Pub Date : 2025-02-04DOI: 10.1016/j.cscee.2025.101136
Nguyen Van Cong , Tran Hoang Kha , Bui Thi Bich Hang , Duong Tri Dung , Tran Sy Nam
This study aims to determine median lethal concentration (LC50) and effects at sublethal levels of quinalphos on brain cholinesterase (ChE) and growth of fingerlings climbing perch (Anabas testudineus). Results showed that LC50-96 h was 1.88 mg L−1. Brain ChE activity was significantly inhibited at concentration of 10 % LC50-96h or higher up to the end 96 h of exposure. In the growth experiment, specific growth rate was inhibited 48.0 % and 34.8 % at treatment 10 % and 20 % LC50-96h, respectively while feed conversion ratio elevated to 164.5 % control at treatment 10 % and to 132.3 % at treatment 20 % LC50-96h. Survival rates were 86 % at 10 % LC50-96h and 34.7 % at 20 % LC50-96h. The study indicated that quinalphos is highly toxic for the climbing perch leading to potential health risk for this species living in rice fields of the Lower Mekong Delta. Monitoring and controlling quinalphos levels in aquatic environments are important acts to mitigating its adverse impacts on aquatic organisms. Promoting the use of less toxic or biodegradable pesticides is urgently needed.
{"title":"Toxicity of insecticide quinalphos-based Kinalux 25EC on fingerling climbing perch (Anabas testudineus): Brain cholinesterase and growth inhibitions","authors":"Nguyen Van Cong , Tran Hoang Kha , Bui Thi Bich Hang , Duong Tri Dung , Tran Sy Nam","doi":"10.1016/j.cscee.2025.101136","DOIUrl":"10.1016/j.cscee.2025.101136","url":null,"abstract":"<div><div>This study aims to determine median lethal concentration (LC50) and effects at sublethal levels of quinalphos on brain cholinesterase (ChE) and growth of fingerlings climbing perch (<em>Anabas testudineus</em>). Results showed that LC<sub>50</sub>-96 h was 1.88 mg L<sup>−1</sup>. Brain ChE activity was significantly inhibited at concentration of 10 % LC<sub>50</sub>-96h or higher up to the end 96 h of exposure. In the growth experiment, specific growth rate was inhibited 48.0 % and 34.8 % at treatment 10 % and 20 % LC50-96h, respectively while feed conversion ratio elevated to 164.5 % control at treatment 10 % and to 132.3 % at treatment 20 % LC50-96h. Survival rates were 86 % at 10 % LC50-96h and 34.7 % at 20 % LC50-96h. The study indicated that quinalphos is highly toxic for the climbing perch leading to potential health risk for this species living in rice fields of the Lower Mekong Delta. Monitoring and controlling quinalphos levels in aquatic environments are important acts to mitigating its adverse impacts on aquatic organisms. Promoting the use of less toxic or biodegradable pesticides is urgently needed.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101136"},"PeriodicalIF":0.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143224183","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 : 2025-01-31DOI: 10.1016/j.cscee.2025.101127
Motasem Y.D. Alazaiza , Tharaa M. Alzghoul , Madhusudhan Bangalore Ramu , Salem S. Abu Amr , Mohammed F.M. Abushammala
Per
and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals known for their persistence in the environment and potential adverse effects on human health. This study conducted a bibliometric analysis of 581 publications from the Scopus database, covering the period from 2015 to November 2024, to assess research trends and developments related to PFAS. The findings reveal a significant increase in research output, with the number of published articles rising from just 7 in 2015 to 134 in 2024, indicating a growing global awareness of PFAS contamination. "Environmental Science" emerges as the leading discipline, accounting for 44.8% of total publications, followed by Chemistry at 15%. The United States is the foremost contributor, with 216 publications and 11,213 citations, followed by China and Sweden. Common PFAS compounds, particularly perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), have been widely detected in various ecosystems, including surface water, groundwater, and soil. These substances pose significant risks to aquatic organisms and human health due to their persistence and potential for bioaccumulation. The analysis highlights effective treatment methods for PFAS removal, such as adsorption and photocatalysis, which are crucial for mitigating environmental contamination. Prominent journals like "Science of the Total Environment" and "Environmental Science and Technology" play vital roles in disseminating research findings, while the "National Natural Science Foundation" of China is identified as a key funding source supporting numerous studies. Overall, the research underscores the need for innovative strategies and integrated management plans to combat PFAS pollution effectively. It emphasizes the importance of interdisciplinary collaboration to enhance understanding of PFAS behavior in ecosystems and to develop effective remediation techniques, ultimately protecting water quality and public health from the multifaceted challenges posed by PFAS contamination.
