Pub Date : 2024-09-30DOI: 10.1016/j.scenv.2024.100164
Simangsa Boro , Bipul Das , Sujata Brahma , Bidangshri Basumatary , Siri Fung Basumatary , Sanjay Basumatary
The current study aims to develop a heterogeneous base catalyst from areca nut (Areca catechu L.) leaf ash incorporated with K2CO3. The composite heterogeneous catalyst was used to catalyze transesterification of a mixture of edible and inedible oils viz. soybean, jatropha and pongamia oil for biodiesel production. The characterization of the catalyst was done by Field emission scanning electron microscopy (FESEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), High resolution transmission electron microscopy (HRTEM), and Brunauer–Emmett–Teller (BET). The highest biodiesel yield of 96.57 ± 0.81 % was attained in 3.35 ± 0.15 h under optimal conditions of 9:1 molar ratio of methanol to oil (MRMO), 15 wt% catalyst concentration at 65 °C temperature. The reusability of the catalyst was successfully studied till 3rd cycle, resulting in 82.76 ± 0.80 % biodiesel yield. The feasibility of the resultant methyl esters was asserted by FT-IR, Carbon-13 nuclear magnetic resonance (13C NMR), Proton nuclear magnetic resonance (1H NMR), and Gas chromatography-Mass spectrometry (GC-MS) analyses. The developed catalyst can be considered an active catalyst, which is advantageous because of its cost-effectiveness and environmentally friendly nature.
{"title":"Biodiesel production using areca nut (Areca catechu L.) leaf ash-K2CO3 catalyst via transesterification from an oil blend of three different feedstocks","authors":"Simangsa Boro , Bipul Das , Sujata Brahma , Bidangshri Basumatary , Siri Fung Basumatary , Sanjay Basumatary","doi":"10.1016/j.scenv.2024.100164","DOIUrl":"10.1016/j.scenv.2024.100164","url":null,"abstract":"<div><div>The current study aims to develop a heterogeneous base catalyst from areca nut (<em>Areca catechu</em> L.) leaf ash incorporated with K<sub>2</sub>CO<sub>3</sub>. The composite heterogeneous catalyst was used to catalyze transesterification of a mixture of edible and inedible oils <em>viz.</em> soybean, jatropha and pongamia oil for biodiesel production. The characterization of the catalyst was done by Field emission scanning electron microscopy (FESEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), High resolution transmission electron microscopy (HRTEM), and Brunauer–Emmett–Teller (BET). The highest biodiesel yield of 96.57 ± 0.81 % was attained in 3.35 ± 0.15 h under optimal conditions of 9:1 molar ratio of methanol to oil (MRMO), 15 wt% catalyst concentration at 65 °C temperature. The reusability of the catalyst was successfully studied till 3rd cycle, resulting in 82.76 ± 0.80 % biodiesel yield. The feasibility of the resultant methyl esters was asserted by FT-IR, Carbon-13 nuclear magnetic resonance (<sup>13</sup>C NMR), Proton nuclear magnetic resonance (<sup>1</sup>H NMR), and Gas chromatography-Mass spectrometry (GC-MS) analyses. The developed catalyst can be considered an active catalyst, which is advantageous because of its cost-effectiveness and environmentally friendly nature.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"8 ","pages":"Article 100164"},"PeriodicalIF":0.0,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, Co/Zn doped α-Fe2O3 (Hematite) nanoparticles (NPs) were synthesized using polyvinylpyrrolidone (PVP) and Azadirachta indica (AI) leaves aqueous extract. The analytical techniques including XRD, UV, SEM, EDX, VSM, Raman, and FTIR, we were able to identify and characterize the structural, morphological and magnetic attributes of the synthesized NPs. The findings demonstrated that the synthesized NPs exhibit homogeneous spherical shapes with particle sizes ranging from 8.64 to 15.32 nm. The NPs have rhombohedral crystal lattices, with crystallite sizes of 23.25 nm for chemically synthesized doped α-Fe2O3 NPs and 12.52 nm for those synthesized using green methods. The magnetic study has shown that the saturation magnetization (Ms) value of NPs, which ranges from 36 to 45 emu/g at ambient temperature, exhibits superparamagnetic properties (300 K). The treatment of industrial wastewater and its reuse for agricultural purposes are the subjects of the current study. Different concentrations of doped α-Fe2O3 NPs were used as photocatalysts to degrade dyes in a bioreactor under UV light in a heterogeneous mixture. The degradation rates achieved were 96.42 % for Congo Red (CR) and 98.36 % for Eosin Yellow (EY). DPPH assays were conducted to evaluate the antioxidant activity of the synthesized doped α-Fe2O3 NPs. The percentage inhibition of DPPH radicals ranged from 71.13 % to 90.35 %. Our findings indicate that AI leaf extract holds promise as a valuable resource for the development of bioactive compounds and environmentally friendly approaches to synthesizing green NPs. This is primarily attributed to the increased accessibility of bioactive components with potent antioxidant properties. The combination of these benefits provides opportunities for novel uses in environmental cleanup, biological applications, and energy conversion.
