The distribution of metallic elements in a submerged membrane bioreactor(MBR) was revealed at different temperatures using inductively coupled plasma-optical emission spectrometry(ICP-OES), and the role of extracellul...The distribution of metallic elements in a submerged membrane bioreactor(MBR) was revealed at different temperatures using inductively coupled plasma-optical emission spectrometry(ICP-OES), and the role of extracellular polymeric substances(EPS) was probed by integrating scanning electron microscopy(SEM) with confocal laser scanning microscopy(CLSM) over long-term operation. More metallic elements in the influent were captured by suspended sludge and built up in the fouling layer at lower temperature. The concentration of metallic elements in the effluent was 5.60 mg/L at 10°C operational temperature, far lower than that in the influent(51.35 mg/L). The total contents of metallic elements in suspended sludge and the membrane fouling layer increased to 40.20 and 52.19 mg/g at 10°C compared to 35.14 and 32.45 mg/g at 30°C, and were dominated by the organically bound fraction. The EPS contents in suspended sludge and membrane fouling layer sharply increased to 37.88 and 101.51 mg/g at 10°C, compared to 16.87 and 30.03 mg/g at 30°C. The increase in EPS content at lower temperature was responsible for the deposition of more metallic ions. The strong bridging between EPS and metallic elements at lower temperature enhanced the compactness of the fouling layer and further decreased membrane flux. This was helpful for understanding the mechanism of membrane fouling at different operational temperatures and the role of EPS, and also of significance for the design of cleaning strategies for fouled membranes after long-term operation.展开更多
Proteins are the major organic component s of waste activated sludge(WAS);the recovery of sludge proteins is economically valuable.To efficiently recover sludge proteins,WAS should undergo hydrolysis pretreatment to f...Proteins are the major organic component s of waste activated sludge(WAS);the recovery of sludge proteins is economically valuable.To efficiently recover sludge proteins,WAS should undergo hydrolysis pretreatment to fully release proteins from sludge flocs and microbial cells into aqueous phase.One of the most widely used chemical methods for that is thermal alkali hydrolysis(TAH).Here,the soluble protein concentration achieved the highest level over 90 min of TAH pretreatment at 80°C;the sludge floc disintegration and microbial cell destruction were maximized according to the content profiles of bound extracellular polymeric substance(EPS)and ribonucleic acid(RNA)of sludge.Both less proteins broken down to materials with small molecular weight and less melanoidin generated were responsible.TAH pretreatment at 80°C for 90 min resulted in the solubilization of 67.59% of sludge proteins.34.64% of solubilized proteins was present in soluble high molecular;1.55% and 4.85% broke down to polypeptides and amino acids.The lost proteins via being converted to ammonium and nitrate nitrogen accounted for 9.44% of solubilized proteins.It was important to understand the fate of sludge proteins during TAH pretreatment in terms of protein recovery,which would be helpful for designing the downstream protein separation method and its potential application.展开更多
To decrease the eutrophication caused by nitrogen(N)and phosphorus(P)in water,magnesium-modified corn stalk biochar(MgB)was prepared under the synergistic impact of the multi-pyrolysis temperatures and Mg^(2+)contents...To decrease the eutrophication caused by nitrogen(N)and phosphorus(P)in water,magnesium-modified corn stalk biochar(MgB)was prepared under the synergistic impact of the multi-pyrolysis temperatures and Mg^(2+)contents for the co-adsorption of ammonium(NH_(4)^(+)-N)and phosphate(PO_(4)^(3−)).The co-adsorption mechanism,slow-release performance and plant application of MgB were systematically studied.The results showed that pyrolysis temperatures(350-650℃)and Mg^(2+)(0-3.6 g/L)contents not only altered the physicochemical properties of biochar,but also significantly affected the adsorption efficacy of MgB.The adsorption of NH_(4)^(+)-N and PO_(4)^(3−)was in accordance with Langmuir-Freundlich and pseudo-second-order kinetic models(Q_(max)=37.72 and 73.29 mg/g,respectively).Based on the characteristics,adsorption kinetics and isotherms results,the adsorption mechanism was determined and found to mainly involve struvite precipitation,ion exchange,and surface precipitation or electrostatic attraction.Compared with the leaching performance of chemical fertilizers(CF),after adsorption of NH_(4)^(+)-N and PO_(4)^(3−)(MgB-A),MgB had a more stable pH and lower conductivity.Leaching of NH_(4)^(+)-N and PO_(4)^(3−)by MgB-A was controlled by both the diffusion mechanism and the dissolution rate of struvite and Mg-P.The excel-lent long-term slow-release performance and abundant Mg^(2+)of MgB-A promoted the growth of Zea mays L.and Lolium perenne L.Overall,this study suggested that MgB could realize a win-win outcome of struvite biochar-based fertiliser production and wastewater treatment.展开更多
