Pub Date : 2024-03-15DOI: 10.51316/jst.172.etsd.2024.34.1.7
Nguyễn Thị, Kim Chi, Nguyễn Văn, Nhàn, Van Ha
The study objective is to provide an initial scientific basis for calculating CO2 equivalent (CO2e) emission reduction from the three technical models such as rice-straw composting, rice-straw fermented for cattle feed, and straw mushroom production, which are rice-straw utilization alternatives instead of open burning them in Chau Thanh district. The study calculation is based on the surveyed practical database, the theoretical emission factors (EF), and the implementation of EasyPol-Ex software version 5 (Ex-Act) to estimate the amount of CO2e emissions when switching. The results show that in 2022, Chau Thanh could avoid 330,236 tons of CO2 emissions by burning 171,637 tons of rice straw. The estimated amount of CO2 emitted from harvesting and rolling rice straw by machine was 4.375 g CO2e per kilogram of rice straw. The EF for transportation of rice straw to model implementation places was 740 gCO2e/kg. The additional EFs for mushroom, composting, and animal feed production models were 222g, 172g and 60g CO2e/kg, respectively. Results indicate that although the EF of rice straw collection and transportation was still high, the total CO2e from three models (including transportation) was still lower than the EF from straw burning. In addition, farmers who own the paddy field earned an extra 500,000 VND/ha per crop, and farmers earned an extra about 1.7 to 2.3 million VND per crop, depending on the model applied. The successful implementation of technical models promoted the concept of circular economy applied to rice production industries.
{"title":"Assessment Environmental and Social Impacts for the Rice Straw Utilization Technical Models to Promote Circular Economy for Rice Production in Chau Thanh District - An Giang Province","authors":"Nguyễn Thị, Kim Chi, Nguyễn Văn, Nhàn, Van Ha","doi":"10.51316/jst.172.etsd.2024.34.1.7","DOIUrl":"https://doi.org/10.51316/jst.172.etsd.2024.34.1.7","url":null,"abstract":"The study objective is to provide an initial scientific basis for calculating CO2 equivalent (CO2e) emission reduction from the three technical models such as rice-straw composting, rice-straw fermented for cattle feed, and straw mushroom production, which are rice-straw utilization alternatives instead of open burning them in Chau Thanh district. The study calculation is based on the surveyed practical database, the theoretical emission factors (EF), and the implementation of EasyPol-Ex software version 5 (Ex-Act) to estimate the amount of CO2e emissions when switching. The results show that in 2022, Chau Thanh could avoid 330,236 tons of CO2 emissions by burning 171,637 tons of rice straw. The estimated amount of CO2 emitted from harvesting and rolling rice straw by machine was 4.375 g CO2e per kilogram of rice straw. The EF for transportation of rice straw to model implementation places was 740 gCO2e/kg. The additional EFs for mushroom, composting, and animal feed production models were 222g, 172g and 60g CO2e/kg, respectively. Results indicate that although the EF of rice straw collection and transportation was still high, the total CO2e from three models (including transportation) was still lower than the EF from straw burning. In addition, farmers who own the paddy field earned an extra 500,000 VND/ha per crop, and farmers earned an extra about 1.7 to 2.3 million VND per crop, depending on the model applied. The successful implementation of technical models promoted the concept of circular economy applied to rice production industries.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":" 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140391703","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 : 2024-03-15DOI: 10.51316/jst.172.etsd.2024.34.1.3
Nguyễn Thị, Quynh, Ngoc, Le Quang Dien, N. Thu, Tran Thi Ha, Thuy, Nguyen Ngoc, Mai