{"title":"Water purification and biological efficacy of green synthesized Co/Zn-Doped α-Fe2O3 nanoparticles","authors":"Pankaj Kumar , Sunil Kumar , Ashwani Tapwal , Surendra Nimesh , Naveen Thakur","doi":"10.1016/j.scenv.2024.100160","DOIUrl":"10.1016/j.scenv.2024.100160","url":null,"abstract":"<div><div>In the present study, Co/Zn doped α-Fe<sub>2</sub>O<sub>3</sub> (Hematite) nanoparticles (NPs) were synthesized using polyvinylpyrrolidone (PVP) and <em>Azadirachta indica</em> (AI) leaves aqueous extract. The analytical techniques including XRD, UV, SEM, EDX, VSM, Raman, and FTIR, we were able to identify and characterize the structural, morphological and magnetic attributes of the synthesized NPs. The findings demonstrated that the synthesized NPs exhibit homogeneous spherical shapes with particle sizes ranging from 8.64 to 15.32 nm. The NPs have rhombohedral crystal lattices, with crystallite sizes of 23.25 nm for chemically synthesized doped α-Fe<sub>2</sub>O<sub>3</sub> NPs and 12.52 nm for those synthesized using green methods. The magnetic study has shown that the saturation magnetization (Ms) value of NPs, which ranges from 36 to 45 emu/g at ambient temperature, exhibits superparamagnetic properties (300 K). The treatment of industrial wastewater and its reuse for agricultural purposes are the subjects of the current study. Different concentrations of doped α-Fe<sub>2</sub>O<sub>3</sub> NPs were used as photocatalysts to degrade dyes in a bioreactor under UV light in a heterogeneous mixture. The degradation rates achieved were 96.42 % for Congo Red (CR) and 98.36 % for Eosin Yellow (EY). DPPH assays were conducted to evaluate the antioxidant activity of the synthesized doped α-Fe<sub>2</sub>O<sub>3</sub> NPs. The percentage inhibition of DPPH radicals ranged from 71.13 % to 90.35 %. Our findings indicate that AI leaf extract holds promise as a valuable resource for the development of bioactive compounds and environmentally friendly approaches to synthesizing green NPs. This is primarily attributed to the increased accessibility of bioactive components with potent antioxidant properties. The combination of these benefits provides opportunities for novel uses in environmental cleanup, biological applications, and energy conversion.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"8 ","pages":"Article 100160"},"PeriodicalIF":0.0,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-26DOI: 10.1016/j.scenv.2024.100163
R.M.N. Sulochani , R.A. Jayasinghe , G. Priyadarshana , A.H.L.R. Nilmini , M. Ashokcline , P.D. Dharmaratne
The textile industry significantly contributes to environmental pollution, generating substantial amounts of waste. The prevailing linear model exacerbates this issue, accumulating a significant portion of the waste in landfills. This research aimed to tackle these challenges by developing value-added composites from post-industrial textile waste and packaging materials, for non-structural building applications. To achieve this, shredded polyester textile waste fibers served as the reinforcement, while waste packaging was used as the matrix. Varying fiber-matrix weight percentages seven composite types were developed. The physical, mechanical, and thermal properties of the composites were evaluated. The findings indicated that these composites exhibited properties comparable to those of commercial partition boards. Notably, composites with fiber weight percentages of 7.5 % and 10 % demonstrated the most favorable performance among the tested variations. Emphasizing the application of sustainable chemistry, this study highlights the potential of these composites to develop substitute materials for non-structural building applications. Moreover, it presents a promising solution to address the textile waste management challenge and value-added materials for the construction industry in a developing context.
