.2 ± 0.1, 1.7 ± 0.1, 1.2 ± 0.1, and 0.51 ± 0.05 (unitless) when comparing empirically (i.e., laboratory observed) sample mass values to theoretically predicted values. The sampling efficiencies and collected sample masses reported herein demonstrate the promising design of PTD-compatible diffusive samplers. When used in conjunction with the PTD method, the prototype samplers present strong evidence for improving analytical sensitivity in exposure assessments of VOCs in the workplace.</p>","PeriodicalId":29801,"journal":{"name":"ACS Environmental Au","volume":"3 4","pages":"242–248"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/e0/d6/vg2c00071.PMC10360198.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9862939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-12DOI: 10.1021/acsenvironau.3c00024
Jie Wang*, Jianguo Tao, Jianghao Ji, Mochen Wu, Yuanze Sun, Jun Li* and Jay Gan,
Although in vitro simulation and in vivo feeding experiments are commonly used to evaluate the carrier role of microplastics in the bioaccumulation of toxic chemicals, there is no direct method for quantitatively determining their vector effect. In this study, we propose a dual-labeled method based on spiking unlabeled hydrophobic organic contaminants (HOCs) into soils and spiking their respective isotope-labeled reference compounds into microplastic particles. The bioaccumulation of the unlabeled and isotope-labeled HOCs in Eisenia fetida earthworms was compared. Earthworms can assimilate both unlabeled and isotope-labeled HOCs via three routes: dermal uptake, soil ingestion, and microplastic ingestion. After 28 days of exposure, the relative fractions of bioaccumulated isotope-labeled HOCs in the soil treated with 1% microplastics ranged from 15.5 to 55.8%, which were 2.9–47.6 times higher than those in the soils treated with 0.1% microplastics. Polyethylene microplastics were observed to have higher relative fractions of bioaccumulated isotope-labeled HOCs, potentially because of their surface hydrophobicity and amorphous rubbery state. The general linear models suggested that the vector effects were mainly due to the microplastic concentration, followed by polymer properties and HOC hydrophobicity. This proposed method and the derived empirical formula contribute to a more comprehensive understanding of the vector effects of microplastics for HOC bioaccumulation.
{"title":"Use of a Dual-Labeled Bioaccumulation Method to Quantify Microplastic Vector Effects for Hydrophobic Organic Contaminants in Soil","authors":"Jie Wang*, Jianguo Tao, Jianghao Ji, Mochen Wu, Yuanze Sun, Jun Li* and Jay Gan, ","doi":"10.1021/acsenvironau.3c00024","DOIUrl":"10.1021/acsenvironau.3c00024","url":null,"abstract":"<p >Although in vitro simulation and in vivo feeding experiments are commonly used to evaluate the carrier role of microplastics in the bioaccumulation of toxic chemicals, there is no direct method for quantitatively determining their vector effect. In this study, we propose a dual-labeled method based on spiking unlabeled hydrophobic organic contaminants (HOCs) into soils and spiking their respective isotope-labeled reference compounds into microplastic particles. The bioaccumulation of the unlabeled and isotope-labeled HOCs in <i>Eisenia fetida</i> earthworms was compared. Earthworms can assimilate both unlabeled and isotope-labeled HOCs via three routes: dermal uptake, soil ingestion, and microplastic ingestion. After 28 days of exposure, the relative fractions of bioaccumulated isotope-labeled HOCs in the soil treated with 1% microplastics ranged from 15.5 to 55.8%, which were 2.9–47.6 times higher than those in the soils treated with 0.1% microplastics. Polyethylene microplastics were observed to have higher relative fractions of bioaccumulated isotope-labeled HOCs, potentially because of their surface hydrophobicity and amorphous rubbery state. The general linear models suggested that the vector effects were mainly due to the microplastic concentration, followed by polymer properties and HOC hydrophobicity. This proposed method and the derived empirical formula contribute to a more comprehensive understanding of the vector effects of microplastics for HOC bioaccumulation.</p>","PeriodicalId":29801,"journal":{"name":"ACS Environmental Au","volume":"3 4","pages":"233–241"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/18/77/vg3c00024.PMC10360207.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10240087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-17DOI: 10.1021/acsenvironau.3c00014
Manabu Shiraiwa*,
