Pub Date : 2025-09-01Epub Date: 2025-08-28DOI: 10.1016/j.scenv.2025.100287
Ilektra C. Feida , Vasileios D. Alampanos , Justyna Płotka-Wasylka , Dimitra A. Lambropoulou
In recent years, there has been increasing interest in developing more environmentally friendly analytical methods. In this context, microextraction techniques have gained wider application, and novel materials are being researched as potential adsorbents. Among these, aerogels and cryogels stand out due to their exceptional attributes, including high porosity, large surface area, excellent adsorption capacity, and favorable mechanical properties. These materials can be combined with various affinity substances to form composites that interact with a wide range of analytes. This manuscript reviews the numerous applications of aerogels and cryogels in microextraction pretreatment processes, focusing on the extraction of organic pollutants from various matrices prior to liquid chromatography (LC) or gas chromatography (GC) analysis. The extraction methods and analytical parameters are thoroughly discussed, highlighting the environmental benefits of using aerogels and cryogels as green adsorbents. The future directions are also pointed out.
{"title":"Aerogels and cryogels as green sorbents for organic contaminant extraction and chromatographic analysis","authors":"Ilektra C. Feida , Vasileios D. Alampanos , Justyna Płotka-Wasylka , Dimitra A. Lambropoulou","doi":"10.1016/j.scenv.2025.100287","DOIUrl":"10.1016/j.scenv.2025.100287","url":null,"abstract":"<div><div>In recent years, there has been increasing interest in developing more environmentally friendly analytical methods. In this context, microextraction techniques have gained wider application, and novel materials are being researched as potential adsorbents. Among these, aerogels and cryogels stand out due to their exceptional attributes, including high porosity, large surface area, excellent adsorption capacity, and favorable mechanical properties. These materials can be combined with various affinity substances to form composites that interact with a wide range of analytes. This manuscript reviews the numerous applications of aerogels and cryogels in microextraction pretreatment processes, focusing on the extraction of organic pollutants from various matrices prior to liquid chromatography (LC) or gas chromatography (GC) analysis. The extraction methods and analytical parameters are thoroughly discussed, highlighting the environmental benefits of using aerogels and cryogels as green adsorbents. The future directions are also pointed out.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"11 ","pages":"Article 100287"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144925506","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}
Climate change and greenhouse gas emissions have sparked interest in developing efficient CO2 conversion technology. Photocatalytic CO2 conversion, using semiconductor materials like Titanium dioxide (TiO2), has shown promise through solar-powered processes. The efficiency of these photocatalysts depends on understanding charge carrier dynamics. Our study compares the charge carrier kinetics in photocatalytic CO2 conversion between TiO2 nanopowder (TiO2-NP) and TiO2 nanofibers (TiO2-NFs). The study uses advanced experimental techniques SEM, XRD, BET, Raman and UV-Vis spectroscopy to analyze the structural and morphological properties of TiO2 nanopowder and nanofibers, demonstrating their various morphologies. The results show significant differences between the two materials, TiO2 nanofibers have reduced recombination rates and longer lifetimes due to enhanced charge separation and increased surface-to-volume ratio. TiO2 nanopowder's increased crystallinity and larger grain size make it harder to segregate charges, leading to shorter lifetimes and higher recombination rates. As result, distinct peaks were seen in the HPLC study of CO2 conversion over the catalysts for methanol and ethanol with enhanced yield of 182.8 and 216.0 mcg/l respectively for nanofibers. These findings could guide the design and optimization of TiO2-based photocatalysts for effective CO2 conversion.