Since the concept of the osmotic microbial lhcl ceil （OsMFC） was introduced in 2011, it has attracted growing interests for its potential applications in wastewater treatment and energy recovery. However, lbrward os...Since the concept of the osmotic microbial lhcl ceil （OsMFC） was introduced in 2011, it has attracted growing interests for its potential applications in wastewater treatment and energy recovery. However, lbrward osmosis （FO） membrane fouling resulting in a severe water flux decline remains a main obstacle. Until now, the lbuling mechanisms of FO membrane especially the development of biofouling layer in the OsMFC are not yet clear. Here, the fouling behavior of FO membrane in OsMFCs was systematically investigated. The results indicated that a thick fouling layer including biofouling and inorganic fouling was existed on the FO membrane sur｜hce. Compared to the inorganic fouling, the biofouling played a more important role in the development of the fouling layer. Further analyses by the confocal laser scanning microscopy （CLSM） implied that the growth of biofouling layer oll the FO membrane surface in the OsMFC could be divided into three stages. Initially, microorganisms associated with β-D-glucopyranose polysaccharides were deposited on the FO membrane surface. After that, the microorganisms grew into a biofilm caused a quick decrease of water flux. Subsequently, some of microorganisms were dead due to lack of nutrient source, in the meantime, polysaccharidc and proteins in the biofotiling layer werc decomposed as nutrient source, thus leading to a slow development of the biofouling layer. Moreover, the microorganisms played a significant role in the fon＇nation and development of the biotbuling layer, and further studies are needed to mitigate the deposition of microorganisms on FO membrane surfaces in OsMFCs.展开更多
Dry eye disease(DED) is a multifactorial chronic inflammatory disease of the ocular surface with complex and unclear etiology. The development of reliable detection tools for the pathology of DED will benefit its trea...Dry eye disease(DED) is a multifactorial chronic inflammatory disease of the ocular surface with complex and unclear etiology. The development of reliable detection tools for the pathology of DED will benefit its treatment, but it is still lacking. In parallel, it has been discovered recently that viscosity changes are involved in inflammation processes. In this regard, we constructed a fluorescent probe V5with an asymmetric donor-acceptor-donor(D-A-D) feature after rational structural modulation for viscosity detection during DED progression. The probe manifested a remarkable fluorescence enhancement(110 folds) in highly viscous conditions without interferences from polarity and reactive species. Specifically, no aggregation effect of the probe was found in glycerol. Moreover, viscosity increment in human corneal epithelial cells(HCECs) induced by hyperosmosis and inflammation was monitored, and ferroptosis in HCECs also led to the viscosity elevation. A reactive oxygen species(ROS)-dependent viscosity changes during DED progression is demonstrated. Finally, viscosity change in corneal epithelial cell layer from mice treated by scopolamine was also visualized for the first time. We anticipate this work can provide a new lens to the pathogenesis study and diagnosis of DED and other ophthalmic diseases using fluorescence methods.展开更多
基金supported by the National Key Research and Development Program (No.2016YFC0400707)the Research and Innovation Project for Postgraduates of Higher Education Institutions of Jiangsu Province (Nos.KYLX16_0812 and SJZZ16_0216)