{"title":"Waste-based composites using post-industrial textile waste and packaging waste from the textile manufacturing industry for non-structural applications","authors":"R.M.N. Sulochani , R.A. Jayasinghe , G. Priyadarshana , A.H.L.R. Nilmini , M. Ashokcline , P.D. Dharmaratne","doi":"10.1016/j.scenv.2024.100163","DOIUrl":"10.1016/j.scenv.2024.100163","url":null,"abstract":"<div><div>The textile industry significantly contributes to environmental pollution, generating substantial amounts of waste. The prevailing linear model exacerbates this issue, accumulating a significant portion of the waste in landfills. This research aimed to tackle these challenges by developing value-added composites from post-industrial textile waste and packaging materials, for non-structural building applications. To achieve this, shredded polyester textile waste fibers served as the reinforcement, while waste packaging was used as the matrix. Varying fiber-matrix weight percentages seven composite types were developed. The physical, mechanical, and thermal properties of the composites were evaluated. The findings indicated that these composites exhibited properties comparable to those of commercial partition boards. Notably, composites with fiber weight percentages of 7.5 % and 10 % demonstrated the most favorable performance among the tested variations. Emphasizing the application of sustainable chemistry, this study highlights the potential of these composites to develop substitute materials for non-structural building applications. Moreover, it presents a promising solution to address the textile waste management challenge and value-added materials for the construction industry in a developing context.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"8 ","pages":"Article 100163"},"PeriodicalIF":0.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-26DOI: 10.1016/j.scenv.2024.100159
Sergio Armando Cruz Briano , Nahum Andrés Medellín Castillo , Juan Carlos Moreno Piraján , Liliana Giraldo Gutiérrez , Guillermo Javier Castro Larragoitia , Pablo Delgado Sánchez , Alfredo Israel Flores Rojas , Hilda Guadalupe Cisneros Ontiveros
In this study, the optimization of the synthesis variables of hydrochar (HC) and pyrohydrochar (PHC) obtained from pleco fish spines that would generate the highest fluoride adsorption capacity and synthesis yield was carried out. For this purpose, a D-Optimal experimental composite central design was established using response surface methodology (RSM) considering three levels for temperature and synthesis time. Hydrochar was produced by hydrothermal carbonization at temperatures of 180–240 °C for 4–8 h in the presence of water under autogenous pressure. On the other hand, pyrohydrochar was obtained by pyrolysis of hydrochar in the absence of water at temperatures of 350–650 °C for 1–2 h at autogenous pressures (2–20 MPa). The results of the D-Optimal design indicated that the materials synthesized at lower temperatures and times, particularly at 180 °C - 4 h (HC1) and 350 °C - 1.5 h (PHC5), achieved the highest adsorption yield and capacity, with values of 87.9 % and 5.27 mg g−1; and 94.8 % and 5.73 mg g−1 for HC1 and PHC5, respectively. Analysis of variance (ANOVA) on the synthesis model revealed that temperature and carbonization time are significant factors, both factors have an influence on HC and PHC fluoride adsorption capacity and HC yield and only temperature affects PHC yield. The optimum synthesis conditions to obtain the highest yields were 180 °C for 4 h and 350 °C for 1 h for HC and PHC, respectively, with 88.4 % and 96.2 % values. As for the maximum adsorption capacity, the optimum temperature and time values were 185 °C for 4 h and 378 °C for 1 h for HC and PHC, respectively, reaching adsorption capacities of 5.27 mg g−1 and 5.64 mg g−1. In addition, HC1 and PHC5 materials were characterized by N2 physisorption, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), CHNS elemental analysis and scanning electron microscopy (SEM). These materials showed differences among themselves, where the higher specific area of PCH5 with 137 m2 g−1, with respect to HC1 with 119 m2 g−1, stands out, as well as a higher concentration of basic sites, being 1.65 and 1.40 meq g−1 for HC1 and PHC5, respectively, on the other hand, the FTIR showed the same functional groups present on the surface, although in the SEM it was observed that the surface of HC1 presented small fractures, which disappeared when subjected to the pyrolysis process, in addition, the TGA showed a greater amount of organic matter in HC1 that could affect the adsorption of fluorides. The effect of pH on the adsorption capacity of HC1 and PHC5 fluorides was also investigated, revealing an increase of this capacity with decreasing solution pH due to electrostatic forces.
