Pub Date : 2025-08-09DOI: 10.1016/j.cscee.2025.101273
D. Bosch , J.O. Back , M. Spruck , A. Hofmann , A. Bockreis
The increasing generation of waste wood (WW) and the demand for activated carbon (AC) in wastewater treatment highlight the need for sustainable alternatives. WW was converted into AC via one-step thermochemical activation using carbon dioxide, steam, or both in a fluidised-bed reactor. A Design of Experiments approach was applied to optimise temperature and residence time. The resulting ACs achieved surface areas up to 708 m2 g−1 and adsorption capacities of 254 mg g−1 for organic micropollutants. The process yielded favourable porosity and surface chemistry. It supports circular economy principles and offers a scalable route aligned with current environmental regulations.
{"title":"One-step thermochemical activation of waste wood for micropollutant adsorption: Optimisation via design of experiments","authors":"D. Bosch , J.O. Back , M. Spruck , A. Hofmann , A. Bockreis","doi":"10.1016/j.cscee.2025.101273","DOIUrl":"10.1016/j.cscee.2025.101273","url":null,"abstract":"<div><div>The increasing generation of waste wood (WW) and the demand for activated carbon (AC) in wastewater treatment highlight the need for sustainable alternatives. WW was converted into AC via one-step thermochemical activation using carbon dioxide, steam, or both in a fluidised-bed reactor. A Design of Experiments approach was applied to optimise temperature and residence time. The resulting ACs achieved surface areas up to 708 m<sup>2</sup> g<sup>−1</sup> and adsorption capacities of 254 mg g<sup>−1</sup> for organic micropollutants. The process yielded favourable porosity and surface chemistry. It supports circular economy principles and offers a scalable route aligned with current environmental regulations.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"12 ","pages":"Article 101273"},"PeriodicalIF":0.0,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144829742","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 : 2025-08-06DOI: 10.1016/j.cscee.2025.101274
Hemen Emmanuel Jijingi, Sara Kazemi Yazdi, Yousif Abdalla Abakr, Azalea Dyah Maysarah Satya
The presence of excessive concentrations of essential elements in wastewater, particularly palm oil mill effluent (POME), contributes to environmental nuisances such as eutrophication, which depletes oxygen levels in water bodies and disrupts aquatic ecosystems due to high nutrient and organic loads. Herein, this study evaluates Chlorella vulgaris as a sustainable treatment route for nutrient removal from POME under three distinct cultivation conditions: (1) Control (CO)—900 mL synthetic growth medium and 100 mL Chlorella vulgaris culture, serving as a reference for microalgae growth under standard conditions without POME; (2) POME + Synthetic Growth Medium + Chlorella vulgaris Culture (PSC)—500 mL filtered POME, 400 mL synthetic growth medium, and 100 mL Chlorella vulgaris culture (POME-to-medium ratio of 2:1), designed to evaluate POME's potential to substitute conventional growth media; and (3) POME + Chlorella vulgaris Culture (PC)-900 mL filtered POME and 100 mL Chlorella vulgaris culture (POME-to-culture ratio of 1:1), evaluating the feasibility of using POME as the sole nutrient source for microalgae growth. Experimental results indicated that the PSC treatment recorded the highest nutrient removal efficiencies, with 94.64 % for total nitrogen (TN), 91.36 % for total phosphorus (TP), 92.31 % for nitrate (NO3−-N), and 90.91 % for ammonia-nitrogen (NH4+-N). The PC treatment exhibited slightly lower efficiencies, whereas the Control treatment showed the least removal effectiveness. Regression modeling was performed using MATLAB to predict optical density (OD) trends over cultivation time. Gaussian Process Regression (GPR) emerged as the best-performing model, with an R2 value of 0.984 and an RMSE of 0.608, demonstrating a strong correlation between OD and biomass accumulation. Linear Regression also demonstrated high accuracy (R2 = 0.978, RMSE = 0.707), confirming that Chlorella vulgaris growth can be effectively modeled over time. These statistical results reinforce the significant role of nutrient-enriched media in enhancing nutrient remediation and biomass accumulation. Hence, this study demonstrates Chlorella vulgaris as a promising candidate for POME bioremediation, paving the way for sustainable wastewater treatment and nutrient recovery technologies. The strong correlation between nutrient removal, biomass accumulation, and optical density growth highlights the potential of microalgal-based wastewater treatment systems in industrial applications.
