Pub Date : 2023-11-27DOI: 10.25073/2588-1094/vnuees.4996
Ngo Thi Tuong Chau, Nguyen Nhu Yen, Nguyen Thi Tu Le, P. Ly, L. Thien
Incorporation of probiotics with edible coatings to preserve and improve the shelf life of fresh fruits has gained more popularity in the food industry. This study aimed to isolate, select lactic acid bacteria (LAB) that are antagonistic to postharvest pathogenic fungi in grapes (Vitis vinifera L.), and determine the optimal conditions for their biomass production. Fungi were isolated from decaying grapes on Potato Dextrose Agar medium (PDA) supplemented with 1% Chloramphenicol at 25 ºC for five to seven days. LAB were isolated on MRS agar medium at 37 ºC for two to three days. Isolates with antifungal capability were selected using the overlay technique. LAB were cultured in MRS broth at pH 4-8, 25-40 ºC for two to five days. Effects of pH and temperature on the antifungal activity of cell-free supernatant (CFS) were investigated at respectively pHs of 4.5 to 6.5 and temperatures of 60, 80 and 100 ºC for 2 hours. We identified and selected the fungal strain Nn4 with high infection density (1.5×105 CFU/g) to be the grape postharvest pathogenic fungus of interest. For antagonistic bacteria, we selected the lactic acid bacterial strain Ln9 with the highest antifungal activity against strain Nn4 (37.9 mm in diameter). The suitable cultivation conditions for biomass production of strain Ln9 were at pH 5.0, 30 ºC for 2 days. The antifungal activity of CFS was drastically reduced when the medium pH was adjusted to 6.5 but not reduced after heat treatment. It is evidential that the antifungal properties of probiotics can be related to the production of organic acids.
{"title":"Isolation, Selection, and Cultivation of Antagonistic Lactic Acid Bacteria Against Postharvest Pathogenic Fungi in Grapes","authors":"Ngo Thi Tuong Chau, Nguyen Nhu Yen, Nguyen Thi Tu Le, P. Ly, L. Thien","doi":"10.25073/2588-1094/vnuees.4996","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4996","url":null,"abstract":"Incorporation of probiotics with edible coatings to preserve and improve the shelf life of fresh fruits has gained more popularity in the food industry. This study aimed to isolate, select lactic acid bacteria (LAB) that are antagonistic to postharvest pathogenic fungi in grapes (Vitis vinifera L.), and determine the optimal conditions for their biomass production. Fungi were isolated from decaying grapes on Potato Dextrose Agar medium (PDA) supplemented with 1% Chloramphenicol at 25 ºC for five to seven days. LAB were isolated on MRS agar medium at 37 ºC for two to three days. Isolates with antifungal capability were selected using the overlay technique. LAB were cultured in MRS broth at pH 4-8, 25-40 ºC for two to five days. Effects of pH and temperature on the antifungal activity of cell-free supernatant (CFS) were investigated at respectively pHs of 4.5 to 6.5 and temperatures of 60, 80 and 100 ºC for 2 hours. We identified and selected the fungal strain Nn4 with high infection density (1.5×105 CFU/g) to be the grape postharvest pathogenic fungus of interest. For antagonistic bacteria, we selected the lactic acid bacterial strain Ln9 with the highest antifungal activity against strain Nn4 (37.9 mm in diameter). The suitable cultivation conditions for biomass production of strain Ln9 were at pH 5.0, 30 ºC for 2 days. The antifungal activity of CFS was drastically reduced when the medium pH was adjusted to 6.5 but not reduced after heat treatment. It is evidential that the antifungal properties of probiotics can be related to the production of organic acids.","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139231535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-11DOI: 10.25073/2588-1094/vnuees.4961
Dao Nguyen Quynh Hoa
: With the aim of evaluating the cyclogenesis predictability of Sonca (2017) using an ensemble prediction system from the local ensemble transform Kalman filter (LETKF) to model WRF, the study proposed a dynamical assessment method with a Lagrangian approach that is stable and independent of time and reference systes. With this approach, the study can clearly distinguish between cases of tropical cyclone (TC) formation and non-formation in the ensemble forecast members. By evaluating the thermodynamic conditions of the low-level circulation between the forming and non-forming groups, the study found that the ocean-atmosphere interaction and the vortex merger process play imnportant roles in the formation of Sonca. The evaluation of the formation location showed that the detected vortex centers from the forming members tended to concentrate near the monsoon trough axis, indicating that this is a highly favorable region for vortex formation in the Vietnam East Sea.
