AIM To clarify the mechanisms involved in the critical endoplasmic reticulum(ER) stress initiating unfolded protein response pathway modified by melatonin.METHODS Hepatoma cells, Hep G2, were cultured in vitro. Flow c...AIM To clarify the mechanisms involved in the critical endoplasmic reticulum(ER) stress initiating unfolded protein response pathway modified by melatonin.METHODS Hepatoma cells, Hep G2, were cultured in vitro. Flow cytometry and TUNEL assay were used to measure Hep G2 cell apoptosis. Western blotting and quantitative reverse transcription-polymerase chain reaction methods were used to determine the protein and messenger RNA levels of ER stress and apoptosis related genes' expression, respectively. Tissue microarray construction from patients was verified by immunohistochemical analysis.RESULTS In the present study, we first identified that melatoninselectively blocked activating transcription factor 6(ATF-6) and then inhibited cyclooxygenase-2 (COX-2) expression, leading to enhanced liver cancer cell apoptosis under ER stress condition. Dramatically increased CCAAT-enhancer-binding protein homologous protein level, suppressed COX-2 and decreased Bcl-2/Bax ratio by melatonin or ATF-6 si RNA contributed the enhanced Hep G2 cell apoptosis under tunicamycin (an ER stress inducer) stimulation. In clinical hepatocellular carcinoma patients, the close relationship between ATF-6 and COX-2 was further confirmed.CONCLUSION These findings indicate that melatonin as a novel selective ATF-6 inhibitor can sensitize human hepatoma cells to ER stress inducing apoptosis.展开更多
Municipal wastewater treatment has long been known as a high-cost and energy-intensive process that destroys most of the energy-containing molecules by spending energy and that leaves little energy and few nutrients a...Municipal wastewater treatment has long been known as a high-cost and energy-intensive process that destroys most of the energy-containing molecules by spending energy and that leaves little energy and few nutrients available for reuse, Over the past few years, some wastewater treatment plants have tried to revamp themselves as "resource factories," enabled by new technologies and the upgrading of old technologies. In particular, there is an renewed interest in anaerobic biotechnologies, which can convert organic matter into usable energy and preserve nutrients for potential reuse. However, considerable technological and economic limitations still exist. Here, we provide an overview of recent advances in several cutting-edge anaerobic biotechnologies for wastewater treatment, including enhanced side- stream anaerobic sludge digestion, anaerobic membrane bioreactors, and microbial electrochemical systems, and discuss future challenges and opportunities for their applications. This review is intended to provide useful information to guide the future design and optimization of municipal wastewater treatment processes.展开更多
Different titanium oxide powders (ATiO2, BTiO2) were pretreated in ammonia (NH3) gas at high temperatures. After the pretreatment, the color of the titanium oxide powders changed from white to yellow or gray depen...Different titanium oxide powders (ATiO2, BTiO2) were pretreated in ammonia (NH3) gas at high temperatures. After the pretreatment, the color of the titanium oxide powders changed from white to yellow or gray depending on the pretreatment temperatures. Morphologies and structures of the treated titanium oxide powders were characterized by physical chemical methods. XRD measurements showed that the crystalline structures were mainly mixture of anatase and rutile for the ATiO2 but only anatase for the BTiO2, Stronger absorption of visible light was observed for both types of samples using UV-Vis diffuse reflectance spectra. X-ray photoelectron spectroscopy demonstrated that doped nitrogen existed on the surface TiO2 after ammonia gas pretreatment. The photocatalytic activities of the treated titanium oxide samples were evaluated via the photodegradation of methyl orange and phenol in aqueous suspensions. No obvious improvement in photocatalytic activity was achieved by ammonia pretreatment although it could enhance the absorption of light. Effects of treatment temperatures on photoactivities were complete different for ATiO2 and BTiO2 (i.e. higher treated temperatures yielded higher activities for BTiO2 but lower for ATiO2). All samples yielded lower activity levels after ammonia pretreatment without regard to pretreatment temperature or the reaction light resource.展开更多
