Pub Date : 2024-01-20DOI: 10.1038/s41545-024-00297-7
Jiu Luo, Mingheng Li, Yi Heng
Ultrapermeable membranes (UPMs) have the potential of improving water production efficiency. However, operating at high water fluxes will intensify concentration polarization and membrane fouling. Inspired by the V-formation of birds in nature we propose a transformative membrane module that enables a doubled mass transfer coefficient with a moderately increased friction loss coefficient. Moreover, we present a practical technological pathway for the UPM systems to achieve 338% improvement of average water flux and 18% energy savings relative to state-of-the-art seawater desalination plants. The work makes it practical to operate at a high average water flux of 84 L m−2 h−1 with a controlled concentration polarization for the UPM systems. It breaks through the module development bottlenecks for the next-generation UPM systems and has enormous potential application for alleviating water scarcity crisis in the coming decades.
超渗透膜（UPM）具有提高水生产效率的潜力。然而，在高水流量下运行会加剧浓度极化和膜堵塞。受自然界鸟类 V 形形态的启发，我们提出了一种可实现双倍传质系数、适度增加摩擦损失系数的转换膜组件。此外，我们还提出了 UPM 系统的实用技术途径，与最先进的海水淡化厂相比，该系统可将平均水流量提高 338%，并节省 18% 的能源。这项工作使 UPM 系统在 84 L m-2 h-1 的高平均水通量下运行并控制浓度极化成为现实。它突破了下一代 UPM 系统的模块开发瓶颈，对缓解未来几十年的水资源短缺危机具有巨大的应用潜力。
{"title":"Bio-inspired design of next-generation ultrapermeable membrane systems","authors":"Jiu Luo, Mingheng Li, Yi Heng","doi":"10.1038/s41545-024-00297-7","DOIUrl":"10.1038/s41545-024-00297-7","url":null,"abstract":"Ultrapermeable membranes (UPMs) have the potential of improving water production efficiency. However, operating at high water fluxes will intensify concentration polarization and membrane fouling. Inspired by the V-formation of birds in nature we propose a transformative membrane module that enables a doubled mass transfer coefficient with a moderately increased friction loss coefficient. Moreover, we present a practical technological pathway for the UPM systems to achieve 338% improvement of average water flux and 18% energy savings relative to state-of-the-art seawater desalination plants. The work makes it practical to operate at a high average water flux of 84 L m−2 h−1 with a controlled concentration polarization for the UPM systems. It breaks through the module development bottlenecks for the next-generation UPM systems and has enormous potential application for alleviating water scarcity crisis in the coming decades.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2024-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-024-00297-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139505746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-16DOI: 10.1038/s41545-023-00292-4
Junhu Zhou, Ziqian Wu, Congran Jin, John X. J. Zhang
This study presents a dual-functional thin film, known as Ag nanoparticles decorated, ZnO nanorods coated silica nanofibers (AgNP-ZnONR-SNF), which demonstrates remarkable capabilities in both water purification and organic pollutants sensing. The 3D fibrous structure of ZnONR-SNF provides a large surface-area-to-volume ratio for piezo- and photo-catalytic degradation of organic pollutants under UV irradiation, achieving over 98% efficiency. Ag nanoparticles decorated on ZnONR-SNF form “hot-spot” that significantly enhance the surface-enhanced Raman spectroscopy (SERS) signal, resulting in an enhancement factor of 1056 and an experimental detection limit of 1 pg mL−1. Furthermore, a machine learning algorithm is developed for the qualitative and quantitative detection of multiple contaminants, achieving high accuracy (92.3%) and specificity (89.3%) without the need for preliminary processing of Raman spectra. This work provides a promising nanoengineering solution for water purification and sensing with improved detection accuracy, purification efficiency, and cost-effectiveness.