G environmental change is real in the Anthropocene. Global warming is happening now, caused by anthropogenic activities with the emission of greenhouse gases. The latest reading of “the Keeling curve” has topped 424 ppm of carbon dioxide, which represents the highest record in continuous measurements of CO2 at Mauna Loa Observatory in Hawaii since 1960. Climate change has become more prominent and more evident that we experience it even in our daily life. Weather events have intensified with recordshattering climate extremes. This winter, we experienced record-breaking rainfall and snowfall associated with the atmospheric river in the West of the United States, while facing off against heat in the East of the United States. Biomass burning and wildfires have increased with higher frequency, longer durations, and longer seasons. Hurricanes have become more frequent and stronger, causing flooding in various places around the globe. These extreme events in a warming planet disrupt and negatively impact our society, restructuring our lifestyles in a myriad of ways, e.g., in sports: a recent study showed that global warming causes a reduction in ballpark air density, promoting more home runs in Major League Baseball games (bad news for pitchers!). Even though they are managed separately, climate change is coupled with air quality. There are cobenefits of climate regulations on improving air quality, but so far there is a lack of tools to rigorously evaluate the implications of addressing these challenges simultaneously. Sebastian D. Eastham and colleagues developed a computationally efficient approach to quantify how combined climate and air quality interventions affect air quality outcomes. Their approach captures spatial heterogeneity and complex atmospheric chemistry involving ozone, nitrogen oxides, volatile organic compounds, ammonia, and particulate matter, enabling rapid assessments modeling air quality−climate interactions. They demonstrate that air quality impact of climate policy depends on precursor emission stringency. In addition to greenhouse gases, particulate matter containing chromophores, so-called brown carbon, affects the climate by posing positive radiative forcing and serving as cloud condensation nuclei (CCN). The chemical composition and climate-relevant properties of brown carbon are highly dynamic, as they evolve upon chemical transformation in the atmosphere. Borduas-Dedekind and colleagues tackle this problem by irradiating lab-generated and field-collected brown carbon samples. They specifically focused on investigating photomineralization, a photodegradation process that fragments organic molecules to CO and CO2. They found that the rates of photomineralization were fastest for lab-generated samples and slowest for ambient brown carbon samples. Despite photobleaching and composition changes in the brown carbon, its CCN abilities did not change substantially. There are three more exciting publications in this issue. Kanel,
{"title":"Facing Global Climate and Environmental Change","authors":"Manabu Shiraiwa*, ","doi":"10.1021/acsenvironau.3c00014","DOIUrl":"10.1021/acsenvironau.3c00014","url":null,"abstract":"G environmental change is real in the Anthropocene. Global warming is happening now, caused by anthropogenic activities with the emission of greenhouse gases. The latest reading of “the Keeling curve” has topped 424 ppm of carbon dioxide, which represents the highest record in continuous measurements of CO2 at Mauna Loa Observatory in Hawaii since 1960. Climate change has become more prominent and more evident that we experience it even in our daily life. Weather events have intensified with recordshattering climate extremes. This winter, we experienced record-breaking rainfall and snowfall associated with the atmospheric river in the West of the United States, while facing off against heat in the East of the United States. Biomass burning and wildfires have increased with higher frequency, longer durations, and longer seasons. Hurricanes have become more frequent and stronger, causing flooding in various places around the globe. These extreme events in a warming planet disrupt and negatively impact our society, restructuring our lifestyles in a myriad of ways, e.g., in sports: a recent study showed that global warming causes a reduction in ballpark air density, promoting more home runs in Major League Baseball games (bad news for pitchers!). Even though they are managed separately, climate change is coupled with air quality. There are cobenefits of climate regulations on improving air quality, but so far there is a lack of tools to rigorously evaluate the implications of addressing these challenges simultaneously. Sebastian D. Eastham and colleagues developed a computationally efficient approach to quantify how combined climate and air quality interventions affect air quality outcomes. Their approach captures spatial heterogeneity and complex atmospheric chemistry involving ozone, nitrogen oxides, volatile organic compounds, ammonia, and particulate matter, enabling rapid assessments modeling air quality−climate interactions. They demonstrate that air quality impact of climate policy depends on precursor emission stringency. In addition to greenhouse gases, particulate matter containing chromophores, so-called brown carbon, affects the climate by posing positive radiative forcing and serving as cloud