{"title":"Optimization of synthesis conditions of hydrochar and pyrohydrochar from fish bones for their use in the adsorption of fluoride from water","authors":"Sergio Armando Cruz Briano , Nahum Andrés Medellín Castillo , Juan Carlos Moreno Piraján , Liliana Giraldo Gutiérrez , Guillermo Javier Castro Larragoitia , Pablo Delgado Sánchez , Alfredo Israel Flores Rojas , Hilda Guadalupe Cisneros Ontiveros","doi":"10.1016/j.scenv.2024.100159","DOIUrl":"10.1016/j.scenv.2024.100159","url":null,"abstract":"<div><div>In this study, the optimization of the synthesis variables of hydrochar (HC) and pyrohydrochar (PHC) obtained from pleco fish spines that would generate the highest fluoride adsorption capacity and synthesis yield was carried out. For this purpose, a D-Optimal experimental composite central design was established using response surface methodology (RSM) considering three levels for temperature and synthesis time. Hydrochar was produced by hydrothermal carbonization at temperatures of 180–240 °C for 4–8 h in the presence of water under autogenous pressure. On the other hand, pyrohydrochar was obtained by pyrolysis of hydrochar in the absence of water at temperatures of 350–650 °C for 1–2 h at autogenous pressures (2–20 MPa). The results of the D-Optimal design indicated that the materials synthesized at lower temperatures and times, particularly at 180 °C - 4 h (HC1) and 350 °C - 1.5 h (PHC5), achieved the highest adsorption yield and capacity, with values of 87.9 % and 5.27 mg g<sup>−1</sup>; and 94.8 % and 5.73 mg g<sup>−1</sup> for HC1 and PHC5, respectively. Analysis of variance (ANOVA) on the synthesis model revealed that temperature and carbonization time are significant factors, both factors have an influence on HC and PHC fluoride adsorption capacity and HC yield and only temperature affects PHC yield. The optimum synthesis conditions to obtain the highest yields were 180 °C for 4 h and 350 °C for 1 h for HC and PHC, respectively, with 88.4 % and 96.2 % values. As for the maximum adsorption capacity, the optimum temperature and time values were 185 °C for 4 h and 378 °C for 1 h for HC and PHC, respectively, reaching adsorption capacities of 5.27 mg g<sup>−1</sup> and 5.64 mg g<sup>−1</sup>. In addition, HC1 and PHC5 materials were characterized by N<sub>2</sub> physisorption, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), CHNS elemental analysis and scanning electron microscopy (SEM). These materials showed differences among themselves, where the higher specific area of PCH5 with 137 m<sup>2</sup> g<sup>−1</sup>, with respect to HC1 with 119 m<sup>2</sup> g<sup>−1</sup>, stands out, as well as a higher concentration of basic sites, being 1.65 and 1.40 meq g<sup>−1</sup> for HC1 and PHC5, respectively, on the other hand, the FTIR showed the same functional groups present on the surface, although in the SEM it was observed that the surface of HC1 presented small fractures, which disappeared when subjected to the pyrolysis process, in addition, the TGA showed a greater amount of organic matter in HC1 that could affect the adsorption of fluorides. The effect of pH on the adsorption capacity of HC1 and PHC5 fluorides was also investigated, revealing an increase of this capacity with decreasing solution pH due to electrostatic forces.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"8 ","pages":"Article 100159"},"PeriodicalIF":0.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-25DOI: 10.1016/j.scenv.2024.100161
Liliana Giraldo , Juan Carlos Moreno-Piraján
The pressing need to mitigate the presence of harmful gases in the atmosphere motivates scientific and engineering endeavors to devise effective adsorption solutions. Achieving practical and specific adsorption is essential for improving capture processes, with CO2 being a prominent target due to its significant environmental repercussions. Metal-organic frameworks (MOFs), distinguished by their high porosity and adaptable structure, have emerged as promising candidates for CO2 adsorption. Especially noteworthy are functionalized MOFs, which augment adsorption capacity, selectivity, and heat of adsorption. This research investigates CO2 adsorption on HKUST-1 modified with three amines of varying strengths, evaluating adsorption capacity and thermal impacts using direct adsorption calorimetry and Van't Hoff thermodynamic models.
{"title":"Investigating discrepancies in adsorption enthalpy predictions: An analysis of CO2 adsorption on HKUSTs","authors":"Liliana Giraldo , Juan Carlos Moreno-Piraján","doi":"10.1016/j.scenv.2024.100161","DOIUrl":"10.1016/j.scenv.2024.100161","url":null,"abstract":"<div><div>The pressing need to mitigate the presence of harmful gases in the atmosphere motivates scientific and engineering endeavors to devise effective adsorption solutions. Achieving practical and specific adsorption is essential for improving capture processes, with CO<sub>2</sub> being a prominent target due to its significant environmental repercussions. Metal-organic frameworks (MOFs), distinguished by their high porosity and adaptable structure, have emerged as promising candidates for CO<sub>2</sub> adsorption. Especially noteworthy are functionalized MOFs, which augment adsorption capacity, selectivity, and heat of adsorption. This research investigates CO<sub>2</sub> adsorption on HKUST-1 modified with three amines of varying strengths, evaluating adsorption capacity and thermal impacts using direct adsorption calorimetry and Van't Hoff thermodynamic models.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"8 ","pages":"Article 100161"},"PeriodicalIF":0.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1016/j.scenv.2024.100162
Sangram Keshari Sahu, Amrita Palai, Dojalisa Sahu
Change in human lifestyle and excessive use of commercial products have caused an ecological deterioration. A major contribution towards this comes from the mixing of toxins and persistent organic pollutants into water bodies, which poses a serious risk to the ecosystem. In the above context, materials scientists are involved in the search for sustainable solutions to address the above environmental challenges by the development of advanced materials. In this study, we prepared nanocomposite materials such as; ZnO-SnO2 and ZnO-MoS2 by wet-chemical approach to degrade dye pollutants like Rhodamine B (RhB) and Congo red (CR) towards achieving environmental remediation. Powder X-ray diffraction (PXRD) measurement was done for structural characterization of the samples and the formation of the nanocomposite phase was validated by the above study. The goal of the field emission scanning electron microscopy (FESEM) study was to examine the morphology of the composites which was accompanied by the energy dispersive analysis of x-rays (EDAX) and electron mapping experiments which verified the presence of Zn, Sn, O, Mo, S elements in the respective samples. Fourier transformed infrared spectroscopy (FTIR) meas urement was conducted to investigate the vibrational properties of the samples. Photocatalytic measurement showed improved degradation efficiency of the composites as compared to the pristine samples. The degradation efficiency was found to increase with irradiation time and attained saturation after 180 min. ZnO-SnO2 nanocomposite show 91.23 % and 88.11 % of degradation for RhB and CR dyes respectively whereas 89.29 % and 83.25 % degradation have been obtained for ZnO-MoS2 for the same dyes. Several aspects of the experiment were varied, including the amount of catalyst employed, the initial dye concentration, and the pH levels, in order to assess the efficacy of the photocatalysts. Both the photocatalysts degraded CR dye most effectively at acidic pH, although RhB dye gets degraded more at neutral and alkaline pH. ZnO-SnO2 was found to be an effective photocatalyst for degrading RhB dye at neutral pH and CR dye at acidic pH. After multiple iterations of experimentation, the photocatalytic mechanism has been extensively described, and the stability and reusability of the photocatalysts have been ensured for effective environmental cleanup.