{"title":"Machine learning assisted dual-functional nanophotonic sensor for organic pollutant detection and degradation in water","authors":"Junhu Zhou, Ziqian Wu, Congran Jin, John X. J. Zhang","doi":"10.1038/s41545-023-00292-4","DOIUrl":"10.1038/s41545-023-00292-4","url":null,"abstract":"This study presents a dual-functional thin film, known as Ag nanoparticles decorated, ZnO nanorods coated silica nanofibers (AgNP-ZnONR-SNF), which demonstrates remarkable capabilities in both water purification and organic pollutants sensing. The 3D fibrous structure of ZnONR-SNF provides a large surface-area-to-volume ratio for piezo- and photo-catalytic degradation of organic pollutants under UV irradiation, achieving over 98% efficiency. Ag nanoparticles decorated on ZnONR-SNF form “hot-spot” that significantly enhance the surface-enhanced Raman spectroscopy (SERS) signal, resulting in an enhancement factor of 1056 and an experimental detection limit of 1 pg mL−1. Furthermore, a machine learning algorithm is developed for the qualitative and quantitative detection of multiple contaminants, achieving high accuracy (92.3%) and specificity (89.3%) without the need for preliminary processing of Raman spectra. This work provides a promising nanoengineering solution for water purification and sensing with improved detection accuracy, purification efficiency, and cost-effectiveness.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-023-00292-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139474078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-06DOI: 10.1038/s41545-023-00295-1
Neda Bagherlou, Elnaz Ghasemi, Parvin Gharbani, Mirzaagha Babazadeh, Ali Mehrizad
This study presents the preparation of SiO2/g-C3N5@NiFe2O4 nanophotocatalyst for the removal of betamethasone from aqueous solutions. The SiO2/g-C3N5@NiFe2O4 nanophotocatalyst was synthesized using the solvothermal method, and its structure and optical properties were characterized and confirmed through XRD, FESEM, EDX, DRS, BET, VSM and PL analysis. Photocatalytic removal of betamethasone was optimized using a central composite design. The band gap of pure g-C3N5, NiFe2O4, and SiO2/g-C3N5@NiFe2O4 was obtained 2.4 eV, 2.7 eV, and 1.4 eV, respectively using the Tauc plot. The F-value of 909.88 and Lack of Fit F-value of 0.41 confirm the obtained model is significant. Also, the value of R2 = 0.9988 along with R2adja = 09977 demonstrates excellent model performance. Maximum removal efficiency of betamethasone was approximately 87.15% under the following optimal conditions: nanophotocatalyst dosage of 0.005 g/50 mL, a betamethasone concentration of 20 mg/L, and an irradiation time of 40 min under visible light. This performance closely aligns with the actual value of 80.65%. In conclusion, the SiO2/g-C3N5@NiFe2O4 nanophotocatalyst demonstrates excellent photocatalytic ability for the removal of betamethasone from aqueous solutions.
{"title":"Optimization and modeling of betamethasone removal from aqueous solutions using a SiO2/g-C3N5@NiFe2O4 nanophotocatalyst by RSM","authors":"Neda Bagherlou, Elnaz Ghasemi, Parvin Gharbani, Mirzaagha Babazadeh, Ali Mehrizad","doi":"10.1038/s41545-023-00295-1","DOIUrl":"10.1038/s41545-023-00295-1","url":null,"abstract":"This study presents the preparation of SiO2/g-C3N5@NiFe2O4 nanophotocatalyst for the removal of betamethasone from aqueous solutions. The SiO2/g-C3N5@NiFe2O4 nanophotocatalyst was synthesized using the solvothermal method, and its structure and optical properties were characterized and confirmed through XRD, FESEM, EDX, DRS, BET, VSM and PL analysis. Photocatalytic removal of betamethasone was optimized using a central composite design. The band gap of pure g-C3N5, NiFe2O4, and SiO2/g-C3N5@NiFe2O4 was obtained 2.4 eV, 2.7 eV, and 1.4 eV, respectively using the Tauc plot. The F-value of 909.88 and Lack of Fit F-value of 0.41 confirm the obtained model is significant. Also, the value of R2 = 0.9988 along with R2adja = 09977 demonstrates excellent model performance. Maximum removal efficiency of betamethasone was approximately 87.15% under the following optimal conditions: nanophotocatalyst dosage of 0.005 g/50 mL, a betamethasone concentration of 20 mg/L, and an irradiation time of 40 min under visible light. This performance closely aligns with the actual value of 80.65%. In conclusion, the SiO2/g-C3N5@NiFe2O4 nanophotocatalyst demonstrates excellent photocatalytic ability for the removal of betamethasone from aqueous solutions.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-023-00295-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139110150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-02DOI: 10.1038/s41545-023-00294-2
Matteo Morciano, Marco Malaguti, Francesco Ricceri, Alberto Tiraferri, Matteo Fasano