As the most mature portable power source,lithium-ion battery has become the mainstream of power source for electric vehicles(EVs)by virtue of its high energy density,long cycle life and relatively low cost.However,an ...As the most mature portable power source,lithium-ion battery has become the mainstream of power source for electric vehicles(EVs)by virtue of its high energy density,long cycle life and relatively low cost.However,an excellent battery management system remained to be a problem for the operational states monitoring and safety guarantee for EVs.In this paper,a function realization of multi-scale modeling is proposed based on cyber hierarchy and interactional network framework,realizing basic functions such as multi-scale mapping and cloud-based modeling.Furthermore,to solve the problem of limited computing capability of the conventional vehicle-end battery management system,the novel system consists of hierarchies of side,edge and cloud,which are designed to take on different computing tasks methodically and swap data iteratively,providing specific services for drivers,enterprise users,etc.Due to a series of promising features,this system has a large range of application scenarios as well as some critical bottlenecks,which will be discussed at the end of the article.Please check and confirm D.-B.Shan"is correctly identified in author group.It’s not correct.There is no"D.-B.Shan"in author group,please just remove it.展开更多
As the lithium-ion battery is widely applied,the reliability of the battery has become a high-profile content in recent years.Accurate estimation and prediction of state of health(SOH)and remaining useful life(RUL)pre...As the lithium-ion battery is widely applied,the reliability of the battery has become a high-profile content in recent years.Accurate estimation and prediction of state of health(SOH)and remaining useful life(RUL)prediction are crucial for battery management systems.In this paper,the core contribution is the construction of a datadriven model with the long short-term memory(LSTM)network applicable to the time-series regression prediction problem with the integration of two methods,data-driven methods and feature signal analysis.The input features of model are extracted from differential thermal voltammetry(DTV)curves,which could characterize the battery degradation characteristics,so that the accurate prediction of battery capacity fade could be accomplished.Firstly,the DTV curve is smoothed by the Savitzky-Golay filter,and six alternate features are selected based on the connection between DTV curves and battery degradation characteristics.Then,a correlation analysis method is used to further filter the input features and three features that are highly associated with capacity fade are selected as input into the data driven model.The LSTM neural network is trained by using the root mean square propagation(RMSprop)technique and the dropout technique.Finally,the data of four batteries with different health levels are deployed for model construction,verification and comparison.The results show that the proposed method has high accuracy in SOH and RUL prediction and the capacity rebound phenomenon can be accurately estimated.This method can greatly reduce the cost and complexity,and increase the practicability,which provides the basis and guidance for battery data collection and the application of cloud technology and digital twin.展开更多
China has the world's largest and still growing wastewater sector and water market,thus its future development will have profound influence on the world.The high-speed development of China's wastewater sector ...China has the world's largest and still growing wastewater sector and water market,thus its future development will have profound influence on the world.The high-speed development of China's wastewater sector over the past 40 years has forged its global leading treatment capacity and innovation ability.However,many problems were left behind,including underdeveloped sewers and sludge disposal facilities,low sustainability of the treatment processes,questionable wastewater treatment plant(WWTP)effluent discharge standards,and lacking global thinking on harmonious development between wastewater management,human society and the nature.Addressing these challenges calls for fundamental changes in target design,policy and technologies.In this mini-review,we revisit the development history of China's municipal wastewater management and identify the remaining challenges.Also,we highlight the future needs of sustainable development and exploring China's own wastewater management path,and outlook the future from several aspects including targets of wastewater management,policies and technologies,especially the new concept WWTP.Furthermore,we envisage the establishment of new-generation WWTPs with the vision of turning WWTP from a site of pollutant removal into a plant of energy,water and fertilizer recovery and an integrated part urban ecology in China.展开更多
Enhancing sludge dewatering is of importance in reducing environmental burden and disposal costs.In this work, a cationic surfactant, cetyl trimethyl ammonium bromide(CTAB), was combined with Fenton’s reagent for slu...Enhancing sludge dewatering is of importance in reducing environmental burden and disposal costs.In this work, a cationic surfactant, cetyl trimethyl ammonium bromide(CTAB), was combined with Fenton’s reagent for sludge dewatering.Results show that the Fenton-CTAB conditioning significantly promotes the sludge dewatering.Using combined techniques of response surface methodology and uniform design, dosages of Fe2+, H2O2, and CTAB for water content response were optimized to be 89, 276, and 233 mg/g dry solids(DS),respectively.The water content of sludge decreased from 79.0% to 66.8% under the optimal conditions.Compared with cationic polyacrylamide, the Fenton-CTAB system exhibited superior sludge dewatering performance.To gain insights into the mechanisms involved in sludge dewatering, the effects of Fenton-CTAB conditioning on the composition of extracellular polymeric substances(EPS) and the morphology of the sludge flocs were investigated.The decomposition of EPS into some dissolved organics and the release of proteins in tightly bound EPS facilitated the conversion of bound water to free water and further reduced the water content of sludge cake.After conditioning, morphology of sludge showed aggregation.Overall, the enhanced sludge dewatering by Fenton-CTAB treatment provides an efficient way for management of sewage sludge.展开更多