{"title":"Morphology influence on charge carrier dynamics in photocatalytic CO2 conversion: Comparative analysis between TiO2 nanopowder and nanofibers","authors":"Karan Gehlot , Anil Chandra Kothari , Sangeeta Tiwari , Rajaram Bal , Sandeep Kumar Tiwari","doi":"10.1016/j.scenv.2025.100272","DOIUrl":"10.1016/j.scenv.2025.100272","url":null,"abstract":"<div><div>Climate change and greenhouse gas emissions have sparked interest in developing efficient CO<sub>2</sub> conversion technology. Photocatalytic CO<sub>2</sub> conversion, using semiconductor materials like Titanium dioxide (TiO<sub>2</sub>), has shown promise through solar-powered processes. The efficiency of these photocatalysts depends on understanding charge carrier dynamics. Our study compares the charge carrier kinetics in photocatalytic CO<sub>2</sub> conversion between TiO<sub>2</sub> nanopowder (TiO<sub>2</sub>-NP) and TiO<sub>2</sub> nanofibers (TiO<sub>2</sub>-NFs). The study uses advanced experimental techniques SEM, XRD, BET, Raman and UV-Vis spectroscopy to analyze the structural and morphological properties of TiO<sub>2</sub> nanopowder and nanofibers, demonstrating their various morphologies. The results show significant differences between the two materials, TiO<sub>2</sub> nanofibers have reduced recombination rates and longer lifetimes due to enhanced charge separation and increased surface-to-volume ratio. TiO<sub>2</sub> nanopowder's increased crystallinity and larger grain size make it harder to segregate charges, leading to shorter lifetimes and higher recombination rates. As result, distinct peaks were seen in the HPLC study of CO<sub>2</sub> conversion over the catalysts for methanol and ethanol with enhanced yield of 182.8 and 216.0 mcg/l respectively for nanofibers. These findings could guide the design and optimization of TiO<sub>2</sub>-based photocatalysts for effective CO<sub>2</sub> conversion.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"11 ","pages":"Article 100272"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144631391","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 : 2025-09-01Epub Date: 2025-08-19DOI: 10.1016/j.scenv.2025.100281
Md. Kawcher Alam , Md. Sahadat Hossain , Takvir Hossan Parhad , Shassatha Paul Saikat , Tasnimul Quader Tazim , Muhammad Shahriar Bashar , Newaz Mohammed Bahadur , Samina Ahmed
Cockle shells and discarded snails were employed as the source of calcium in this study to synthesize industrially essential minerals, known as gypsum, utlilizing a wet chemical precipitation technique. Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD) were used for analyzing the generated gypsums. XRD data were also used to determine several crystallographic parameters, including growth preference, residual stress, microstrain, dislocation density, crystallinity index, and crystallite size (using the Scherrer equation and other model equations). Based on the information from XRD, the previously specified models were employed to determine that all the generated gypsum displays a crystallite size within the authorized range of 1–150 nm. The images captured by the scanning electron microscope (SEM) show that the gypsum crystals have a distinct morphology that takes the shape of plates. The texture coefficient (Tc) provides an approximate representation of the given plane's texture, indicating a similar preferred orientation along the stated crystallographic planes. Furthermore, the EDX examination (Ca, S, and O percentages) and Rietveld refinement (nearly 99 % gypsum) supported the nature of the final gypsum samples.
{"title":"Utilization of solid marine wastes from snail and cockle shells for the sustainable synthesis of nanocrystalline Gypsum","authors":"Md. Kawcher Alam , Md. Sahadat Hossain , Takvir Hossan Parhad , Shassatha Paul Saikat , Tasnimul Quader Tazim , Muhammad Shahriar Bashar , Newaz Mohammed Bahadur , Samina Ahmed","doi":"10.1016/j.scenv.2025.100281","DOIUrl":"10.1016/j.scenv.2025.100281","url":null,"abstract":"<div><div>Cockle shells and discarded snails were employed as the source of calcium in this study to synthesize industrially essential minerals, known as gypsum, utlilizing a wet chemical precipitation technique. Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD) were used for analyzing the generated gypsums. XRD data were also used to determine several crystallographic parameters, including growth preference, residual stress, microstrain, dislocation density, crystallinity index, and crystallite size (using the Scherrer equation and other model equations). Based on the information from XRD, the previously specified models were employed to determine that all the generated gypsum displays a crystallite size within the authorized range of 1–150 nm. The images captured by the scanning electron microscope (SEM) show that the gypsum crystals have a distinct morphology that takes the shape of plates. The texture coefficient (T<sub>c</sub>) provides an approximate representation of the given plane's texture, indicating a similar preferred orientation along the stated crystallographic planes. Furthermore, the EDX examination (Ca, S, and O percentages) and Rietveld refinement (nearly 99 % gypsum) supported the nature of the final gypsum samples.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"11 ","pages":"Article 100281"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144885799","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 : 2025-09-01Epub Date: 2025-06-28DOI: 10.1016/j.scenv.2025.100266
Debajyoti Bose , Riya Bhattacharya , M. Gopinath , Abhijeeta Sarkar , Ravindra Singh Pandya , Apurva Jaiswal
Bioelectricity generation from degradation of contaminants is the central premise for Microbial fuel cell or MFC operation. There has been a logarithmic increase in the refinement of MFC architecture that can support stable microbial biofilms over the years. In this work the advances with MFCs are covered with their design aspects. An overview is presented of the electrodes used in such systems with the capacity for contamination removal and bioelectricity production. Additionally, the importance of exoelectrogens in facilitating extracellular electron transfer mechanisms is evaluated. Further the factors, such as pH influencing proton transfer with temperature influencing microbial kinetics is also covered. The importance of biofilm formation in both synthetic and real time wastewater is analysed with the help of the MFC reactor design and the capacity of the cathode to act as a terminal electron acceptor. The cost analysis of MFC technologies with anaerobic digesters shows some profitable aspect which can be further improvised through mathematical models. Designing robust MFC systems adaptable to varying wastewater conditions is critical for advancing practical applications and achieving sustainable energy recovery.