Natural rubber (NR) is a polymer that has many applications in daily life. However, the traditional rubber industry relies heavily on petroleum-based materials, causing environmental pollution problems. Therefore, to reduce environmental challenges, products created from NR are combined with non-toxic chemicals and natural fillers such as cellulose nanofibers (CNF). This study presents the effect of CNF on the thermal properties of novel composites made from CNF and deproteinized natural rubber grafted methyl methacrylate (DPNR-g-MMA) under air and nitrogen atmosphere. Graft copolymerization of MMA onto DPNR to produce DPNR-g-PMMA was performed in the latex phase. The CNF/DPNR-g-PMMA composite was created by dispersing CNF in DPNR-g-PMMA at ratios of 0.5%, 1%, and 1.5% using ultrasonic waves. DPNR-g-PMMA was employed as the composite's matrix and CNF served as its reinforcing phase. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectroscopy (1H NMR) were used to confirm the success of the graft copolymerization. The thermal properties of materials were studied by Thermalgravimetric analysis (TGA) and Differential scanning calorimetry (DSC), in which the thermal stability of composites was examined via TGA under air and nitrogen atmosphere. The obtained data illustrate that, in comparison to DPNR and DPNR-g-PMMA, the decomposition temperature of all CNF/DPNR-g-PMMA composites, especially at CNF ratio of 1%. After blending CNF to DPNR-g-PMMA, the decomposition temperatures of CNF/DPNR-g-PMMA 1% increased by nearly 2 °C in nitrogen atmosphere and by 5.27 °C in air atmosphere. These results prove that the CNF is a key role in the thermal stability of DPNR-g-PMMA.
{"title":"Investigation of Thermal Decomposition and Thermal Oxidative Degradation of a Composite of Cellulose Nanofibers and Deproteinized Natural Rubber Grafted Methyl Methacrylate","authors":"Nguyễn Thị, Quynh, Ngoc, Le Quang Dien, N. Thu, Tran Thi Ha, Thuy, Nguyen Ngoc, Mai","doi":"10.51316/jst.172.etsd.2024.34.1.3","DOIUrl":"https://doi.org/10.51316/jst.172.etsd.2024.34.1.3","url":null,"abstract":"Natural rubber (NR) is a polymer that has many applications in daily life. However, the traditional rubber industry relies heavily on petroleum-based materials, causing environmental pollution problems. Therefore, to reduce environmental challenges, products created from NR are combined with non-toxic chemicals and natural fillers such as cellulose nanofibers (CNF). This study presents the effect of CNF on the thermal properties of novel composites made from CNF and deproteinized natural rubber grafted methyl methacrylate (DPNR-g-MMA) under air and nitrogen atmosphere. Graft copolymerization of MMA onto DPNR to produce DPNR-g-PMMA was performed in the latex phase. The CNF/DPNR-g-PMMA composite was created by dispersing CNF in DPNR-g-PMMA at ratios of 0.5%, 1%, and 1.5% using ultrasonic waves. DPNR-g-PMMA was employed as the composite's matrix and CNF served as its reinforcing phase. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectroscopy (1H NMR) were used to confirm the success of the graft copolymerization. The thermal properties of materials were studied by Thermalgravimetric analysis (TGA) and Differential scanning calorimetry (DSC), in which the thermal stability of composites was examined via TGA under air and nitrogen atmosphere. The obtained data illustrate that, in comparison to DPNR and DPNR-g-PMMA, the decomposition temperature of all CNF/DPNR-g-PMMA composites, especially at CNF ratio of 1%. After blending CNF to DPNR-g-PMMA, the decomposition temperatures of CNF/DPNR-g-PMMA 1% increased by nearly 2 °C in nitrogen atmosphere and by 5.27 °C in air atmosphere. These results prove that the CNF is a key role in the thermal stability of DPNR-g-PMMA.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":" 121","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140392235","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 : 2024-03-15DOI: 10.51316/jst.172.etsd.2024.34.1.1
Hoang Lan, Kim Anh Nghiem, Tuan Anh To, Pham
Chitin, a natural polysaccharide, is the second most abundant biopolymer in the world after cellulose. It consists of N-acetylglucosamine (NAG) monomers and finds widespread applications in the food, cosmetics, and pharmaceutical industries. In this study, we selected pigmented yeast strains to synthesize carotenoids from NAG and optimized the conditions for carotenoid production. The results demonstrated that the selected strain Sporidiobolus pararoseus Q could accumulate β-carotene and carotenoids, reaching 518.84 µg/g dry biomass and 595.48 µg/g dry biomass, respectively, after 96 hours of fermentation with 30 g/L NAG at pH 5. The two-step fermentation first with 80 g/L of glucose and then 50 g/L of NAG increased the carotenoids and b-carotene yields by 41% and 35%, achieving 786.69 µg/g and 632.19 µg/g, respectively. The ability to use NAG as the feedstock for carotenoid production not only adds value to shrimp by-products but also contributes to controlling environmental pollution.