{"title":"Photocatalytic applications of metal oxide-based nanocomposites for sustainable environmental remediation","authors":"Sangram Keshari Sahu, Amrita Palai, Dojalisa Sahu","doi":"10.1016/j.scenv.2024.100162","DOIUrl":"10.1016/j.scenv.2024.100162","url":null,"abstract":"<div><div>Change in human lifestyle and excessive use of commercial products have caused an ecological deterioration. A major contribution towards this comes from the mixing of toxins and persistent organic pollutants into water bodies, which poses a serious risk to the ecosystem. In the above context, materials scientists are involved in the search for sustainable solutions to address the above environmental challenges by the development of advanced materials. In this study, we prepared nanocomposite materials such as; ZnO-SnO<sub>2</sub> and ZnO-MoS<sub>2</sub> by wet-chemical approach to degrade dye pollutants like Rhodamine B (RhB) and Congo red (CR) towards achieving environmental remediation. Powder X-ray diffraction (PXRD) measurement was done for structural characterization of the samples and the formation of the nanocomposite phase was validated by the above study. The goal of the field emission scanning electron microscopy (FESEM) study was to examine the morphology of the composites which was accompanied by the energy dispersive analysis of x-rays (EDAX) and electron mapping experiments which verified the presence of Zn, Sn, O, Mo, S elements in the respective samples. Fourier transformed infrared spectroscopy (FTIR) meas urement was conducted to investigate the vibrational properties of the samples. Photocatalytic measurement showed improved degradation efficiency of the composites as compared to the pristine samples. The degradation efficiency was found to increase with irradiation time and attained saturation after 180 min. ZnO-SnO<sub>2</sub> nanocomposite show 91.23 % and 88.11 % of degradation for RhB and CR dyes respectively whereas 89.29 % and 83.25 % degradation have been obtained for ZnO-MoS<sub>2</sub> for the same dyes. Several aspects of the experiment were varied, including the amount of catalyst employed, the initial dye concentration, and the pH levels, in order to assess the efficacy of the photocatalysts. Both the photocatalysts degraded CR dye most effectively at acidic pH, although RhB dye gets degraded more at neutral and alkaline pH. ZnO-SnO<sub>2</sub> was found to be an effective photocatalyst for degrading RhB dye at neutral pH and CR dye at acidic pH. After multiple iterations of experimentation, the photocatalytic mechanism has been extensively described, and the stability and reusability of the photocatalysts have been ensured for effective environmental cleanup.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"8 ","pages":"Article 100162"},"PeriodicalIF":0.0,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-23DOI: 10.1016/j.scenv.2024.100158
Diwakar Kumar Singh, Anurag Garg
Hydrothermal pretreatment (HTP) is used to convert biomass into hydrochar (HC) through the application of heat and pressure in a water-based medium. The HC has emerged as a promising material for various environmental applications including wastewater treatment, soil amendment, and carbon sequestration. In this study, the applicability of sewage sludge (SS) derived HC was tested as an adsorbent for methylene blue (MB) dye removal from wastewater. The HC was also subjected to chemical activation with KOH before the adsorption study. The HC samples were characterized for structural morphology and molecular functionalities using instrumental analysis. All the HC samples exhibited almost similar adsorption capacity (∼190 mg/g) for MB after 24 h of contact time (MB concentration = 200 mg/L, solution pH = 7 and adsorbent dose = 1 g/L). The equilibrium data could be adequately fit in Langmuir model equation. The negative value of free energy indicated favorable MB adsorption process. The study demonstrated that the SS derived HC can be recycled as adsorbent in wastewater treatment plant which is not only an environment-friendly approach but also may reduce cost of tertiary treatment at sewage treatment plant often required to remove emerging contaminants.