{"title":"Exploring the potential of Chlorella vulgaris for nutrient removal and biomass accumulation in palm oil mill effluent (POME): A sustainable and green technology approach","authors":"Hemen Emmanuel Jijingi, Sara Kazemi Yazdi, Yousif Abdalla Abakr, Azalea Dyah Maysarah Satya","doi":"10.1016/j.cscee.2025.101274","DOIUrl":"10.1016/j.cscee.2025.101274","url":null,"abstract":"<div><div>The presence of excessive concentrations of essential elements in wastewater, particularly palm oil mill effluent (POME), contributes to environmental nuisances such as eutrophication, which depletes oxygen levels in water bodies and disrupts aquatic ecosystems due to high nutrient and organic loads. Herein, this study evaluates <em>Chlorella vulgaris</em> as a sustainable treatment route for nutrient removal from POME under three distinct cultivation conditions: (1) Control (CO)—900 mL synthetic growth medium and 100 mL <em>Chlorella vulgaris</em> culture, serving as a reference for microalgae growth under standard conditions without POME; (2) POME + Synthetic Growth Medium + <em>Chlorella vulgaris</em> Culture (PSC)—500 mL filtered POME, 400 mL synthetic growth medium, and 100 mL <em>Chlorella vulgaris</em> culture (POME-to-medium ratio of 2:1), designed to evaluate POME's potential to substitute conventional growth media; and (3) POME + <em>Chlorella vulgaris</em> Culture (PC)-900 mL filtered POME and 100 mL <em>Chlorella vulgaris</em> culture (POME-to-culture ratio of 1:1), evaluating the feasibility of using POME as the sole nutrient source for microalgae growth. Experimental results indicated that the PSC treatment recorded the highest nutrient removal efficiencies, with 94.64 % for total nitrogen (TN), 91.36 % for total phosphorus (TP), 92.31 % for nitrate (NO<sub>3</sub><sup>−</sup>-N), and 90.91 % for ammonia-nitrogen (NH<sub>4</sub><sup>+</sup>-N). The PC treatment exhibited slightly lower efficiencies, whereas the Control treatment showed the least removal effectiveness. Regression modeling was performed using MATLAB to predict optical density (OD) trends over cultivation time. Gaussian Process Regression (GPR) emerged as the best-performing model, with an R<sup>2</sup> value of 0.984 and an RMSE of 0.608, demonstrating a strong correlation between OD and biomass accumulation. Linear Regression also demonstrated high accuracy (R<sup>2</sup> = 0.978, RMSE = 0.707), confirming that <em>Chlorella vulgaris</em> growth can be effectively modeled over time. These statistical results reinforce the significant role of nutrient-enriched media in enhancing nutrient remediation and biomass accumulation. Hence, this study demonstrates <em>Chlorella vulgaris</em> as a promising candidate for POME bioremediation, paving the way for sustainable wastewater treatment and nutrient recovery technologies. The strong correlation between nutrient removal, biomass accumulation, and optical density growth highlights the potential of microalgal-based wastewater treatment systems in industrial applications.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"12 ","pages":"Article 101274"},"PeriodicalIF":0.0,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144829373","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 : 2025-08-05DOI: 10.1016/j.cscee.2025.101272
Dieter Rahmadiawan , Hairul Abral , Shih-Chen Shi , Ilham Chayri Iby , Razan Muhammad Railis , Melbi Mahardika , Dian Juliadmi , Fazhar Akbar
Polyvinyl alcohol (PVA) films mixed with boric acid (BA) and Uncaria gambir (UG) offer excellent UV shielding and moisture resistance but suffer from brittleness. This study introduces a water immersion technique to improve flexibility. The untreated film showed high tensile strength (57.7 MPa) and modulus (3.7 GPa) but low elongation (∼43 %) and toughness (20.2 MJ/m3). After 7 days of immersion, tensile strength and modulus decreased to 41.2 MPa and 1.94 GPa, while elongation and toughness increased to ∼150 % and 58.1 MJ/m3, respectively. This green approach effectively enhances the ductility of PVA-based biopolymer films.