甲壳素是一种天然多糖，是世界上含量仅次于纤维素的生物聚合物。它由 N-乙酰葡糖胺（NAG）单体组成，在食品、化妆品和制药行业中应用广泛。在本研究中，我们选择了色素酵母菌株从 NAG 中合成类胡萝卜素，并优化了类胡萝卜素的生产条件。结果表明，所选菌株 Sporidiobolus pararoseus Q 能积累β-胡萝卜素和类胡萝卜素，在 pH 值为 5、30 g/L 的 NAG 发酵 96 小时后，β-胡萝卜素和类胡萝卜素含量分别达到 518.84 µg/g 干生物量和 595.48 µg/g 干生物量。先用 80 克/升葡萄糖，再用 50 克/升 NAG 进行两步发酵，类胡萝卜素和 b-胡萝卜素的产量分别提高了 41% 和 35%，达到 786.69 微克/克和 632.19 微克/克。使用 NAG 作为类胡萝卜素生产的原料，不仅能增加对虾副产品的价值，还有助于控制环境污染。
{"title":"Bioconversion of Shrimp By-Product into Carotenoids Using Pigmented Yeast Sporidiobolus Pararoseus Q","authors":"Hoang Lan, Kim Anh Nghiem, Tuan Anh To, Pham","doi":"10.51316/jst.172.etsd.2024.34.1.1","DOIUrl":"https://doi.org/10.51316/jst.172.etsd.2024.34.1.1","url":null,"abstract":"Chitin, a natural polysaccharide, is the second most abundant biopolymer in the world after cellulose. It consists of N-acetylglucosamine (NAG) monomers and finds widespread applications in the food, cosmetics, and pharmaceutical industries. In this study, we selected pigmented yeast strains to synthesize carotenoids from NAG and optimized the conditions for carotenoid production. The results demonstrated that the selected strain Sporidiobolus pararoseus Q could accumulate β-carotene and carotenoids, reaching 518.84 µg/g dry biomass and 595.48 µg/g dry biomass, respectively, after 96 hours of fermentation with 30 g/L NAG at pH 5. The two-step fermentation first with 80 g/L of glucose and then 50 g/L of NAG increased the carotenoids and b-carotene yields by 41% and 35%, achieving 786.69 µg/g and 632.19 µg/g, respectively. The ability to use NAG as the feedstock for carotenoid production not only adds value to shrimp by-products but also contributes to controlling environmental pollution.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":" 78","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140391778","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 : 2024-03-15DOI: 10.51316/jst.172.etsd.2024.34.1.6
Diep Thi My, Hanh, Jacques Gurgand, Pham Bach Viet, Nguyen Khac Dieu, Marc Pignal, R. V. Lebbe
The Phu An bamboo village, created in 1999, maintains over 200 taxa of living bamboo, collected in Viet Nam, Laos and Cambodia, and was awarded the UNDP Equatorial Prize in 2010. This ex situ conservation not only provides data for basic research and preserves biodiversity resources, but also contributes to actions on CO2 to reduce the greenhouse effect in climate change and create sustainable livelihoods for the community. From the Phu An Bamboo village, the "Bamboo Route" has been built since 2016 from the north to the south of Viet Nam, with the aim of multiplying bamboo in situ conservation sites, associated with research programs and public awareness actions on the importance and environmental benefits of bamboos. Along the bamboo route, an ex situ conservation site has been developed at Dong Thap with plants of 67 different vernacular species, another at Phan Rang, in the arid region, with 62 species, and a third at Dak Nong, where the climate is more favourable, with 12 different vernacular species from the in situ conservation site at Chieng Ban, Son La, where 19 vernacular species have been recorded. Thanks to its fast-growing characteristics and large biomass production, bamboo plays an important role in carbon sequestration. Research to mesure CO2 absorption was done in three different habitats on three different bamboo species. The CO2 absorption capacity of Bambusa blumeana Schultes in Gao Giong, Dong Thap province, indicates an important role of this thorny bamboo under climate change conditions. On the " Route of Bamboo", we studied also the surface area of bare soil from north to south, except in the Mekong Delta, we can plant more than 200,000 ha of thorny bamboo to complete the existing surface area of 1.5 million ha which could contribute 30% of Viet Nam’s CO2 absorption. This enables us to estimate how planting 50% of these areas could contribute to Viet Nam’s Net 0 2050 target.