文摘The distribution of metallic elements in a submerged membrane bioreactor(MBR) was revealed at different temperatures using inductively coupled plasma-optical emission spectrometry(ICP-OES), and the role of extracellular polymeric substances(EPS) was probed by integrating scanning electron microscopy(SEM) with confocal laser scanning microscopy(CLSM) over long-term operation. More metallic elements in the influent were captured by suspended sludge and built up in the fouling layer at lower temperature. The concentration of metallic elements in the effluent was 5.60 mg/L at 10°C operational temperature, far lower than that in the influent(51.35 mg/L). The total contents of metallic elements in suspended sludge and the membrane fouling layer increased to 40.20 and 52.19 mg/g at 10°C compared to 35.14 and 32.45 mg/g at 30°C, and were dominated by the organically bound fraction. The EPS contents in suspended sludge and membrane fouling layer sharply increased to 37.88 and 101.51 mg/g at 10°C, compared to 16.87 and 30.03 mg/g at 30°C. The increase in EPS content at lower temperature was responsible for the deposition of more metallic ions. The strong bridging between EPS and metallic elements at lower temperature enhanced the compactness of the fouling layer and further decreased membrane flux. This was helpful for understanding the mechanism of membrane fouling at different operational temperatures and the role of EPS, and also of significance for the design of cleaning strategies for fouled membranes after long-term operation.
文摘Proteins are the major organic component s of waste activated sludge(WAS);the recovery of sludge proteins is economically valuable.To efficiently recover sludge proteins,WAS should undergo hydrolysis pretreatment to fully release proteins from sludge flocs and microbial cells into aqueous phase.One of the most widely used chemical methods for that is thermal alkali hydrolysis(TAH).Here,the soluble protein concentration achieved the highest level over 90 min of TAH pretreatment at 80°C;the sludge floc disintegration and microbial cell destruction were maximized according to the content profiles of bound extracellular polymeric substance(EPS)and ribonucleic acid(RNA)of sludge.Both less proteins broken down to materials with small molecular weight and less melanoidin generated were responsible.TAH pretreatment at 80°C for 90 min resulted in the solubilization of 67.59% of sludge proteins.34.64% of solubilized proteins was present in soluble high molecular;1.55% and 4.85% broke down to polypeptides and amino acids.The lost proteins via being converted to ammonium and nitrate nitrogen accounted for 9.44% of solubilized proteins.It was important to understand the fate of sludge proteins during TAH pretreatment in terms of protein recovery,which would be helpful for designing the downstream protein separation method and its potential application.
基金the National Key Research and Development Project(No.2016YFC0400707)Postgraduate Research and Practice Innovation Program of Jiangsu Provence(No.KYCX17_1453).
文摘To decrease the eutrophication caused by nitrogen(N)and phosphorus(P)in water,magnesium-modified corn stalk biochar(MgB)was prepared under the synergistic impact of the multi-pyrolysis temperatures and Mg^(2+)contents for the co-adsorption of ammonium(NH_(4)^(+)-N)and phosphate(PO_(4)^(3−)).The co-adsorption mechanism,slow-release performance and plant application of MgB were systematically studied.The results showed that pyrolysis temperatures(350-650℃)and Mg^(2+)(0-3.6 g/L)contents not only altered the physicochemical properties of biochar,but also significantly affected the adsorption efficacy of MgB.The adsorption of NH_(4)^(+)-N and PO_(4)^(3−)was in accordance with Langmuir-Freundlich and pseudo-second-order kinetic models(Q_(max)=37.72 and 73.29 mg/g,respectively).Based on the characteristics,adsorption kinetics and isotherms results,the adsorption mechanism was determined and found to mainly involve struvite precipitation,ion exchange,and surface precipitation or electrostatic attraction.Compared with the leaching performance of chemical fertilizers(CF),after adsorption of NH_(4)^(+)-N and PO_(4)^(3−)(MgB-A),MgB had a more stable pH and lower conductivity.Leaching of NH_(4)^(+)-N and PO_(4)^(3−)by MgB-A was controlled by both the diffusion mechanism and the dissolution rate of struvite and Mg-P.The excel-lent long-term slow-release performance and abundant Mg^(2+)of MgB-A promoted the growth of Zea mays L.and Lolium perenne L.Overall,this study suggested that MgB could realize a win-win outcome of struvite biochar-based fertiliser production and wastewater treatment.
