Rhizoremediation has emerged as a burgeoning approach for the removal of petroleum hydrocarbons(PHCs)from soil,with a primary emphasis on terrestrial plant systems.However,the mechanism of how soil microbiomes influen...Rhizoremediation has emerged as a burgeoning approach for the removal of petroleum hydrocarbons(PHCs)from soil,with a primary emphasis on terrestrial plant systems.However,the mechanism of how soil microbiomes influence the dissipation of PHCs within a hygrophyte planting system has yet to be fully elucidated.This work concentrated on the potential evolution of soil microbiomes and their effects on PHC dissipation within the Suaeda salsa(L.)Pall.planting system in a pot experiment.Two representative compounds,polycyclic aromatic hydrocarbons(PAHs)and n-alkanes,were used as target PHCs.The findings revealed a significant efficiency in the dissipation of PHCs in soil with Suaeda salsa cultivation,particularly with respect to n-alkanes.The high dissipation efficiency of PHCs was the synergistic result of root accumulation and microbial biodegradation.The key microbes involved in PHC dissipation were revealed,with the dominant phylum Proteobacteria and genus Salinimicrobium.The alterations in microbial diversity and abundance were closely associated with root exudation and PHC exposure.Significant differences in enzyme activities,an indicator of soil health and fertility,were observed between the rhizospheric and non-rhizospheric soils,which was attributed to root exudation.This study offers novel insights into the phytoremediation potential for Suaeda in PHC-contaminated soils and serves as a valuable scientific reference for the phytoremediation of such soils.展开更多
The Cu^(+)/Cu^(0)sites of copper-based catalysts are crucial for enhancing the production of multicarbon(C_(2+))products from electrochemical CO_(2)reduction reaction(eCO_(2)RR).However,the unstable Cu^(+)and insuffic...The Cu^(+)/Cu^(0)sites of copper-based catalysts are crucial for enhancing the production of multicarbon(C_(2+))products from electrochemical CO_(2)reduction reaction(eCO_(2)RR).However,the unstable Cu^(+)and insufficient Cu^(+)/Cu^(0)active sites lead to their limited selectivity and stability for C_(2+)production.Herein,we embedded copper oxide(CuO_(x))particles into porous nitrogen-doped carbon nanofibers(CuO_(x)@PCNF)by pyrolysis of the electrospun fiber film containing ZIF-8 and Cu_(2)O particles.The porous nitrogendoped carbon nanofibers protected and dispersed Cu^(+)species,and its micro porous structure enhanced the interaction between CuO_(x)and reactants during eCO_(2)RR.The obtained CuO_(x)@PCNF created more effective and stable Cu^(+)/Cu^(0)active sites.It showed a high Faradaic efficiency of 62.5%for C_(2+)products in Hcell,which was 2 times higher than that of bare CuO_(x)(~31.1%).Furthermore,it achieved a maximum Faradaic efficiency of 80.7%for C_(2+)products in flow cell.In situ characterization and density functional theory(DFT)calculation confirmed that the N-doped carbon layer protected Cu^(+)from electrochemical reduction and lowered the energy barrier for the dimerization of^(*)CO.Stable and exposed Cu^(+)/Cu^(0)active sites enhanced the enrichment of^(*)CO and promoted the C-C coupling reaction on the catalyst surface,which facilitated the formation of C_(2+)products.展开更多
In sulfidic anoxic environments,iron sulfides are widespread solid phases that play an important role in the arsenic(As)biogeochemical cycle.This work investigated the transformation process of FeS-As coprecipitates,t...In sulfidic anoxic environments,iron sulfides are widespread solid phases that play an important role in the arsenic(As)biogeochemical cycle.This work investigated the transformation process of FeS-As coprecipitates,the concurrent behavior,and the speciation of associated As under anoxic conditions.The results showed that FeS-As coprecipitates could convert to greigite and pyrite.The transformation degree of the produced solid phases was dependent upon the pH conditions and initial As species.These results showed that the As mobilization was closely associated with the solid phase transformation.The solid phase transformationwent from disordered mackinawite to crystallinemackinawite,then greigite and finally pyrite.The As in the coprecipitates underwent a process of release,fixation,and release again.Both reduction of As(Ⅴ)and oxidation of As(Ⅲ)were observed in the aqueous and solid phases during reactions.Our study may have important implications for further understanding of As behavior and Fe/S cycling thatmay occur under an anoxic environment more comprehensively.展开更多
