Conghui Huang, Timothy R. Ginn, Gemma G. Clark, Farzana R. Zaki, Jungeun Won, Stephen A. Boppart, Thanh H. Nguyen
Disinfectant decay by biofilms in distribution networks during stagnation can allow opportunistic pathogens' transmission and thus compromise drinking water safety. Applying phosphate-based corrosion inhibitors to the system can exacerbate disinfectant decay by providing nutrients to biofilms growing inside premise plumbings. In this study, we evaluate the impacts of corrosion inhibitors on biofilms' structural and chemical properties that form in premise plumbing, and the resulting implications for disinfectant decay. Two commonly used phosphate-based (phosphate blends and phosphate) corrosion inhibitors were added separately to simulated drinking water for biofilm development over 1 to 2 years. Optical coherence tomography (OCT) imaging showed that the studied biofilms' thickness, porosity, and porous structure did not change after exposure to free chlorine for 24 h or monochloramine for 120 h. Compared with groundwater biofilms, phosphate-based biofilms had the highest overall porosity due to their many connecting channels. The phosphate-based biofilms consumed free chlorine or monochloramine at a faster rate than groundwater biofilms. Experimental results showed that phosphate-based biofilms consumed more monochloramine after 96 h of contact than other biofilms. A separate set of experiments involving disinfectant decay with suspended biomass material, together with the OCT results, provided parameters for a simplified quasi-first-order reaction–diffusion model so that predictive modeling of decay in biofilms under stagnation conditions could be attempted without parameter fitting. The biofilm modeling results provided a close estimate for free chlorine decay while underestimating monochloramine decay. In agreement with the experimental results, the model results indicate that the phosphate-based biofilms led to slightly faster free chlorine consumption and monochloramine consumption than groundwater biofilms and indicate that diffusion limitation imposed by biofilm pore structure on disinfectant decay is important. The study results suggest that using phosphate-based corrosion inhibitors may lead to a rapid depletion of residual disinfectant during stagnation in the presence of biofilms.
{"title":"Phosphate-Based Corrosion Inhibition in Drinking Water Systems and Effects on Disinfectant Decay and Biofilm Growth","authors":"Conghui Huang, Timothy R. Ginn, Gemma G. Clark, Farzana R. Zaki, Jungeun Won, Stephen A. Boppart, Thanh H. Nguyen","doi":"10.1089/ees.2023.0065","DOIUrl":"https://doi.org/10.1089/ees.2023.0065","url":null,"abstract":"Disinfectant decay by biofilms in distribution networks during stagnation can allow opportunistic pathogens' transmission and thus compromise drinking water safety. Applying phosphate-based corrosion inhibitors to the system can exacerbate disinfectant decay by providing nutrients to biofilms growing inside premise plumbings. In this study, we evaluate the impacts of corrosion inhibitors on biofilms' structural and chemical properties that form in premise plumbing, and the resulting implications for disinfectant decay. Two commonly used phosphate-based (phosphate blends and phosphate) corrosion inhibitors were added separately to simulated drinking water for biofilm development over 1 to 2 years. Optical coherence tomography (OCT) imaging showed that the studied biofilms' thickness, porosity, and porous structure did not change after exposure to free chlorine for 24 h or monochloramine for 120 h. Compared with groundwater biofilms, phosphate-based biofilms had the highest overall porosity due to their many connecting channels. The phosphate-based biofilms consumed free chlorine or monochloramine at a faster rate than groundwater biofilms. Experimental results showed that phosphate-based biofilms consumed more monochloramine after 96 h of contact than other biofilms. A separate set of experiments involving disinfectant decay with suspended biomass material, together with the OCT results, provided parameters for a simplified quasi-first-order reaction–diffusion model so that predictive modeling of decay in biofilms under stagnation conditions could be attempted without parameter fitting. The biofilm modeling results provided a close estimate for free chlorine decay while underestimating monochloramine decay. In agreement with the experimental results, the model results indicate that the phosphate-based biofilms led to slightly faster free chlorine consumption and monochloramine consumption than groundwater biofilms and indicate that diffusion limitation imposed by biofilm pore structure on disinfectant decay is important. The study results suggest that using phosphate-based corrosion inhibitors may lead to a rapid depletion of residual disinfectant during stagnation in the presence of biofilms.","PeriodicalId":11777,"journal":{"name":"Environmental Engineering Science","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136102752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Veronica Lima Gonsalez, Michael D. Lee, Katherine A. Muller, C. Andrew Ramsburg