{"title":"Enhancing the flexibility of polyvinyl alcohol/Uncaria gambir extract/boric acid biopolymer films via prolonged water immersion post-treatment","authors":"Dieter Rahmadiawan , Hairul Abral , Shih-Chen Shi , Ilham Chayri Iby , Razan Muhammad Railis , Melbi Mahardika , Dian Juliadmi , Fazhar Akbar","doi":"10.1016/j.cscee.2025.101272","DOIUrl":"10.1016/j.cscee.2025.101272","url":null,"abstract":"<div><div>Polyvinyl alcohol (PVA) films mixed with boric acid (BA) and <em>Uncaria gambir</em> (UG) offer excellent UV shielding and moisture resistance but suffer from brittleness. This study introduces a water immersion technique to improve flexibility. The untreated film showed high tensile strength (57.7 MPa) and modulus (3.7 GPa) but low elongation (∼43 %) and toughness (20.2 MJ/m<sup>3</sup>). After 7 days of immersion, tensile strength and modulus decreased to 41.2 MPa and 1.94 GPa, while elongation and toughness increased to ∼150 % and 58.1 MJ/m<sup>3</sup>, respectively. This green approach effectively enhances the ductility of PVA-based biopolymer films.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"12 ","pages":"Article 101272"},"PeriodicalIF":0.0,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773144","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 : 2025-07-29DOI: 10.1016/j.cscee.2025.101271
Reinhard Lerchbammer, Eva Gerold, Helmut Antrekowitsch
This study underscores the increasing relevance of organic acids as environmentally sustainable alternatives to conventional inorganic leaching agents. Beyond reducing the ecological footprint of leaching processes, organic acids offer improved selectivity and efficiency in metal recovery. Among them, gluconic acid has proven to be a particularly effective agent for the extraction of valuable metals.
Through statistical optimization, the leaching process achieved extraction efficiencies exceeding 98 % for lithium, nickel, cobalt, and manganese from end-of-life lithium-ion batteries (EoL-LIBs), while significantly limiting the co-dissolution of copper, iron, and aluminum.
Subsequently, nickel, cobalt, and manganese were selectively recovered through precipitation using oxalic and sulphide agents. Oxalic acid demonstrated high selectivity, leaving lithium and aluminum in solution, and enabling recovery rates of 99 %, 100 %, and 86 % for nickel, cobalt, and manganese, respectively. Sulphide precipitation was similarly effective, achieving over 97 % recovery of nickel and cobalt at pH 4.
The work consolidates current knowledge on gluconic acid-based leaching and systematically evaluates its combination with conventional precipitation methods. Although complex chemical interactions in gluconate matrices occur, this study achieves high extraction and recovery efficiencies, demonstrating the practicality and potential integration of this combined approach into existing industrial recovery systems.