condensation nuclei (CCN). The chemical composition and climate-relevant properties of brown carbon are highly dynamic, as they evolve upon chemical transformation in the atmosphere. Borduas-Dedekind and colleagues tackle this problem by irradiating lab-generated and field-collected brown carbon samples. They specifically focused on investigating photomineralization, a photodegradation process that fragments organic molecules to CO and CO2. They found that the rates of photomineralization were fastest for lab-generated samples and slowest for ambient brown carbon samples. Despite photobleaching and composition changes in the brown carbon, its CCN abilities did not change substantially. There are three more exciting publications in this issue. Kanel,","PeriodicalId":29801,"journal":{"name":"ACS Environmental Au","volume":"3 3","pages":"121–122"},"PeriodicalIF":0.0,"publicationDate":"2023-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/57/71/vg3c00014.PMC10266710.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10029377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Catalytic complete oxidation is an efficient approach to reducing methane emissions, a significant contributor to global warming. This approach requires active catalysts that are highly resistant to sintering and water vapor. In this work, we demonstrate that Pd nanoparticles confined within silicalite-1 zeolites (Pd@S-1), fabricated using a facile in situ encapsulation strategy, are highly active and stable in catalyzing methane oxidation and are superior to those supported on the S-1 surface due to a confinement effect. The activity of the confined Pd catalysts was further improved by co-confining a suitable amount of Ce within the S-1 zeolite (PdCe0.4@S-1), which is attributed to confinement-reinforced Pd–Ce interactions that promote the formation of oxygen vacancies and highly reactive oxygen species. Furthermore, the introduction of Ce improves the hydrophobicity of the S-1 zeolite and, by forming Pd–Ce mixed oxides, inhibits the transformation of the active PdO phase to inactive Pd(OH)2 species. Overall, the bimetallic PdCe0.4@S-1 catalyst delivers exceptional outstanding activity and durability in complete methane oxidation, even in the presence of water vapor. This study may provide new prospects for the rational design of high-performance and durable Pd catalysts for complete methane oxidation.
{"title":"Unlocking High-Efficiency Methane Oxidation with Bimetallic Pd–Ce Catalysts under Zeolite Confinement","authors":"Xiaomai Chen, Xuefeng Shi, Peirong Chen, Bowen Liu, Meiyin Liu, Longwen Chen, Daiqi Ye, Xin Tu*, Wei Fan* and Junliang Wu*, ","doi":"10.1021/acsenvironau.3c00008","DOIUrl":"10.1021/acsenvironau.3c00008","url":null,"abstract":"<p >Catalytic complete oxidation is an efficient approach to reducing methane emissions, a significant contributor to global warming. This approach requires active catalysts that are highly resistant to sintering and water vapor. In this work, we demonstrate that Pd nanoparticles confined within silicalite-1 zeolites (Pd@S-1), fabricated using a facile in situ encapsulation strategy, are highly active and stable in catalyzing methane oxidation and are superior to those supported on the S-1 surface due to a confinement effect. The activity of the confined Pd catalysts was further improved by co-confining a suitable amount of Ce within the S-1 zeolite (PdCe<sub>0.4</sub>@S-1), which is attributed to confinement-reinforced Pd–Ce interactions that promote the formation of oxygen vacancies and highly reactive oxygen species. Furthermore, the introduction of Ce improves the hydrophobicity of the S-1 zeolite and, by forming Pd–Ce mixed oxides, inhibits the transformation of the active PdO phase to inactive Pd(OH)<sub>2</sub> species. Overall, the bimetallic PdCe<sub>0.4</sub>@S-1 catalyst delivers exceptional outstanding activity and durability in complete methane oxidation, even in the presence of water vapor. This study may provide new prospects for the rational design of high-performance and durable Pd catalysts for complete methane oxidation.</p>","PeriodicalId":29801,"journal":{"name":"ACS Environmental Au","volume":"3 4","pages":"223–232"},"PeriodicalIF":0.0,"publicationDate":"2023-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsenvironau.3c00008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10220847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-05DOI: 10.1021/acsenvironau.3c00001
Shion Watabe, Hannah A. C. Lohman, Yalin Li, Victoria L. Morgan, Lewis S. Rowles, Tyler Stephen, Hsiang-Yang Shyu, Robert A. Bair, Cynthia J. Castro, Roland D. Cusick, Daniel H. Yeh and Jeremy S. Guest*,