{"title":"Creation of the Route of Bamboo, a Contribution to Net Zero by 2050 in Vietnam","authors":"Diep Thi My, Hanh, Jacques Gurgand, Pham Bach Viet, Nguyen Khac Dieu, Marc Pignal, R. V. Lebbe","doi":"10.51316/jst.172.etsd.2024.34.1.6","DOIUrl":"https://doi.org/10.51316/jst.172.etsd.2024.34.1.6","url":null,"abstract":"The Phu An bamboo village, created in 1999, maintains over 200 taxa of living bamboo, collected in Viet Nam, Laos and Cambodia, and was awarded the UNDP Equatorial Prize in 2010. This ex situ conservation not only provides data for basic research and preserves biodiversity resources, but also contributes to actions on CO2 to reduce the greenhouse effect in climate change and create sustainable livelihoods for the community. From the Phu An Bamboo village, the \"Bamboo Route\" has been built since 2016 from the north to the south of Viet Nam, with the aim of multiplying bamboo in situ conservation sites, associated with research programs and public awareness actions on the importance and environmental benefits of bamboos. Along the bamboo route, an ex situ conservation site has been developed at Dong Thap with plants of 67 different vernacular species, another at Phan Rang, in the arid region, with 62 species, and a third at Dak Nong, where the climate is more favourable, with 12 different vernacular species from the in situ conservation site at Chieng Ban, Son La, where 19 vernacular species have been recorded. Thanks to its fast-growing characteristics and large biomass production, bamboo plays an important role in carbon sequestration. Research to mesure CO2 absorption was done in three different habitats on three different bamboo species. The CO2 absorption capacity of Bambusa blumeana Schultes in Gao Giong, Dong Thap province, indicates an important role of this thorny bamboo under climate change conditions. On the \" Route of Bamboo\", we studied also the surface area of bare soil from north to south, except in the Mekong Delta, we can plant more than 200,000 ha of thorny bamboo to complete the existing surface area of 1.5 million ha which could contribute 30% of Viet Nam’s CO2 absorption. This enables us to estimate how planting 50% of these areas could contribute to Viet Nam’s Net 0 2050 target.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":" 26","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140391658","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}
"In this study, silica from waste materials - rice husk (silica TT) and byproduct of quartz stone grinding (silica TA) - modified with bis (3-ethoxy propylsilane) tetrasulphide (TESPT) were characterized. Their particle sizes are mostly under 30 μm, quite suitable for plastic filling. Some factors influencing the properties of injectional compounds based on HDPE/LDPE blend and silica from waste materials were carried out. It was found that the processing conditions which including maximum temperature of 190-200 oC and screw speed of 50-100 rpm are suitable for stable compound properties. Processing aid additives ratios such as stearic acid/zinc stearate and PE wax/paraffinic oil affect mostly compound melt flow index, but HDPE/LDPE ratio strongly affects both melt flow index and mechanical properties of compounds: change HDPE/LDPE ratio from 90/10 to 60/40 decrease tensile from 15.2 MPa to 12.5 MPa, bending strength from 15.5 MPa to10.6 MPa while melt flow index decrease almost twice but elongation at break increase from 34.4% to 72.2%. Also, using PE-g-MA as a compatibilizer may remarkably enhance the mechanical properties of compounds: the PE-g-MA content of 0.8-1.0 (%wt) increases tensile, bending strength, and impact resistance of compound by about 10-30% in comparison with the compound without PE-g-MA. "