On October 18th 2021,the inaugural ceremony for the first wastewater resource recovery factory(WRRF)in China,Yixing Concept WRRF(Fig.1),was held in the Environmental Science Park,Yixing,Jiangsu Province(Li,2021).It is...On October 18th 2021,the inaugural ceremony for the first wastewater resource recovery factory(WRRF)in China,Yixing Concept WRRF(Fig.1),was held in the Environmental Science Park,Yixing,Jiangsu Province(Li,2021).It is a milestone for water pollution control,which opens a new chapter for sustainable wastewater management.展开更多
Direct formic acid fuel cells are a promising portable power-generating device, and the development of efficient anodic catalysts is essential for such a fuel cell. In this work Pt-Bi nanoparticles supported on micro-...Direct formic acid fuel cells are a promising portable power-generating device, and the development of efficient anodic catalysts is essential for such a fuel cell. In this work Pt-Bi nanoparticles supported on micro-fabri- cated gold wire array substrate were synthesized using an electrochemical deposition method for formic acid oxida- tion in fuel cells. The surface morphology and element components of the Pt-Bi/Au nanoparticles were character- ized, and the catalytic activities of the three Pt-Bi/Au nanoparticle electrodes with different Pt/Bi ratios for formic acid oxidation were evaluated. It was found that Pt4Bi96/Au had a much higher catalytic activity than Pt11Bis89/Au and Pt13Bis87/Au, and Pt4Bi96/Au exhibited a current density of 2.7mA.cm^-2, which was 27-times greater than that of Pt/Au. The electro-catalytic activity of the Pt-Bi/Au electrode for formic acid oxidation increased with the increasing Bi content, suggesting that it would be possible to achieve an efficient formic acid oxidation on the low Pt-loading. Therefore, the Pt-Bi/Au electrode offers a promising catalyst with a high activity for direct oxidation of formic acid in fuel cells.展开更多
The development of cost-effective and highly efficient anode materials Ibr extracellular electron uptake is important to improve the electricity generation ofbioelectrochemical systems. An effective approach to mitiga...The development of cost-effective and highly efficient anode materials Ibr extracellular electron uptake is important to improve the electricity generation ofbioelectrochemical systems. An effective approach to mitigate harmful algal bloom (HAB) is mechanical harvesting of algal biomass, thus subsequent processing for the collected algal biomass is desired. In this study, a low-cost biochar derived from algal biomass via pyrolysis was utilized as an anode material tbr efficient electron uptake. Electrochemical properties of the algal biochar and graphite plate electrodes were characterized in a bioelectrochemical system (BES). Compared with graphite plate electrode, the algal biochar electrode could effectively utilize both indirect and direct electron transfer pathways tbr current production, and showed stronger electrochemical response and better adsorption of redox mediators. The maximum current density of algal biochar anode was about 4.1 times higher than graphite plate anode in BES. This work provides an application potential for collected HAB to develop a cost-effective anode material for eff-cient extracellular electron uptake in BES and to achieve waste resource utilization.展开更多
Quinones are common organic compounds frequently used as model dissolved organic matters in water, and their redox properties are usually characterized by either electrochemical or spectroscopic methods separately. In...Quinones are common organic compounds frequently used as model dissolved organic matters in water, and their redox properties are usually characterized by either electrochemical or spectroscopic methods separately. In this work, electrochemical methodology was combined with two fluorescence spectroelectrochemical techniques, cyclic voltafluorescence spectrometry (CVF) and derivative cyclic voltafluorescence spectrometry (DCVF), to determine the electrochemical properties of p-benzoQuinone in dimethvl sulfoxide, an aprotic solution. The CVF results show that the electrochemical reduction ofp-benzoquinone resulted in the formation of radical anion and dianion, which exhibited a lower fluorescence intensity and red-shift of the emission spectra compared to that of p-benzoauinone. The fluorescence intensity was found to vary along with the electrochemical oxidation and reduction ofp-benzoquinone. The CVF and DCVF results were in good consistence. Thus, the combined method offers a powerful tool to investigate the electrochemical process of p-benzoquinone and other natural organic compounds.展开更多