Permeable reactive barriers (PRBs) are being considered for treatment where the discharge of nitrate plumes contributes to eutrophication (e.g., Cape Cod, MA). PRBs enhance denitrification through the addition of carbon-based amendments such as the injection of emulsified vegetable oil (EVO). The use of EVO to stimulate denitrification foregrounds aspects of carbon utilization, dosing, longevity, and secondary effects in ways that differ from the application of EVO at hazardous waste sites. The overall objective of this study was to develop and evaluate a process-based modeling approach for simulating denitrification stimulated and supported by EVO. A series of one-dimensional column experiments assessed emulsion retention, production of soluble substrate, and utilization of carbon for nitrate reduction. Retention of 5.5 g dispersed phase emulsion resulted in sustained reduction of nitrate (∼43 mg/day) at ∼2 m/day porewater velocity. Biokinetic processes underlying the model are based on the two-step denitrification description of the Activated Sludge Model (ASM) No. 3. Biokinetic processes were integrated within the flow and transport simulator COMSOL to simulate the column experiment. The model capitalizes on the biokinetic parameters available in the ASM literature to limit the number of site-specific fits of model parameters. Simulation results demonstrate how this approach can result in reasonable predictions, although model performance was enhanced by fitting two parameters—yield coefficients for nitrate and nitrite. Comparisons with existing biokinetic transport models that were similarly fit to the column data suggest that the better overall descriptions of the column data using the process-based model stem from a more robust handling of spatial and temporal distribution of biomass. Sensitivity analyses highlight the importance of accurately describing the transformation of complex carbon into soluble substrate, and the subsequent utilization of that substrate. This research establishes a foundation for exploring implications of carbon processing on dosing, longevity, and effectiveness in denitrifying PRBs.
{"title":"Process-Based Model to Describe Treatment of Nitrate-Rich Groundwater Using Emulsified Oil","authors":"Veronica Lima Gonsalez, Michael D. Lee, Katherine A. Muller, C. Andrew Ramsburg","doi":"10.1089/ees.2023.0053","DOIUrl":"https://doi.org/10.1089/ees.2023.0053","url":null,"abstract":"Permeable reactive barriers (PRBs) are being considered for treatment where the discharge of nitrate plumes contributes to eutrophication (e.g., Cape Cod, MA). PRBs enhance denitrification through the addition of carbon-based amendments such as the injection of emulsified vegetable oil (EVO). The use of EVO to stimulate denitrification foregrounds aspects of carbon utilization, dosing, longevity, and secondary effects in ways that differ from the application of EVO at hazardous waste sites. The overall objective of this study was to develop and evaluate a process-based modeling approach for simulating denitrification stimulated and supported by EVO. A series of one-dimensional column experiments assessed emulsion retention, production of soluble substrate, and utilization of carbon for nitrate reduction. Retention of 5.5 g dispersed phase emulsion resulted in sustained reduction of nitrate (∼43 mg/day) at ∼2 m/day porewater velocity. Biokinetic processes underlying the model are based on the two-step denitrification description of the Activated Sludge Model (ASM) No. 3. Biokinetic processes were integrated within the flow and transport simulator COMSOL to simulate the column experiment. The model capitalizes on the biokinetic parameters available in the ASM literature to limit the number of site-specific fits of model parameters. Simulation results demonstrate how this approach can result in reasonable predictions, although model performance was enhanced by fitting two parameters—yield coefficients for nitrate and nitrite. Comparisons with existing biokinetic transport models that were similarly fit to the column data suggest that the better overall descriptions of the column data using the process-based model stem from a more robust handling of spatial and temporal distribution of biomass. Sensitivity analyses highlight the importance of accurately describing the transformation of complex carbon into soluble substrate, and the subsequent utilization of that substrate. This research establishes a foundation for exploring implications of carbon processing on dosing, longevity, and effectiveness in denitrifying PRBs.","PeriodicalId":11777,"journal":{"name":"Environmental Engineering Science","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136102748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Susan J. Masten, Raymond M. Hozalski, Thanh H. Helen Nguyen, Catherine A. Peters, Kristine H. Wammer
This special issue honors them: Edward (Ed) Bouwer (1955–2019), Michael (Mike) Aitken (1956–2020), James (Jim) J. Morgan (1932–2020), Deborah (Deb) Swackhamer (1954–2021), and Philip (Phil) Singer (1942–2020). The 16 papers focus on the innovative microbial and chemical processes for addressing both classic problems (e.g., nutrient recovery and wastewater treatment) as well as emerging problems (e.g., biodiversity loss, plastic pollution, biotransformation of organic chemicals, cyanotoxins, and disinfection byproducts).