{"title":"Study on Influencing Factors on Properties of Injectional Compounds Based on Polyethylene and Silica from Waste Materials","authors":"Nguyen Pham, Duy Linh, Nguyen Huy, Tung, Bui Chuong","doi":"10.51316/jst.172.etsd.2024.34.1.4","DOIUrl":"https://doi.org/10.51316/jst.172.etsd.2024.34.1.4","url":null,"abstract":"\"In this study, silica from waste materials - rice husk (silica TT) and byproduct of quartz stone grinding (silica TA) - modified with bis (3-ethoxy propylsilane) tetrasulphide (TESPT) were characterized. Their particle sizes are mostly under 30 μm, quite suitable for plastic filling. Some factors influencing the properties of injectional compounds based on HDPE/LDPE blend and silica from waste materials were carried out. It was found that the processing conditions which including maximum temperature of 190-200 oC and screw speed of 50-100 rpm are suitable for stable compound properties. Processing aid additives ratios such as stearic acid/zinc stearate and PE wax/paraffinic oil affect mostly compound melt flow index, but HDPE/LDPE ratio strongly affects both melt flow index and mechanical properties of compounds: change HDPE/LDPE ratio from 90/10 to 60/40 decrease tensile from 15.2 MPa to 12.5 MPa, bending strength from 15.5 MPa to10.6 MPa while melt flow index decrease almost twice but elongation at break increase from 34.4% to 72.2%. Also, using PE-g-MA as a compatibilizer may remarkably enhance the mechanical properties of compounds: the PE-g-MA content of 0.8-1.0 (%wt) increases tensile, bending strength, and impact resistance of compound by about 10-30% in comparison with the compound without PE-g-MA. \"","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":" 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140391832","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 : 2024-03-15DOI: 10.51316/jst.172.etsd.2024.34.1.2
L. Thinh, Dang Xuan, Hien, T. Nhan
Pangasius farming is a process of putting a large amount of material into the pond but then only harvesting a small amount of the farmed fish and discharging the rest as waste into the aquatic environment. This practice pollutes water sources and degrades the water environment in nearby rivers and canals. To address this issue, it is necessary to establish a mathematical model that can simulate the nutrient transformation processes in the pond. This study aims to set up a mathematical model to simulate the variation in the compositions of major nutrients in Pangasius ponds, determine the key parameters affecting the model, optimize the culture regime, enhance fish quality, and minimize environmental impact. The results have shown that the model’s output data after calibration is relatively close to reality and the key parameters of the model were defined.