{"title":"Assessing the Ensemble Assimilation System for Forecasting the Genesis of Tropical Cyclone Sonca (2017) in the Vietnam East Sea using a Lagrangian Approach","authors":"Dao Nguyen Quynh Hoa","doi":"10.25073/2588-1094/vnuees.4961","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4961","url":null,"abstract":": With the aim of evaluating the cyclogenesis predictability of Sonca (2017) using an ensemble prediction system from the local ensemble transform Kalman filter (LETKF) to model WRF, the study proposed a dynamical assessment method with a Lagrangian approach that is stable and independent of time and reference systes. With this approach, the study can clearly distinguish between cases of tropical cyclone (TC) formation and non-formation in the ensemble forecast members. By evaluating the thermodynamic conditions of the low-level circulation between the forming and non-forming groups, the study found that the ocean-atmosphere interaction and the vortex merger process play imnportant roles in the formation of Sonca. The evaluation of the formation location showed that the detected vortex centers from the forming members tended to concentrate near the monsoon trough axis, indicating that this is a highly favorable region for vortex formation in the Vietnam East Sea.
 
 
","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135984322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-11DOI: 10.25073/2588-1094/vnuees.4966
Phan Dang Minh, Hoang Quoc Anh, Tran Thi Lieu, Phan Dinh Quang, Nguyen Trong Nghia, Nguyen Thi Chuc, Nguyen Thi Anh Huong, Le Huu Tuyen, Nguyen Thi Quynh Hoa
Per- and polyfluoroalkyl substances (PFASs) are considered as persistent organic pollutants (POPs), which should be restricted or eliminated. In this study, concentrations of four perfluoroalkyl carboxylic acids (perfluorobutanoic acid PFBA, perfluorohexanoic acid PFHxA, perfluorooctanoic acid PFOA, perfluorodecanoic acid PFDA) and four perfluoroalkyl sulfonates (perfluorobutane sulfonate PFBS, perfluorohexane sulfonate PFHxS, perfluorooctane sulfonate PFOS, perfluorodecane sulfonate PFDS) were analyzed in food contact materials (FCM) collected from Hanoi, Vietnam. A total of 15 FCM samples was obtained including several categories such as instant drink/food boxes, bags, cups, wrappers, and tray. The FCM samples were untrasonic extracted with methanol, concentrated, and filtered before analysis by a liquid chromatography–tandem mass spectrometry (LC-MS/MS) system. Recoveries of native and surrogate standards ranged from 70% to 130% with RSD < 20% in replicated analysis. Method detection limits of PFASs ranged from 0.04 to 0.08 ng/g. Concentrations of S8PFASs ranged from not detected (ND) to 1.46 (average ± SD: 0.417 ± 0.479) ng/g. Detection frequencies of PFASs decreased in the order: PFDA (33%) > PFBA, PFOA, PFHxS, PFOS (27%) > PFDS (13%) > PFHxA (7%) > PFBS (0%). Average concentrations of individual compounds decreased in the order: PFOS > PFDA > PFHxS > PFOA > PFBA > PFHxA > PFDS > PFBS. Relatively low PFAS concentrations found in the FCM samples of this study indicated that these substances were mainly derived from unintentional sources rather than intentionally added to the materials.