{"title":"Advances in microbial fuel cell technologies for bioremediation and energy recovery from wastewater","authors":"Debajyoti Bose , Riya Bhattacharya , M. Gopinath , Abhijeeta Sarkar , Ravindra Singh Pandya , Apurva Jaiswal","doi":"10.1016/j.scenv.2025.100266","DOIUrl":"10.1016/j.scenv.2025.100266","url":null,"abstract":"<div><div>Bioelectricity generation from degradation of contaminants is the central premise for Microbial fuel cell or MFC operation. There has been a logarithmic increase in the refinement of MFC architecture that can support stable microbial biofilms over the years. In this work the advances with MFCs are covered with their design aspects. An overview is presented of the electrodes used in such systems with the capacity for contamination removal and bioelectricity production. Additionally, the importance of exoelectrogens in facilitating extracellular electron transfer mechanisms is evaluated. Further the factors, such as pH influencing proton transfer with temperature influencing microbial kinetics is also covered. The importance of biofilm formation in both synthetic and real time wastewater is analysed with the help of the MFC reactor design and the capacity of the cathode to act as a terminal electron acceptor. The cost analysis of MFC technologies with anaerobic digesters shows some profitable aspect which can be further improvised through mathematical models. Designing robust MFC systems adaptable to varying wastewater conditions is critical for advancing practical applications and achieving sustainable energy recovery.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"11 ","pages":"Article 100266"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144514420","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 : 2025-09-01Epub Date: 2025-08-28DOI: 10.1016/j.scenv.2025.100286
Rois Uddin Mahmud , M Abu Darda , Md Tanvir Hossain , Md. Ahasan Habib , Ranajit Kumar Nag , Md. Palash Sarker
Non-biodegradability and widespread use of plastics have made them a significant environmental threat by polluting the atmosphere, degrading ecosystems, and endangering wildlife. Researchers are trying hard to find alternatives to non-biodegradable plastic. Environmentally friendly biopolymer film can be an excellent alternative to non-biodegradable plastic explored from starch and cellulose. This study developed sustainable bioplastics from corn and potato starch reinforced with waste cotton to be used for eco-friendly packaging. The compression molding was employed to fabricate the samples, and thickness, solubility, water absorbency, tensile strength, fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), biodegradability, and moisture management properties (MMP) tests were employed to characterize the samples. Physical properties such as thickness (1.8 mm), solubility (41.43 %), and water absorbency (21.51 %) have shown the possibility of using this material as packaging. Also, the material has good tensile characteristics, with a maximum tensile strength of 2.80 MPa, and can withstand external forces during its intended application. FTIR spectra validate the existence of starch and cellulose (3309.85 cm−1) in the chemical structure of the bioplastic. The intensity and position of XRD peaks provide valuable information about cellulose and starch's crystalline structure and orientation within the bioplastic matrix. Moreover, the MMP demonstrates the waterproof properties of developed bioplastic. Additionally, the soil burial biodegradability test reveals a 76 % weight loss by day 35, demonstrating its excellent biodegradable nature and making it an eco-friendly alternative to plastics.