{"title":"Identifying the Key Parameters in Mathematical Model to Simulate the Main Nutrients Transformation Process in Vietnamese Catfish (Pangasianodon Hypophthalmus) Ponds","authors":"L. Thinh, Dang Xuan, Hien, T. Nhan","doi":"10.51316/jst.172.etsd.2024.34.1.2","DOIUrl":"https://doi.org/10.51316/jst.172.etsd.2024.34.1.2","url":null,"abstract":"Pangasius farming is a process of putting a large amount of material into the pond but then only harvesting a small amount of the farmed fish and discharging the rest as waste into the aquatic environment. This practice pollutes water sources and degrades the water environment in nearby rivers and canals. To address this issue, it is necessary to establish a mathematical model that can simulate the nutrient transformation processes in the pond. This study aims to set up a mathematical model to simulate the variation in the compositions of major nutrients in Pangasius ponds, determine the key parameters affecting the model, optimize the culture regime, enhance fish quality, and minimize environmental impact. The results have shown that the model’s output data after calibration is relatively close to reality and the key parameters of the model were defined.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":" 42","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140391988","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 : 2023-11-15DOI: 10.51316/jst.170.etsd.2023.33.5.4
The study investigated the performance of a novel biochar derived from coffee husks (BCFH) and its alkaline-activated product (BCFH-NaOH) for ammonium removal in the aqueous solution. Several batch experiments were conducted with the synthetic solution to determine the adsorption properties of the biochars. At the initial ammonium concentration of 50 mg/L, the optimal dosage for both materials was 10 g/L, while the ideal pH range was 4-9. The equilibration adsorption time on both materials is within 30 minutes, indicating their high practical applicability. Both the pseudo-first order and pseudo-second order kinetic were applied successfully to describe the adsorption kinetics (R2 >0.95). The isotherms can be defined by both Langmuir and Freundlich models, showing that ammonium removal by biochars is a complex process. BCFH-NaOH showed better performance, with the maximum adsorption capacity reaching 9.97 mg-NH4/g, compared to 6.64 mg-NH4/g of BFCH. Finally, BCFH-NaOH was tested with a practical groundwater sample (Co = 11.5 mg-NH4/L), achieving a sorption efficiency of up to 80 % while eliminating most of the hardness. These results show that the modified coffee husk biochar could be applied as a low-cost, environmentally friendly adsorbent for ammonium removal.
{"title":"Utilizing Coffee Husk Biochar as an Effective Adsorbent for Ammonium Removal in Groundwater","authors":"","doi":"10.51316/jst.170.etsd.2023.33.5.4","DOIUrl":"https://doi.org/10.51316/jst.170.etsd.2023.33.5.4","url":null,"abstract":"The study investigated the performance of a novel biochar derived from coffee husks (BCFH) and its alkaline-activated product (BCFH-NaOH) for ammonium removal in the aqueous solution. Several batch experiments were conducted with the synthetic solution to determine the adsorption properties of the biochars. At the initial ammonium concentration of 50 mg/L, the optimal dosage for both materials was 10 g/L, while the ideal pH range was 4-9. The equilibration adsorption time on both materials is within 30 minutes, indicating their high practical applicability. Both the pseudo-first order and pseudo-second order kinetic were applied successfully to describe the adsorption kinetics (R2 >0.95). The isotherms can be defined by both Langmuir and Freundlich models, showing that ammonium removal by biochars is a complex process. BCFH-NaOH showed better performance, with the maximum adsorption capacity reaching 9.97 mg-NH4/g, compared to 6.64 mg-NH4/g of BFCH. Finally, BCFH-NaOH was tested with a practical groundwater sample (Co = 11.5 mg-NH4/L), achieving a sorption efficiency of up to 80 % while eliminating most of the hardness. These results show that the modified coffee husk biochar could be applied as a low-cost, environmentally friendly adsorbent for ammonium removal.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":"6 19","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136228651","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 : 2023-11-15DOI: 10.51316/jst.170.etsd.2023.33.5.9
The study is a continuation of our previous research on the impact of business organization factors on circular economy (CE) practices towards the development of a decision support tool to facilitate the adoption, implementation, development and strategy of CE activities in the Vietnamese industry. The tool helps to quickly assess the status of CE practice in the enterprises and makes a structural chart according to the CE maturity models. Having a positive direction in the management organization and application of CE theory, the electronics companies are illustrated as a case study for the application of the tool. As the results, one organization form (namely, the System) aligning with three business models (namely, Resource Models, Design Models, Lifetime Extention Models) and five supporting processes (namely, Digitization and Datafication, Return Logistics, Competences, Technical Infrastruture, Setting Up Processes, Quality Monitoring) are proposed for visualization of strategic interventions and recommendations for the electronics industry on business sustainability, competitiveness, alignment between their business objectives, priorities, and key performance indicators towards CE practice.