{"title":"Microbial and Chemical Processes in Natural and Engineered Systems","authors":"Susan J. Masten, Raymond M. Hozalski, Thanh H. Helen Nguyen, Catherine A. Peters, Kristine H. Wammer","doi":"10.1089/ees.2023.0239","DOIUrl":"https://doi.org/10.1089/ees.2023.0239","url":null,"abstract":"This special issue honors them: Edward (Ed) Bouwer (1955–2019), Michael (Mike) Aitken (1956–2020), James (Jim) J. Morgan (1932–2020), Deborah (Deb) Swackhamer (1954–2021), and Philip (Phil) Singer (1942–2020). The 16 papers focus on the innovative microbial and chemical processes for addressing both classic problems (e.g., nutrient recovery and wastewater treatment) as well as emerging problems (e.g., biodiversity loss, plastic pollution, biotransformation of organic chemicals, cyanotoxins, and disinfection byproducts).","PeriodicalId":11777,"journal":{"name":"Environmental Engineering Science","volume":"312 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135117216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heidi L. Gough, Abigail Kargol, David A.C. Beck, Benjamin G. Therrien, Bed Mani Dahal, Michael D. Marsolek
Family-scale rural digesters are widely implemented in Nepal for waste management, resource recovery, and environmental stewardship for distributed communities. However, there is little documentation on the microbial community structures in real-world family farm digesters. This work compared microbial community structures in four family digesters with a near-by municipal digester. Included in the family digesters was a high-altitude family digester located on Mt. Everest in Mosi, Nepal (2,634 m elevation). Differences in the community structures included the prevalence in family digesters of Bathyarchaeota MGC-6. MCG-6 is an archaeal population putatively involved in autotrophic acetate generation and conversion of cellulose to sugars. In addition, Rikenellaceae DMER64, a population thought to degrade sugars, was more prevalent in the family digesters. The ratio of Methanothrix to hydrogenotrophic methanogens was higher in the family digesters. In addition, the dominant species of syntrophic hydrogen-producing bacteria differed. Syntrophobacter and Syntrophomonas species, documented for their critical roles in waste activated sludge digesters, were not detected. In conclusion, observed differences in microbial community composition suggested a capacity to support different substrate conversion pathways and a major role of Archaea beyond methanogenesis among the studied digesters.
{"title":"Microbial Community Structures in Family Anaerobic Digesters Reveal Potentially Differing Waste Conversion Pathways","authors":"Heidi L. Gough, Abigail Kargol, David A.C. Beck, Benjamin G. Therrien, Bed Mani Dahal, Michael D. Marsolek","doi":"10.1089/ees.2023.0038","DOIUrl":"https://doi.org/10.1089/ees.2023.0038","url":null,"abstract":"Family-scale rural digesters are widely implemented in Nepal for waste management, resource recovery, and environmental stewardship for distributed communities. However, there is little documentation on the microbial community structures in real-world family farm digesters. This work compared microbial community structures in four family digesters with a near-by municipal digester. Included in the family digesters was a high-altitude family digester located on Mt. Everest in Mosi, Nepal (2,634 m elevation). Differences in the community structures included the prevalence in family digesters of Bathyarchaeota MGC-6. MCG-6 is an archaeal population putatively involved in autotrophic acetate generation and conversion of cellulose to sugars. In addition, Rikenellaceae DMER64, a population thought to degrade sugars, was more prevalent in the family digesters. The ratio of Methanothrix to hydrogenotrophic methanogens was higher in the family digesters. In addition, the dominant species of syntrophic hydrogen-producing bacteria differed. Syntrophobacter and Syntrophomonas species, documented for their critical roles in waste activated sludge digesters, were not detected. In conclusion, observed differences in microbial community composition suggested a capacity to support different substrate conversion pathways and a major role of Archaea beyond methanogenesis among the studied digesters.","PeriodicalId":11777,"journal":{"name":"Environmental Engineering Science","volume":"126 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136102581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The biotransformation of atenolol, sotalol, and metoprolol by mixed culture denitrifying communities was examined as a function of carbon availability and pharmaceutical concentration to explore the possible roles of cometabolism and direct substrate utilization. Sotalol and metoprolol were not found to be transformed. A matrix of conditions explored the biotransformation of water resource recovery facility relevant (25 μg/L) and chemical oxygen demand (COD)-equivalent (10–100 mg/L) atenolol concentrations in batch reactors (1 L) containing 25 mg-N/L nitrate. Carbon (MicroC® 2000) conditions included Nonlimiting (COD:N ratio >10), Partially Limiting (COD:N ratio = 2–3), and Limiting (COD:N ratio <1). Reactors without atenolol served as denitrification control experiments. Results suggest that atenolol did not appreciably influence nitrate reduction. The extent of atenolol degradation was independent of carbon availability. In the experiments conducted in the μg/L range, 30–40% biotransformation was observed. Scant degradation at higher concentrations suggested that direct utilization of the pharmaceutical was either unlikely or occurring slowly and independent of the pharmaceutical concentration. Process-based modeling using the Activated Sludge Model framework assessed denitrification across carbon availability conditions and incorporated three individual pharmaceutical biotransformation modeling strategies: (1) direct metabolism model; (2) cometabolic model, and (3) biotransformation kinetic model. Results suggest that there was insufficient evidence to suspect direct metabolism meaningfully contributed to the reduction in atenolol concentration. The cometabolic process-based model, including both growth and nongrowth-linked rate coefficients offered the best model performance, although growth-linked cometabolism was limited and not readily apparent across all experiments (growth-linked transformation coefficient <0.4 g-atenolol·g-COD−1). Thus, the biotransformation kinetic model is favored for monitoring and forecasting biotransformation in larger-scale systems because use of the parsimonious model (rate coefficient of 7 mg-atenolol·g-COD−1·d−1) resulted in only modest performance reductions. The biotransformation model represents an improvement over pseudo first-order models as it is a mixed-order kinetic model that is linked to transient biomass conditions.