Volatile organic compounds(VOCs)are a crucial kind of pollutants in the environment due to their obvious features of severe toxicity,high volatility,and poor degradability.It is particularly urgent to control the emis...Volatile organic compounds(VOCs)are a crucial kind of pollutants in the environment due to their obvious features of severe toxicity,high volatility,and poor degradability.It is particularly urgent to control the emission of VOCs due to the persistent increase of concentration and the stringent regulations.In China,clear directions and requirements for reduction of VOCs have been given in the“national plan on environmental improvement for the 13th Five-Year Plan period”.Therefore,the development of efficient technologies for removal and recovery of VOCs is of great significance.Recovery technologies are favored by researchers due to their advantages in both recycling VOCs and reducing carbon emissions.Among them,adsorption and membrane separation processes have been extensively studied due to their remarkable industrial prospects.This overview was to provide an up-to-date progress of adsorption and membrane separation for removal and recovery of VOCs.Firstly,adsorption and membrane separation were found to be the research hotspots through bibliometric analysis.Then,a comprehensive understanding of their mechanisms,factors,and current application statuses was discussed.Finally,the challenges and perspectives in this emerging field were briefly highlighted.展开更多
This work was designed to explore the characteristics of photodegradation of herbicides in the copper-polluted water body. The results showed that Cu（Ⅱ） alone could induce a photo Fenton-like reaction to enhance th...This work was designed to explore the characteristics of photodegradation of herbicides in the copper-polluted water body. The results showed that Cu（Ⅱ） alone could induce a photo Fenton-like reaction to enhance the degradation of atrazine, in which hydroxyl radical （.OH） was a main active species. Humic acids restrained atrazine degradation, nevertheless, when introducing Cu（Ⅱ）, the photodegradation was accelerated, in which singlet oxygen （102） replaced -OH acting as the prevailing species. A feasible mechanism for the photochemical process was also proposed, which is helpful for better understanding the environmental photochemistry of atrazine in the copper-polluted water.展开更多
Thermal decomposition of polylactic acid （PLA） was studied in the presence of pine wood sawdust （PS）, walnut shell （WS）, corncob （CC） in order to understand the pyrolytic behavior of these components occurring...Thermal decomposition of polylactic acid （PLA） was studied in the presence of pine wood sawdust （PS）, walnut shell （WS）, corncob （CC） in order to understand the pyrolytic behavior of these components occurring in waste. A thermogravimetric analyzer （TGA） was applied for monitoring the mass loss profiles under heating rate of 10℃·min^-1. Results obtained from this comprehensive investigation indicated that PLA was decomposed in the temperature range 300 -372℃, whereas the thermal degradation temperature of biomass is 183-462℃. The difference of mass loss （AW） between experimental and theoretical ones, calculated as algebraic sums of those from each separated component, is about 17%-46% at 300-400℃. These experimental results indicated a significant synergistic effect during PLA and biomass copyrolysis. Moreover, a kinetic analysis was performed to fit thermogravimetric data, the global processes being considered as one to two consecutive reactions. A reasonable fit to the experimental data was obtained for all materials and their blends.展开更多
The coupled effects of nitrogen source and methane monooxygenase（MMO） on the growth and poly-β-hydroxybutyrate（PHB） accumulation capacity of methanotrophs were explored.The ammonia-supplied methanotrophs expressi...The coupled effects of nitrogen source and methane monooxygenase（MMO） on the growth and poly-β-hydroxybutyrate（PHB） accumulation capacity of methanotrophs were explored.The ammonia-supplied methanotrophs expressing soluble MMO（s MMO） grew at the highest rate, while N2-fixing bacteria expressing particulate MMO（p MMO） grew at the lowest rate. Further study showed that more hydroxylamine and nitrite was formed by ammonia-supplied bacteria containing p MMO, which might cause their slightly lower growth rate. The highest PHB content（51.0%） was obtained under nitrogen-limiting conditions with the inoculation of nitrate-supplied bacteria containing p MMO. Ammoniasupplied bacteria also accumulated a higher content of PHB（45.2%） with the expression of p MMO, while N2-fixing bacteria containing p MMO only showed low PHB production capacity（32.1%）. The maximal PHB contents of bacteria expressing s MMO were low, with no significant change under different nitrogen source conditions. The low MMO activity,low cell growth rate and low PHB production capacity of methanotrophs continuously cultivated with N2 with the expression of p MMO were greatly improved in the cyclic NO3-N2 cultivation regime, indicating that long-term deficiency of nitrogen sources was detrimental to the activity of methanotrophs expressing pMMO.展开更多