The rising demand for sustainable wastewater management and high-value resource recovery is pressing industries involved in, e.g., textiles, metals, and food production, to adopt energy-efficient and flexible liquid separation methods. The current techniques often fall short in achieving zero liquid discharge and enhancing socio-economic growth sustainably. Osmotic membrane distillation (OMD) has emerged as a low-temperature separation process designed to concentrate valuable elements and substances in dilute feed streams. The efficacy of OMD hinges on the solvent’s migration from the feed to the draw stream through a hydrophobic membrane, driven by the vapor pressure difference induced by both temperature and concentration gradients. However, the intricate interplay of heat and mass processes steering this mechanism is not yet fully comprehended or accurately modeled. In this research, we conducted a combined theoretical and experimental study to explore the capabilities and thermodynamic limitations of OMD. Under diverse operating conditions, the experimental campaign aimed to corroborate our theoretical assertions. We derived a novel equation to govern water flux based on foundational principles and introduced a streamlined version for more straightforward application. Our findings spotlight complex transport-limiting and self-adjusting mechanisms linked with temperature and concentration polarization phenomena. Compared with traditional methods like membrane distillation and osmotic dilution, which are driven by solely temperature or concentration gradients, OMD may provide improved and flexible performance in target applications. For instance, we show that OMD—if properly optimized—can achieve water vapor fluxes 50% higher than osmotic dilution. Notably, OMD operation at reduced feed temperatures can lead to energy savings ranging between 5 and 95%, owing to the use of highly concentrated draw solutions. This study underscores the potential of OMD in real-world applications, such as concentrating lithium in wastewater streams. By enhancing our fundamental understanding of OMD’s potential and constraints, we aim to broaden its adoption as a pivotal liquid separation tool, with focus on sustainable resource recovery.
{"title":"Process optimization of osmotic membrane distillation for the extraction of valuable resources from water streams","authors":"Matteo Morciano, Marco Malaguti, Francesco Ricceri, Alberto Tiraferri, Matteo Fasano","doi":"10.1038/s41545-023-00294-2","DOIUrl":"10.1038/s41545-023-00294-2","url":null,"abstract":"The rising demand for sustainable wastewater management and high-value resource recovery is pressing industries involved in, e.g., textiles, metals, and food production, to adopt energy-efficient and flexible liquid separation methods. The current techniques often fall short in achieving zero liquid discharge and enhancing socio-economic growth sustainably. Osmotic membrane distillation (OMD) has emerged as a low-temperature separation process designed to concentrate valuable elements and substances in dilute feed streams. The efficacy of OMD hinges on the solvent’s migration from the feed to the draw stream through a hydrophobic membrane, driven by the vapor pressure difference induced by both temperature and concentration gradients. However, the intricate interplay of heat and mass processes steering this mechanism is not yet fully comprehended or accurately modeled. In this research, we conducted a combined theoretical and experimental study to explore the capabilities and thermodynamic limitations of OMD. Under diverse operating conditions, the experimental campaign aimed to corroborate our theoretical assertions. We derived a novel equation to govern water flux based on foundational principles and introduced a streamlined version for more straightforward application. Our findings spotlight complex transport-limiting and self-adjusting mechanisms linked with temperature and concentration polarization phenomena. Compared with traditional methods like membrane distillation and osmotic dilution, which are driven by solely temperature or concentration gradients, OMD may provide improved and flexible performance in target applications. For instance, we show that OMD—if properly optimized—can achieve water vapor fluxes 50% higher than osmotic dilution. Notably, OMD operation at reduced feed temperatures can lead to energy savings ranging between 5 and 95%, owing to the use of highly concentrated draw solutions. This study underscores the potential of OMD in real-world applications, such as concentrating lithium in wastewater streams. By enhancing our fundamental understanding of OMD’s potential and constraints, we aim to broaden its adoption as a pivotal liquid separation tool, with focus on sustainable resource recovery.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-023-00294-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139076617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-21DOI: 10.1038/s41545-023-00296-0
Seongeom Jeong, Boram Gu, Sanghun Park, Kyunghwa Cho, Alicia Kyoungjin An, Sanghyun Jeong