{"title":"Fabrication of waste cotton reinforced corn and potato starch sustainable bioplastics for eco-friendly packaging material","authors":"Rois Uddin Mahmud , M Abu Darda , Md Tanvir Hossain , Md. Ahasan Habib , Ranajit Kumar Nag , Md. Palash Sarker","doi":"10.1016/j.scenv.2025.100286","DOIUrl":"10.1016/j.scenv.2025.100286","url":null,"abstract":"<div><div>Non-biodegradability and widespread use of plastics have made them a significant environmental threat by polluting the atmosphere, degrading ecosystems, and endangering wildlife. Researchers are trying hard to find alternatives to non-biodegradable plastic. Environmentally friendly biopolymer film can be an excellent alternative to non-biodegradable plastic explored from starch and cellulose. This study developed sustainable bioplastics from corn and potato starch reinforced with waste cotton to be used for eco-friendly packaging. The compression molding was employed to fabricate the samples, and thickness, solubility, water absorbency, tensile strength, fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), biodegradability, and moisture management properties (MMP) tests were employed to characterize the samples. Physical properties such as thickness (1.8 mm), solubility (41.43 %), and water absorbency (21.51 %) have shown the possibility of using this material as packaging. Also, the material has good tensile characteristics, with a maximum tensile strength of 2.80 MPa, and can withstand external forces during its intended application. FTIR spectra validate the existence of starch and cellulose (3309.85 cm<sup>−1</sup>) in the chemical structure of the bioplastic. The intensity and position of XRD peaks provide valuable information about cellulose and starch's crystalline structure and orientation within the bioplastic matrix. Moreover, the MMP demonstrates the waterproof properties of developed bioplastic. Additionally, the soil burial biodegradability test reveals a 76 % weight loss by day 35, demonstrating its excellent biodegradable nature and making it an eco-friendly alternative to plastics.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"11 ","pages":"Article 100286"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921586","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 work brings forth a novel porous solid sorbent, thio-methylene-pyridine (TMP) ligand grafted polymeric resin (TMP resin), for selective mercury removal over a wide range of acidity in which the bi-functional group catered to sorption of both cationic and anionic species of Hg2 + in aqueous hydrochloric acid medium. TMP resin showed quantitative sorption of ‘Hg2+’ in high as well as low acidic solutions (chloride medium) with uptake capacity in the range of 70–80 mg Hg/g, indicating sorption of ‘Hg2+’ in both cationic and anionic form as (HgCl4)2-, hence utilizing the bi-functionality of TMP ligand. Spectroscopic investigation on metal-ligand interactions, as well as DFT calculations indicated towards two separate mechanisms, one being preference for soft-soft co-ordinate complexation at lower acidity and other being anion exchange of Hg-chloride complex by pyridinium group at higher acidity. Near complete back extraction of Hg2+ from the Hg-loaded sorbent was achieved using 0.1 M thiourea solution at 0.1 M HCl. Resin was regenerated upto 5 cycles of repeated loading and elution wherein there was no appreciable change in the performance with respect to Hg2+ sorption & desorption.
这项工作提出了一种新的多孔固体吸附剂，巯基亚甲基吡啶（TMP）配体接枝聚合物树脂（TMP树脂），用于在广泛的酸度范围内选择性除汞，其中双官能团迎合了水溶液中Hg2 +的阳离子和阴离子的吸附。TMP树脂对Hg2+在高酸性和低酸性溶液（氯介质）中的定量吸附能力在70-80 mg Hg/g范围内，表明阳离子和阴离子形式的Hg2+都能以（HgCl4）2-的形式吸附，从而利用了TMP配体的双官能性。金属-配体相互作用的光谱研究以及DFT计算表明了两种不同的机制，一种是在较低酸度下倾向于软-软配位配合，另一种是在较高酸度下汞-氯配合物与吡啶基团的阴离子交换。在0.1 M硫脲溶液中，以0.1 M HCl的浓度，对Hg2+进行了近乎完全的反萃取。树脂可再生至5次重复加载和洗脱，其中在Hg2+吸附方面没有明显的变化；解吸。
{"title":"Novel bifunctional thio-methylene-pyridine grafted polymeric resin for mercury removal from acidic solutions","authors":"Nikhilesh Iyer , Ritesh Ruhela , Suvarna Saundarajan , Sanjukta Abhay Kumar , Dhruva Kumar Singh","doi":"10.1016/j.scenv.2025.100280","DOIUrl":"10.1016/j.scenv.2025.100280","url":null,"abstract":"<div><div>This work brings forth a novel porous solid sorbent, thio-methylene-pyridine (TMP) ligand grafted polymeric resin (TMP resin), for selective mercury removal over a wide range of acidity in which the bi-functional group catered to sorption of both cationic and anionic species of Hg<sup>2 +</sup> in aqueous hydrochloric acid medium. TMP resin showed quantitative sorption of ‘Hg<sup>2+</sup>’ in high as well as low acidic solutions (chloride medium) with uptake capacity in the range of 70–80 mg Hg/g, indicating sorption of ‘Hg<sup>2+</sup>’ in both cationic and anionic form as (HgCl<sub>4</sub>)<sup>2-</sup>, hence utilizing the bi-functionality of TMP ligand. Spectroscopic investigation on metal-ligand interactions, as well as DFT calculations indicated towards two separate mechanisms, one being preference for soft-soft co-ordinate complexation at lower acidity and other being anion exchange of Hg-chloride complex by pyridinium group at higher acidity. Near complete back extraction of Hg<sup>2+</sup> from the Hg-loaded sorbent was achieved using 0.1 M thiourea solution at 0.1 M HCl. Resin was regenerated upto 5 cycles of repeated loading and elution wherein there was no appreciable change in the performance with respect to Hg<sup>2+</sup> sorption & desorption.