{"title":"Atenolol Biotransformation by Denitrifying Mixed Culture Communities","authors":"Amy E. Hunter, C. Andrew Ramsburg","doi":"10.1089/ees.2023.0064","DOIUrl":"https://doi.org/10.1089/ees.2023.0064","url":null,"abstract":"The biotransformation of atenolol, sotalol, and metoprolol by mixed culture denitrifying communities was examined as a function of carbon availability and pharmaceutical concentration to explore the possible roles of cometabolism and direct substrate utilization. Sotalol and metoprolol were not found to be transformed. A matrix of conditions explored the biotransformation of water resource recovery facility relevant (25 μg/L) and chemical oxygen demand (COD)-equivalent (10–100 mg/L) atenolol concentrations in batch reactors (1 L) containing 25 mg-N/L nitrate. Carbon (MicroC® 2000) conditions included Nonlimiting (COD:N ratio >10), Partially Limiting (COD:N ratio = 2–3), and Limiting (COD:N ratio <1). Reactors without atenolol served as denitrification control experiments. Results suggest that atenolol did not appreciably influence nitrate reduction. The extent of atenolol degradation was independent of carbon availability. In the experiments conducted in the μg/L range, 30–40% biotransformation was observed. Scant degradation at higher concentrations suggested that direct utilization of the pharmaceutical was either unlikely or occurring slowly and independent of the pharmaceutical concentration. Process-based modeling using the Activated Sludge Model framework assessed denitrification across carbon availability conditions and incorporated three individual pharmaceutical biotransformation modeling strategies: (1) direct metabolism model; (2) cometabolic model, and (3) biotransformation kinetic model. Results suggest that there was insufficient evidence to suspect direct metabolism meaningfully contributed to the reduction in atenolol concentration. The cometabolic process-based model, including both growth and nongrowth-linked rate coefficients offered the best model performance, although growth-linked cometabolism was limited and not readily apparent across all experiments (growth-linked transformation coefficient <0.4 g-atenolol·g-COD−1). Thus, the biotransformation kinetic model is favored for monitoring and forecasting biotransformation in larger-scale systems because use of the parsimonious model (rate coefficient of 7 mg-atenolol·g-COD−1·d−1) resulted in only modest performance reductions. The biotransformation model represents an improvement over pseudo first-order models as it is a mixed-order kinetic model that is linked to transient biomass conditions.","PeriodicalId":11777,"journal":{"name":"Environmental Engineering Science","volume":"201 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135510078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sreekanth Bojjagani, S.S. Kalikinkar Mahanta, Hari Om Prasad, Altaf Husain Khan, Ganesh Chandra Kisku
Land use changes in the wake of urbanization have arranged the urban residential sites to be encircled by anthropogenic activities, resulting in greater exposure to air pollution. There are limited studies carried out on source apportionment of urban landscape-induced air pollution and their spatial representativeness for urban residential sites, and the present study addressed this issue. Characterization, dissemination analysis, and source apportionment of particulate matter (PM)2.5 in a residential area, Lucknow have been carried out. Samples of PM2.5 were collected during mid-winter 2021–2022 at near-road-locations (viz. L1, L2, L3, and L4) of the study area. Samples of PM2.5 chemical speciation were done by inductively coupled plasma mass spectrometry and ion chromatography for 26-elements and 5-ions, respectively. Mean PM2.5 was recorded highest at L3 in the daytime and lowest at L4 in the nighttime with the values 166 μg/m3 and 76 μg/m3 respectively. ArcGIS-inverse distance weighing (IDW) simulations identified the representativeness of PM2.5 for the entire residential site. IDW mapping identified the PM2.5 propagation up to 200 m–500 m over the study area. The diversity in the concentration of PM2.5 observed within the residential area due to the influence of the respective day and night times, multiple sources mix and their spatial distribution. Chemical speciation data of PM2.5 applied to Positive Matrix Factorization version 5.0—as receptor model (PMF v5.0) run for individual sites separately and pool all four sites' data together as a single dataset, which ultimately confirmed seven factors. The PMF model outputs ascertained the mean apportionment of PM2.5 by the determined seven local sources that is, vehicular exhaust—21%, resuspended road dust—15%, cooking fuel emission—12%, waste burning—12%, diesel generator sets exhaust—10%, secondary aerosols—10%, and Construction and Demolition—7%. The remaining 13% mean contribution to PM2.5 was evidenced by unaccounted sources. The present study outcomes qualify the significance to undertake source apportionment studies in connection with urban landscape patterns for air pollution abatement specifically for rapidly changing cities.