Rapid monitoring of water quality is crucial to the operation of municipal wastewater treatment plants (WWTPs). Fluorescence excitation-emission matrix (EEM) in combination with parallel lhctor analysis (PARAFAC...Rapid monitoring of water quality is crucial to the operation of municipal wastewater treatment plants (WWTPs). Fluorescence excitation-emission matrix (EEM) in combination with parallel lhctor analysis (PARAFAC) has been used as a powerful tool for the characterization of dissolved organic matter (DOM) in WWTPs. However, a recent work has revealed the drawback of PARAFAC analysis, i.e., overestimating the component number. A novel method, parallel lhctor framework-clustering analysis (PFFCA),"has been cleveloped in our earlier work to resolve this drawback of PARAFAC. In the present work, both PARAFAC and PFFCA were used to analyze the EEMs of water samples from a full-scale WWTP from a practical application point of view. The component number and goodness-of- fit from these two methods were compared and the relationship between the relative score change of component and the actual concentration was investigated to evaluate the estimation error introduced by 9 both methods. PFFCA score and actual concentration exhibited a higher correlation coefficient (R- = 0.870) compared with PARAFAC (R2〈 0.771), indicating that PFFCA provided a more accurate relative change estimation than PARAFAC. The results suggest that use of PARAFAC may cause confusion in selecting the component number, while EEM-PFFCA is a more reliable alternative approach for monitoring water quality in WWTPs.展开更多
Biological synthesis of quantum dots (QDs) as an environmental-friendly and facile preparation method has attracted increasing interests. However, it is difficult to distinguish the roles ofbio-thiols in QDs synthes...Biological synthesis of quantum dots (QDs) as an environmental-friendly and facile preparation method has attracted increasing interests. However, it is difficult to distinguish the roles ofbio-thiols in QDs synthesis process because of the complex nature in organisms. In this work, the CdSe QDs synthesis conditions in organisms were reconstructed by using a simplified in vitro approach to uncover the roles of two small bio-thiols in the QDs formation. CdSe QDs were synthesized with glutathione (GSH) and L-cysteine (Cys) respectively. Compared with Cys at the same molar concentration, the CdSe QDs synthesized by GSH had a larger and broader particle size distribution with improved optical properties and crystal structure. Furthermore, quantum chemical calculations indicate that the stronger Cd^2+ binding capacity ofGSH contributed a lot to the CdSe QDs formation despite ofthe greater capability Cys for selenite reduction. This work clearly demonstrates the different roles of small thiols in the Cd2^+- stabilization in the environment and biomimetic QDs synthesis process.展开更多
The effect of microwave pretreatment on the anaerobic degradation of hyacinth was investigated using response surface methodology (RSM). The components oflignin and the other constituents of hyacinth were altered by...The effect of microwave pretreatment on the anaerobic degradation of hyacinth was investigated using response surface methodology (RSM). The components oflignin and the other constituents of hyacinth were altered by microwave pretreatment. Comparison of the near-infrared spectra of hyacinth pretreated by microwave irradiation and water-heating pretreatment revealed that no new compounds were generated during hyacinth pretreatment by microwave irradiation. Atomic force microscopy observations indicated that the physical structures of hyacinth were disrupted by microwave pretreatment. The yield of methane per gram of the microwave-irradiated substrate increased by 38.3% as compared to that of the substrate pretreated via water-heating. A maximum methane yield of 221 mL·g-sub^-1 was obtained under the optimum pretreatment conditions (substrate concentration (pSC) = 20.1 g·L^-1 and pretreatment time (PT) = 14.6 min) using RSM analysis. A maximum methane production rate of 0.76 mL·h^-1· g-sub^-1 was obtained by applying PSC = 9.5 g·L^-1 and PT= 11 min. Interactive item coefficient analysis showed that methane production was dependent on the PSC and PT, separately, whereas the interactive effect of the PSC and PT on methane production was not significant. The same trend was also observed for the methane production rate.展开更多
Since the living microorganisms in activated sludge continuously change, it is difficult to conduct controlled experiments and achieve reproducible results for evaluating sludge characteristics. Synthetic sludge, as a...Since the living microorganisms in activated sludge continuously change, it is difficult to conduct controlled experiments and achieve reproducible results for evaluating sludge characteristics. Synthetic sludge, as a chemical surrogate to activated sludge, could be used to investigate the sludge physicochemical properties, and it is desirable to prepare synthetic sludge with similar structure and properties to real activated sludge to explore the flocculation and settlement processes in activated sludge systems. In this work, a high-strength synthetic sludge was prepared with functional polystyrene latex particles as the framework and extracellular polymeric substances (EPS) to modify its surface. The flocculation and settling characteristics of the microspheres and the prepared synthetic sludge were tested. Compared with other three functional polystyrene latex microspheres, the synthetic sludge prepared with EPS-modified polystyrene latex microspheres showed good settling characteristics and a significantly higher strength. They could be used for studying the physicochemical properties of activated sludge.展开更多