{"title":"Presence of Perfluoroalkyl Carboxylic Acids and Sulfonates in Vietnamese Food Contact Materials","authors":"Phan Dang Minh, Hoang Quoc Anh, Tran Thi Lieu, Phan Dinh Quang, Nguyen Trong Nghia, Nguyen Thi Chuc, Nguyen Thi Anh Huong, Le Huu Tuyen, Nguyen Thi Quynh Hoa","doi":"10.25073/2588-1094/vnuees.4966","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4966","url":null,"abstract":"Per- and polyfluoroalkyl substances (PFASs) are considered as persistent organic pollutants (POPs), which should be restricted or eliminated. In this study, concentrations of four perfluoroalkyl carboxylic acids (perfluorobutanoic acid PFBA, perfluorohexanoic acid PFHxA, perfluorooctanoic acid PFOA, perfluorodecanoic acid PFDA) and four perfluoroalkyl sulfonates (perfluorobutane sulfonate PFBS, perfluorohexane sulfonate PFHxS, perfluorooctane sulfonate PFOS, perfluorodecane sulfonate PFDS) were analyzed in food contact materials (FCM) collected from Hanoi, Vietnam. A total of 15 FCM samples was obtained including several categories such as instant drink/food boxes, bags, cups, wrappers, and tray. The FCM samples were untrasonic extracted with methanol, concentrated, and filtered before analysis by a liquid chromatography–tandem mass spectrometry (LC-MS/MS) system. Recoveries of native and surrogate standards ranged from 70% to 130% with RSD < 20% in replicated analysis. Method detection limits of PFASs ranged from 0.04 to 0.08 ng/g. Concentrations of S8PFASs ranged from not detected (ND) to 1.46 (average ± SD: 0.417 ± 0.479) ng/g. Detection frequencies of PFASs decreased in the order: PFDA (33%) > PFBA, PFOA, PFHxS, PFOS (27%) > PFDS (13%) > PFHxA (7%) > PFBS (0%). Average concentrations of individual compounds decreased in the order: PFOS > PFDA > PFHxS > PFOA > PFBA > PFHxA > PFDS > PFBS. Relatively low PFAS concentrations found in the FCM samples of this study indicated that these substances were mainly derived from unintentional sources rather than intentionally added to the materials.
","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135981392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-07DOI: 10.25073/2588-1094/vnuees.4967
Vo Anh Thu, Dang Thi Thom, Duong Tuan Manh, Le Xuan Thanh Thao, Mai Huong, Phạm Thu Huyền, Hoang Anh Le, Do Van Manh
Microplastics are a growing concern in the environments and especially agricultural soil due to numerous negative impacts on the ecosystems and human health. This study aimed to investigate the properties of microplastics (including quantity, shape, size, and polymer types) in five samples (DA1-5) taken from agriculture soil in Dong Anh district, Hanoi using Nicolet iN10 MX Fourier transform infrared (µFTIR) microscope. The study found that the microplastic content in these soils ranging from 494 ± 292 items/kg dry weight to 1031 ± 379 items/kg dry weight. In terms of shape, microplastic fragments accounted for the majority of microplastics found in soil (65% - 86% of the total microplastics). Fifteen types of microplastic polymers were identified in the soil samples, with PET being the most common polymer of 38%, followed by urea-formaldehyde resin of 15%, and nylon of 13%. Microplastics with sizes ranging from 50-150 µm were the dominant group (39% - 57% of the total microplastics). This study provides an initial assessment of the presence of microplastics in the agricultural soil of the suburban area of Hanoi, highlighting the potential risk of contamination that may effect on environment and pose a threat to human health.
{"title":"Preliminary Investigation of Microplastic Pollution in Agricultural Soil in Dong Anh District, Hanoi City","authors":"Vo Anh Thu, Dang Thi Thom, Duong Tuan Manh, Le Xuan Thanh Thao, Mai Huong, Phạm Thu Huyền, Hoang Anh Le, Do Van Manh","doi":"10.25073/2588-1094/vnuees.4967","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4967","url":null,"abstract":"Microplastics are a growing concern in the environments and especially agricultural soil due to numerous negative impacts on the ecosystems and human health. This study aimed to investigate the properties of microplastics (including quantity, shape, size, and polymer types) in five samples (DA1-5) taken from agriculture soil in Dong Anh district, Hanoi using Nicolet iN10 MX Fourier transform infrared (µFTIR) microscope. The study found that the microplastic content in these soils ranging from 494 ± 292 items/kg dry weight to 1031 ± 379 items/kg dry weight. In terms of shape, microplastic fragments accounted for the majority of microplastics found in soil (65% - 86% of the total microplastics). Fifteen types of microplastic polymers were identified in the soil samples, with PET being the most common polymer of 38%, followed by urea-formaldehyde resin of 15%, and nylon of 13%. Microplastics with sizes ranging from 50-150 µm were the dominant group (39% - 57% of the total microplastics). This study provides an initial assessment of the presence of microplastics in the agricultural soil of the suburban area of Hanoi, highlighting the potential risk of contamination that may effect on environment and pose a threat to human health. \u0000 \u0000 \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114350887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-21DOI: 10.25073/2588-1094/vnuees.4952
Tran Le Chau, N. Phuong, N. T. Giang, Le Quyet Tam, Nguyen Tien Phu, Nguyen Dinh Than, Trinh Dinh Huan
This study investigated the geological properties of the uranium ore found in Pa Lua - Pa Rong area for potential industrial exploitation. A combination of field measurements, modeling and several mathematical approaches were employed to characterize the geological properties of the uranium ore. We found: i) The thickness of the ore bodies ranges from thin to medium, exhibiting varying degrees of instability (Vm = 83.8÷102.8%). The average U3O8 content indicates that the ore bodies belong to the poor ore type, with an unevenly distribution (Vc = 57.9÷100.9%); ii) The morphology and structure of the ore bodies are highly complex, exhibiting irregular variations. The thickness of the ore bodies shows a positive correlation with the uranium content in each body (R = 0.6-0.7); iii) The variograms of the U3O8 concentration and the thickness in various directions exhibit a spherical pattern, indicating an autogenous effect. The most significant variation in uranium content aligns with the dip direction (50°±12.5°), while the least variation aligns with the strike of the ore body (140°±12.5°). The variations in ore body thickness are more straightforward and consistent with those of the uranium content. In summary, these findings provide valuable insights into the characteristics of uranium ore in Pa Lua – Pa Rong area. The results contribute to a better understanding of the geological processes and can inform some effective exploration strategies for uranium resources in this region.