Nitrogen-containing organic pollutants(quinoline,pyridine and indole)are widely distributed in coking wastewater,and bioaugmentation with specific microorganisms may enhance the removal of these recalcitrant pollutant...Nitrogen-containing organic pollutants(quinoline,pyridine and indole)are widely distributed in coking wastewater,and bioaugmentation with specific microorganisms may enhance the removal of these recalcitrant pollutants.The bioaugmented system(group B)was constructed through inoculation of two aromatics-degrading bacteria,Comamonas sp.Z1(quinoline degrader)and Acinetobacter sp.JW(indole degrader),into the activated sludge for treatment of quinoline,indole and pyridine,and the non-bioaugmented activated sludge was used as the control(group C).Both groups maintained high efficiencies(>94%)for removal of nitrogen-containing organic pollutants and chemical oxygen demand(COD)during the long-term operation,and group B was highly effective at the starting period and the operation stage fed with raw wastewater.High-throughput sequencing analysis indicated that nitrogen-containing organic pollutants could shape the microbial community structure,and communities of bioaugmented group B were clearly separated from those of non-bioaugmented group C as observed in non-metric multidimensional scaling(NMDS)plot.Although the inoculants did not remain their dominance in group B,bioaugmentation could induce the formation of effective microbial community,and the indigenous microbes might play the key role in removal of nitrogen-containing organic pollutants,including Dokdonella,Comamonas and Pseudoxanthomonas.Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt)analysis suggested that bioaugmentation could facilitate the enrichment of functional genes related to xenobiotics biodegradation and metabolism,probably leading to the improved performance in group B.This study indicated that bioaugmentation could promote the removal of nitrogen-containing organic pollutants,which should be an effective strategy for wastewater treatment.展开更多
This study investigated catalytic decomposition and mass transfer of aqueous ozone promoted by Fe-MnCu/γ-Al_(2)O_(3)(Cat)in a rotating packed bed(RPB)for the first time.The results showed that the value of the overal...This study investigated catalytic decomposition and mass transfer of aqueous ozone promoted by Fe-MnCu/γ-Al_(2)O_(3)(Cat)in a rotating packed bed(RPB)for the first time.The results showed that the value of the overall decomposition rate constant of ozone(K_(c))and overall volumetric mass transfer coefficient(K_(L)a)are 4.28×10^(-3) s^(-1) and 11.60×10^(-3) s^(-1) respectively at an initial pH of 6,βof 40,Co3(g)of 60 mg·L^(-1)and Q_(L) of 85 L·h^(-1) in deionized water,respectively.Meanwhile,the K_(c) and K_(L)a values of Fenhe water are0.88×10^(-3) s^(-1) and 2.51×10^(-3) s^(-1) lower than deionized water,respectively.In addition,the K_(c) and K_(L)a values in deionized water for the Cat/O_(3)-RPB system are 44.86%and 47.41%higher than that for the Cat/O_(3)-BR(bubbling reactor)system,respectively,indicating that the high gravity technology can facilitate the decomposition and mass transfer of ozone in heterogeneous catalytic ozonation and provide some insights into the industrial wastewater.展开更多
Estuarine wetland is the transitional interface linking terrestrial with marine ecosystems,and wetland microbes are crucial to the biogeochemical cycles of nutrients.The soil samples were collected in four seasons(spr...Estuarine wetland is the transitional interface linking terrestrial with marine ecosystems,and wetland microbes are crucial to the biogeochemical cycles of nutrients.The soil samples were collected in four seasons(spring,S1;summer,S2;autumn,S3;and winter,S4)from Suaeda wetland of Shuangtaizi River estuary,Northeast China,and the variations of bacterial community were evaluated by high-throughput sequencing.Soil properties presented a significant seasonal change,including p H,carbon(C)and total nitrogen(TN),and the microbial diversity,richness and structure also differed with seasons.Canonical correspondence analysis(CCA)and Mantel tests implied that soil p H,C and TN were the key factors structuring the microbial community.Gillisia(belonging to Bacteroidetes)and Woeseia(affiliating with Gammaproteobacteria)were the two primary components in the rhizosphere soils,displaying opposite variations with seasons.Based on PICRUSt(Phylogenetic Investigation of Communities by Reconstruction of Unobserved States)prediction,the xenobiotics biodegradation related genes exhibited a seasonal decline,while the majority of biomarker genes involved in nitrogen cycle showed an ascending trend.These findings could advance the understanding of rhizosphere microbiota of Suaeda in estuarine wetland.展开更多