{"title":"Source Apportionment and Analysis of Spatial Representativeness of Fine Particle Pollution for an Urban Residential Area in Lucknow, India","authors":"Sreekanth Bojjagani, S.S. Kalikinkar Mahanta, Hari Om Prasad, Altaf Husain Khan, Ganesh Chandra Kisku","doi":"10.1089/ees.2023.0120","DOIUrl":"https://doi.org/10.1089/ees.2023.0120","url":null,"abstract":"Land use changes in the wake of urbanization have arranged the urban residential sites to be encircled by anthropogenic activities, resulting in greater exposure to air pollution. There are limited studies carried out on source apportionment of urban landscape-induced air pollution and their spatial representativeness for urban residential sites, and the present study addressed this issue. Characterization, dissemination analysis, and source apportionment of particulate matter (PM)2.5 in a residential area, Lucknow have been carried out. Samples of PM2.5 were collected during mid-winter 2021–2022 at near-road-locations (viz. L1, L2, L3, and L4) of the study area. Samples of PM2.5 chemical speciation were done by inductively coupled plasma mass spectrometry and ion chromatography for 26-elements and 5-ions, respectively. Mean PM2.5 was recorded highest at L3 in the daytime and lowest at L4 in the nighttime with the values 166 μg/m3 and 76 μg/m3 respectively. ArcGIS-inverse distance weighing (IDW) simulations identified the representativeness of PM2.5 for the entire residential site. IDW mapping identified the PM2.5 propagation up to 200 m–500 m over the study area. The diversity in the concentration of PM2.5 observed within the residential area due to the influence of the respective day and night times, multiple sources mix and their spatial distribution. Chemical speciation data of PM2.5 applied to Positive Matrix Factorization version 5.0—as receptor model (PMF v5.0) run for individual sites separately and pool all four sites' data together as a single dataset, which ultimately confirmed seven factors. The PMF model outputs ascertained the mean apportionment of PM2.5 by the determined seven local sources that is, vehicular exhaust—21%, resuspended road dust—15%, cooking fuel emission—12%, waste burning—12%, diesel generator sets exhaust—10%, secondary aerosols—10%, and Construction and Demolition—7%. The remaining 13% mean contribution to PM2.5 was evidenced by unaccounted sources. The present study outcomes qualify the significance to undertake source apportionment studies in connection with urban landscape patterns for air pollution abatement specifically for rapidly changing cities.","PeriodicalId":11777,"journal":{"name":"Environmental Engineering Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135413702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qunbiao Wu, Tao Liang, Haifeng Fang, Yangyang Wei, Mingqiang Wang, Defang He
In light of the rapid development of human society, there has been a notable surge in waste production, which has resulted in environmental pollution and degradation. This is a pervasive issue that requires attention. To address the environmental problems caused by waste generation and advance the development of recyclable domestic waste detection, this article proposes waste classification as a solution. Traditional waste sorting methods have proven to be inefficient and prone to errors, hence the need for a more effective approach. A multiobjective recyclable domestic waste detection and classification method based on improved You Only Look Once v5s (YOLOv5s) is proposed in this study. In this study, the network structure is enhanced through the implementation of the Bidirectional Pyramid Network (BiFPN). The coordinate attention mechanism is then incorporated to elevate the accuracy of the model. Additionally, the loss function is refined by adopting the Efficient Intersection Over Union Loss (EIOU_Loss) metric to further optimize network performance. Finally, the introduction of the Ghost convolution module reduces parameter count and significantly improves the real-time detection speed. The waste dataset named Multi-classified Recyclable Domestic Trash Identification Dataset (MULTI-TRASH), which is composed of machine shooting, web crawler, and artificial photography, is used for verification due to its good generalization and representativeness. The mean Average Precision at a threshold of 0.5 ([email protected]) value of 94.8% is achieved by the improved model, which is a 30.72% reduction in the number of parameters and a 1.2% improvement in the [email protected] value compared with YOLOv5s. The effectiveness of the proposed algorithm is proved by a comparison with other target detection algorithms. This study aims to provide technical references for the development of a recyclable domestic waste detection system.