Achieving safely managed sanitation and resource recovery in areas that are rural, geographically challenged, or experiencing rapidly increasing population density may not be feasible with centralized facilities due to space requirements, site-specific concerns, and high costs of sewer installation. Nonsewered sanitation (NSS) systems have the potential to provide safely managed sanitation and achieve strict wastewater treatment standards. One such NSS treatment technology is the NEWgenerator, which includes an anaerobic membrane bioreactor (AnMBR), nutrient recovery via ion exchange, and electrochlorination. The system has been shown to achieve robust treatment of real waste for over 100 users, but the technology’s relative life cycle sustainability remains unclear. This study characterizes the financial viability and life cycle environmental impacts of the NEWgenerator and prioritizes opportunities to advance system sustainability through targeted improvements and deployment. The costs and greenhouse gas (GHG) emissions of the NEWgenerator (general case) leveraging grid electricity were 0.139 [0.113–0.168] USD cap–1 day–1 and 79.7 [55.0–112.3] kg CO2-equiv cap–1 year–1, respectively. A transition to photovoltaic-generated electricity would increase costs to 0.145 [0.118–0.181] USD cap–1 day–1 but decrease GHG emissions to 56.1 [33.8–86.2] kg CO2-equiv cap–1 year–1. The deployment location analysis demonstrated reduced median costs for deployment in China (−38%), India (−53%), Senegal (−31%), South Africa (−31%), and Uganda (−35%), but at comparable or increased GHG emissions (−2 to +16%). Targeted improvements revealed the relative change in median cost and GHG emissions to be −21 and −3% if loading is doubled (i.e., doubled users per unit), −30 and −12% with additional sludge drying, and +9 and −25% with the addition of a membrane contactor, respectively, with limited benefits (0–5% reductions) from an alternative photovoltaic battery, low-cost housing, or improved frontend operation. This research demonstrates that the NEWgenerator is a low-cost, low-emission NSS treatment technology with the potential for resource recovery to increase access to safe sanitation.
{"title":"Advancing the Economic and Environmental Sustainability of the NEWgenerator Nonsewered Sanitation System","authors":"Shion Watabe, Hannah A. C. Lohman, Yalin Li, Victoria L. Morgan, Lewis S. Rowles, Tyler Stephen, Hsiang-Yang Shyu, Robert A. Bair, Cynthia J. Castro, Roland D. Cusick, Daniel H. Yeh and Jeremy S. Guest*, ","doi":"10.1021/acsenvironau.3c00001","DOIUrl":"10.1021/acsenvironau.3c00001","url":null,"abstract":"<p >Achieving safely managed sanitation and resource recovery in areas that are rural, geographically challenged, or experiencing rapidly increasing population density may not be feasible with centralized facilities due to space requirements, site-specific concerns, and high costs of sewer installation. Nonsewered sanitation (NSS) systems have the potential to provide safely managed sanitation and achieve strict wastewater treatment standards. One such NSS treatment technology is the NEWgenerator, which includes an anaerobic membrane bioreactor (AnMBR), nutrient recovery via ion exchange, and electrochlorination. The system has been shown to achieve robust treatment of real waste for over 100 users, but the technology’s relative life cycle sustainability remains unclear. This study characterizes the financial viability and life cycle environmental impacts of the NEWgenerator and prioritizes opportunities to advance system sustainability through targeted improvements and deployment. The costs and greenhouse gas (GHG) emissions of the NEWgenerator (general case) leveraging grid electricity were 0.139 [0.113–0.168] USD cap<sup>–1</sup> day<sup>–1</sup> and 79.7 [55.0–112.3] kg CO<sub>2</sub>-equiv cap<sup>–1</sup> year<sup>–1</sup>, respectively. A transition to photovoltaic-generated electricity would increase costs to 0.145 [0.118–0.181] USD cap<sup>–1</sup> day<sup>–1</sup> but decrease GHG emissions to 56.1 [33.8–86.2] kg CO<sub>2</sub>-equiv cap<sup>–1</sup> year<sup>–1</sup>. The deployment location analysis demonstrated reduced median costs for deployment in China (−38%), India (−53%), Senegal (−31%), South Africa (−31%), and Uganda (−35%), but at comparable or increased GHG emissions (−2 to +16%). Targeted improvements revealed the relative change in median cost and GHG emissions to be −21 and −3% if loading is doubled (i.e., doubled users per unit), −30 and −12% with additional sludge drying, and +9 and −25% with the addition of a membrane contactor, respectively, with limited benefits (0–5% reductions) from an alternative photovoltaic battery, low-cost housing, or improved frontend operation. This research demonstrates that the NEWgenerator is a low-cost, low-emission NSS treatment technology with the potential for resource recovery to increase access to safe sanitation.</p>","PeriodicalId":29801,"journal":{"name":"ACS Environmental Au","volume":"3 4","pages":"209–222"},"PeriodicalIF":0.0,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsenvironau.3c00001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9862942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-19DOI: 10.1021/acsenvironau.2c00061