{"title":"PFAS Contamination and Mitigation: A Comprehensive Analysis of Research Trends and Global Contributions","authors":"Motasem Y.D. Alazaiza , Tharaa M. Alzghoul , Madhusudhan Bangalore Ramu , Salem S. Abu Amr , Mohammed F.M. Abushammala","doi":"10.1016/j.cscee.2025.101127","DOIUrl":"10.1016/j.cscee.2025.101127","url":null,"abstract":"<div><h3>Per</h3><div>and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals known for their persistence in the environment and potential adverse effects on human health. This study conducted a bibliometric analysis of 581 publications from the Scopus database, covering the period from 2015 to November 2024, to assess research trends and developments related to PFAS. The findings reveal a significant increase in research output, with the number of published articles rising from just 7 in 2015 to 134 in 2024, indicating a growing global awareness of PFAS contamination. \"Environmental Science\" emerges as the leading discipline, accounting for 44.8% of total publications, followed by Chemistry at 15%. The United States is the foremost contributor, with 216 publications and 11,213 citations, followed by China and Sweden. Common PFAS compounds, particularly perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), have been widely detected in various ecosystems, including surface water, groundwater, and soil. These substances pose significant risks to aquatic organisms and human health due to their persistence and potential for bioaccumulation. The analysis highlights effective treatment methods for PFAS removal, such as adsorption and photocatalysis, which are crucial for mitigating environmental contamination. Prominent journals like \"Science of the Total Environment\" and \"Environmental Science and Technology\" play vital roles in disseminating research findings, while the \"National Natural Science Foundation\" of China is identified as a key funding source supporting numerous studies. Overall, the research underscores the need for innovative strategies and integrated management plans to combat PFAS pollution effectively. It emphasizes the importance of interdisciplinary collaboration to enhance understanding of PFAS behavior in ecosystems and to develop effective remediation techniques, ultimately protecting water quality and public health from the multifaceted challenges posed by PFAS contamination.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101127"},"PeriodicalIF":0.0,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147796","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 : 2025-01-31DOI: 10.1016/j.cscee.2025.101130
Thanya Crespo-Toledo , Francisco Avelar-González , Alma Guerrero-Barrera , Kerry Mitchell , Laura Yamamoto-Flores , Oscar Flores-Amaro
Residual metals from mining activities pose significant risks to both the environment and human health, especially when they exist in bioavailable and mobile forms. In areas where complex physicochemical characteristics make it difficult to estimate metal mobility, assessing these risks requires an integrated approach. In this case study environmental risk was assessed by integrating the following indicators: ratio between total metal concentration and reference values, geoaccumulation index (Igeo), risk characterization ratio (RCR) and mobility factor (MF). The highest concentrations of Cd, Pb, Cu and Zn in sediments were 45.95, 743.01, 220.24 and 2992.84 mg/Kg, respectively while the concentrations in soils were 26.23, 953, 553.46, and 11948.80 mg/Kg, respectively. The Igeo confirmed moderate to heavily contaminated soils and sediments. Additionally, the RCR exceeded the quotient 1 for all metals, suggesting a significant ecological risk. High MF (up to 70 %) was observed for Cd in both sediments and soils. However, for Pb, Cu and Zn an average of 15 % was observed only in sediments. This study reveals that physicochemical characteristics, pH, Eh, texture, organic matter and CEC influence metal mobility and indicate anthropogenic metal contamination in readily available forms, highlighting the importance of comprehensive physicochemical evaluations and integrative use of different pollution indicators when assessing contamination levels and evaluating associated risks of polluted environments to both human health and the environment.