随着人类社会的快速发展，垃圾的产生急剧增加，造成了环境的污染和退化。这是一个普遍存在的问题，需要引起注意。为了解决垃圾产生带来的环境问题，促进可回收生活垃圾检测的发展，本文提出了垃圾分类作为解决方案。传统的废物分类方法效率低下，容易出错，因此需要一种更有效的方法。本研究提出了一种基于改进You Only Look Once v5s (YOLOv5s)的多目标可回收生活垃圾检测分类方法。在本研究中，通过实施双向金字塔网络(Bidirectional Pyramid network, BiFPN)来增强网络结构。为了提高模型的准确性，引入了坐标注意机制。此外，通过采用EIOU_Loss (Efficient Intersection Over Union loss)度量对损失函数进行细化，进一步优化网络性能。最后，Ghost卷积模块的引入减少了参数数量，显著提高了实时检测速度。由于具有较好的泛化和代表性，我们使用了多分类可回收生活垃圾识别数据集(MULTI-TRASH)进行验证，该数据集由机器拍摄、网络爬虫和人工摄影组成。改进的模型在阈值为0.5 ([email protected])时的平均平均精度为94.8%，与YOLOv5s相比，参数数量减少了30.72%，[email protected]值提高了1.2%。通过与其他目标检测算法的比较，证明了该算法的有效性。本研究旨在为可回收生活垃圾检测系统的开发提供技术参考。
{"title":"A Lightweight Deep Learning Algorithm for Multi-Objective Detection of Recyclable Domestic Waste","authors":"Qunbiao Wu, Tao Liang, Haifeng Fang, Yangyang Wei, Mingqiang Wang, Defang He","doi":"10.1089/ees.2023.0138","DOIUrl":"https://doi.org/10.1089/ees.2023.0138","url":null,"abstract":"In light of the rapid development of human society, there has been a notable surge in waste production, which has resulted in environmental pollution and degradation. This is a pervasive issue that requires attention. To address the environmental problems caused by waste generation and advance the development of recyclable domestic waste detection, this article proposes waste classification as a solution. Traditional waste sorting methods have proven to be inefficient and prone to errors, hence the need for a more effective approach. A multiobjective recyclable domestic waste detection and classification method based on improved You Only Look Once v5s (YOLOv5s) is proposed in this study. In this study, the network structure is enhanced through the implementation of the Bidirectional Pyramid Network (BiFPN). The coordinate attention mechanism is then incorporated to elevate the accuracy of the model. Additionally, the loss function is refined by adopting the Efficient Intersection Over Union Loss (EIOU_Loss) metric to further optimize network performance. Finally, the introduction of the Ghost convolution module reduces parameter count and significantly improves the real-time detection speed. The waste dataset named Multi-classified Recyclable Domestic Trash Identification Dataset (MULTI-TRASH), which is composed of machine shooting, web crawler, and artificial photography, is used for verification due to its good generalization and representativeness. The mean Average Precision at a threshold of 0.5 ([email protected]) value of 94.8% is achieved by the improved model, which is a 30.72% reduction in the number of parameters and a 1.2% improvement in the [email protected] value compared with YOLOv5s. The effectiveness of the proposed algorithm is proved by a comparison with other target detection algorithms. This study aims to provide technical references for the development of a recyclable domestic waste detection system.","PeriodicalId":11777,"journal":{"name":"Environmental Engineering Science","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136356846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jorge L. Calabria, Armando Oliva, Piet N.L. Lens, Daniel H. Yeh
Nitrogen-rich effluents from anaerobic processes present nutrient resource recovery opportunities for fertilizer applications in hydroponic systems, thus facilitating agricultural production in less conventional contexts such as urbanized areas. However, the high ammonia and soluble chemical oxygen demand, which is common in anaerobic digestate, can inhibit crop development in a hydroponic system, requiring conditioning to enable optimal performance of the system. This study examines the use of three nutrient sources to support the growth of lettuce (Lactuca sativa) in vertical hydroponic systems: (i) synthetic permeate (SP) solution, (ii) desorption solution (DS) from an anaerobic membrane bioreactor (AnMBR), and (iii) DS modified with acetic acid addition. Two light conditions were used to observe the effect of photon flux (from 150–200 to 10–15 μmol/[m2·s]) on lettuce crop development and nitrification efficiency of the treated AnMBR permeate. Fresh and dry mass of the harvested lettuce crops as well as chlorophyll content were measured as an indicator of crop quality after a 13-day development period. Crops grown under well-lit conditions in DS had harvested fresh weight (2929.0 ± 454.6 mg/plant) than SP-grown crops (2646.2 ± 908.8 mg/plant). The lighting conditions did not significantly impact the nitrification efficiency; thus nitrate, the preferred form of nitrogen for supporting lettuce crop development, was sufficiently available to support crop growth in the recirculating hydroponic systems.