Reid A. Simmer, Emily J. Jansen, Kyle J. Patterson and Jerald L. Schnoor*,
Since the beginning of the industrial revolution, humans have burned enormous quantities of coal, oil, and natural gas, rivaling nature’s elemental cycles of C, N, and S. The result has been a disruption in a steady state of CO2 and other greenhouse gases in the atmosphere, a warming of the planet, and changes in master variables (temperature, pH, and pε) of the sea affecting critical physical, chemical, and biological reactions. Humans have also produced copious quantities of N and P fertilizers producing widespread coastal hypoxia and low dissolved oxygen conditions, which now threaten even the open ocean. Consequently, our massive alteration of state variables diminishes coral reefs, fisheries, and marine ecosystems, which are the foundation of life on Earth. We point to a myriad of actions and alternatives which will help to stem the tide of climate change and its effects on the sea while, at the same time, creating a more sustainable future for humans and ecosystems alike.
{"title":"Climate Change and the Sea: A Major Disruption in Steady State and the Master Variables","authors":"Reid A. Simmer, Emily J. Jansen, Kyle J. Patterson and Jerald L. Schnoor*, ","doi":"10.1021/acsenvironau.2c00061","DOIUrl":"10.1021/acsenvironau.2c00061","url":null,"abstract":"<p >Since the beginning of the industrial revolution, humans have burned enormous quantities of coal, oil, and natural gas, rivaling nature’s elemental cycles of C, N, and S. The result has been a disruption in a steady state of CO<sub>2</sub> and other greenhouse gases in the atmosphere, a warming of the planet, and changes in master variables (temperature, pH, and pε) of the sea affecting critical physical, chemical, and biological reactions. Humans have also produced copious quantities of N and P fertilizers producing widespread coastal hypoxia and low dissolved oxygen conditions, which now threaten even the open ocean. Consequently, our massive alteration of state variables diminishes coral reefs, fisheries, and marine ecosystems, which are the foundation of life on Earth. We point to a myriad of actions and alternatives which will help to stem the tide of climate change and its effects on the sea while, at the same time, creating a more sustainable future for humans and ecosystems alike.</p>","PeriodicalId":29801,"journal":{"name":"ACS Environmental Au","volume":"3 4","pages":"195–208"},"PeriodicalIF":0.0,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsenvironau.2c00061","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9862941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-27DOI: 10.1021/acsenvironau.2c00067
Hannah A. C. Lohman, Victoria L. Morgan, Yalin Li, Xinyi Zhang, Lewis S. Rowles, Sherri M. Cook and Jeremy S. Guest*,
In resource-limited settings, conventional sanitation systems often fail to meet their goals─with system failures stemming from a mismatch among community needs, constraints, and deployed technologies. Although decision-making tools exist to help assess the appropriateness of conventional sanitation systems in a specific context, there is a lack of a holistic decision-making framework to guide sanitation research, development, and deployment (RD&D) of technologies. In this study, we introduce DMsan─an open-source multi-criteria decision analysis Python package that enables users to transparently compare sanitation and resource recovery alternatives and characterize the opportunity space for early-stage technologies. Informed by the methodological choices frequently used in literature, the core structure of DMsan includes five criteria (technical, resource recovery, economic, environmental, and social), 28 indicators, criteria weight scenarios, and indicator weight scenarios tailored to 250 countries/territories, all of which can be adapted by end-users. DMsan integrates with the open-source Python package QSDsan (quantitative sustainable design for sanitation and resource recovery systems) for system design and simulation to calculate quantitative economic (via techno-economic analysis), environmental (via life cycle assessment), and resource recovery indicators under uncertainty. Here, we illustrate the core capabilities of DMsan using an existing, conventional sanitation system and two proposed alternative systems for Bwaise, an informal settlement in Kampala, Uganda. The two example use cases are (i) use by implementation decision makers to enhance decision-making transparency and understand the robustness of sanitation choices given uncertain and/or varying stakeholder input and technology ability and (ii) use by technology developers seeking to identify and expand the opportunity space for their technologies. Through these examples, we demonstrate the utility of DMsan to evaluate sanitation and resource recovery systems tailored to individual contexts and increase transparency in technology evaluations, RD&D prioritization, and context-specific decision making.