{"title":"Integrative assessment of heavy metal risks in mining polluted sediments and soils of Aguascalientes, Mexico","authors":"Thanya Crespo-Toledo , Francisco Avelar-González , Alma Guerrero-Barrera , Kerry Mitchell , Laura Yamamoto-Flores , Oscar Flores-Amaro","doi":"10.1016/j.cscee.2025.101130","DOIUrl":"10.1016/j.cscee.2025.101130","url":null,"abstract":"<div><div>Residual metals from mining activities pose significant risks to both the environment and human health, especially when they exist in bioavailable and mobile forms. In areas where complex physicochemical characteristics make it difficult to estimate metal mobility, assessing these risks requires an integrated approach. In this case study environmental risk was assessed by integrating the following indicators: ratio between total metal concentration and reference values, geoaccumulation index (Igeo), risk characterization ratio (RCR) and mobility factor (MF). The highest concentrations of Cd, Pb, Cu and Zn in sediments were 45.95, 743.01, 220.24 and 2992.84 mg/Kg, respectively while the concentrations in soils were 26.23, 953, 553.46, and 11948.80 mg/Kg, respectively. The Igeo confirmed moderate to heavily contaminated soils and sediments. Additionally, the RCR exceeded the quotient 1 for all metals, suggesting a significant ecological risk. High MF (up to 70 %) was observed for Cd in both sediments and soils. However, for Pb, Cu and Zn an average of 15 % was observed only in sediments. This study reveals that physicochemical characteristics, pH, Eh, texture, organic matter and CEC influence metal mobility and indicate anthropogenic metal contamination in readily available forms, highlighting the importance of comprehensive physicochemical evaluations and integrative use of different pollution indicators when assessing contamination levels and evaluating associated risks of polluted environments to both human health and the environment.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101130"},"PeriodicalIF":0.0,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143224182","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}
Due to rising demand, the worldwide cement market is expected to increase from $340.61 billion in 2022 to $481.73 billion by 2029. Quarrying, raw material processing, and calcination are steps in cement production. The societies in India and Nepal have to deal with environmental issues such as air pollution, resource depletion, and the effects of climate change. A case study of Nepal's Udayapur Cement Industry Limited (UCIL) exposed antiquated production methods that reduce energy efficiency. Utilizing regression models like Extra Trees (Extremely Randomized Trees) Regressor, CatBoost (Categorial Boosting) Regressor, and XGBoost (eXtreme Gradient Boosting) Regressor, Random Forest and Ensemble of Sparse Embedded Trees (SET) machine learning is used to examine the demand, supply, and Gross Domestic Product (GDP) performance of cement manufacturing in India which shares a common cement related infrastructure to Nepal. Since businesses understand how important sustainability is to attract new customers and minimizing environmental effects, our study emphasizes the necessity of sustainable practices in the cement production industry. On evaluation, the Extra Trees Regressor showed strong performance, along with the SET (Stacking) model, which was further validated using a nested cross-validation technique. Random Forest, on the other hand, had trouble; it displayed the greatest RMSE (15617.85) and the lowest testing (0.8117), suggesting poorer generalization. The SET (Stacking) Ensemble model gained a testing R2 score (0.9372) and a testing RMSE (9019.76). In cross-validation, the Extra Trees model with a mean cross-validation R2 score of 0.93 and a low standard deviation of 0.04 proved to be the best-performing model, as evidenced by lower differences in R2 score across folds compared to other models, demonstrating its high predictive performance. The SHAP (SHapley Additive exPlanations) interpretability analysis indicates that population is the primary factor influencing GDP estimates. A Tkinter-based application was also developed to forecast GDP using the training model. To attain sustainability and lessen the effects of climate change on the cement sector, these findings highlight the adoption of cutting-edge technologies and energy-efficient procedures.