{"title":"Study on Decision Support Tool Towards Circular Economy Practice – A Case Study for Electronics Companies","authors":"","doi":"10.51316/jst.170.etsd.2023.33.5.9","DOIUrl":"https://doi.org/10.51316/jst.170.etsd.2023.33.5.9","url":null,"abstract":"The study is a continuation of our previous research on the impact of business organization factors on circular economy (CE) practices towards the development of a decision support tool to facilitate the adoption, implementation, development and strategy of CE activities in the Vietnamese industry. The tool helps to quickly assess the status of CE practice in the enterprises and makes a structural chart according to the CE maturity models. Having a positive direction in the management organization and application of CE theory, the electronics companies are illustrated as a case study for the application of the tool. As the results, one organization form (namely, the System) aligning with three business models (namely, Resource Models, Design Models, Lifetime Extention Models) and five supporting processes (namely, Digitization and Datafication, Return Logistics, Competences, Technical Infrastruture, Setting Up Processes, Quality Monitoring) are proposed for visualization of strategic interventions and recommendations for the electronics industry on business sustainability, competitiveness, alignment between their business objectives, priorities, and key performance indicators towards CE practice.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136228649","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 : 2023-11-15DOI: 10.51316/jst.170.etsd.2023.33.5.6
Microplastics (MPs) has been recently attracted the attention of many researches due to their existence for a long time in the environment. MPs are considered as an alarming pollution issue such as their occurence in water, sediment, and organism. In this research, the characteristics of MPs such as their concentration, size, shape and composition of the polymers in the shoreline sediments at the two layers (0- 5 cm and 5 -10 cm) collected from seven beaches on Danang city were investigated by the Fourier-transform infrared (µ-FTIR) method. Consequently, the average concentration of MPs was found at 5565 ± 2359 items 〖kg〗^(-1)dry weight (d.w.) in two layers. The upper layer of beach sediment (0-5 cm) has the majority of MPs with average abundance of 7679 ± 3363 items 〖kg〗^(-1)d.w. MPs had a wide range of sizes from 22.4 μm to 2797.2 μm with an average of 93.4 ± 18.8 μm in sampling sites. In addition, the range size from 20 to 150 μm was the most dominance in both layers.The morphology of MPs was found in the sediment with the most diversity of fragment. The variation of the polymer types of the MPs in two sampling layers was determined. Polyamide (PA) was the main polymer type found in both sediment layers while polyether sulfone (PES) was observed only at 4/7 sampling beaches.These results showed the diversity of the MPs in the two sediment layers of the seven beaches in Danang city and it is necessary to study on MPs pollution in sediment on beaches of Vietnam in future.
{"title":"Characteristics of Microplastics in Sediment at Danang Beaches - Vietnam","authors":"","doi":"10.51316/jst.170.etsd.2023.33.5.6","DOIUrl":"https://doi.org/10.51316/jst.170.etsd.2023.33.5.6","url":null,"abstract":"Microplastics (MPs) has been recently attracted the attention of many researches due to their existence for a long time in the environment. MPs are considered as an alarming pollution issue such as their occurence in water, sediment, and organism. In this research, the characteristics of MPs such as their concentration, size, shape and composition of the polymers in the shoreline sediments at the two layers (0- 5 cm and 5 -10 cm) collected from seven beaches on Danang city were investigated by the Fourier-transform infrared (µ-FTIR) method. Consequently, the average concentration of MPs was found at 5565 ± 2359 items 〖kg〗^(-1)dry weight (d.w.) in two layers. The upper layer of beach sediment (0-5 cm) has the majority of MPs with average abundance of 7679 ± 3363 items 〖kg〗^(-1)d.w. MPs had a wide range of sizes from 22.4 μm to 2797.2 μm with an average of 93.4 ± 18.8 μm in sampling sites. In addition, the range size from 20 to 150 μm was the most dominance in both layers.The morphology of MPs was found in the sediment with the most diversity of fragment. The variation of the polymer types of the MPs in two sampling layers was determined. Polyamide (PA) was the main polymer type found in both sediment layers while polyether sulfone (PES) was observed only at 4/7 sampling beaches.These results showed the diversity of the MPs in the two sediment layers of the seven beaches in Danang city and it is necessary to study on MPs pollution in sediment on beaches of Vietnam in future.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":"6 16","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136228654","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 : 2023-11-15DOI: 10.51316/jst.170.etsd.2023.33.5.5