{"title":"DMsan: A Multi-Criteria Decision Analysis Framework and Package to Characterize Contextualized Sustainability of Sanitation and Resource Recovery Technologies","authors":"Hannah A. C. Lohman, Victoria L. Morgan, Yalin Li, Xinyi Zhang, Lewis S. Rowles, Sherri M. Cook and Jeremy S. Guest*, ","doi":"10.1021/acsenvironau.2c00067","DOIUrl":"10.1021/acsenvironau.2c00067","url":null,"abstract":"<p >In resource-limited settings, conventional sanitation systems often fail to meet their goals─with system failures stemming from a mismatch among community needs, constraints, and deployed technologies. Although decision-making tools exist to help assess the appropriateness of conventional sanitation systems in a specific context, there is a lack of a holistic decision-making framework to guide sanitation research, development, and deployment (RD&D) of technologies. In this study, we introduce DMsan─an open-source multi-criteria decision analysis Python package that enables users to transparently compare sanitation and resource recovery alternatives and characterize the opportunity space for early-stage technologies. Informed by the methodological choices frequently used in literature, the core structure of DMsan includes five criteria (technical, resource recovery, economic, environmental, and social), 28 indicators, criteria weight scenarios, and indicator weight scenarios tailored to 250 countries/territories, all of which can be adapted by end-users. DMsan integrates with the open-source Python package QSDsan (quantitative sustainable design for sanitation and resource recovery systems) for system design and simulation to calculate quantitative economic (via techno-economic analysis), environmental (via life cycle assessment), and resource recovery indicators under uncertainty. Here, we illustrate the core capabilities of DMsan using an existing, conventional sanitation system and two proposed alternative systems for Bwaise, an informal settlement in Kampala, Uganda. The two example use cases are (i) use by implementation decision makers to enhance decision-making transparency and understand the robustness of sanitation choices given uncertain and/or varying stakeholder input and technology ability and (ii) use by technology developers seeking to identify and expand the opportunity space for their technologies. Through these examples, we demonstrate the utility of DMsan to evaluate sanitation and resource recovery systems tailored to individual contexts and increase transparency in technology evaluations, RD&D prioritization, and context-specific decision making.</p>","PeriodicalId":29801,"journal":{"name":"ACS Environmental Au","volume":"3 3","pages":"179–192"},"PeriodicalIF":0.0,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsenvironau.2c00067","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9506550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-17DOI: 10.1021/acsenvironau.2c00055
Silvan Müller, Chiara Giorio and Nadine Borduas-Dedekind*,
Organic aerosols affect the planet’s radiative balance by absorbing and scattering light as well as by activating cloud droplets. These organic aerosols contain chromophores, termed brown carbon (BrC), and can undergo indirect photochemistry, affecting their ability to act as cloud condensation nuclei (CCN). Here, we investigated the effect of photochemical aging by tracking the conversion of organic carbon into inorganic carbon, termed the photomineralization mechanism, and its effect on the CCN abilities in four different types of BrC samples: (1) laboratory-generated (NH4)2SO4-methylglyoxal solutions, (2) dissolved organic matter isolate from Suwannee River fulvic acid (SRFA), (3) ambient firewood smoke aerosols, and (4) ambient urban wintertime particulate matter in Padua, Italy. Photomineralization occurred in all BrC samples albeit at different rates, evidenced by photobleaching and by loss of organic carbon up to 23% over a simulated 17.6 h of sunlight exposure. These losses were correlated with the production of CO up to 4% and of CO2 up to 54% of the initial organic carbon mass, monitored by gas chromatography. Photoproducts of formic, acetic, oxalic and pyruvic acids were also produced during irradiation of the BrC solutions, but at different yields depending on the sample. Despite these chemical changes, CCN abilities did not change substantially for the BrC samples. In fact, the CCN abilities were dictated by the salt content of the BrC solution, trumping a photomineralization effect on the CCN abilities for the hygroscopic BrC samples. Solutions of (NH4)2SO4-methylglyoxal, SRFA, firewood smoke, and ambient Padua samples had hygroscopicity parameters κ of 0.6, 0.1, 0.3, and 0.6, respectively. As expected, the SRFA solution with a κ of 0.1 was most impacted by the photomineralization mechanism. Overall, our results suggest that the photomineralization mechanism is expected in all BrC samples and can drive changes in the optical properties and chemical composition of aging organic aerosols.