{"title":"Exploring cement Production's role in GDP using explainable AI and sustainability analysis in Nepal","authors":"Ramhari Poudyal , Biplov Paneru , Bishwash Paneru , Tilak Giri , Bibek Paneru , Tim Reynolds , Khem Narayan Poudyal , Mohan B. Dangi","doi":"10.1016/j.cscee.2025.101128","DOIUrl":"10.1016/j.cscee.2025.101128","url":null,"abstract":"<div><div>Due to rising demand, the worldwide cement market is expected to increase from $340.61 billion in 2022 to $481.73 billion by 2029. Quarrying, raw material processing, and calcination are steps in cement production. The societies in India and Nepal have to deal with environmental issues such as air pollution, resource depletion, and the effects of climate change. A case study of Nepal's Udayapur Cement Industry Limited (UCIL) exposed antiquated production methods that reduce energy efficiency. Utilizing regression models like Extra Trees (Extremely Randomized Trees) Regressor, CatBoost (Categorial Boosting) Regressor, and XGBoost (eXtreme Gradient Boosting) Regressor, Random Forest and Ensemble of Sparse Embedded Trees (SET) machine learning is used to examine the demand, supply, and Gross Domestic Product (GDP) performance of cement manufacturing in India which shares a common cement related infrastructure to Nepal. Since businesses understand how important sustainability is to attract new customers and minimizing environmental effects, our study emphasizes the necessity of sustainable practices in the cement production industry. On evaluation, the Extra Trees Regressor showed strong performance, along with the SET (Stacking) model, which was further validated using a nested cross-validation technique. Random Forest, on the other hand, had trouble; it displayed the greatest RMSE (15617.85) and the lowest testing (0.8117), suggesting poorer generalization. The SET (Stacking) Ensemble model gained a testing R<sup>2</sup> score (0.9372) and a testing RMSE (9019.76). In cross-validation, the Extra Trees model with a mean cross-validation R<sup>2</sup> score of 0.93 and a low standard deviation of 0.04 proved to be the best-performing model, as evidenced by lower differences in R<sup>2</sup> score across folds compared to other models, demonstrating its high predictive performance. The SHAP (SHapley Additive exPlanations) interpretability analysis indicates that population is the primary factor influencing GDP estimates. A Tkinter-based application was also developed to forecast GDP using the training model. To attain sustainability and lessen the effects of climate change on the cement sector, these findings highlight the adoption of cutting-edge technologies and energy-efficient procedures.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101128"},"PeriodicalIF":0.0,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143224184","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}
This study presents an investigation into the vibration resonance of Mindlin piezoelectric polymeric nanoplates under electromechanical loading, particularly in the presence of a rotating nanoparticle. The novelty of this research lies in the application of non-local piezoelasticity, which effectively incorporates the influence of small-scale factors on the resonance behavior of the nanoplate. By employing a variational approach to derive the governing equations, this work advances the understanding of how various parameters such as the non-local parameter, dimensions of the nanoplate, excitation voltage, and mass of the nanoparticle affect resonance frequencies. The Galerkin method is utilized to solve the partial differential equations governing the dynamics of the piezoelectric polymeric nanoplate, marking a significant methodological contribution to the field. The incremental harmonic balance approach is then applied to estimate the system's resonance frequencies, with numerical simulations confirming their existence. This research not only elucidates the complex interactions affecting resonance behavior but also highlights the potential for optimizing the design of nanostructures in various applications, including sensors and energy-harvesting devices. The findings suggest that increasing the non-local parameter softens the nanoplate's rigidity, leading to decreased resonance frequencies, while modifications in dimensions and applied voltages can enhance these frequencies. Overall, this study lays the groundwork for future explorations into the dynamic behavior of piezoelectric materials, emphasizing the importance of small-scale effects in nanotechnology applications.
{"title":"Non-local piezoelasticity to incorporate the influence of small-scale factors on the resonance behavior of the Mindlin piezoelectric polymeric nanoplates","authors":"Narinderjit Singh Sawaran Singh , Waqed H. Hassan , Zainab Mоhammed Ameen Ahmed , Younis Mohamed Atiah Al-zahy , Soheil Salahshour , Mostafa Pirmoradian","doi":"10.1016/j.cscee.2025.101125","DOIUrl":"10.1016/j.cscee.2025.101125","url":null,"abstract":"<div><div>This study presents an investigation into the vibration resonance of Mindlin piezoelectric polymeric nanoplates under electromechanical loading, particularly in the presence of a rotating nanoparticle. The novelty of this research lies in the application of non-local piezoelasticity, which effectively incorporates the influence of small-scale factors on the resonance behavior of the nanoplate. By employing a variational approach to derive the governing equations, this work advances the understanding of how various parameters such as the non-local parameter, dimensions of the nanoplate, excitation voltage, and mass of the nanoparticle affect resonance frequencies. The Galerkin method is utilized to solve the partial differential equations governing the dynamics of the piezoelectric polymeric nanoplate, marking a significant methodological contribution to the field. The incremental harmonic balance approach is then applied to estimate the system's resonance frequencies, with numerical simulations confirming their existence. This research not only elucidates the complex interactions affecting resonance behavior but also highlights the potential for optimizing the design of nanostructures in various applications, including sensors and energy-harvesting devices. The findings suggest that increasing the non-local parameter softens the nanoplate's rigidity, leading to decreased resonance frequencies, while modifications in dimensions and applied voltages can enhance these frequencies. Overall, this study lays the groundwork for future explorations into the dynamic behavior of piezoelectric materials, emphasizing the importance of small-scale effects in nanotechnology applications.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101125"},"PeriodicalIF":0.0,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147415","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 : 2025-01-28DOI: 10.1016/j.cscee.2025.101122
Manassé Kushenga Cibangwa , Daniel Ikhu-Omoregbe , Myalelo Nomnqa
This study investigates the rheological and optical performance of water-based paints using Hydrophobically Modified Ethoxylated Urethane (HEUR) and Hydrophobically Modified Alkali Swellable Emulsions (HASE) as thickeners with styrene acrylic (SA) and pure acrylic (PA) binders. Novel insights include the superior thickening efficiency and elasticity of HASE with PA binders, while HEUR maintained consistent performance across binders. Importantly, a correlation between rheology and optical attributes such as gloss and opacity has been established, highlighting rheology's critical role in optimizing paint formulations for application and aesthetic performance. This study bridges the gap in understanding binder-thickener interactions in decorative paints.