基金grants from the National Natural Science Foundation of China,No.81572430 and No.81272739
文摘AIM To clarify the mechanisms involved in the critical endoplasmic reticulum(ER) stress initiating unfolded protein response pathway modified by melatonin.METHODS Hepatoma cells, Hep G2, were cultured in vitro. Flow cytometry and TUNEL assay were used to measure Hep G2 cell apoptosis. Western blotting and quantitative reverse transcription-polymerase chain reaction methods were used to determine the protein and messenger RNA levels of ER stress and apoptosis related genes' expression, respectively. Tissue microarray construction from patients was verified by immunohistochemical analysis.RESULTS In the present study, we first identified that melatoninselectively blocked activating transcription factor 6(ATF-6) and then inhibited cyclooxygenase-2 (COX-2) expression, leading to enhanced liver cancer cell apoptosis under ER stress condition. Dramatically increased CCAAT-enhancer-binding protein homologous protein level, suppressed COX-2 and decreased Bcl-2/Bax ratio by melatonin or ATF-6 si RNA contributed the enhanced Hep G2 cell apoptosis under tunicamycin (an ER stress inducer) stimulation. In clinical hepatocellular carcinoma patients, the close relationship between ATF-6 and COX-2 was further confirmed.CONCLUSION These findings indicate that melatonin as a novel selective ATF-6 inhibitor can sensitize human hepatoma cells to ER stress inducing apoptosis.
基金Acknowledgements The authors wish to thank the National Natural Science Foundation of China (51522811 and 51278479), and the NSFC-RGC fund (21261160489) for the support of this work.
文摘Municipal wastewater treatment has long been known as a high-cost and energy-intensive process that destroys most of the energy-containing molecules by spending energy and that leaves little energy and few nutrients available for reuse, Over the past few years, some wastewater treatment plants have tried to revamp themselves as "resource factories," enabled by new technologies and the upgrading of old technologies. In particular, there is an renewed interest in anaerobic biotechnologies, which can convert organic matter into usable energy and preserve nutrients for potential reuse. However, considerable technological and economic limitations still exist. Here, we provide an overview of recent advances in several cutting-edge anaerobic biotechnologies for wastewater treatment, including enhanced side- stream anaerobic sludge digestion, anaerobic membrane bioreactors, and microbial electrochemical systems, and discuss future challenges and opportunities for their applications. This review is intended to provide useful information to guide the future design and optimization of municipal wastewater treatment processes.
基金V. ACKN0WLEDGMENT This work was supported by the National Natural Science Foundation of China (No.50478065) and the Excellent Youth Foundation of Anhui Province (No.04044077) to X. H. Huang, the Science and Technology Foundation of Ministry of Construction (No.05- k2-25), the Important Foundation of Anhui Science and Technology Department (No.05022126), and the Natural Science Foundation of Anhui Education Department (No.2006KJ139B) to Y. C. Tang.
文摘Different titanium oxide powders (ATiO2, BTiO2) were pretreated in ammonia (NH3) gas at high temperatures. After the pretreatment, the color of the titanium oxide powders changed from white to yellow or gray depending on the pretreatment temperatures. Morphologies and structures of the treated titanium oxide powders were characterized by physical chemical methods. XRD measurements showed that the crystalline structures were mainly mixture of anatase and rutile for the ATiO2 but only anatase for the BTiO2, Stronger absorption of visible light was observed for both types of samples using UV-Vis diffuse reflectance spectra. X-ray photoelectron spectroscopy demonstrated that doped nitrogen existed on the surface TiO2 after ammonia gas pretreatment. The photocatalytic activities of the treated titanium oxide samples were evaluated via the photodegradation of methyl orange and phenol in aqueous suspensions. No obvious improvement in photocatalytic activity was achieved by ammonia pretreatment although it could enhance the absorption of light. Effects of treatment temperatures on photoactivities were complete different for ATiO2 and BTiO2 (i.e. higher treated temperatures yielded higher activities for BTiO2 but lower for ATiO2). All samples yielded lower activity levels after ammonia pretreatment without regard to pretreatment temperature or the reaction light resource.