The effects of various quinone compounds on the decolorization rates of sulfonated azo dyes by Sphingomonas xenophaga QYY were investigated.The results showed that anthraquinone-2-sulfonate(AQS)was the most effective ...The effects of various quinone compounds on the decolorization rates of sulfonated azo dyes by Sphingomonas xenophaga QYY were investigated.The results showed that anthraquinone-2-sulfonate(AQS)was the most effective redox mediator and AQS reduction was the rate-limited step of AQS-mediated decolorization of sulfonated azo dyes.Based on AQS biological toxicity tests,it was assumed that AQS might enter the cells and kill them.In the cytoplasmic extracts from strain QYY,AQS more effectively increased decolorization rates of sulfonated azo dyes than other quinone compounds.In addition,we found a NADH/FMN-dependent AQS reductase using nondenaturing polyacrylamide gel electrophoresis(Native-PAGE).展开更多
Understanding the impact of biological activities on the soil phosphorus(P)distribution under long-term fertilizer application can facilitate better soil P fertility management.Therefore,the primary objectives of this...Understanding the impact of biological activities on the soil phosphorus(P)distribution under long-term fertilizer application can facilitate better soil P fertility management.Therefore,the primary objectives of this study were to investigate the effect of long-term(since 1981)fertilizer application on the soil P fractions and microbial community and to evaluate correlations between the microbial community structure and P distribution.The following treatments were implemented in a long-term field trial:no fertilization(CK),inorganic N and K(NK),inorganic P and K(PK),inorganic N,P and K(NPK)and manure+NPK(MNPK)fertilization.The study showed that the soil pH,soil organic carbon and total and available N and P concentrations were considerably higher in the MNPK treatment than in the CK treatment.The soil microbial biomass C,N and P concentrations were also significantly higher in the MNPK treatment than in the CK treatment.Among fertilization treatments,theβ-1,4-glucosidase,α-1,4-glucosidase,urease,acid phosphatase and phosphodiesterase activities were the highest in the MNPK treatment.Compared to inorganic fertilization,the MNPK treatment increased the labile soil P fractions and decreased the residual soil P concentration.Continuous fertilization significantly affected the soil microbial composition.The total phospholipid fatty acid(PLFA)concentrations in the NK,PK,NPK and MNPK treatments were 23.3,43.1,48.7 and 87.7%higher,respectively,than in the CK treatment.A significant correlation was observed between the microbial community and soil P fractions.Moreover,the aggregated boosted tree(ABT)model showed that among the various soil biochemical properties,the total PLFA concentration was the factor that most influenced the active P pool,accounting for 35.4%of the relative influence of all soil biochemical properties examined.These findings reveal that combined manure and inorganic fertilizer application is a better approach than applying inorganic fertilizer alone for sustaining long-term P fertility by mediating soil biological activity.展开更多
CO and formaldehyde(HCHO)oxidation reactions were investigated over mesoporous Ag/Co3O4 catalysts prepared by one-pot(OP)and impregnation(IM)methods.It was found that the one-pot method was superior to the impregnatio...CO and formaldehyde(HCHO)oxidation reactions were investigated over mesoporous Ag/Co3O4 catalysts prepared by one-pot(OP)and impregnation(IM)methods.It was found that the one-pot method was superior to the impregnation method for synthesizing Ag/Co3O4 catalysts with high activity for both reactions.It was also found that the catalytic behavior of mesoporous Co3O4 and Ag/Co3O4 catalysts for the both reactions was different.And the addition of silver on mesoporous Co3O4 did not always enhance the catalytic activity of final catalyst for CO oxidation at room temperature(20 C),but could significantly improve the catalytic activity of final catalyst for HCHO oxidation at low temperature(90 C).The high surface area,uniform pore structure and the pretty good dispersion degree of the silver particle should be responsible for the excellent low-temperature CO oxidation activity.However,for HCHO oxidation,the addition of silver played an important role in the activity enhancement.And the silver particle size and the reducibility of Co3O4 should be indispensable for the high activity of HCHO oxidation at low temperature.展开更多