基金This work was supportcd by the National Natural Science Foundation of China （Grant No. 51578265） the Fundamental Research Funds for the Central Universities （Grant No. JUSRP 51728A）+1 种基金 the National Key Research and Development Program of China （Grant No. 2016YFC0400707） and Jiangsu Cooperative Innovation Center of Technology and Matcrial of Water Treatment.
文摘Since the concept of the osmotic microbial lhcl ceil （OsMFC） was introduced in 2011, it has attracted growing interests for its potential applications in wastewater treatment and energy recovery. However, lbrward osmosis （FO） membrane fouling resulting in a severe water flux decline remains a main obstacle. Until now, the lbuling mechanisms of FO membrane especially the development of biofouling layer in the OsMFC are not yet clear. Here, the fouling behavior of FO membrane in OsMFCs was systematically investigated. The results indicated that a thick fouling layer including biofouling and inorganic fouling was existed on the FO membrane sur｜hce. Compared to the inorganic fouling, the biofouling played a more important role in the development of the fouling layer. Further analyses by the confocal laser scanning microscopy （CLSM） implied that the growth of biofouling layer oll the FO membrane surface in the OsMFC could be divided into three stages. Initially, microorganisms associated with β-D-glucopyranose polysaccharides were deposited on the FO membrane surface. After that, the microorganisms grew into a biofilm caused a quick decrease of water flux. Subsequently, some of microorganisms were dead due to lack of nutrient source, in the meantime, polysaccharidc and proteins in the biofotiling layer werc decomposed as nutrient source, thus leading to a slow development of the biofouling layer. Moreover, the microorganisms played a significant role in the fon＇nation and development of the biotbuling layer, and further studies are needed to mitigate the deposition of microorganisms on FO membrane surfaces in OsMFCs.
基金supported by the National Natural Science Foundation of China(No.22075281)Zhejiang Provincial Natural Science of Foundation of China(No.LZ21B010001)+1 种基金University of Chinese Academy of Science(No.WIUCASQD2020008)。
文摘Dry eye disease(DED) is a multifactorial chronic inflammatory disease of the ocular surface with complex and unclear etiology. The development of reliable detection tools for the pathology of DED will benefit its treatment, but it is still lacking. In parallel, it has been discovered recently that viscosity changes are involved in inflammation processes. In this regard, we constructed a fluorescent probe V5with an asymmetric donor-acceptor-donor(D-A-D) feature after rational structural modulation for viscosity detection during DED progression. The probe manifested a remarkable fluorescence enhancement(110 folds) in highly viscous conditions without interferences from polarity and reactive species. Specifically, no aggregation effect of the probe was found in glycerol. Moreover, viscosity increment in human corneal epithelial cells(HCECs) induced by hyperosmosis and inflammation was monitored, and ferroptosis in HCECs also led to the viscosity elevation. A reactive oxygen species(ROS)-dependent viscosity changes during DED progression is demonstrated. Finally, viscosity change in corneal epithelial cell layer from mice treated by scopolamine was also visualized for the first time. We anticipate this work can provide a new lens to the pathogenesis study and diagnosis of DED and other ophthalmic diseases using fluorescence methods.