基金supported by the National Natural Science Foundation of China(No.52102470)the Science and Technology Development Project of Jilin Province(No.20200501012GX)。
文摘As the most mature portable power source,lithium-ion battery has become the mainstream of power source for electric vehicles(EVs)by virtue of its high energy density,long cycle life and relatively low cost.However,an excellent battery management system remained to be a problem for the operational states monitoring and safety guarantee for EVs.In this paper,a function realization of multi-scale modeling is proposed based on cyber hierarchy and interactional network framework,realizing basic functions such as multi-scale mapping and cloud-based modeling.Furthermore,to solve the problem of limited computing capability of the conventional vehicle-end battery management system,the novel system consists of hierarchies of side,edge and cloud,which are designed to take on different computing tasks methodically and swap data iteratively,providing specific services for drivers,enterprise users,etc.Due to a series of promising features,this system has a large range of application scenarios as well as some critical bottlenecks,which will be discussed at the end of the article.Please check and confirm D.-B.Shan"is correctly identified in author group.It’s not correct.There is no"D.-B.Shan"in author group,please just remove it.
基金financially supported by the National Natural Science Foundation of China(No.52102470)the Science and Technology Development Project of Jilin province(No.20200501012GX)。
文摘As the lithium-ion battery is widely applied,the reliability of the battery has become a high-profile content in recent years.Accurate estimation and prediction of state of health(SOH)and remaining useful life(RUL)prediction are crucial for battery management systems.In this paper,the core contribution is the construction of a datadriven model with the long short-term memory(LSTM)network applicable to the time-series regression prediction problem with the integration of two methods,data-driven methods and feature signal analysis.The input features of model are extracted from differential thermal voltammetry(DTV)curves,which could characterize the battery degradation characteristics,so that the accurate prediction of battery capacity fade could be accomplished.Firstly,the DTV curve is smoothed by the Savitzky-Golay filter,and six alternate features are selected based on the connection between DTV curves and battery degradation characteristics.Then,a correlation analysis method is used to further filter the input features and three features that are highly associated with capacity fade are selected as input into the data driven model.The LSTM neural network is trained by using the root mean square propagation(RMSprop)technique and the dropout technique.Finally,the data of four batteries with different health levels are deployed for model construction,verification and comparison.The results show that the proposed method has high accuracy in SOH and RUL prediction and the capacity rebound phenomenon can be accurately estimated.This method can greatly reduce the cost and complexity,and increase the practicability,which provides the basis and guidance for battery data collection and the application of cloud technology and digital twin.
文摘China has the world's largest and still growing wastewater sector and water market,thus its future development will have profound influence on the world.The high-speed development of China's wastewater sector over the past 40 years has forged its global leading treatment capacity and innovation ability.However,many problems were left behind,including underdeveloped sewers and sludge disposal facilities,low sustainability of the treatment processes,questionable wastewater treatment plant(WWTP)effluent discharge standards,and lacking global thinking on harmonious development between wastewater management,human society and the nature.Addressing these challenges calls for fundamental changes in target design,policy and technologies.In this mini-review,we revisit the development history of China's municipal wastewater management and identify the remaining challenges.Also,we highlight the future needs of sustainable development and exploring China's own wastewater management path,and outlook the future from several aspects including targets of wastewater management,policies and technologies,especially the new concept WWTP.Furthermore,we envisage the establishment of new-generation WWTPs with the vision of turning WWTP from a site of pollutant removal into a plant of energy,water and fertilizer recovery and an integrated part urban ecology in China.
基金supported by the China Postdoctoral Science foundation (No.2018M642479)the National Natural Science Foundation of China (No.51821006)the Postdoctoral Science Foundation of Zhejiang Province (No.zj20180141).
文摘Enhancing sludge dewatering is of importance in reducing environmental burden and disposal costs.In this work, a cationic surfactant, cetyl trimethyl ammonium bromide(CTAB), was combined with Fenton’s reagent for sludge dewatering.Results show that the Fenton-CTAB conditioning significantly promotes the sludge dewatering.Using combined techniques of response surface methodology and uniform design, dosages of Fe2+, H2O2, and CTAB for water content response were optimized to be 89, 276, and 233 mg/g dry solids(DS),respectively.The water content of sludge decreased from 79.0% to 66.8% under the optimal conditions.Compared with cationic polyacrylamide, the Fenton-CTAB system exhibited superior sludge dewatering performance.To gain insights into the mechanisms involved in sludge dewatering, the effects of Fenton-CTAB conditioning on the composition of extracellular polymeric substances(EPS) and the morphology of the sludge flocs were investigated.The decomposition of EPS into some dissolved organics and the release of proteins in tightly bound EPS facilitated the conversion of bound water to free water and further reduced the water content of sludge cake.After conditioning, morphology of sludge showed aggregation.Overall, the enhanced sludge dewatering by Fenton-CTAB treatment provides an efficient way for management of sewage sludge.