{"title":"Tracking the Photomineralization Mechanism in Irradiated Lab-Generated and Field-Collected Brown Carbon Samples and Its Effect on Cloud Condensation Nuclei Abilities","authors":"Silvan Müller, Chiara Giorio and Nadine Borduas-Dedekind*, ","doi":"10.1021/acsenvironau.2c00055","DOIUrl":"10.1021/acsenvironau.2c00055","url":null,"abstract":"<p >Organic aerosols affect the planet’s radiative balance by absorbing and scattering light as well as by activating cloud droplets. These organic aerosols contain chromophores, termed brown carbon (BrC), and can undergo indirect photochemistry, affecting their ability to act as cloud condensation nuclei (CCN). Here, we investigated the effect of photochemical aging by tracking the conversion of organic carbon into inorganic carbon, termed the photomineralization mechanism, and its effect on the CCN abilities in four different types of BrC samples: (1) laboratory-generated (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>-methylglyoxal solutions, (2) dissolved organic matter isolate from Suwannee River fulvic acid (SRFA), (3) ambient firewood smoke aerosols, and (4) ambient urban wintertime particulate matter in Padua, Italy. Photomineralization occurred in all BrC samples albeit at different rates, evidenced by photobleaching and by loss of organic carbon up to 23% over a simulated 17.6 h of sunlight exposure. These losses were correlated with the production of CO up to 4% and of CO<sub>2</sub> up to 54% of the initial organic carbon mass, monitored by gas chromatography. Photoproducts of formic, acetic, oxalic and pyruvic acids were also produced during irradiation of the BrC solutions, but at different yields depending on the sample. Despite these chemical changes, CCN abilities did not change substantially for the BrC samples. In fact, the CCN abilities were dictated by the salt content of the BrC solution, trumping a photomineralization effect on the CCN abilities for the hygroscopic BrC samples. Solutions of (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>-methylglyoxal, SRFA, firewood smoke, and ambient Padua samples had hygroscopicity parameters κ of 0.6, 0.1, 0.3, and 0.6, respectively. As expected, the SRFA solution with a κ of 0.1 was most impacted by the photomineralization mechanism. Overall, our results suggest that the photomineralization mechanism is expected in all BrC samples and can drive changes in the optical properties and chemical composition of aging organic aerosols.</p>","PeriodicalId":29801,"journal":{"name":"ACS Environmental Au","volume":"3 3","pages":"164–178"},"PeriodicalIF":0.0,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsenvironau.2c00055","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9557436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-15DOI: 10.1021/acsenvironau.3c00005
Xiangdong Li*, Ian T. Cousins and Keri C. Hornbuckle,
S the first issue of ACS Environmental Au was published in November 2021, we have been delighted to publish many high-quality and impactful Articles, Letters, Reviews, and Perspectives in the journal. We are extremely grateful to our authors, reviewers, Editorial Advisory Board (EAB) members, and readers for their consistent support in developing this new, premier open access environmental science and technology journal. To recognize some of the outstanding publications published in 2021 and 2022, we are very pleased to share our first ACS Environmental Au Best Paper Awards. We, as Editors, nominated papers to be considered for the award, including all article types and research topics published in the last two years. We highlighted those that demonstrated key elements of quality, such as scientific rigor, novelty, significance, and impact on the community. From a shortlist of candidate papers, we invited all of our EAB members to select their top five choices that best reflected the journal’s outstanding publications in 2021−2022. We are delighted to highlight the awardees of our first ACS Environmental Au Best Paper Awards, 2021−2022. Tehya Stockman, Shelly L. Miller et al. Measurements and Simulations of Aerosol Released while Singing and Playing Wind Instruments. ACS Environ. Au 2021 1 (1), 71−84. DOI: 10.1021/acsenvironau.1c00007. The COVID-19 pandemic drastically changed our lives in the last three years. Understanding the transmission of bioaerosols in the air is very important in designing effective measures to control infection risk in public places. The teams of Tehya Stockman and Shelly Miller conducted important research on aerosol generation and transport while singing and playing wind instruments in choir and theater environments. The study utilized flow visualization, aerosol and