{"title":"Chemical Characteristics of Industrial Geological Parameters and Their Implications in Uranian Overview of Pa Lua - Pa Rong Area","authors":"Tran Le Chau, N. Phuong, N. T. Giang, Le Quyet Tam, Nguyen Tien Phu, Nguyen Dinh Than, Trinh Dinh Huan","doi":"10.25073/2588-1094/vnuees.4952","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4952","url":null,"abstract":"This study investigated the geological properties of the uranium ore found in Pa Lua - Pa Rong area for potential industrial exploitation. A combination of field measurements, modeling and several mathematical approaches were employed to characterize the geological properties of the uranium ore. We found: i) The thickness of the ore bodies ranges from thin to medium, exhibiting varying degrees of instability (Vm = 83.8÷102.8%). The average U3O8 content indicates that the ore bodies belong to the poor ore type, with an unevenly distribution (Vc = 57.9÷100.9%); ii) The morphology and structure of the ore bodies are highly complex, exhibiting irregular variations. The thickness of the ore bodies shows a positive correlation with the uranium content in each body (R = 0.6-0.7); iii) The variograms of the U3O8 concentration and the thickness in various directions exhibit a spherical pattern, indicating an autogenous effect. The most significant variation in uranium content aligns with the dip direction (50°±12.5°), while the least variation aligns with the strike of the ore body (140°±12.5°). The variations in ore body thickness are more straightforward and consistent with those of the uranium content. In summary, these findings provide valuable insights into the characteristics of uranium ore in Pa Lua – Pa Rong area. The results contribute to a better understanding of the geological processes and can inform some effective exploration strategies for uranium resources in this region. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123256529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study was carried out to verify and evaluate a method to quantify the relative Sudan I color product using ultra-high performance liquid chromatography coupled with tandem massspectrometry (UPLC/MS/MS). Sudan I was extracted through an Oasis HLB 3cc Vac Cartridge solid phase extraction column 60 mg, after that quantified by UPLC/MS/MS. The program uses a C18 column (2.1 x 100 mm, 1.7 µm), the mobile phase is acetonitrile and water containing 0.1% formic acid, the flow rate is 0.4 ml/min. Running conditions of MRM (Multiple Reaction Monitoring) mode, select molecular ion fragment 249 amu. The verification results have good linearity, the limit of detection (LOD) and the limit of quantification (LOQ) of the analytical procedure are 1.17 and 3.72 ng/g, respectively. The Sudan I recovery efficiency ranged from 82.00-107.33% with the relative standard deviation (RSD) between 4.35-9.04%. Highly sensitive sample extraction procedure is suitable for the determination of Sudan I in food based on 4 ionic fragments characteristics, meeting the requirements of the decision 2002/657/EC of the common European community. The verified analytical procedure was applied to quantitatively identify Sudan I in 21 chili samples. The results showed that Sudan I was not detected in all analyzed samples. The analytical procedure of Sudan I in this study could be used for food safety testing.