文摘On October 18th 2021,the inaugural ceremony for the first wastewater resource recovery factory(WRRF)in China,Yixing Concept WRRF(Fig.1),was held in the Environmental Science Park,Yixing,Jiangsu Province(Li,2021).It is a milestone for water pollution control,which opens a new chapter for sustainable wastewater management.
文摘Direct formic acid fuel cells are a promising portable power-generating device, and the development of efficient anodic catalysts is essential for such a fuel cell. In this work Pt-Bi nanoparticles supported on micro-fabri- cated gold wire array substrate were synthesized using an electrochemical deposition method for formic acid oxida- tion in fuel cells. The surface morphology and element components of the Pt-Bi/Au nanoparticles were character- ized, and the catalytic activities of the three Pt-Bi/Au nanoparticle electrodes with different Pt/Bi ratios for formic acid oxidation were evaluated. It was found that Pt4Bi96/Au had a much higher catalytic activity than Pt11Bis89/Au and Pt13Bis87/Au, and Pt4Bi96/Au exhibited a current density of 2.7mA.cm^-2, which was 27-times greater than that of Pt/Au. The electro-catalytic activity of the Pt-Bi/Au electrode for formic acid oxidation increased with the increasing Bi content, suggesting that it would be possible to achieve an efficient formic acid oxidation on the low Pt-loading. Therefore, the Pt-Bi/Au electrode offers a promising catalyst with a high activity for direct oxidation of formic acid in fuel cells.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 21477121 and 51538012) and the Fundamental Research Funds for the Central Universities.
文摘The development of cost-effective and highly efficient anode materials Ibr extracellular electron uptake is important to improve the electricity generation ofbioelectrochemical systems. An effective approach to mitigate harmful algal bloom (HAB) is mechanical harvesting of algal biomass, thus subsequent processing for the collected algal biomass is desired. In this study, a low-cost biochar derived from algal biomass via pyrolysis was utilized as an anode material tbr efficient electron uptake. Electrochemical properties of the algal biochar and graphite plate electrodes were characterized in a bioelectrochemical system (BES). Compared with graphite plate electrode, the algal biochar electrode could effectively utilize both indirect and direct electron transfer pathways tbr current production, and showed stronger electrochemical response and better adsorption of redox mediators. The maximum current density of algal biochar anode was about 4.1 times higher than graphite plate anode in BES. This work provides an application potential for collected HAB to develop a cost-effective anode material for eff-cient extracellular electron uptake in BES and to achieve waste resource utilization.
基金Acknowledgements The authors wish to thank the National Natural Science Foundation of China (Grant Nos. 21505074 and 21477120) and the Natural Science Foundation of Jiangsu Province (BK20140781) for partial support of this study.
文摘Quinones are common organic compounds frequently used as model dissolved organic matters in water, and their redox properties are usually characterized by either electrochemical or spectroscopic methods separately. In this work, electrochemical methodology was combined with two fluorescence spectroelectrochemical techniques, cyclic voltafluorescence spectrometry (CVF) and derivative cyclic voltafluorescence spectrometry (DCVF), to determine the electrochemical properties of p-benzoQuinone in dimethvl sulfoxide, an aprotic solution. The CVF results show that the electrochemical reduction ofp-benzoquinone resulted in the formation of radical anion and dianion, which exhibited a lower fluorescence intensity and red-shift of the emission spectra compared to that of p-benzoauinone. The fluorescence intensity was found to vary along with the electrochemical oxidation and reduction ofp-benzoquinone. The CVF and DCVF results were in good consistence. Thus, the combined method offers a powerful tool to investigate the electrochemical process of p-benzoquinone and other natural organic compounds.
基金We thank the National Natural Science Foundation of China (Grant No. 51538011), the Collaborative Innovation Center of Suzhou Nano Science and Technology of the Ministry of Education of China for the support of this study.