{"title":"High yield gluconic acid leaching and recovery of valuable metals from end-of-life lithium-ion batteries","authors":"Reinhard Lerchbammer, Eva Gerold, Helmut Antrekowitsch","doi":"10.1016/j.cscee.2025.101271","DOIUrl":"10.1016/j.cscee.2025.101271","url":null,"abstract":"<div><div>This study underscores the increasing relevance of organic acids as environmentally sustainable alternatives to conventional inorganic leaching agents. Beyond reducing the ecological footprint of leaching processes, organic acids offer improved selectivity and efficiency in metal recovery. Among them, gluconic acid has proven to be a particularly effective agent for the extraction of valuable metals.</div><div>Through statistical optimization, the leaching process achieved extraction efficiencies exceeding 98 % for lithium, nickel, cobalt, and manganese from end-of-life lithium-ion batteries (EoL-LIBs), while significantly limiting the co-dissolution of copper, iron, and aluminum.</div><div>Subsequently, nickel, cobalt, and manganese were selectively recovered through precipitation using oxalic and sulphide agents. Oxalic acid demonstrated high selectivity, leaving lithium and aluminum in solution, and enabling recovery rates of 99 %, 100 %, and 86 % for nickel, cobalt, and manganese, respectively. Sulphide precipitation was similarly effective, achieving over 97 % recovery of nickel and cobalt at pH 4.</div><div>The work consolidates current knowledge on gluconic acid-based leaching and systematically evaluates its combination with conventional precipitation methods. Although complex chemical interactions in gluconate matrices occur, this study achieves high extraction and recovery efficiencies, demonstrating the practicality and potential integration of this combined approach into existing industrial recovery systems.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"12 ","pages":"Article 101271"},"PeriodicalIF":0.0,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749579","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 : 2025-07-28DOI: 10.1016/j.cscee.2025.101268
Zaharaddeen N. Garba , Chavalit Ratanatamskul
This study developed a new adsorbent (HPL-ACTF) from agricultural waste, specifically leaves of Hamelia patens Jacq. The batch experiment examined the operating conditions including pH, temperature, contact time, and adsorbate concentrations to determine the maximum adsorption potential. The novel adsorbent demonstrated the adsorption capacities of 273.25 mg/g for 2,4,6-TCP and 232.47 mg/g for 2,4-DCP. The adsorption characteristics were evaluated using Langmuir, Freundlich, and Temkin isotherm models. The Langmuir model provided the best fit for both adsorbates. Kinetic analysis indicated that adsorption followed a pseudo-second-order model, and regeneration studies confirmed that HPL-ACTF could be effectively reused for up to five cycles.
{"title":"Kinetics, adsorption mechanism, and economic viability of an eco-friendly amorphous carbon thin-film adsorbent synthesized from agricultural waste for removal of 2,4-dichlorophenol and 2,4,6-trichlorophenol in water environment","authors":"Zaharaddeen N. Garba , Chavalit Ratanatamskul","doi":"10.1016/j.cscee.2025.101268","DOIUrl":"10.1016/j.cscee.2025.101268","url":null,"abstract":"<div><div>This study developed a new adsorbent (HPL-ACTF) from agricultural waste, specifically leaves of <em>Hamelia patens</em> Jacq. The batch experiment examined the operating conditions including pH, temperature, contact time, and adsorbate concentrations to determine the maximum adsorption potential. The novel adsorbent demonstrated the adsorption capacities of 273.25 mg/g for 2,4,6-TCP and 232.47 mg/g for 2,4-DCP. The adsorption characteristics were evaluated using Langmuir, Freundlich, and Temkin isotherm models. The Langmuir model provided the best fit for both adsorbates. Kinetic analysis indicated that adsorption followed a pseudo-second-order model, and regeneration studies confirmed that HPL-ACTF could be effectively reused for up to five cycles.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"12 ","pages":"Article 101268"},"PeriodicalIF":0.0,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749578","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 paper investigates the effect of two-step sintering on the mechanical properties and microstructure of Sm2Zr2O7 ceramics obtained from submicron powders after high-energy milling. Two key parameters of the two-step sintering process are analyzed: temperature and duration, as both can significantly influence grain growth processes in ceramics. It was found that extending the sintering duration at lower temperatures promotes ceramic densification while preserving a relatively narrow grain size distribution. In contrast, higher sintering temperatures combined with shorter durations result in broader grain size distributions and more pronounced exaggerated grain growth. Despite differences in microstructure and grain size distribution, both the sample sintered at 1350 °C for 20 hours and the one sintered at 1700 °C for 10 minutes exhibited the highest mechanical properties, with microhardness values HV1 ∼1200 and biaxial flexural strength reaching ∼125 MPa. This suggests that the enhancement of mechanical performance may be linked to a reduction in internal stresses, either due to the elevated temperature during the first sintering step or the extended holding time during the second step. Thus, in both types of sintering, whether based on prolonged holding time or elevated temperature, changes in sample morphology and grain size do not appear to have a significant impact on the mechanical properties of the resulting ceramics.