水热预处理（HTP）是通过在水基介质中施加热量和压力，将生物质转化为水炭（HC）。碳氢化合物已成为一种很有前景的材料，可用于各种环境应用，包括废水处理、土壤改良和碳封存。本研究测试了污水污泥（SS）衍生的碳氢化合物作为吸附剂去除废水中亚甲基蓝（MB）染料的适用性。在进行吸附研究之前，还用 KOH 对 HC 进行了化学活化。利用仪器分析对 HC 样品的结构形态和分子功能进行了表征。接触 24 小时后（甲基溴浓度 = 200 毫克/升，溶液 pH = 7，吸附剂剂量 = 1 克/升），所有 HC 样品对甲基溴的吸附能力（∼190 毫克/克）几乎相似。平衡数据可以用 Langmuir 模型方程充分拟合。自由能的负值表明甲基溴的吸附过程是有利的。研究结果表明，从 SS 中提取的 HC 可作为吸附剂在污水处理厂中循环使用，这不仅是一种环境友好型方法，还可以降低污水处理厂为去除新出现的污染物通常需要进行的三级处理的成本。
{"title":"Application of sewage sludge derived hydrochar as an adsorbent for removal of methylene blue","authors":"Diwakar Kumar Singh, Anurag Garg","doi":"10.1016/j.scenv.2024.100158","DOIUrl":"10.1016/j.scenv.2024.100158","url":null,"abstract":"<div><div>Hydrothermal pretreatment (HTP) is used to convert biomass into hydrochar (HC) through the application of heat and pressure in a water-based medium. The HC has emerged as a promising material for various environmental applications including wastewater treatment, soil amendment, and carbon sequestration. In this study, the applicability of sewage sludge (SS) derived HC was tested as an adsorbent for methylene blue (MB) dye removal from wastewater. The HC was also subjected to chemical activation with KOH before the adsorption study. The HC samples were characterized for structural morphology and molecular functionalities using instrumental analysis. All the HC samples exhibited almost similar adsorption capacity (∼190 mg/g) for MB after 24 h of contact time (MB concentration = 200 mg/L, solution pH = 7 and adsorbent dose = 1 g/L). The equilibrium data could be adequately fit in Langmuir model equation. The negative value of free energy indicated favorable MB adsorption process. The study demonstrated that the SS derived HC can be recycled as adsorbent in wastewater treatment plant which is not only an environment-friendly approach but also may reduce cost of tertiary treatment at sewage treatment plant often required to remove emerging contaminants.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"8 ","pages":"Article 100158"},"PeriodicalIF":0.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There is a constant search for new extraction methods for secondary metabolites from plants to improve efficiency and reduce the process cost and waste. Green extraction techniques such as microwave-assisted extraction, ultrasonic-assisted extraction, and shock wave-assisted extraction are an alternative that minimizes energy intake and reduces extraction time. Additionally, using green solvents reduces waste pollution to the environment by eliminating organic solvents. Using green extraction methods along with green solvents such as natural deep eutectic solvents, deep eutectic solvents, CO2 in supercritical conditions, water, and ethanol challenge the efficiency of traditional extraction methods and organic solvents. It is well known that plants are a rich source of diverse secondary metabolites that can be used in pharmacology and biomedicine for health purposes. On the downside, in the extraction process, toxic adducts can be frequently obtained because of the use of elevated temperature and organic solvents. The use of novel green extraction methods enhances extraction yield by cell disruption omitting heat and preventing structural damage to the secondary metabolites. Green extraction pursues that using safer and less hazardous reagents, cleaner extraction methods, and the obtention of safer products can develop environmentally friendly chemistry that can be a healthy alternative for biological applications. The objective of this review was to lay out different extraction methods used to obtain secondary metabolites from plants, comparing the efficiency of green extraction methods using green solvents in contrast with traditional extraction methods using organic solvents. In this review, we outline the state-of-the-art the last five years of the green extraction methods used for the obtention of secondary metabolites from plants. Positively, an overview of the green extraction methods will present the researcher with a wide range of cleaner techniques that can replace traditional extraction methods of secondary metabolites obtained from plants.