"In the study, the free chlorine residual and microbiological parameters in supply water of centralized supply water companies were assessed with a total of 1,612 samples in the period of 2020 and 2022. The results showed that 334 samples did not meet the permitted limit QCVN 01-1:2018/BYT for free chlorine residual (0.2-1.0 mg/L), of which, about 80% of sample have concentration less than the lower limit. The reason is due to the inaccurately used chloramine dose, mainly quantified without adjusting for actual output quality and distribution system. Some companies even periodically disinfect water 1-3 times/week. In many cases, the water samples at the companies’ storage tanks have high free chlorine residual, about 2 times greater than upper limit (>2.0 mg/L). Regarding microbiological parameters, for total coliforms about 40-50% surveyed provinces have water samples that were non-compliance with the acceptable quality standard for QCVN 01-1:2018/BYT with total of 102, 57 and 105 samples. For those water samples, free chlorine residual found also lower than required limit (<0.06 mg/L). Apart from total coliforms and E. coli, Pseudomonas aeruginosa (Ps. aeruginosa) was also detected in water samples in some provinces and cities with levels exceeding the allowable standards from several times to dozens of times. In addition, the number of provinces/cities where Ps. aeruginosa was detected in supply water also increased over the years but insignificantly. Water samples that did not meet the standard are mostly from water supply companies with a capacity of less than 1,000 m3/day. Correlation analysis by regression coefficient R2 and Pearson correlation coefficient showed that there was a negative correlation between free chlorine residual and microbiological parameters (total coliforms, E.coli), but the correlation was low and non-linear."
{"title":"Assessment of Free Chlorine Residual and Microbiological Parameters in Supply Water of Centralized Supply Water Companies in Vietnam","authors":"","doi":"10.51316/jst.170.etsd.2023.33.5.5","DOIUrl":"https://doi.org/10.51316/jst.170.etsd.2023.33.5.5","url":null,"abstract":"\"In the study, the free chlorine residual and microbiological parameters in supply water of centralized supply water companies were assessed with a total of 1,612 samples in the period of 2020 and 2022. The results showed that 334 samples did not meet the permitted limit QCVN 01-1:2018/BYT for free chlorine residual (0.2-1.0 mg/L), of which, about 80% of sample have concentration less than the lower limit. The reason is due to the inaccurately used chloramine dose, mainly quantified without adjusting for actual output quality and distribution system. Some companies even periodically disinfect water 1-3 times/week. In many cases, the water samples at the companies’ storage tanks have high free chlorine residual, about 2 times greater than upper limit (>2.0 mg/L). Regarding microbiological parameters, for total coliforms about 40-50% surveyed provinces have water samples that were non-compliance with the acceptable quality standard for QCVN 01-1:2018/BYT with total of 102, 57 and 105 samples. For those water samples, free chlorine residual found also lower than required limit (<0.06 mg/L). Apart from total coliforms and E. coli, Pseudomonas aeruginosa (Ps. aeruginosa) was also detected in water samples in some provinces and cities with levels exceeding the allowable standards from several times to dozens of times. In addition, the number of provinces/cities where Ps. aeruginosa was detected in supply water also increased over the years but insignificantly. Water samples that did not meet the standard are mostly from water supply companies with a capacity of less than 1,000 m3/day. Correlation analysis by regression coefficient R2 and Pearson correlation coefficient showed that there was a negative correlation between free chlorine residual and microbiological parameters (total coliforms, E.coli), but the correlation was low and non-linear.\"","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":"5 27","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136229835","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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