{"title":"Comparative rheological evaluation of associative thickeners in water-based paint: Influence of polymeric binder and thickener concentration","authors":"Manassé Kushenga Cibangwa , Daniel Ikhu-Omoregbe , Myalelo Nomnqa","doi":"10.1016/j.cscee.2025.101122","DOIUrl":"10.1016/j.cscee.2025.101122","url":null,"abstract":"<div><div>This study investigates the rheological and optical performance of water-based paints using Hydrophobically Modified Ethoxylated Urethane (HEUR) and Hydrophobically Modified Alkali Swellable Emulsions (HASE) as thickeners with styrene acrylic (SA) and pure acrylic (PA) binders. Novel insights include the superior thickening efficiency and elasticity of HASE with PA binders, while HEUR maintained consistent performance across binders. Importantly, a correlation between rheology and optical attributes such as gloss and opacity has been established, highlighting rheology's critical role in optimizing paint formulations for application and aesthetic performance. This study bridges the gap in understanding binder-thickener interactions in decorative paints.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101122"},"PeriodicalIF":0.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147413","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}
Sugarcane bagasse, with a 25–28 % lignin content, can be converted into biochar, serving as a promising adsorbent due to its high surface area. Nano-zero-valent iron (nZVI) is known for its strong magnetization and ability to bind heavy metals. In this research, biochar derived from sugarcane bagasse was composited with nZVI at varying ratios (1:1, 2:1, and 3:1) to improve adsorption efficiency for Cr (VI) removal. The composites were synthesized using the biochar from the plasma pyrolysis method, followed by nZVI incorporation. Batch adsorption tests were conducted with different Cr (VI) concentrations, contact times, pH levels, and adsorbent doses to determine the optimum conditions for each ratio. Characterization of the adsorbent included XRD, BET, FTIR, SEM, VSM, and Zeta potential analysis. XRD analysis of sugarcane bagasse and biochar demonstrated crystallinity and particle size improvements post-pyrolysis. BET results showed that sugarcane bagasse biomass had a surface area of 0.061 m2/g, which increased to 87.50 m2/g after conversion to biochar. However, once composited with nZVI, the surface area decreased to 37.44 m2/g (1:1), 49.26 m2/g (2:1), and 62.37 m2/g (3:1). FTIR and SEM analyses revealed the interactions between biochar and nZVI, as well as the binding of Cr (VI) to the composite surfaces. VSM showed a reduction in magnetization after adsorption, confirming the oxidation of nZVI to various iron oxides (e.g., FeO, Fe₂O₃, Fe₃O₄), which are less magnetic. The adsorption tests indicated that the adsorption capacity increased with a higher SBB/nZVI ratio. The biochar alone had an adsorption capacity of 77.82 mg/g. In comparison, the composites achieved 86.47 mg/g (1:1), 95.12 mg/g (2:1), and 112.41 mg/g (3:1). Optimal removal was achieved at an initial Cr (VI) concentration of 175 mg/L, a contact time of 180 minutes, and a pH of 2. The Langmuir isotherm model best described the adsorption behavior, and the adsorption kinetics followed a pseudo-second-order model, indicating chemisorption as the primary mechanism. The study concluded that the composite's adsorption efficiency increased with a higher nZVI ratio, making the 3:1 ratio the most effective for Cr (VI) removal.