{"title":"Green extraction of secondary metabolites from plants: Obstacles, current status, and trends","authors":"Daniela Torres-Ortiz , Guadalupe García-Alcocer , Laura Cristina Berumen-Segura , Miriam Estévez","doi":"10.1016/j.scenv.2024.100157","DOIUrl":"10.1016/j.scenv.2024.100157","url":null,"abstract":"<div><div>There is a constant search for new extraction methods for secondary metabolites from plants to improve efficiency and reduce the process cost and waste. Green extraction techniques such as microwave-assisted extraction, ultrasonic-assisted extraction, and shock wave-assisted extraction are an alternative that minimizes energy intake and reduces extraction time. Additionally, using green solvents reduces waste pollution to the environment by eliminating organic solvents. Using green extraction methods along with green solvents such as natural deep eutectic solvents, deep eutectic solvents, CO<sub>2</sub> in supercritical conditions, water, and ethanol challenge the efficiency of traditional extraction methods and organic solvents. It is well known that plants are a rich source of diverse secondary metabolites that can be used in pharmacology and biomedicine for health purposes. On the downside, in the extraction process, toxic adducts can be frequently obtained because of the use of elevated temperature and organic solvents. The use of novel green extraction methods enhances extraction yield by cell disruption omitting heat and preventing structural damage to the secondary metabolites. Green extraction pursues that using safer and less hazardous reagents, cleaner extraction methods, and the obtention of safer products can develop environmentally friendly chemistry that can be a healthy alternative for biological applications. The objective of this review was to lay out different extraction methods used to obtain secondary metabolites from plants, comparing the efficiency of green extraction methods using green solvents in contrast with traditional extraction methods using organic solvents. In this review, we outline the state-of-the-art the last five years of the green extraction methods used for the obtention of secondary metabolites from plants. Positively, an overview of the green extraction methods will present the researcher with a wide range of cleaner techniques that can replace traditional extraction methods of secondary metabolites obtained from plants.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"8 ","pages":"Article 100157"},"PeriodicalIF":0.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Increased industrialization has elevated heavy metal pollution in soil. Considering their hazardous impact on the ecosystem, it is important to lower heavy metals concentration from the polluted soil. Standard physicochemical methods for metal remediation are quick, effective, and operational; nevertheless, they come with a high cost and are not appropriate for large contaminated areas. They require a lot of energy, produce a large amount of toxic sludge, are not practical for low metal concentrations, and are not eco-friendly. An effective technique for eradicating hazardous heavy metals from contaminated soil is desperately needed given the state of environmental degradation that exists today. Using microorganisms, particularly bacteria resistant to hazardous metals, is the most economical method known as bioremediation. Owing to the enduring characteristics of heavy metals in polluted soil, inhabitant microorganisms require bioengineering in order to assess an appropriate biotechnical method for the removal and/or detoxification of heavy metals in contaminated soil. Many microorganisms have been reported with the ability to alleviate heavy metals from a contaminated environment; Lysinibacillus being one of them. This review highlights the efficiency of Lysinibacillus in heavy metal remediation and how exactly this genus dealt with metal stress at the cellular level. We have evaluated various studies of bioremediation by this particular genus and also illuminated its plant growth-promoting properties.
{"title":"Revolutionizing remediation: Unveiling the power of Lysinibacillus sp. in tackling heavy metal stress","authors":"Akanksha Gupta, Chhavi Siwach, Virendra Kumar Mishra","doi":"10.1016/j.scenv.2024.100156","DOIUrl":"10.1016/j.scenv.2024.100156","url":null,"abstract":"<div><div>Increased industrialization has elevated heavy metal pollution in soil. Considering their hazardous impact on the ecosystem, it is important to lower heavy metals concentration from the polluted soil. Standard physicochemical methods for metal remediation are quick, effective, and operational; nevertheless, they come with a high cost and are not appropriate for large contaminated areas. They require a lot of energy, produce a large amount of toxic sludge, are not practical for low metal concentrations, and are not eco-friendly. An effective technique for eradicating hazardous heavy metals from contaminated soil is desperately needed given the state of environmental degradation that exists today. Using microorganisms, particularly bacteria resistant to hazardous metals, is the most economical method known as bioremediation. Owing to the enduring characteristics of heavy metals in polluted soil, inhabitant microorganisms require bioengineering in order to assess an appropriate biotechnical method for the removal and/or detoxification of heavy metals in contaminated soil. Many microorganisms have been reported with the ability to alleviate heavy metals from a contaminated environment; <em>Lysinibacillus</em> being one of them. This review highlights the efficiency of <em>Lysinibacillus</em> in heavy metal remediation and how exactly this genus dealt with metal stress at the cellular level. We have evaluated various studies of bioremediation by this particular genus and also illuminated its plant growth-promoting properties.</div></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"8 ","pages":"Article 100156"},"PeriodicalIF":0.0,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949839224000993/pdfft?md5=8f6027b411c1360129255ddfc2f85987&pid=1-s2.0-S2949839224000993-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1016/j.scenv.2024.100155
Abir Chakravorty , Somnath Roy
The industrial revolution has improved living standards while destroying the natural world, and as a result, environmental pollution has become a serious concern for both developed and developing countries. Furthermore, photocatalysis is a chemical process that uses light energy to accelerate thermodynamically demanding operations, such as photosynthesis, which makes it a viable substitute for deep solar energy storage. Reduced exposure to chemicals and toxins released into the environment by industrial activity is another great benefit of this method. First and foremost, photocatalysis allows fossil fuels to be used for other purposes by substituting low-temperature pollution removal processes with high-temperature ones. Since they may exist in numerous valences and have excellent catalytic efficiency, various photocatalytic materials such as AgCl, P-doped g-C3N4, and Z-scheme photocatalysts coupled with Fe3O4/H2O2 have received interest as photocatalysts. One issue covered in the reviews is the Z-scheme strategy, which focuses on creating heterojunctions with appropriate band alignments to improve electron transport pathways and increase MnO2's photocatalytic activity. The review discusses the latest developments in photocatalysis, MnO2-based composites for photocatalytic capabilities, and the Z-scheme charge carrier mechanism. The electrical, photoelectric, and crystallographic properties of MnO2 are discussed in the review article, with a focus on the relevance of the Z-scheme electron transfer pathway in augmenting photocatalytic activity. Exploring several electron transport channels in MnO2-based composites, various characterization approaches offer insights into the Z-scheme mechanism. Moreover, we have reviewed various Photocatalysis, basic principles, processes, and materials.