Soil organic carbon(SOC)and nitrogen(N)are two of the most important indicators for agricultural productivity.The primary objective of this study was to investigate the changes in SOC and N in the deep soil profile(up...Soil organic carbon(SOC)and nitrogen(N)are two of the most important indicators for agricultural productivity.The primary objective of this study was to investigate the changes in SOC and N in the deep soil profile(up to 100 cm)and their relationships with crop productivity under the influence of long-term(since 1990)fertilization in the wheat-maize cropping system.Treatments included CK(control),NP(inorganic N and phosphorus(P)fertilizers),NPK(inorganic N,P and potassium fertilizers),NPKM(NPK plus manure),and M(manure).Crop yield and the properties of topsoil were measured yearly from 2001 to 2009.C and N contents were measured at five different depths in 2001 and 2009.The results showed that wheat and maize yields decreased between 2001 and 2009 under the inorganic fertilizer(NP and NPK)treatments.The average yield between 2001 and 2009 under the NP,NPK,NPKM,and M treatments(compared with the CK treatment)increased by 38,115,383,and 381%,respectively,for wheat and 348,891,2738,and 1845%,respectively,for maize.Different long-term fertilization treatments significantly changed coarse free particulate(cf POC),fine free particulate(ff POC),intramicroaggregate particulate(i POC),and mineral-associated(m SOC)organic carbon fractions.In the experimental years of 2001 and 2009,soil fractions occurred in the following order for all treatments:m SOC>cf POC>i POC>ff POC.All fractions were higher under the manure application treatments than under the inorganic fertilization treatments.Compared to the inorganic fertilization treatments,manure input enhanced the stocks of SOC and total N in the surface layer(0–20 cm)but decreased SOC and N in the deep soil layer(80–100 cm).This reveals the efficiency of manure in increasing yield productivity and decreasing risk of vertical loss of nutrients,especially N,compared to inorganic fertilization treatments.The findings provide opportunities for understanding deep soil C and N dynamics,which could help mitigate climate change impact on agricultural production and maintain soil health.展开更多
Fresh TiO2 was found to possess a strong germicidal activity even without UV irradiation. Live Yeast （Saccharomyces cerevisiae） cells in contact with fresh TiO2 were found deformed and dead after 15min contact. The ...Fresh TiO2 was found to possess a strong germicidal activity even without UV irradiation. Live Yeast （Saccharomyces cerevisiae） cells in contact with fresh TiO2 were found deformed and dead after 15min contact. The cause of germicidal activity was discussed from the observed cell deformation, lysis and increased absorption at 1680 cm^-1 in FT-IR spectra of the affected cells, which proved the oxidizing effect of fresh TiO2 to cells. The deformation caused by the stretching of cell wail and pressure built-up inside the cell, led to cell burst and release of intracellular materials. The degree of cell deformation was found positively related with the wetting property of TiO2. Cells are negatively charged, for Gram-negative cell （thinner ceil wail）, a higher germicidal effect was observed than Gram-positive cells. The germicidal effect of TiO2 gradually decreased after exposure to air at room temperature, as the wetting property decreased. This kind of germicidal activity was more effective compared to other germicidal process such as UVA/TiO2 or Ag＋. This shed light on designing new germicidal material either maintained by visible light irradiation, or by oxidation effect generated by reactive oxygen species.展开更多
Glutathione S-transferases （GSTs） are phase II enzymes that facilitate the detoxification of xenobioties and play important roles in antioxidant defense. We investigated the expression patterns of seven Venerupis ph...Glutathione S-transferases （GSTs） are phase II enzymes that facilitate the detoxification of xenobioties and play important roles in antioxidant defense. We investigated the expression patterns of seven Venerupis philippinarum GSTs （VpGSTs） and four Mytilus galloprovincialis GSTs （MgGSTs） following exposure to BDE-47. Differential expressions of the seven VpGSTs and four MgGSTs transcripts were observed, with differences between the hepatopancreas and gills. Among these GSTs, the sigma classes （VpGSTS1, VpGSTS2, VpGSTS3, MgGST1, and MgGST3） were highly expressed in response to BDE-47 exposure, demonstrating their potential as molecular biomarkers for environmental biomonitoring studies. We obtained the three-dimensional crystal structures of VpGSTs and MgGSTs by homologous modeling. A model to elucidate the binding interactions between the ligands and receptors was defined by molecular docking, Hydrophobic and n were the most often observed interactions between BDE-47 and the GSTs.展开更多