文摘Rapid monitoring of water quality is crucial to the operation of municipal wastewater treatment plants (WWTPs). Fluorescence excitation-emission matrix (EEM) in combination with parallel lhctor analysis (PARAFAC) has been used as a powerful tool for the characterization of dissolved organic matter (DOM) in WWTPs. However, a recent work has revealed the drawback of PARAFAC analysis, i.e., overestimating the component number. A novel method, parallel lhctor framework-clustering analysis (PFFCA),"has been cleveloped in our earlier work to resolve this drawback of PARAFAC. In the present work, both PARAFAC and PFFCA were used to analyze the EEMs of water samples from a full-scale WWTP from a practical application point of view. The component number and goodness-of- fit from these two methods were compared and the relationship between the relative score change of component and the actual concentration was investigated to evaluate the estimation error introduced by 9 both methods. PFFCA score and actual concentration exhibited a higher correlation coefficient (R- = 0.870) compared with PARAFAC (R2〈 0.771), indicating that PFFCA provided a more accurate relative change estimation than PARAFAC. The results suggest that use of PARAFAC may cause confusion in selecting the component number, while EEM-PFFCA is a more reliable alternative approach for monitoring water quality in WWTPs.
基金Acknowledgements The work was supported by the National Natural Science Foundation of China (Grant No. 21590812), and the Collaborative Innovation Center of Suzhou Nano Science and Technology.
文摘Biological synthesis of quantum dots (QDs) as an environmental-friendly and facile preparation method has attracted increasing interests. However, it is difficult to distinguish the roles ofbio-thiols in QDs synthesis process because of the complex nature in organisms. In this work, the CdSe QDs synthesis conditions in organisms were reconstructed by using a simplified in vitro approach to uncover the roles of two small bio-thiols in the QDs formation. CdSe QDs were synthesized with glutathione (GSH) and L-cysteine (Cys) respectively. Compared with Cys at the same molar concentration, the CdSe QDs synthesized by GSH had a larger and broader particle size distribution with improved optical properties and crystal structure. Furthermore, quantum chemical calculations indicate that the stronger Cd^2+ binding capacity ofGSH contributed a lot to the CdSe QDs formation despite ofthe greater capability Cys for selenite reduction. This work clearly demonstrates the different roles of small thiols in the Cd2^+- stabilization in the environment and biomimetic QDs synthesis process.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China (Grant No. 51308010), the Scientific Research Project of Beijing Educational Committee (No. KM201210005028), the Research Fund for the Doctoral Program of Higher Education of China (No. 20131103120017), and the Top Youth Team of Ministry, Department of Beijing Municipal Party Committee (No. Q0004018201502).
文摘The effect of microwave pretreatment on the anaerobic degradation of hyacinth was investigated using response surface methodology (RSM). The components oflignin and the other constituents of hyacinth were altered by microwave pretreatment. Comparison of the near-infrared spectra of hyacinth pretreated by microwave irradiation and water-heating pretreatment revealed that no new compounds were generated during hyacinth pretreatment by microwave irradiation. Atomic force microscopy observations indicated that the physical structures of hyacinth were disrupted by microwave pretreatment. The yield of methane per gram of the microwave-irradiated substrate increased by 38.3% as compared to that of the substrate pretreated via water-heating. A maximum methane yield of 221 mL·g-sub^-1 was obtained under the optimum pretreatment conditions (substrate concentration (pSC) = 20.1 g·L^-1 and pretreatment time (PT) = 14.6 min) using RSM analysis. A maximum methane production rate of 0.76 mL·h^-1· g-sub^-1 was obtained by applying PSC = 9.5 g·L^-1 and PT= 11 min. Interactive item coefficient analysis showed that methane production was dependent on the PSC and PT, separately, whereas the interactive effect of the PSC and PT on methane production was not significant. The same trend was also observed for the methane production rate.
文摘Since the living microorganisms in activated sludge continuously change, it is difficult to conduct controlled experiments and achieve reproducible results for evaluating sludge characteristics. Synthetic sludge, as a chemical surrogate to activated sludge, could be used to investigate the sludge physicochemical properties, and it is desirable to prepare synthetic sludge with similar structure and properties to real activated sludge to explore the flocculation and settlement processes in activated sludge systems. In this work, a high-strength synthetic sludge was prepared with functional polystyrene latex particles as the framework and extracellular polymeric substances (EPS) to modify its surface. The flocculation and settling characteristics of the microspheres and the prepared synthetic sludge were tested. Compared with other three functional polystyrene latex microspheres, the synthetic sludge prepared with EPS-modified polystyrene latex microspheres showed good settling characteristics and a significantly higher strength. They could be used for studying the physicochemical properties of activated sludge.