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"11 ","pages":"Article 100280"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144843014","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}
Coffee shells and silverskins, which are underutilized by-products of the coffee processing industry, offer the potential for value-added products. This study investigated the use of binary and ternary deep eutectic solvents (DESs), choline chloride/oxalic acid (Chcl/OA), and choline chloride/oxalic acid/glycerol (Chcl/OA/Gly), respectively, to pretreat these residues to enhance efficiencies of downstream processes. Optimization experiments identified the optimal pretreatment conditions for coffee shells at 173 min, 120 °C, and 13.99 % and 15.76 % solid loading for binary and ternary DES, respectively. For coffee silverskins, 180 min, 120 °C, and 10 % and 10.21 % solid loadings were found to be optimal. Ternary DES pretreatment enriched the cellulose content and removed hemicellulose and lignin. Enzymatic hydrolysis after pretreatment yielded a two-fold increase in glucose for coffee shells (205.55 mg/g raw biomass) with binary DESs and for coffee silverskins (179.14 mg/g raw biomass) with ternary DESs. Fermentation with Saccharomyces cerevisiae and Kluyveromyces marxianus increased ethanol yields by up to 75 % for coffee shells and 77 % for coffee silverskins. The maximum yields of ethanol production of 33.29 g/L and 32.05 g/L, respectively, were obtained from coffee shells and silverskins, respectively, by using K. marxianus. Volatile aroma compounds, including phenylethyl alcohol and ethyl acetate, were produced during fermentation, indicating potential applications in food and cosmetics. The ternary DES demonstrated superior performance in the recovery of the cellulose content and improvement of ethanol yield, warranting further research to optimize volatile compound production for industrial use.
{"title":"Production of bioethanol and aroma compounds from pretreated coffee shell and coffee silverskins with binary and ternary deep eutectic solvents","authors":"Prapakorn Tantayotai , Elizabeth Jayex Panakkal , Charoen Trisomboon , Thanyarat Singphrom , Suchata Kirdponpattara , Santi Chuetor , Nagaraju Kottam , Widya Fatriasari , Yu-Shen Cheng , Malinee Sriariyanun","doi":"10.1016/j.scenv.2025.100276","DOIUrl":"10.1016/j.scenv.2025.100276","url":null,"abstract":"<div><div>Coffee shells and silverskins, which are underutilized by-products of the coffee processing industry, offer the potential for value-added products. This study investigated the use of binary and ternary deep eutectic solvents (DESs), choline chloride/oxalic acid (Chcl/OA), and choline chloride/oxalic acid/glycerol (Chcl/OA/Gly), respectively, to pretreat these residues to enhance efficiencies of downstream processes. Optimization experiments identified the optimal pretreatment conditions for coffee shells at 173 min, 120 °C, and 13.99 % and 15.76 % solid loading for binary and ternary DES, respectively. For coffee silverskins, 180 min, 120 °C, and 10 % and 10.21 % solid loadings were found to be optimal. Ternary DES pretreatment enriched the cellulose content and removed hemicellulose and lignin. Enzymatic hydrolysis after pretreatment yielded a two-fold increase in glucose for coffee shells (205.55 mg/g raw biomass) with binary DESs and for coffee silverskins (179.14 mg/g raw biomass) with ternary DESs. Fermentation with <em>Saccharomyces cerevisiae</em> and <em>Kluyveromyces marxianus</em> increased ethanol yields by up to 75 % for coffee shells and 77 % for coffee silverskins. The maximum yields of ethanol production of 33.29 g/L and 32.05 g/L, respectively, were obtained from coffee shells and silverskins, respectively, by using <em>K. marxianus</em>. Volatile aroma compounds, including phenylethyl alcohol and ethyl acetate, were produced during fermentation, indicating potential applications in food and cosmetics. The ternary DES demonstrated superior performance in the recovery of the cellulose content and improvement of ethanol yield, warranting further research to optimize volatile compound production for industrial use.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"11 ","pages":"Article 100276"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144654988","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 : 2025-09-01Epub Date: 2025-07-13DOI: 10.1016/j.scenv.2025.100273