Nanoporous carbons（NPCs） derived from metal–organic frameworks（MOFs） are attracting increasing attention in many areas by virtue of their high specific surface area, large pore volume and unique porosity. The pre...Nanoporous carbons（NPCs） derived from metal–organic frameworks（MOFs） are attracting increasing attention in many areas by virtue of their high specific surface area, large pore volume and unique porosity. The present work reports the preparation of an NPC with high surface area（1731 m^2/g） and pore volume（1.68 cm^3/g） by direct carbonization of MOF-5. We examined the adsorption of three typical contaminants from aqueous solutions, i.e., sulfamethoxazole（SMX）,bisphenol A（BPA） and methyl orange（MO）, by using the as-prepared NPC. The results demonstrated that NPC could adsorb the contaminants effectively, with adsorption capacity（qm） of 625 mg/g（SMX）, 757 mg/g（BPA） and 872 mg/g（MO）, respectively. These values were approximately 1.0-3.2 times higher than those obtained for single-walled carbon nanotubes（SWCNTs） and commercial powder active carbon（PAC） under the same conditions. With its high surface area and unique meso/macropore structure, the enhanced adsorption of NPC most likely originates from the cooperative interaction of a pore-filling mechanism, electrostatic interaction,and hydrogen bonding. In particular, the p H value has a crucial impact on adsorption, suggesting the significant contribution of electrostatic interaction between NPC and the contaminants. This study provides a proof-of-concept demonstration of MOF-derived nanoporous carbons as effective adsorbents of contaminants for water treatment.展开更多
A novel biphenyl-degrading bacterial strain LA-4 was isolated from activated sludge.It was identified as Dyella ginsengisoli according to phylogenetic similarity of 16S rRNA gene sequence.This isolate could utilize bi...A novel biphenyl-degrading bacterial strain LA-4 was isolated from activated sludge.It was identified as Dyella ginsengisoli according to phylogenetic similarity of 16S rRNA gene sequence.This isolate could utilize biphenyl as sole source of carbon and energy,which degraded over 95 mg/L biphenyl within 36 h.The major metabolites formed from biphenyl,such as 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid(HOPDA)and benzoic acid,were identified by LC-MS.The crude cell extract of strain LA-4 exhibited the activity of 2,3-dihydroxybiphenyl 1,2-dioxygenase(2,3-DHBD)and the kinetic parameters Km was 26.48μmol/L and Vmax was 8.12 U/mg protein.A conserved region of the biphenyl dioxygenase gene bphA1 of strain LA-4 was amplified by PCR and confirmed by DNA sequencing.展开更多
The reference values of serum perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) concentrations were evaluated based on the human blood samples collected from Kashi, Xinjiang. And human serum samples of fa...The reference values of serum perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) concentrations were evaluated based on the human blood samples collected from Kashi, Xinjiang. And human serum samples of family members from Liaoning were evaluated for levels of PFOS and PFOA with the purpose to compare exposure pathways for family members. Among the 110 blood specimens from Kashi, the detection frequency of PFOS and PFOA was 93% and 6%, respectively. Reference values of serum PFOS, evaluated as the 90th percentiles of the concentrations, were determined to be 6.44 μg/L. Significant positive correlations were observed for serum levels of PFOS and PFOA among family members in Liaoning. Specially, stronger correlation between mother and offspring was observed than that between father and offspring. And stronger correlation of serum PFOS and PFOA levels was observed among fam- ily members in rural areas than those in big and small-medium cities. Difference in the association of serum PFOS and PFOA level among family members suggested that exposure in the outdoor and working environment of different oc- cupations should be evaluated. Present study provides reference values for exposure assessment in China and potential pathways of human exposure to PFOS and PFOA.展开更多