{"title":"Recirculating Vertical Hydroponic Systems: Effect of Light and Nutrient Solution Composition on Nitrification Activity","authors":"Jorge L. Calabria, Armando Oliva, Piet N.L. Lens, Daniel H. Yeh","doi":"10.1089/ees.2023.0181","DOIUrl":"https://doi.org/10.1089/ees.2023.0181","url":null,"abstract":"Nitrogen-rich effluents from anaerobic processes present nutrient resource recovery opportunities for fertilizer applications in hydroponic systems, thus facilitating agricultural production in less conventional contexts such as urbanized areas. However, the high ammonia and soluble chemical oxygen demand, which is common in anaerobic digestate, can inhibit crop development in a hydroponic system, requiring conditioning to enable optimal performance of the system. This study examines the use of three nutrient sources to support the growth of lettuce (Lactuca sativa) in vertical hydroponic systems: (i) synthetic permeate (SP) solution, (ii) desorption solution (DS) from an anaerobic membrane bioreactor (AnMBR), and (iii) DS modified with acetic acid addition. Two light conditions were used to observe the effect of photon flux (from 150–200 to 10–15 μmol/[m2·s]) on lettuce crop development and nitrification efficiency of the treated AnMBR permeate. Fresh and dry mass of the harvested lettuce crops as well as chlorophyll content were measured as an indicator of crop quality after a 13-day development period. Crops grown under well-lit conditions in DS had harvested fresh weight (2929.0 ± 454.6 mg/plant) than SP-grown crops (2646.2 ± 908.8 mg/plant). The lighting conditions did not significantly impact the nitrification efficiency; thus nitrate, the preferred form of nitrogen for supporting lettuce crop development, was sufficiently available to support crop growth in the recirculating hydroponic systems.","PeriodicalId":11777,"journal":{"name":"Environmental Engineering Science","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135690003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elizabeth Dach, Lara David, Julian Van der Made, Mariah Pope, Joshua Chabeda, Adam Brown, John C. Foo, Ngai Yin Yip
Showerhead filters are point-of-use devices installed just before showerheads to alter bathing water quality. Such products are gaining popularity but are presently not under any regulatory oversight. Sellers of showerhead filters make wide-ranging claims, including removing harmful substances, modifying pH, and adding elements to the water matrix, and tout health and cosmetic benefits, but without providing substantiating evidence upfront. This study evaluates selected water chemistry parameters, including pH and concentrations of vitamin C, fluoride, and chlorine, of five showerhead filters sold on AMAZON.COM and finds that most of the sellers' water quality claims are not met. Instead, some filters change a number of water quality parameters opposite to what is marketed, for example, water hardness and dissolved oxygen. We conclude that the sellers of showerhead filters are, at the very least, guilty of promoting misleading advertisements, but more likely culpable of exploiting pseudoscience to profit from consumers' poor literacy in water chemistry. This study is the outcome of a course-based research experience for senior undergraduate and junior graduate students implemented in a technical elective on environmental physicochemical processes. Through sharing the design and execution of this experimental investigation and discussing the wider pedagogical benefits, this study further aims to stimulate others to explore the integration of research and education. On a broader perspective, this study sheds light on the worrying contagion of pseudoscience in water quality engineering and underscores the urgent need to enlighten the public and promote their scientific literacy.