{"title":"The effect of mechanical milling and two-step sintering technique on the microstructure, microhardness, strength, and dielectric properties of Sm2Zr2O7 ceramics","authors":"I.E. Kenzhina , A.L. Kozlovskiy , R.I. Shakirzyanov , M.E. Kaliyekperov , N.O. Volodina , S.A. Maznykh , M. Begentayev , S.K. Askerbekov , Zh.A. Zaurbekova , A.U. Tolenova , P.A. Blynskiy","doi":"10.1016/j.cscee.2025.101270","DOIUrl":"10.1016/j.cscee.2025.101270","url":null,"abstract":"<div><div>This paper investigates the effect of two-step sintering on the mechanical properties and microstructure of Sm<sub>2</sub>Zr<sub>2</sub>O<sub>7</sub> ceramics obtained from submicron powders after high-energy milling. Two key parameters of the two-step sintering process are analyzed: temperature and duration, as both can significantly influence grain growth processes in ceramics. It was found that extending the sintering duration at lower temperatures promotes ceramic densification while preserving a relatively narrow grain size distribution. In contrast, higher sintering temperatures combined with shorter durations result in broader grain size distributions and more pronounced exaggerated grain growth. Despite differences in microstructure and grain size distribution, both the sample sintered at 1350 °C for 20 hours and the one sintered at 1700 °C for 10 minutes exhibited the highest mechanical properties, with microhardness values HV1 ∼1200 and biaxial flexural strength reaching ∼125 MPa. This suggests that the enhancement of mechanical performance may be linked to a reduction in internal stresses, either due to the elevated temperature during the first sintering step or the extended holding time during the second step. Thus, in both types of sintering, whether based on prolonged holding time or elevated temperature, changes in sample morphology and grain size do not appear to have a significant impact on the mechanical properties of the resulting ceramics.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"12 ","pages":"Article 101270"},"PeriodicalIF":0.0,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723148","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 is focused on synthesizing biosorbents from water hyacinth (Eichhornia crassipes), WH. Three biosorbents were obtained: WH modified with citric acid (WH-CA), hydrocarbonized WH (WHHC), and WHHC modified with CA (WHHC-CA). The capacity of these biosorbents to adsorb Cd(II) from water solutions was ascertained. WH and WHHC were modified hydrothermally using 2, 1 and 0.5 M CA solutions and were designated using CA concentration. All biosorbents were characterized using various techniques. At pH = 6 and 25 °C, WHHC-CA1 exhibited the highest capacity for adsorbing Cd(II) of 166.6 mg/g, so the optimal CA concentration is 1 M.