M. Aswin , Prammitha Rajaram , Ambrose Rejo Jeice
The increasing contamination of water sources poses a serious threat to clean water availability. Photocatalytic degradation offers a sustainable solution for wastewater treatment by utilizing light energy to break down pollutants without generating secondary waste. In this study, Rhinacanthus nasutus leaf extract serves as a green reducing and stabilizing agent for the eco-friendly synthesis of CuO bio-nanoparticles (BNPs). The bioactive compounds in the extract facilitate NPs formation while enhancing stability and functional properties. Various characterization techniques, including XRD, UV-Vis spectroscopy, FTIR, SEM-EDX, micro-Raman, and HRTEM analysis, were employed. The bio-fabricated CuO BNPs as monoclinic in crystalline structure with 19 nm size, and 1.61 eV band gap energy of CuO BNPs via UV–vis spectra and irregular spherical shape in morphology were found. The findings of the antimicrobial investigation demonstrated that the CuO BNPs caused the zones that were inhibitors to microorganisms as S. aureus, E. coli and A. flavus. Against three cationic dyes, Methylene Blue, Brilliant Green, and Rhodamine B, CuO NPs demonstrated photocatalytic activity, reaching degradation efficiencies of 92.86 %, 92.83 %, and 93.44 %, respectively.
{"title":"Bio-fabricated CuO nanoparticles using Rhinacanthus nasutus leaf extract for antimicrobial and photocatalytic facets","authors":"M. Aswin , Prammitha Rajaram , Ambrose Rejo Jeice","doi":"10.1016/j.scenv.2025.100273","DOIUrl":"10.1016/j.scenv.2025.100273","url":null,"abstract":"<div><div>The increasing contamination of water sources poses a serious threat to clean water availability. Photocatalytic degradation offers a sustainable solution for wastewater treatment by utilizing light energy to break down pollutants without generating secondary waste. In this study, <em>Rhinacanthus nasutus</em> leaf extract serves as a green reducing and stabilizing agent for the eco-friendly synthesis of CuO bio-nanoparticles (BNPs). The bioactive compounds in the extract facilitate NPs formation while enhancing stability and functional properties. Various characterization techniques, including XRD, UV-Vis spectroscopy, FTIR, SEM-EDX, micro-Raman, and HRTEM analysis, were employed. The bio-fabricated CuO BNPs as monoclinic in crystalline structure with 19 nm size, and 1.61 eV band gap energy of CuO BNPs via UV–vis spectra and irregular spherical shape in morphology were found. The findings of the antimicrobial investigation demonstrated that the CuO BNPs caused the zones that were inhibitors to microorganisms as <em>S. aureus, E. coli</em> and <em>A. flavus</em>. Against three cationic dyes, Methylene Blue, Brilliant Green, and Rhodamine B, CuO NPs demonstrated photocatalytic activity, reaching degradation efficiencies of 92.86 %, 92.83 %, and 93.44 %, respectively.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"11 ","pages":"Article 100273"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704452","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}
Gypsum production in South Africa has surged due to the country’s dependence on coal-fired power plants, resulting in increased generation of fly ash (FA), wet flue gas desulfurization gypsum (WFGDG), and basic oxygen furnace slag (BOFS). This study proposes a sustainable solution for repurposing these industrial by-products into eco-friendly construction materials. A novel binder was developed by blending varying proportions of WFGDG, FA, and BOFS. In these composite blocks, up to 50 wt% of WFGDG was substituted with FA and BOFS. The blends were evaluated for compressive strength, durability, resistance to wet-dry cycles, and environmental impact. The optimum mix-containing 10 wt% FA and 40 wt% BOFS - achieved a compressive strength of 4.4 MPa after 90 days of ambient curing at 40 °C, exceeding the SANS 10145 requirement for Class III mortar. Compaction tests showed that increasing FA content reduced reactivity, with the best performance observed at the mentioned ratio. Microstructural analysis using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) revealed the development of new hydration products and confirmed crystallinity. Despite FA's pozzolanic potential, it does not self-activate due to the absence of alkalis and sulfates. Environmental compliance was verified through the Toxicity Characteristic Leaching Procedure (TCLP), meeting the safety criteria of SANS 227:2007 and ASTM C34–13. The study highlights the potential of these waste-derived composite bricks for load-bearing applications, offering an environmentally and economically sustainable alternative for the construction sector.