Membrane scaling is a barrier to membrane distillation (MD). In this study, 3D-printed carbon nanotube (CNT) spacer was used to investigate its capability for mitigating membrane scaling during MD and to elucidate the scaling mechanism experimentally and theoretically. CNT spacer was tested under temperature-dependent calcium sulfate scaling conditions, and optical coherence tomography (OCT) and scanning electron microscopy (SEM) were used to measure scaling quantitatively. CNT spacer exhibited unique membrane scaling mechanism, where only a 37% reduction (29 Lm−2h−1) in the initial flux was achieved, even above a volume concentration factor (VCF) of 4. On the other hand, the membrane with a polylactic acid (PLA) spacer (controls) entirely lost flux before reaching a VCF of 3.5. Interestingly, bubble formation was observed in CNT spacer, which could be attributed to the enhanced flux and vaporization rate on membrane surface in the presence of rough-surfaced CNT spacer. Bubbly flow along the membrane channel with CNT spacer can potentially reduce surface scaling on membrane during MD. Moreover, due to the surface roughness of CNT spacer, the initial nuclei might be detached more easily from CNT spacer surface than from smooth PLA surface and grow further into larger crystals in the bulk, resulting in reduced dissolved solutes in the solution. This phenomenon was indirectly corroborated by comparing the experimentally measured fluxes and theoretically computed values from our mechanistic model of MD-crystallization developed in this study. Therefore, this study revealed that CNT spacer with rough surfaces can potentially have benefit of mitigating membrane scaling during MD.
{"title":"Mechanism elucidation and scaling control in membrane distillation using 3D printed carbon nanotube spacer","authors":"Seongeom Jeong, Boram Gu, Sanghun Park, Kyunghwa Cho, Alicia Kyoungjin An, Sanghyun Jeong","doi":"10.1038/s41545-023-00296-0","DOIUrl":"10.1038/s41545-023-00296-0","url":null,"abstract":"Membrane scaling is a barrier to membrane distillation (MD). In this study, 3D-printed carbon nanotube (CNT) spacer was used to investigate its capability for mitigating membrane scaling during MD and to elucidate the scaling mechanism experimentally and theoretically. CNT spacer was tested under temperature-dependent calcium sulfate scaling conditions, and optical coherence tomography (OCT) and scanning electron microscopy (SEM) were used to measure scaling quantitatively. CNT spacer exhibited unique membrane scaling mechanism, where only a 37% reduction (29 Lm−2h−1) in the initial flux was achieved, even above a volume concentration factor (VCF) of 4. On the other hand, the membrane with a polylactic acid (PLA) spacer (controls) entirely lost flux before reaching a VCF of 3.5. Interestingly, bubble formation was observed in CNT spacer, which could be attributed to the enhanced flux and vaporization rate on membrane surface in the presence of rough-surfaced CNT spacer. Bubbly flow along the membrane channel with CNT spacer can potentially reduce surface scaling on membrane during MD. Moreover, due to the surface roughness of CNT spacer, the initial nuclei might be detached more easily from CNT spacer surface than from smooth PLA surface and grow further into larger crystals in the bulk, resulting in reduced dissolved solutes in the solution. This phenomenon was indirectly corroborated by comparing the experimentally measured fluxes and theoretically computed values from our mechanistic model of MD-crystallization developed in this study. Therefore, this study revealed that CNT spacer with rough surfaces can potentially have benefit of mitigating membrane scaling during MD.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-023-00296-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138822821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Both piezoelectricity and self-Fenton catalysis are effective ways to degrade water pollution, but little research has combined them to construct a more efficient water pollution treatment method. Here, a Fe-doped SnS2 (Sn1-xFexS2) piezoelectric self-Fenton system was constructed, which shows superior water treatment performance. The best piezoelectric properties of the Sn0.97Fe0.03S2 system were verified by degrading rhodamine B (RhB). The toxicity analysis of degradation intermediates and solutions confirmed that the toxicity of RhB decreased after degradation. In addition, Kelvin probe force microscopy and photoelectrochemical analysis confirmed the better piezoelectric properties of Sn0.97Fe0.03S2. It has demonstrated the enhancement of systematic piezoelectricity by Fe lattice defects and the formation of self-Fenton by Fe as an active center in the degradation of RhB. In this work, an efficient piezoelectric and self-Fenton technology is constructed to remove organic pollutants from water, which is significant for developing water treatment technology.