{"title":"Composite adsorbent from sugarcane (Saccharum officinarum) bagasse biochar generated from atmospheric pressure microwave plasma pyrolysis process and nano zero valent iron (nZVI) for rapid and highly efficient Cr(VI) adsorption","authors":"Denny Dermawan , Aulia Diva Satriavi , Dyah Isna Nurhidayati , Rahmad Firnandi , Novi Eka Mayangsari , Tarikh Azis Ramadani , Dika Rahayu Widiana , Anda Iviana Juniani , Dwi Rasy Mujiyanti , Ya-Fen Wang","doi":"10.1016/j.cscee.2025.101123","DOIUrl":"10.1016/j.cscee.2025.101123","url":null,"abstract":"<div><div>Sugarcane bagasse, with a 25–28 % lignin content, can be converted into biochar, serving as a promising adsorbent due to its high surface area. Nano-zero-valent iron (nZVI) is known for its strong magnetization and ability to bind heavy metals. In this research, biochar derived from sugarcane bagasse was composited with nZVI at varying ratios (1:1, 2:1, and 3:1) to improve adsorption efficiency for Cr (VI) removal. The composites were synthesized using the biochar from the plasma pyrolysis method, followed by nZVI incorporation. Batch adsorption tests were conducted with different Cr (VI) concentrations, contact times, pH levels, and adsorbent doses to determine the optimum conditions for each ratio. Characterization of the adsorbent included XRD, BET, FTIR, SEM, VSM, and Zeta potential analysis. XRD analysis of sugarcane bagasse and biochar demonstrated crystallinity and particle size improvements post-pyrolysis. BET results showed that sugarcane bagasse biomass had a surface area of 0.061 m<sup>2</sup>/g, which increased to 87.50 m<sup>2</sup>/g after conversion to biochar. However, once composited with nZVI, the surface area decreased to 37.44 m<sup>2</sup>/g (1:1), 49.26 m<sup>2</sup>/g (2:1), and 62.37 m<sup>2</sup>/g (3:1). FTIR and SEM analyses revealed the interactions between biochar and nZVI, as well as the binding of Cr (VI) to the composite surfaces. VSM showed a reduction in magnetization after adsorption, confirming the oxidation of nZVI to various iron oxides (e.g., FeO, Fe₂O₃, Fe₃O₄), which are less magnetic. The adsorption tests indicated that the adsorption capacity increased with a higher SBB/nZVI ratio. The biochar alone had an adsorption capacity of 77.82 mg/g. In comparison, the composites achieved 86.47 mg/g (1:1), 95.12 mg/g (2:1), and 112.41 mg/g (3:1). Optimal removal was achieved at an initial Cr (VI) concentration of 175 mg/L, a contact time of 180 minutes, and a pH of 2. The Langmuir isotherm model best described the adsorption behavior, and the adsorption kinetics followed a pseudo-second-order model, indicating chemisorption as the primary mechanism. The study concluded that the composite's adsorption efficiency increased with a higher nZVI ratio, making the 3:1 ratio the most effective for Cr (VI) removal.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101123"},"PeriodicalIF":0.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147411","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}
This study investigated seasonal and meteorological factors affecting the concentration levels of 1,2-dichloroethane, benzene, and 1,3-butadiene and conducted health risk assessments inside and outside the industrial estate in Rayong Province, Thailand. Volatile organic compound concentrations and meteorological data from 2019 to 2023 were analysed. Temperature and relative humidity showed a medium-level linear relationship with the concentration of 1,2-dichloroethane at Wat Nong Fab (R2 = 0.549, p < 0.01). Inhalation exposure of 1,3-butadiene posed the highest risk in the cold season (hazard quotient (HQ) = 7.949), with an annual average HQ of 2.72. Therefore, the controlling exposure to 1,3-butadiene and tracking health outcomes when exposure occurs is paramount, especially during the cold season.