{"title":"Utilizing basic oxygen furnace slag and fly ash to stabilize wet flue gas desulfurization gypsum for construction applications","authors":"Dumisane Mahlangu , Keletso Mphahlele , Nomcebo Mthombeni , Bridjesh Pappula , Seshibe Makgato","doi":"10.1016/j.scenv.2025.100278","DOIUrl":"10.1016/j.scenv.2025.100278","url":null,"abstract":"<div><div>Gypsum production in South Africa has surged due to the country’s dependence on coal-fired power plants, resulting in increased generation of fly ash (FA), wet flue gas desulfurization gypsum (WFGDG), and basic oxygen furnace slag (BOFS). This study proposes a sustainable solution for repurposing these industrial by-products into eco-friendly construction materials. A novel binder was developed by blending varying proportions of WFGDG, FA, and BOFS. In these composite blocks, up to 50 wt% of WFGDG was substituted with FA and BOFS. The blends were evaluated for compressive strength, durability, resistance to wet-dry cycles, and environmental impact. The optimum mix-containing 10 wt% FA and 40 wt% BOFS - achieved a compressive strength of 4.4 MPa after 90 days of ambient curing at 40 °C, exceeding the SANS 10145 requirement for Class III mortar. Compaction tests showed that increasing FA content reduced reactivity, with the best performance observed at the mentioned ratio. Microstructural analysis using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) revealed the development of new hydration products and confirmed crystallinity. Despite FA's pozzolanic potential, it does not self-activate due to the absence of alkalis and sulfates. Environmental compliance was verified through the Toxicity Characteristic Leaching Procedure (TCLP), meeting the safety criteria of SANS 227:2007 and ASTM C34–13. The study highlights the potential of these waste-derived composite bricks for load-bearing applications, offering an environmentally and economically sustainable alternative for the construction sector.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"11 ","pages":"Article 100278"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852581","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 : 2025-09-01Epub Date: 2025-07-14DOI: 10.1016/j.scenv.2025.100274
John Elisa Kumar, Mihir Kumar Sahoo
<div><div>Azo dyes are widely used in industries such as textiles and paper, but their complex molecular structures make them resistant to conventional wastewater treatments. Advanced oxidation processes (AOPs) have emerged as efficient alternatives by generating highly reactive radicals for effective degradation. These processes are based on the generation of highly reactive oxidative species, such as hydroxyl radicals and sulphate radicals, for the destruction of the toxic organic pollutants into carbon dioxide, water, and inorganic salts. This study reviews AOPs such as Fenton and Fenton-like processes, UV photolysis, and photo-Fenton methods for azo dye degradation. The Fenton process (<span><math><mrow><msup><mrow><mi>Fe</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup><mo>/</mo><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span>) produces hydroxyl radicals at an optimal pH of ∼3, while the Fenton-type process (<span><math><msup><mrow><mi>Fe</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span>/<span><math><mrow><msub><mrow><mi>S</mi></mrow><mrow><mn>2</mn></mrow></msub><msubsup><mrow><mi>O</mi></mrow><mrow><mn>8</mn></mrow><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></mrow></math></span>) generates sulfate radicals with higher oxidation potential (2.5–3.1 V). UV-assisted processes enhance oxidation by accelerating radical formation. Photo-Fenton and photo-Fenton-type processes integrate UV light to improve <span><math><msup><mrow><mi>Fe</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> regeneration, minimizing sludge formation and increasing efficiency. The efficiency of this process does not depend on a single parameter but on numerous parameters such as the concentration of the oxidant, catalyst doses, pH, treatment period, etc., to attain maximum removal of contaminants. Therefore, it becomes very challenging for the researchers to design an effective and efficient process under suitable operational parameters for the treatment processes. Excess oxidants cause radical