{"title":"Application of Uplc/Ms/Ms Method for Dertermination of Sudan I in Chili Sauces","authors":"Nguyen Kieu Hung, Truong Quang Hien, Tran Ngoc Hien, Nguyen Thi Thuy Linh, Nguyen Thi Ha","doi":"10.25073/2588-1094/vnuees.4963","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4963","url":null,"abstract":"This study was carried out to verify and evaluate a method to quantify the relative Sudan I color product using ultra-high performance liquid chromatography coupled with tandem massspectrometry (UPLC/MS/MS). Sudan I was extracted through an Oasis HLB 3cc Vac Cartridge solid phase extraction column 60 mg, after that quantified by UPLC/MS/MS. The program uses a C18 column (2.1 x 100 mm, 1.7 µm), the mobile phase is acetonitrile and water containing 0.1% formic acid, the flow rate is 0.4 ml/min. Running conditions of MRM (Multiple Reaction Monitoring) mode, select molecular ion fragment 249 amu. The verification results have good linearity, the limit of detection (LOD) and the limit of quantification (LOQ) of the analytical procedure are 1.17 and 3.72 ng/g, respectively. The Sudan I recovery efficiency ranged from 82.00-107.33% with the relative standard deviation (RSD) between 4.35-9.04%. Highly sensitive sample extraction procedure is suitable for the determination of Sudan I in food based on 4 ionic fragments characteristics, meeting the requirements of the decision 2002/657/EC of the common European community. The verified analytical procedure was applied to quantitatively identify Sudan I in 21 chili samples. The results showed that Sudan I was not detected in all analyzed samples. The analytical procedure of Sudan I in this study could be used for food safety testing. \u0000 \u0000 \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128549376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-16DOI: 10.25073/2588-1094/vnuees.4953
Do Van Dang, Tran Thi Chi Linh, L. T. Sơn
Methylene Blue (MB) is a common dye that has various applications in different fields, including medicine, biology, and environmental science. While it can be beneficial in certain contexts, it can also have negative effects on the environment under certain circumstances. In this study, the photodegradation of MB under visible light irradiation using a novel heterojunction CoWO4/g-C3N4 catalyst was investigated. A series of CoWO4/g-C3N4 composites were synthesized and characterized using various techniques, including XRD, SEM, SEM-EDS, FT-IR, and UV–DRS. The results revealed that the 0.3CoWO4/g-C3N4 composite showed the highest efficiency (93%) in degrading MB during the 80-minute photodegradation process, aligning with the pseudo-first-order kinetics. The results provide clear evidence that the formation of CoWO4/g-C3N4 heterojunction greatly enhances the efficiency of photocatalysis by facilitating the swift separation of electron-hole pairs and boosting the redox capability. Additionally, the photodegradation efficiency remained above 90% even after four cycles, suggesting the stability of the catalyst.
{"title":"Using a Novel Heterojunction CoWO4/g-C3N4 as Visible Light Photocatalyst for Photodegradation of Organic Pollutant","authors":"Do Van Dang, Tran Thi Chi Linh, L. T. Sơn","doi":"10.25073/2588-1094/vnuees.4953","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4953","url":null,"abstract":"Methylene Blue (MB) is a common dye that has various applications in different fields, including medicine, biology, and environmental science. While it can be beneficial in certain contexts, it can also have negative effects on the environment under certain circumstances. In this study, the photodegradation of MB under visible light irradiation using a novel heterojunction CoWO4/g-C3N4 catalyst was investigated. A series of CoWO4/g-C3N4 composites were synthesized and characterized using various techniques, including XRD, SEM, SEM-EDS, FT-IR, and UV–DRS. The results revealed that the 0.3CoWO4/g-C3N4 composite showed the highest efficiency (93%) in degrading MB during the 80-minute photodegradation process, aligning with the pseudo-first-order kinetics. The results provide clear evidence that the formation of CoWO4/g-C3N4 heterojunction greatly enhances the efficiency of photocatalysis by facilitating the swift separation of electron-hole pairs and boosting the redox capability. Additionally, the photodegradation efficiency remained above 90% even after four cycles, suggesting the stability of the catalyst. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133509034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-21DOI: 10.25073/2588-1094/vnuees.4957
Le Hoang Tu, Pham Thi Ha, Vo Ngoc Quynh Tram, Nguyen Thi Ngoc Thuy, Dang Nguyen Dong Phuong, Tran Thong Nhat, Nguyen Kim Loi
The role of environmental management is extremely important in human life because of its contribution to environmental protection and strategies. In modern society, nevertheless, facing the challenges in land, water, and air quality management in reality is unavoidable. Understanding the information on variability and features of environmental issues is necessary to support decision-makers in establishing environmental management planning. Spatial information and data should be considered as basic initial knowledge of environmental management. Among various technologies, Geographic Information Systems (GIS) is known as one of the most popular tools to store, analyze, and visualize data relating to geographically referenced information which can mitigate these challenges more effectively and accurately. The main purpose of this paper is to emphasize how GIS applications in environmental management, discuss the challenges of GIS technology in environmental management, and provide recommendations for future research directions. Many articles over the last decades were reviewed to highlight the application of GIS in environmental management. These results indicated GIS applications support land, water, air quality, and waste management. Moreover, it is a useful tool to monitor and assess environmental quality and in environmental planning and decision-making. For the limitation of GIS application, it is obvious that accuracy assessment and sensitivity analysis should be noticed and assessed although GIS application may strongly support decision-making in environmental management. Emerging GIS technologies and tendencies could help address these challenges. In future, GIS should be integrated along with new technologies and different decision-making algorithms in further steps for developing and supporting spatial decision-support systems more efficiently.