{"title":"Are Showerhead Filters Retailed Online a Scam? Investigating Water Quality Claims Through a Course-Based Research Experience","authors":"Elizabeth Dach, Lara David, Julian Van der Made, Mariah Pope, Joshua Chabeda, Adam Brown, John C. Foo, Ngai Yin Yip","doi":"10.1089/ees.2023.0099","DOIUrl":"https://doi.org/10.1089/ees.2023.0099","url":null,"abstract":"Showerhead filters are point-of-use devices installed just before showerheads to alter bathing water quality. Such products are gaining popularity but are presently not under any regulatory oversight. Sellers of showerhead filters make wide-ranging claims, including removing harmful substances, modifying pH, and adding elements to the water matrix, and tout health and cosmetic benefits, but without providing substantiating evidence upfront. This study evaluates selected water chemistry parameters, including pH and concentrations of vitamin C, fluoride, and chlorine, of five showerhead filters sold on AMAZON.COM and finds that most of the sellers' water quality claims are not met. Instead, some filters change a number of water quality parameters opposite to what is marketed, for example, water hardness and dissolved oxygen. We conclude that the sellers of showerhead filters are, at the very least, guilty of promoting misleading advertisements, but more likely culpable of exploiting pseudoscience to profit from consumers' poor literacy in water chemistry. This study is the outcome of a course-based research experience for senior undergraduate and junior graduate students implemented in a technical elective on environmental physicochemical processes. Through sharing the design and execution of this experimental investigation and discussing the wider pedagogical benefits, this study further aims to stimulate others to explore the integration of research and education. On a broader perspective, this study sheds light on the worrying contagion of pseudoscience in water quality engineering and underscores the urgent need to enlighten the public and promote their scientific literacy.","PeriodicalId":11777,"journal":{"name":"Environmental Engineering Science","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135324153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Environmental Engineering ScienceAhead of Print AEESP Spotlight: Late 2023David A. LadnerDavid A. Ladner*Corresponding author: Department of Environmental Engineering and Earth Sciences, Clemson University, 342 Computer Court, Anderson, SC 29625, USA. Phone: 1-864-656-5572; E-mail Address: [email protected]https://orcid.org/0000-0002-9214-783XDepartment of Environmental Engineering and Earth Sciences, Clemson University, Anderson, South Carolina, USA.†Member of AEESP.Search for more papers by this authorPublished Online:3 Oct 2023https://doi.org/10.1089/ees.2023.0245AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View article"AEESP Spotlight: Late 2023." Environmental Engineering Science, , pp. FiguresReferencesRelatedDetails Volume 0Issue 0 InformationCopyright 2023, Mary Ann Liebert, Inc., publishersTo cite this article:David A. Ladner.AEESP Spotlight: Late 2023.Environmental Engineering Science.ahead of printhttp://doi.org/10.1089/ees.2023.0245Online Ahead of Print:October 3, 2023PDF download
david A. Ladner*通讯作者:Clemson University环境工程与地球科学系，342 Computer Court, Anderson, SC 29625, USA。电话:1-864-656-5572;电子邮件地址:[email protected]https://orcid.org/0000-0002-9214-783XDepartment美国南卡罗来纳州安德森市克莱姆森大学环境工程与地球科学学院。†AEESP成员。搜索本文作者的更多论文发表在线:2023年10月3日https://doi.org/10.1089/ees.2023.0245AboutSectionsView文章查看全文pdf /EPUB权限和引文下载CitationsTrack引文添加到收藏夹返回出版物ShareShare onFacebookTwitterLinked InRedditEmail查看文章“AEESP Spotlight: Late 2023”。环境工程科学，第0卷第0期信息版权所有2023,Mary Ann Liebert, Inc.， publisher .本文来源:David A. Ladner。AEESP焦点:2023年末。环境工程科学。提前打印://doi.org/10.1089/ees.2023.0245Online提前打印:2023年10月3日pdf下载
{"title":"AEESP Spotlight: Late 2023","authors":"David A. Ladner","doi":"10.1089/ees.2023.0245","DOIUrl":"https://doi.org/10.1089/ees.2023.0245","url":null,"abstract":"Environmental Engineering ScienceAhead of Print AEESP Spotlight: Late 2023David A. LadnerDavid A. Ladner*Corresponding author: Department of Environmental Engineering and Earth Sciences, Clemson University, 342 Computer Court, Anderson, SC 29625, USA. Phone: 1-864-656-5572; E-mail Address: [email protected]https://orcid.org/0000-0002-9214-783XDepartment of Environmental Engineering and Earth Sciences, Clemson University, Anderson, South Carolina, USA.†Member of AEESP.Search for more papers by this authorPublished Online:3 Oct 2023https://doi.org/10.1089/ees.2023.0245AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View article\"AEESP Spotlight: Late 2023.\" Environmental Engineering Science, , pp. FiguresReferencesRelatedDetails Volume 0Issue 0 InformationCopyright 2023, Mary Ann Liebert, Inc., publishersTo cite this article:David A. Ladner.AEESP Spotlight: Late 2023.Environmental Engineering Science.ahead of printhttp://doi.org/10.1089/ees.2023.0245Online Ahead of Print:October 3, 2023PDF download","PeriodicalId":11777,"journal":{"name":"Environmental Engineering Science","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134935275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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