scavenging, while inorganic anions (<span><math><msup><mrow><mi>Cl</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span>, <span><math><msubsup><mrow><mi>CO</mi></mrow><mrow><mn>3</mn></mrow><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></math></span>, <span><math><msubsup><mrow><mi>HCO</mi></mrow><mrow><mn>3</mn></mrow><mrow><mo>−</mo></mrow></msubsup></math></span> and <span><math><msubsup><mrow><mi>PO</mi></mrow><mrow><mn>4</mn></mrow><mrow><mn>3</mn><mo>−</mo></mrow></msubsup></math></span>) can inhibit degradation. Temperature (∼25–30°C) affects reaction rates, while excess <span><math><msup><mrow><mi>Fe</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> can lead to sludge formation. Given their economic feasibility and environmental sustainability, AOPs offer a promising solution for mitigating dye pollution and improving wastewater treatme
{"title":"A review on effect of operational parameters for the degradation of azo dyes by some advanced oxidation processes","authors":"John Elisa Kumar, Mihir Kumar Sahoo","doi":"10.1016/j.scenv.2025.100274","DOIUrl":"10.1016/j.scenv.2025.100274","url":null,"abstract":"<div><div>Azo dyes are widely used in industries such as textiles and paper, but their complex molecular structures make them resistant to conventional wastewater treatments. Advanced oxidation processes (AOPs) have emerged as efficient alternatives by generating highly reactive radicals for effective degradation. These processes are based on the generation of highly reactive oxidative species, such as hydroxyl radicals and sulphate radicals, for the destruction of the toxic organic pollutants into carbon dioxide, water, and inorganic salts. This study reviews AOPs such as Fenton and Fenton-like processes, UV photolysis, and photo-Fenton methods for azo dye degradation. The Fenton process (<span><math><mrow><msup><mrow><mi>Fe</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup><mo>/</mo><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span>) produces hydroxyl radicals at an optimal pH of ∼3, while the Fenton-type process (<span><math><msup><mrow><mi>Fe</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span>/<span><math><mrow><msub><mrow><mi>S</mi></mrow><mrow><mn>2</mn></mrow></msub><msubsup><mrow><mi>O</mi></mrow><mrow><mn>8</mn></mrow><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></mrow></math></span>) generates sulfate radicals with higher oxidation potential (2.5–3.1 V). UV-assisted processes enhance oxidation by accelerating radical formation. Photo-Fenton and photo-Fenton-type processes integrate UV light to improve <span><math><msup><mrow><mi>Fe</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> regeneration, minimizing sludge formation and increasing efficiency. The efficiency of this process does not depend on a single parameter but on numerous parameters such as the concentration of the oxidant, catalyst doses, pH, treatment period, etc., to attain maximum removal of contaminants. Therefore, it becomes very challenging for the researchers to design an effective and efficient process under suitable operational parameters for the treatment processes. Excess oxidants cause radical scavenging, while inorganic anions (<span><math><msup><mrow><mi>Cl</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span>, <span><math><msubsup><mrow><mi>CO</mi></mrow><mrow><mn>3</mn></mrow><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></math></span>, <span><math><msubsup><mrow><mi>HCO</mi></mrow><mrow><mn>3</mn></mrow><mrow><mo>−</mo></mrow></msubsup></math></span> and <span><math><msubsup><mrow><mi>PO</mi></mrow><mrow><mn>4</mn></mrow><mrow><mn>3</mn><mo>−</mo></mrow></msubsup></math></span>) can inhibit degradation. Temperature (∼25–30°C) affects reaction rates, while excess <span><math><msup><mrow><mi>Fe</mi></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> can lead to sludge formation. Given their economic feasibility and environmental sustainability, AOPs offer a promising solution for mitigating dye pollution and improving wastewater treatme","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"11 ","pages":"Article 100274"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144662405","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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