{"title":"Seasonal impact and meteorological factors affecting the distribution of volatile organic compound concentrations and health risk assessment inside and outside industrial estates: A case study of Rayong Province, Thailand","authors":"Teeranun Nakyai , Chan Pattama Polyong , Marissa Kongsombatsuk , Tanunchai Boonnuk , Anamai Thetkathuek","doi":"10.1016/j.cscee.2025.101121","DOIUrl":"10.1016/j.cscee.2025.101121","url":null,"abstract":"<div><div>This study investigated seasonal and meteorological factors affecting the concentration levels of 1,2-dichloroethane, benzene, and 1,3-butadiene and conducted health risk assessments inside and outside the industrial estate in Rayong Province, Thailand. Volatile organic compound concentrations and meteorological data from 2019 to 2023 were analysed. Temperature and relative humidity showed a medium-level linear relationship with the concentration of 1,2-dichloroethane at Wat Nong Fab (<em>R</em><sup>2</sup> = 0.549, <em>p</em> < 0.01). Inhalation exposure of 1,3-butadiene posed the highest risk in the cold season (hazard quotient (HQ) = 7.949), with an annual average HQ of 2.72. Therefore, the controlling exposure to 1,3-butadiene and tracking health outcomes when exposure occurs is paramount, especially during the cold season.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101121"},"PeriodicalIF":0.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147410","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 : 2025-01-27DOI: 10.1016/j.cscee.2025.101117
Mohammed Al-Saad , Ali B.M. Ali , Mohammed Al-Mosallam , Mohammad N. Fares , Mohammad Ali Fazilati , Soheil Salahshour , Rozbeh Sabetvand
Considering the wide application of double-pipe heat exchanger made their performance improvement very important. Employing aqueous nanofluid (NF) of Ag and Al2O3 as the working fluid inside the inner tube of the heat exchanger and its rotation as the respective passive and active enhancing methods are investigated numerically using the two-phase mixture method. The sensitivity analysis was performed to reveal the effect of Reynolds (Re) number, NF concentration and tube rotational speeds on heat transfer coefficient, heat transfer effectiveness, and efficiency ratio. The Re number, NF concentration, and rotation speed lie in 1000-3000, 0–4 %, and 300–500 rpm, respectively. The results show the higher improving effect of Ag rather than Al2O3 nanoparticle; for Re = 1000, 1500 and 2000 the efficiency ratio averaged between different concentrations are 39 %, 30 %, 20 % for Al2O3/water and 62 %, 65 % and 26 % for Ag/water NFs, respectively. By increasing the Re number, the enhancing effect of velocity increment on heat transfer rate prevails and hinders that of employing NF. Also, in rotating mode, the enhancement made by increasing the Re number is higher in the rotation speed of 500 rather than 300 rpm. The overall change of efficiency ratio versus the Re number increment is decreasing and the greatest improving effect of using NF is for the lowest Re numbers. Also, the enhancement due to increasing the Re number increment is higher at a rotational speed of 500 rather than 300 rpm.
{"title":"Ag and Al2O3/water two-phase transient flow analysis in a double-pipe heat exchanger equipped with baffles and rotating inner tube","authors":"Mohammed Al-Saad , Ali B.M. Ali , Mohammed Al-Mosallam , Mohammad N. Fares , Mohammad Ali Fazilati , Soheil Salahshour , Rozbeh Sabetvand","doi":"10.1016/j.cscee.2025.101117","DOIUrl":"10.1016/j.cscee.2025.101117","url":null,"abstract":"<div><div>Considering the wide application of double-pipe heat exchanger made their performance improvement very important. Employing aqueous nanofluid (<em>NF</em>) of <em>Ag</em> and <em>Al</em><sub><em>2</em></sub><em>O</em><sub>3</sub> as the working fluid inside the inner tube of the heat exchanger and its rotation as the respective passive and active enhancing methods are investigated numerically using the two-phase mixture method. The sensitivity analysis was performed to reveal the effect of Reynolds (<em>Re</em>) number, <em>NF</em> concentration and tube rotational speeds on heat transfer coefficient, heat transfer effectiveness, and efficiency ratio. The <em>Re</em> number, <em>NF</em> concentration, and rotation speed lie in 1000-3000, 0–4 %, and 300–500 rpm, respectively. The results show the higher improving effect of Ag rather than Al<sub>2</sub>O<sub>3</sub> nanoparticle; for <em>Re</em> = 1000, 1500 and 2000 the efficiency ratio averaged between different concentrations are 39 %, 30 %, 20 % for Al<sub>2</sub>O<sub>3</sub>/water and 62 %, 65 % and 26 % for <em>Ag</em>/water <em>NF</em>s, respectively. By increasing the <em>Re</em> number, the enhancing effect of velocity increment on heat transfer rate prevails and hinders that of employing <em>NF</em>. Also, in rotating mode, the enhancement made by increasing the <em>Re</em> number is higher in the rotation speed of 500 rather than 300 rpm<strong>.