工业革命在提高生活水平的同时也破坏了自然界，因此，环境污染已成为发达国家和发展中国家严重关切的问题。此外，光催化是一种利用光能加速热力学要求较高的操作（如光合作用）的化学过程，这使其成为深度太阳能储存的可行替代品。减少接触工业活动释放到环境中的化学物质和毒素是这种方法的另一大好处。最重要的是，光催化技术可以用高温工艺代替低温除污工艺，从而将化石燃料用于其他用途。各种光催化材料，如 AgCl、掺杂 P 的 g-C3N4，以及与 Fe3O4/H2O2 相结合的 Z 型光催化剂，因其可能以多种价态存在并具有出色的催化效率而作为光催化剂受到关注。综述中涉及的一个问题是 Z 型策略，其重点是创建具有适当带排列的异质结，以改善电子传输途径并提高 MnO2 的光催化活性。综述讨论了光催化的最新发展、基于二氧化锰的复合材料的光催化能力以及 Z 型电荷载流子机制。综述文章讨论了二氧化锰的电学、光电和晶体学特性，重点是 Z 型电子传递途径在增强光催化活性方面的相关性。我们探讨了基于二氧化锰的复合材料中的几种电子传递途径，并通过各种表征方法深入探讨了 Z 型电子传递机制。此外，我们还回顾了各种光催化的基本原理、过程和材料。
{"title":"A review of photocatalysis, basic principles, processes, and materials","authors":"Abir Chakravorty , Somnath Roy","doi":"10.1016/j.scenv.2024.100155","DOIUrl":"10.1016/j.scenv.2024.100155","url":null,"abstract":"<div><p>The industrial revolution has improved living standards while destroying the natural world, and as a result, environmental pollution has become a serious concern for both developed and developing countries. Furthermore, photocatalysis is a chemical process that uses light energy to accelerate thermodynamically demanding operations, such as photosynthesis, which makes it a viable substitute for deep solar energy storage. Reduced exposure to chemicals and toxins released into the environment by industrial activity is another great benefit of this method. First and foremost, photocatalysis allows fossil fuels to be used for other purposes by substituting low-temperature pollution removal processes with high-temperature ones. Since they may exist in numerous valences and have excellent catalytic efficiency, various photocatalytic materials such as AgCl, P-doped g-C<sub>3</sub>N<sub>4</sub>, and Z-scheme photocatalysts coupled with Fe<sub>3</sub>O<sub>4</sub>/H<sub>2</sub>O<sub>2</sub> have received interest as photocatalysts. One issue covered in the reviews is the Z-scheme strategy, which focuses on creating heterojunctions with appropriate band alignments to improve electron transport pathways and increase MnO<sub>2</sub>'s photocatalytic activity. The review discusses the latest developments in photocatalysis, MnO2-based composites for photocatalytic capabilities, and the Z-scheme charge carrier mechanism. The electrical, photoelectric, and crystallographic properties of MnO<sub>2</sub> are discussed in the review article, with a focus on the relevance of the Z-scheme electron transfer pathway in augmenting photocatalytic activity. Exploring several electron transport channels in MnO<sub>2</sub>-based composites, various characterization approaches offer insights into the Z-scheme mechanism. Moreover, we have reviewed various Photocatalysis, basic principles, processes, and materials.</p></div>","PeriodicalId":101196,"journal":{"name":"Sustainable Chemistry for the Environment","volume":"8 ","pages":"Article 100155"},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949839224000981/pdfft?md5=b143ed1adca7b097e577e87ad31066f3&pid=1-s2.0-S2949839224000981-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142168055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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