CO2 measurements, and computational fluid dynamics modeling to understand the different components that can lead to SARSCoV-2 transmission risks. The results showed that plumes from musical performances were highly directional, unsteady and varied considerably in time and space. Face and bell masks attenuated plume velocities and lengths and decreased aerosol concentrations. This research generated substantial public interest and was quoted in numerous news reports and social media posts. This is also a great example of how open access can support disseminating new, rigorous science to the public, stakeholders, and policymakers. Asha de Vos and Anna P. M. Michel et al. The M/V X-Press Pearl Nurdle Spill: Contamination of Burnt Plastic and Unburnt Nurdles along Sri Lanka’s Beaches. ACS Environ. Au 2022, 2 (2), 128−135. DOI: 10.1021/acsenvironau.1c00031. An international team led by Asha de Vos and Anna P. M. Michel conducted a rapid response study on a massive plastic spill event off the west coast of Sri Lanka. The M/V XPress Pearl cargo ship caught fire in May 2021 and spilled 70−75 billion pellets of preproduction plastic material, known as nurdles, into
{"title":"ACS Environmental Au Best Paper Awards 2021–2022","authors":"Xiangdong Li*, Ian T. Cousins and Keri C. Hornbuckle, ","doi":"10.1021/acsenvironau.3c00005","DOIUrl":"https://doi.org/10.1021/acsenvironau.3c00005","url":null,"abstract":"S the first issue of ACS Environmental Au was published in November 2021, we have been delighted to publish many high-quality and impactful Articles, Letters, Reviews, and Perspectives in the journal. We are extremely grateful to our authors, reviewers, Editorial Advisory Board (EAB) members, and readers for their consistent support in developing this new, premier open access environmental science and technology journal. To recognize some of the outstanding publications published in 2021 and 2022, we are very pleased to share our first ACS Environmental Au Best Paper Awards. We, as Editors, nominated papers to be considered for the award, including all article types and research topics published in the last two years. We highlighted those that demonstrated key elements of quality, such as scientific rigor, novelty, significance, and impact on the community. From a shortlist of candidate papers, we invited all of our EAB members to select their top five choices that best reflected the journal’s outstanding publications in 2021−2022. We are delighted to highlight the awardees of our first ACS Environmental Au Best Paper Awards, 2021−2022. Tehya Stockman, Shelly L. Miller et al. Measurements and Simulations of Aerosol Released while Singing and Playing Wind Instruments. ACS Environ. Au 2021 1 (1), 71−84. DOI: 10.1021/acsenvironau.1c00007. The COVID-19 pandemic drastically changed our lives in the last three years. Understanding the transmission of bioaerosols in the air is very important in designing effective measures to control infection risk in public places. The teams of Tehya Stockman and Shelly Miller conducted important research on aerosol generation and transport while singing and playing wind instruments in choir and theater environments. The study utilized flow visualization, aerosol and CO2 measurements, and computational fluid dynamics modeling to understand the different components that can lead to SARSCoV-2 transmission risks. The results showed that plumes from musical performances were highly directional, unsteady and varied considerably in time and space. Face and bell masks attenuated plume velocities and lengths and decreased aerosol concentrations. This research generated substantial public interest and was quoted in numerous news reports and social media posts. This is also a great example of how open access can support disseminating new, rigorous science to the public, stakeholders, and policymakers. Asha de Vos and Anna P. M. Michel et al. The M/V X-Press Pearl Nurdle Spill: Contamination of Burnt Plastic and Unburnt Nurdles along Sri Lanka’s Beaches. ACS Environ. Au 2022, 2 (2), 128−135. DOI: 10.1021/acsenvironau.1c00031. An international team led by Asha de Vos and Anna P. M. Michel conducted a rapid response study on a massive plastic spill event off the west coast of Sri Lanka. The M/V XPress Pearl cargo ship caught fire in May 2021 and spilled 70−75 billion pellets of preproduction plastic material, known as nurdles, into","PeriodicalId":29801,"journal":{"name":"ACS Environmental Au","volume":"3 2","pages":"56–57"},"PeriodicalIF":0.0,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsenvironau.3c00005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49768531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}