{"title":"Lattice distortion SnS2 piezoelectric self-Fenton system for efficient degradation and detoxification of pollutants","authors":"Runren Jiang, Guanghua Lu, Min Wang, Yufang Chen, Jianchao Liu, Zhenhua Yan, Haijiao Xie","doi":"10.1038/s41545-023-00293-3","DOIUrl":"10.1038/s41545-023-00293-3","url":null,"abstract":"Both piezoelectricity and self-Fenton catalysis are effective ways to degrade water pollution, but little research has combined them to construct a more efficient water pollution treatment method. Here, a Fe-doped SnS2 (Sn1-xFexS2) piezoelectric self-Fenton system was constructed, which shows superior water treatment performance. The best piezoelectric properties of the Sn0.97Fe0.03S2 system were verified by degrading rhodamine B (RhB). The toxicity analysis of degradation intermediates and solutions confirmed that the toxicity of RhB decreased after degradation. In addition, Kelvin probe force microscopy and photoelectrochemical analysis confirmed the better piezoelectric properties of Sn0.97Fe0.03S2. It has demonstrated the enhancement of systematic piezoelectricity by Fe lattice defects and the formation of self-Fenton by Fe as an active center in the degradation of RhB. In this work, an efficient piezoelectric and self-Fenton technology is constructed to remove organic pollutants from water, which is significant for developing water treatment technology.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-023-00293-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138455537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to concerns about the accessibility of clean water and the quality of treated wastewater, developing a suitable solution to enhance the water quality is critical. Thus, the current study focused on the synthesis of cadmium-doped CdIn2S4 incorporated in chitosan, forming Cd/CdIn2S4@Ch quantum dots using a solvothermal technique for the efficient photodegradation of hazardous pollutants like ofloxacin and para-nitrophenol through H2O2-mediated AOP. Cd/CdIn2S4@Ch quantum dots were characterized by several advanced methods, including XRD, PL, UV-DRS, FTIR, SEM, HR-TEM, XPS, DSC, TGA, EDX, and Elemental mapping analysis. The influence of varying reaction parameters, such as the effect of organic compounds, inorganic ions, and water matrices, was also investigated. The prepared composite showed outstanding photodegradation efficiency of 85.51 ± 1.35% and 96.70 ± 1.31%, with a rate constant of 0.02334 and 0.15134 min−1, which is about 1.24 and 2.07 times higher than pristine CdIn2S4 for ofloxacin and para-nitrophenol, respectively. The COD values were reduced to 80.67 ± 1.67% for ofloxacin and 88.36 ± 1.43% for para-nitrophenol, whereas the TOC values reduced to 73.49% and 86.34%, respectively, from their initial values. The improved performance is ascribed to the encapsulation of CdIn2S4 by chitosan, leading to the self-doping of cadmium into the photocatalyst, as the incorporated cadmium doping site can generate a local electron accumulation point, improving the charge separation efficacy and surface charge mitigation capability of chitosan nanosheets even further. The scavenger experiments showed that hydroxyl and superoxide radicals played a significant part in the photodegradation of contaminants. Additionally, the quantum dots showed excellent constancy and were recyclable up to six times, suggesting exceptional stability and reusability of the manufactured photocatalyst. The fabricated Cd/CdIn2S4@Ch quantum dots could be an excellent photocatalyst for removing organic pollutants from wastewater in the near future.