研究了水葫芦（Eichhornia crassipes）的生物吸附剂的合成。得到了三种生物吸附剂：柠檬酸修饰WH-CA、碳化WH （WHHC）和CA修饰WHHC （WHHC-CA）。确定了这些生物吸附剂从水溶液中吸附Cd（II）的能力。分别使用2、1和0.5 M CA溶液对WH和WHHC进行水热改性，并使用CA浓度进行命名。使用各种技术对所有生物吸附剂进行了表征。在pH = 6和25℃条件下，WHHC-CA1对Cd（II）的吸附量最高，为166.6 mg/g，最佳CA浓度为1 M。
{"title":"CADMIUM(II) removal from aqueous solution by adsorption on water hyacinth (Eichhornia crassipes) hydrochar modified with citric acid","authors":"Carolina Vázquez-Mendoza , Roberto Leyva-Ramos , Nahum Andrés Medellín-Castillo , Damarys Haidee Carrales-Alvarado , Antonio Aragón-Piña","doi":"10.1016/j.cscee.2025.101267","DOIUrl":"10.1016/j.cscee.2025.101267","url":null,"abstract":"<div><div>This study is focused on synthesizing biosorbents from water hyacinth (<em>Eichhornia crassipes</em>), WH. Three biosorbents were obtained: WH modified with citric acid (WH-CA), hydrocarbonized WH (WHHC), and WHHC modified with CA (WHHC-CA). The capacity of these biosorbents to adsorb Cd(II) from water solutions was ascertained. WH and WHHC were modified hydrothermally using 2, 1 and 0.5 M CA solutions and were designated using CA concentration. All biosorbents were characterized using various techniques. At pH = 6 and 25 °C, WHHC-CA1 exhibited the highest capacity for adsorbing Cd(II) of 166.6 mg/g, so the optimal CA concentration is 1 M.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"12 ","pages":"Article 101267"},"PeriodicalIF":0.0,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739248","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 examines the relationship between Land Surface Temperature and Land Use/Land Cover in Sikhottabong District, Laos, for the years 1992 and 2023, utilizing Landsat imagery from 1992 to 2023. Geospatial techniques in Google Earth Engine were used to assess Land Use/Land Cover transitions and estimate Land Surface Temperature. Results show that built-up areas have doubled, forests have declined by 30 %, and agricultural areas have increased by 24 %. Land Surface Temperature positively correlates with the Normalized Difference Built-up Index and the Normalized Difference Bare Soil Index, and negatively with the Normalized Difference Water Index. The findings highlight how urban expansion raises Land Surface Temperature, while water bodies help mitigate it. To address the observed rise in Land Surface Temperature, strategies such as enhancing urban green spaces, promoting afforestation, and improving urban water management are recommended to mitigate the heat island effect and support sustainable urban development in Sikhottabong District.
{"title":"Analytical study on the relationship among Land Surface Temperature, Land Use Land Cover, and spectral indices using geospatial techniques over Sikhottabong District, Laos","authors":"Jedtavong Thepvongsa , Erni Saurmalinda Butar Butar","doi":"10.1016/j.cscee.2025.101269","DOIUrl":"10.1016/j.cscee.2025.101269","url":null,"abstract":"<div><div>This study examines the relationship between Land Surface Temperature and Land Use/Land Cover in Sikhottabong District, Laos, for the years 1992 and 2023, utilizing Landsat imagery from 1992 to 2023. Geospatial techniques in Google Earth Engine were used to assess Land Use/Land Cover transitions and estimate Land Surface Temperature. Results show that built-up areas have doubled, forests have declined by 30 %, and agricultural areas have increased by 24 %. Land Surface Temperature positively correlates with the Normalized Difference Built-up Index and the Normalized Difference Bare Soil Index, and negatively with the Normalized Difference Water Index. The findings highlight how urban expansion raises Land Surface Temperature, while water bodies help mitigate it. To address the observed rise in Land Surface Temperature, strategies such as enhancing urban green spaces, promoting afforestation, and improving urban water management are recommended to mitigate the heat island effect and support sustainable urban development in Sikhottabong District.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"12 ","pages":"Article 101269"},"PeriodicalIF":0.0,"publicationDate":"2025-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144763705","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}
The widespread presence of BPA in water bodies poses significant environmental and health concerns, highlighting the need for sustainable and efficient removal technologies. This study presents an innovative approach for BPA remediation using biochar derived from king coconut shells—a readily available agricultural waste and by-product of a popular drink in many parts of Asia. Biochar pyrolyzed at 800 °C exhibited the highest removal efficiency, which was significantly enhanced to 80.1 ± 0.9 % following HCl activation. Further reduction of the particle size from 1.0–4.0 mm to 75–105 μm resulted in complete (100 %) removal of BPA. Batch adsorption experiments revealed optimal removal at pH 3–7, with a dosage of 5.0 g/L and an initial BPA concentration of 100.0 ppm. The adsorption process was best described by the Langmuir isotherm model (R2 = 0.99), with a maximum capacity of 39.53 mg/g. Kinetic studies demonstrated that the pseudo-second-order model accurately represented the adsorption dynamics, implying chemisorption as the rate-limiting step. Regeneration experiments using ethanol demonstrated the reusability of the adsorbent, maintaining over 79.6 % removal efficiency after five consecutive cycles. These findings highlight the effectiveness of KBC800–HCl as a sustainable and high-performance adsorbent, demonstrating the broader potential of agricultural waste valorization in environmental remediation.