{"title":"GIS Application in Environmental Management: A Review","authors":"Le Hoang Tu, Pham Thi Ha, Vo Ngoc Quynh Tram, Nguyen Thi Ngoc Thuy, Dang Nguyen Dong Phuong, Tran Thong Nhat, Nguyen Kim Loi","doi":"10.25073/2588-1094/vnuees.4957","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4957","url":null,"abstract":"The role of environmental management is extremely important in human life because of its contribution to environmental protection and strategies. In modern society, nevertheless, facing the challenges in land, water, and air quality management in reality is unavoidable. Understanding the information on variability and features of environmental issues is necessary to support decision-makers in establishing environmental management planning. Spatial information and data should be considered as basic initial knowledge of environmental management. Among various technologies, Geographic Information Systems (GIS) is known as one of the most popular tools to store, analyze, and visualize data relating to geographically referenced information which can mitigate these challenges more effectively and accurately. The main purpose of this paper is to emphasize how GIS applications in environmental management, discuss the challenges of GIS technology in environmental management, and provide recommendations for future research directions. Many articles over the last decades were reviewed to highlight the application of GIS in environmental management. These results indicated GIS applications support land, water, air quality, and waste management. Moreover, it is a useful tool to monitor and assess environmental quality and in environmental planning and decision-making. For the limitation of GIS application, it is obvious that accuracy assessment and sensitivity analysis should be noticed and assessed although GIS application may strongly support decision-making in environmental management. Emerging GIS technologies and tendencies could help address these challenges. In future, GIS should be integrated along with new technologies and different decision-making algorithms in further steps for developing and supporting spatial decision-support systems more efficiently.","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134466093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-21DOI: 10.25073/2588-1094/vnuees.4956
Nguyen Duc Hanh, Nguyen Tien Giang, Dang Tran Duc Minh, Dao Ba Huy, Le Huu Minh Quan, Nguyen Thi Tinh
Observed discharge time series is essential data for hydrological analysis, streamflow forecasting, as well as water resources planning and management. Estimation of continuous discharge time series is generally based on the curves (or empirical models) that can properly simulate the relationships between water levels (stages) and concurrent water discharges observed at a particular hydrological station. For stations with complex hydraulic conditions, in addition to gauged stages at the discharge gauging section, another variable such as stage measured at an auxiliary station (to calculate the slope) or rate of change in stage is added to the estimation process. This paper presents the results of applying the first-kind Chebyshev polynomial approximation method in constructing rating curves for three hydrological stations in the Da river basin, each having different basin characteristics and various influencing factors. The analysis results using five evaluation indices (MAE, σ, Pbias, KGE, and MAPE) show that the Chebyshev polynomials are highly effective in modelling both simple and complex stage-discharge relationships. The Chebyshev polynomial approximation method is suggested to be used for establishing stage-discharge relationships in hydrometry.