{"title":"Inorganic–organic hybrid quantum dots for AOP-mediated photodegradation of ofloxacin and para-nitrophenol in diverse water matrices","authors":"Soumya Ranjan Mishra, Vishal Gadore, Md. Ahmaruzzaman","doi":"10.1038/s41545-023-00291-5","DOIUrl":"10.1038/s41545-023-00291-5","url":null,"abstract":"Due to concerns about the accessibility of clean water and the quality of treated wastewater, developing a suitable solution to enhance the water quality is critical. Thus, the current study focused on the synthesis of cadmium-doped CdIn2S4 incorporated in chitosan, forming Cd/CdIn2S4@Ch quantum dots using a solvothermal technique for the efficient photodegradation of hazardous pollutants like ofloxacin and para-nitrophenol through H2O2-mediated AOP. Cd/CdIn2S4@Ch quantum dots were characterized by several advanced methods, including XRD, PL, UV-DRS, FTIR, SEM, HR-TEM, XPS, DSC, TGA, EDX, and Elemental mapping analysis. The influence of varying reaction parameters, such as the effect of organic compounds, inorganic ions, and water matrices, was also investigated. The prepared composite showed outstanding photodegradation efficiency of 85.51 ± 1.35% and 96.70 ± 1.31%, with a rate constant of 0.02334 and 0.15134 min−1, which is about 1.24 and 2.07 times higher than pristine CdIn2S4 for ofloxacin and para-nitrophenol, respectively. The COD values were reduced to 80.67 ± 1.67% for ofloxacin and 88.36 ± 1.43% for para-nitrophenol, whereas the TOC values reduced to 73.49% and 86.34%, respectively, from their initial values. The improved performance is ascribed to the encapsulation of CdIn2S4 by chitosan, leading to the self-doping of cadmium into the photocatalyst, as the incorporated cadmium doping site can generate a local electron accumulation point, improving the charge separation efficacy and surface charge mitigation capability of chitosan nanosheets even further. The scavenger experiments showed that hydroxyl and superoxide radicals played a significant part in the photodegradation of contaminants. Additionally, the quantum dots showed excellent constancy and were recyclable up to six times, suggesting exceptional stability and reusability of the manufactured photocatalyst. The fabricated Cd/CdIn2S4@Ch quantum dots could be an excellent photocatalyst for removing organic pollutants from wastewater in the near future.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-023-00291-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138293445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-07DOI: 10.1038/s41545-023-00290-6
Guo Zewei, Ouyang Wei, Chen Ming, Roberto Xavier Supe Tulcan, Wang Lei, Lin Chunye, He Mengchang
Precipitation variation profoundly affects agricultural development and increases the diffuse pollution risk, which may weaken the positive effects of pesticide reduction policy. This study aimed to analyze the response of pesticide discharge loads in the large vulnerable watershed to pesticide application intensity and precipitation variance before and after implementing the pesticide reduction policy. We integrated empirical models, field observation and statistics to explore the sensitive factors of the typical pesticide atrazine before and after the pesticide reduction policy in the Yellow River Watershed. The results showed that the implementation of pesticide reduction policy effectively decreased the annual discharge load of atrazine within the watershed. In addition, the most sensitive factor of atrazine discharge loads shifted from precipitation to the atrazine application intensity after implementing the pesticide reduction policy. However, the discharge loads of atrazine significantly increased in an unusual high precipitation year in the context of increasing precipitation variability.
{"title":"Increasing precipitation deteriorates the progress of pesticide reduction policy in the vulnerable watershed","authors":"Guo Zewei, Ouyang Wei, Chen Ming, Roberto Xavier Supe Tulcan, Wang Lei, Lin Chunye, He Mengchang","doi":"10.1038/s41545-023-00290-6","DOIUrl":"10.1038/s41545-023-00290-6","url":null,"abstract":"Precipitation variation profoundly affects agricultural development and increases the diffuse pollution risk, which may weaken the positive effects of pesticide reduction policy. This study aimed to analyze the response of pesticide discharge loads in the large vulnerable watershed to pesticide application intensity and precipitation variance before and after implementing the pesticide reduction policy. We integrated empirical models, field observation and statistics to explore the sensitive factors of the typical pesticide atrazine before and after the pesticide reduction policy in the Yellow River Watershed. The results showed that the implementation of pesticide reduction policy effectively decreased the annual discharge load of atrazine within the watershed. In addition, the most sensitive factor of atrazine discharge loads shifted from precipitation to the atrazine application intensity after implementing the pesticide reduction policy. However, the discharge loads of atrazine significantly increased in an unusual high precipitation year in the context of increasing precipitation variability.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-023-00290-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71524241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-07DOI: 10.1038/s41545-023-00286-2
Mohit Chaudhary, Michal Sela-Adler, Avner Ronen, Oded Nir
Drinking water contamination by per- and polyfluorinated alkyl substances (PFAS) is a global concern. Nanofiltration is a promising PFAS removal technology due to its scalability and cost-effectiveness. However, nanofiltration cannot typically reduce PFAS concentrations below current drinking water recommendations. To enhance PFAS removal, we developed mixed-matrix-composite nanofiltration (MMCNF) membranes—an active nanofiltration layer on porous adsorptive support that synergetically combines filtration and adsorption. We synthesized MMCNF membranes comprising thin polyelectrolyte multilayer films deposited on thick (~400 µm) polyethersulfone supports incorporating β-cyclodextrin microparticles. These membranes achieved near complete removal (>99.9%) of model PFAS (PFOA: perfluorooctanoic acid) for significantly longer filtration times compared to a control membrane without β-cyclodextrin, but otherwise identical. The spent MMCNF membrane was regenerated using ethanol, and high PFOA removal performance was regained during three filtration cycles. Perfluorooctanoic acid was concentrated 38-fold in the ethanol eluent. Further concentration by evaporation is straightforward and can enable eluent recycling and effective PFAS removal.