{"title":"From waste to resource: King coconut biochar as a green adsorbent for bisphenol A removal","authors":"Hashinika Matharage , Mahesh Jayaweera , Nilanthi Bandara , Jagath Manatunge , Daham Jayawardana , Janith Dissanayake","doi":"10.1016/j.cscee.2025.101261","DOIUrl":"10.1016/j.cscee.2025.101261","url":null,"abstract":"<div><div>The widespread presence of BPA in water bodies poses significant environmental and health concerns, highlighting the need for sustainable and efficient removal technologies. This study presents an innovative approach for BPA remediation using biochar derived from king coconut shells—a readily available agricultural waste and by-product of a popular drink in many parts of Asia. Biochar pyrolyzed at 800 °C exhibited the highest removal efficiency, which was significantly enhanced to 80.1 ± 0.9 % following HCl activation. Further reduction of the particle size from 1.0–4.0 mm to 75–105 μm resulted in complete (100 %) removal of BPA. Batch adsorption experiments revealed optimal removal at pH 3–7, with a dosage of 5.0 g/L and an initial BPA concentration of 100.0 ppm. The adsorption process was best described by the Langmuir isotherm model (R<sup>2</sup> = 0.99), with a maximum capacity of 39.53 mg/g. Kinetic studies demonstrated that the pseudo-second-order model accurately represented the adsorption dynamics, implying chemisorption as the rate-limiting step. Regeneration experiments using ethanol demonstrated the reusability of the adsorbent, maintaining over 79.6 % removal efficiency after five consecutive cycles. These findings highlight the effectiveness of KBC800–HCl as a sustainable and high-performance adsorbent, demonstrating the broader potential of agricultural waste valorization in environmental remediation.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"12 ","pages":"Article 101261"},"PeriodicalIF":0.0,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704504","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 : 2025-07-23DOI: 10.1016/j.cscee.2025.101262
Nasmi Herlina Sari, Emmy Dyah Sulistyowati, Suteja, Muhammad Zulfadli
This study aims to develop and evaluate sustainable bio-composites using cellulose powder derived fromNicotiana tabacumstem waste, focusing on how varying filler content influences their structural, mechanical, and thermal properties. The cellulose powder was extracted through 5 % NaOH treatment and incorporated at various weight fractions to form composite formulations: BTN (10/90), BTL (15/85), BTK (20/80), BTI (25/75), BTH (30/70), and BTD (40/60), where the numbers represent the cellulose/resin ratio (% w/w). The composites were fabricated using hot press molding and evaluated for physical, mechanical, and thermal properties. Results showed that increasing cellulose content significantly enhanced performance. The highest tensile strength was achieved at 159.47 ± 11.49 MPa for the BTD composite (40 % cellulose), representing a substantial improvement over lower filler loadings. Flexural strength similarly peaked at 174.92 ± 8.9 MPa, and thermal stability increased, with a decomposition onset near 380 °C. FTIR analysis confirmed the presence of cellulose-related functional groups and improved interfacial bonding, while SEM images revealed reduced voids and better dispersion at higher filler contents. The wear resistance also improved, with the lowest wear rate of 0.073 mm3/Nm observed for BTD. These findings underscore the potential of Nicotiana tabacum-based composites as eco-friendly materials for structural and thermal applications.
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