{"title":"Modelling Stage-discharge Relationships for Hydrological Stations in the Da River Basin using First-kind Chebyshev Polynomial Approximation","authors":"Nguyen Duc Hanh, Nguyen Tien Giang, Dang Tran Duc Minh, Dao Ba Huy, Le Huu Minh Quan, Nguyen Thi Tinh","doi":"10.25073/2588-1094/vnuees.4956","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4956","url":null,"abstract":"Observed discharge time series is essential data for hydrological analysis, streamflow forecasting, as well as water resources planning and management. Estimation of continuous discharge time series is generally based on the curves (or empirical models) that can properly simulate the relationships between water levels (stages) and concurrent water discharges observed at a particular hydrological station. For stations with complex hydraulic conditions, in addition to gauged stages at the discharge gauging section, another variable such as stage measured at an auxiliary station (to calculate the slope) or rate of change in stage is added to the estimation process. This paper presents the results of applying the first-kind Chebyshev polynomial approximation method in constructing rating curves for three hydrological stations in the Da river basin, each having different basin characteristics and various influencing factors. The analysis results using five evaluation indices (MAE, σ, Pbias, KGE, and MAPE) show that the Chebyshev polynomials are highly effective in modelling both simple and complex stage-discharge relationships. The Chebyshev polynomial approximation method is suggested to be used for establishing stage-discharge relationships in hydrometry. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115837701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-21DOI: 10.25073/2588-1094/vnuees.4903
Nguyen Thi Thanh Binh, Ha Tran Quang Nghiem
The presence of metals in soil may impact the environment, as well as agricultural products. Biochar can alter some physical and chemical properties of the soil, reducing the concentrations of exchangeable metals in the soil. The aim of this study was to examine the effects of biochar on the exchangeable metal concentration in two paddy soils that have different organic carbon (OC) contents. A pot experiment was conducted in a greenhouse using two soils with high (3.05%) and low (0.54%) OC content mixed with biochar at rates of 0, 1.5, 3, 6, and 12%, and planted with rice in two consecutive seasons. At the end of each season, 30 soil samples (2 soil types x 5 biochar rates x 3 replicates) were collected to determine the exchangeable concentration of Al, Fe, Mn, Cd, Ni, Pb, and Zn, as well as pH. The metal quality index was calculated using principal component/factor analysis. The results showed that biochar increased the pH value after the first rice crop but did not improve after the second rice season. Biochar reduced the exchangeable concentration of some metals, including Al, Fe, Ni, Cd, Pb, and Zn. Compared to the no-biochar treatment, biochar application increased the soil metal quality index from 4.1 to 12.8% after the first crop and from 9.6 to 188.7% after the second rice crop, depending on soil properties and used biochar rate. This effect could be related to the increased pH in biochar-added soil and biochar's adsorption capacity. In conclusion, biochar has promising prospects for reducing exchangeable metal content in arable soils, thus exhibiting the potential to be used in paddy fields to remediate metal-contaminated soils.
{"title":"The Effects of Biochar on Exchangeable Metal Concentration in Paddy Soils","authors":"Nguyen Thi Thanh Binh, Ha Tran Quang Nghiem","doi":"10.25073/2588-1094/vnuees.4903","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4903","url":null,"abstract":"The presence of metals in soil may impact the environment, as well as agricultural products. Biochar can alter some physical and chemical properties of the soil, reducing the concentrations of exchangeable metals in the soil. The aim of this study was to examine the effects of biochar on the exchangeable metal concentration in two paddy soils that have different organic carbon (OC) contents. A pot experiment was conducted in a greenhouse using two soils with high (3.05%) and low (0.54%) OC content mixed with biochar at rates of 0, 1.5, 3, 6, and 12%, and planted with rice in two consecutive seasons. At the end of each season, 30 soil samples (2 soil types x 5 biochar rates x 3 replicates) were collected to determine the exchangeable concentration of Al, Fe, Mn, Cd, Ni, Pb, and Zn, as well as pH. The metal quality index was calculated using principal component/factor analysis. The results showed that biochar increased the pH value after the first rice crop but did not improve after the second rice season. Biochar reduced the exchangeable concentration of some metals, including Al, Fe, Ni, Cd, Pb, and Zn. Compared to the no-biochar treatment, biochar application increased the soil metal quality index from 4.1 to 12.8% after the first crop and from 9.6 to 188.7% after the second rice crop, depending on soil properties and used biochar rate. This effect could be related to the increased pH in biochar-added soil and biochar's adsorption capacity. In conclusion, biochar has promising prospects for reducing exchangeable metal content in arable soils, thus exhibiting the potential to be used in paddy fields to remediate metal-contaminated soils. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130800406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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