{"title":"Efficient PFOA removal from drinking water by a dual-functional mixed-matrix-composite nanofiltration membrane","authors":"Mohit Chaudhary, Michal Sela-Adler, Avner Ronen, Oded Nir","doi":"10.1038/s41545-023-00286-2","DOIUrl":"10.1038/s41545-023-00286-2","url":null,"abstract":"Drinking water contamination by per- and polyfluorinated alkyl substances (PFAS) is a global concern. Nanofiltration is a promising PFAS removal technology due to its scalability and cost-effectiveness. However, nanofiltration cannot typically reduce PFAS concentrations below current drinking water recommendations. To enhance PFAS removal, we developed mixed-matrix-composite nanofiltration (MMCNF) membranes—an active nanofiltration layer on porous adsorptive support that synergetically combines filtration and adsorption. We synthesized MMCNF membranes comprising thin polyelectrolyte multilayer films deposited on thick (~400 µm) polyethersulfone supports incorporating β-cyclodextrin microparticles. These membranes achieved near complete removal (>99.9%) of model PFAS (PFOA: perfluorooctanoic acid) for significantly longer filtration times compared to a control membrane without β-cyclodextrin, but otherwise identical. The spent MMCNF membrane was regenerated using ethanol, and high PFOA removal performance was regained during three filtration cycles. Perfluorooctanoic acid was concentrated 38-fold in the ethanol eluent. Further concentration by evaporation is straightforward and can enable eluent recycling and effective PFAS removal.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-023-00286-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71524240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Water heating and disinfection with reduced energy and CO2 footprint demands new and efficient materials for solar-thermal conversion technologies. Here, we demonstrate nanostructured porous hard-carbon florets (NCF) as effective solar absorber coating achieving excellent photon thermalization efficiency (87%). Functional NCF coating on three-dimensionally tapered helical solar receivers generate high surface temperatures (up to 95 °C). Such ‘green-heat’ is channeled to heat water up to 82 °C that simultaneously results in water disinfection through thermal shock. Untreated lake-water with high turbidity (5 NTU), high bacterial load (106 CFU mL−1) and pathogenic fungi is effectively disinfected in a continuous flow process. Translating this, a fully automated SWAP prototype (solar water antimicrobial purifier), delivers bacteria free hot water at an output capacity of 42 L m−2 day−1 with the lowest CO2 footprint (5 kg L−1) in comparison to all other existing approaches (>40 kg L−1).
{"title":"Scalable and high throughput photothermal water disinfection with negligible CO2 footprint utilizing nanostructured carbon coatings","authors":"Ananya Sah, Atindra Kanti Mandal, Shubham Tiwari, Soumyo Mukherji, Chandramouli Subramaniam","doi":"10.1038/s41545-023-00284-4","DOIUrl":"10.1038/s41545-023-00284-4","url":null,"abstract":"Water heating and disinfection with reduced energy and CO2 footprint demands new and efficient materials for solar-thermal conversion technologies. Here, we demonstrate nanostructured porous hard-carbon florets (NCF) as effective solar absorber coating achieving excellent photon thermalization efficiency (87%). Functional NCF coating on three-dimensionally tapered helical solar receivers generate high surface temperatures (up to 95 °C). Such ‘green-heat’ is channeled to heat water up to 82 °C that simultaneously results in water disinfection through thermal shock. Untreated lake-water with high turbidity (5 NTU), high bacterial load (106 CFU mL−1) and pathogenic fungi is effectively disinfected in a continuous flow process. Translating this, a fully automated SWAP prototype (solar water antimicrobial purifier), delivers bacteria free hot water at an output capacity of 42 L m−2 day−1 with the lowest CO2 footprint (5 kg L−1) in comparison to all other existing approaches (>40 kg L−1).","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":11.4,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-023-00284-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71507483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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