</strong> The overall change of efficiency ratio versus the <em>Re</em> number increment is decreasing and the greatest improving effect of using <em>NF</em> is for the lowest <em>Re</em> numbers. Also, the enhancement due to increasing the <em>Re</em> number increment is higher at a rotational speed of 500 rather than 300 rpm.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101117"},"PeriodicalIF":0.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147414","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 : 2025-01-27DOI: 10.1016/j.cscee.2025.101115
Ahmed Shawqi Sadeq , Rassol Hamed Rasheed , Shaima Albazzaz , Mohammad N. Fares , Soheil Salahshour , Rozbeh Sabetvand
This research investigates the impact of varying external electric field amplitudes on the atomic and thermal properties of a paraffin/copper composite in a tube with non-interconnected rotating ribs, using molecular dynamics simulation as the primary analytical tool. To ensure model accuracy, a preliminary equilibration phase is conducted for 10 ns under controlled conditions. This stabilized the temperature at 300 K and established a consistent total energy of 1.450 kcal/mol. After equilibration, an analysis examined how varying external electric field amplitudes influenced the thermal properties of composite with 7 % copper concentration. The results indicate that as external electric field amplitudes increased from 0.01 to 0.05 V/m, various parameters of the simulated atomic sample show notable variations. Specifically, maximum density decreased from 0.0848 to 0.0836 atom/ų, while maximum velocity increased from 0.00496 to 0.00519 atom/Å. Additionally, maximum temperature increases from 770 to 789 K, and heat flux increases from 5.59 to 5.71 W/m2. Thermal conductivity increases from 0.72 to 0.78 W/m·K, and charging time decreases from 6.17 to 5.99 ns. When external electric field amplitude increases from 0.01 to 0.03 V/m, discharge time decreases from 7.16 to 7.05 ns; however, at 0.05 V/m, discharge time slightly increases to 7.09 ns. These findings have practical implications for optimizing materials in thermal management and energy storage systems by tailoring electric field conditions to enhance performance.
{"title":"Investigating the effect of electric field amplitude on the thermal behavior of paraffin/Cu nanostructure in a tube containing non-connected rotating ribs using molecular dynamics simulation","authors":"Ahmed Shawqi Sadeq , Rassol Hamed Rasheed , Shaima Albazzaz , Mohammad N. Fares , Soheil Salahshour , Rozbeh Sabetvand","doi":"10.1016/j.cscee.2025.101115","DOIUrl":"10.1016/j.cscee.2025.101115","url":null,"abstract":"<div><div>This research investigates the impact of varying external electric field amplitudes on the atomic and thermal properties of a paraffin/copper composite in a tube with non-interconnected rotating ribs, using molecular dynamics simulation as the primary analytical tool. To ensure model accuracy, a preliminary equilibration phase is conducted for 10 ns under controlled conditions. This stabilized the temperature at 300 K and established a consistent total energy of 1.450 kcal/mol. After equilibration, an analysis examined how varying external electric field amplitudes influenced the thermal properties of composite with 7 % copper concentration. The results indicate that as external electric field amplitudes increased from 0.01 to 0.05 V/m, various parameters of the simulated atomic sample show notable variations. Specifically, maximum density decreased from 0.0848 to 0.0836 atom/Å<sup>³</sup>, while maximum velocity increased from 0.00496 to 0.00519 atom/Å. Additionally, maximum temperature increases from 770 to 789 K, and heat flux increases from 5.59 to 5.71 W/m<sup>2</sup>. Thermal conductivity increases from 0.72 to 0.78 W/m·K, and charging time decreases from 6.17 to 5.99 ns. When external electric field amplitude increases from 0.01 to 0.03 V/m, discharge time decreases from 7.16 to 7.05 ns; however, at 0.05 V/m, discharge time slightly increases to 7.09 ns. These findings have practical implications for optimizing materials in thermal management and energy storage systems by tailoring electric field conditions to enhance performance.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101115"},"PeriodicalIF":0.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147794","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}
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