Considering that cathode of microbial electrochemical system(MES)is a good electrons source for methane production via direct/indirect electron transfer to electroactive microorganisms,and that Fe(0)is also a confirme...Considering that cathode of microbial electrochemical system(MES)is a good electrons source for methane production via direct/indirect electron transfer to electroactive microorganisms,and that Fe(0)is also a confirmed electron donor for some electroactive microorganisms through metal-microbe direct electron transfer(DET),Fe(0)-cathode was equipped into an MES digester to enhance cathodic methane production.The results of this study indicated that the potential DET participator,Clostridium possibly obtained electrons directly from Fe(0)-cathode via metal-microbe electrons transfer,then transferred electrons directly to the definite DET participators,Methanosarcina/Methanothrix via microbemicrobe electrons transfer for CH_(4)production.In addition,Methanobacterium is another specially enriched methanogen on Fe(0)-cathode,which might obtain electrons directly from Fe(0)-cathode to produce CH_(4) via metal/electrode-microbe DET.The increment of conductivity of cathodic sludge in Fe(0)-cathode MES digester(R1)further confirmed the enrichment of electroactive microorganisms participating in DET process.As a consequence,a higher CH_(4) production(1205–1508 m L/d)and chemical oxygen demand(COD)removal(79.0%-93.8%)were achieved in R1 compared with graphite-cathode MES digester(R2,720–1090 m L/d and 63.6%-85.6%)and the conventional anaerobic digester(R3,384–428 m L/d and 35.2%-41.0%).In addition,energy efficiency calculated indicated that the output energy of CH_(4) production was 8.16 folds of electricity input in Fe(0)-cathode MES digester.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22176025 and 22136007)the National Key Research and Development Program of China(No.2022YFC3701404)the Petro China Innovation Foundation(No.D2019-5007-0502)。
文摘Rhizoremediation has emerged as a burgeoning approach for the removal of petroleum hydrocarbons(PHCs)from soil,with a primary emphasis on terrestrial plant systems.However,the mechanism of how soil microbiomes influence the dissipation of PHCs within a hygrophyte planting system has yet to be fully elucidated.This work concentrated on the potential evolution of soil microbiomes and their effects on PHC dissipation within the Suaeda salsa(L.)Pall.planting system in a pot experiment.Two representative compounds,polycyclic aromatic hydrocarbons(PAHs)and n-alkanes,were used as target PHCs.The findings revealed a significant efficiency in the dissipation of PHCs in soil with Suaeda salsa cultivation,particularly with respect to n-alkanes.The high dissipation efficiency of PHCs was the synergistic result of root accumulation and microbial biodegradation.The key microbes involved in PHC dissipation were revealed,with the dominant phylum Proteobacteria and genus Salinimicrobium.The alterations in microbial diversity and abundance were closely associated with root exudation and PHC exposure.Significant differences in enzyme activities,an indicator of soil health and fertility,were observed between the rhizospheric and non-rhizospheric soils,which was attributed to root exudation.This study offers novel insights into the phytoremediation potential for Suaeda in PHC-contaminated soils and serves as a valuable scientific reference for the phytoremediation of such soils.
基金supported by the National Natural Science Foundation of China(22222601 and 22076019)the Fundamental Research Funds for the Central Universities(DUT23LAB611).
文摘The Cu^(+)/Cu^(0)sites of copper-based catalysts are crucial for enhancing the production of multicarbon(C_(2+))products from electrochemical CO_(2)reduction reaction(eCO_(2)RR).However,the unstable Cu^(+)and insufficient Cu^(+)/Cu^(0)active sites lead to their limited selectivity and stability for C_(2+)production.Herein,we embedded copper oxide(CuO_(x))particles into porous nitrogen-doped carbon nanofibers(CuO_(x)@PCNF)by pyrolysis of the electrospun fiber film containing ZIF-8 and Cu_(2)O particles.The porous nitrogendoped carbon nanofibers protected and dispersed Cu^(+)species,and its micro porous structure enhanced the interaction between CuO_(x)and reactants during eCO_(2)RR.The obtained CuO_(x)@PCNF created more effective and stable Cu^(+)/Cu^(0)active sites.It showed a high Faradaic efficiency of 62.5%for C_(2+)products in Hcell,which was 2 times higher than that of bare CuO_(x)(~31.1%).Furthermore,it achieved a maximum Faradaic efficiency of 80.7%for C_(2+)products in flow cell.In situ characterization and density functional theory(DFT)calculation confirmed that the N-doped carbon layer protected Cu^(+)from electrochemical reduction and lowered the energy barrier for the dimerization of^(*)CO.Stable and exposed Cu^(+)/Cu^(0)active sites enhanced the enrichment of^(*)CO and promoted the C-C coupling reaction on the catalyst surface,which facilitated the formation of C_(2+)products.
基金supported by the National Key Research and Development Program of China(No.2022YFC3701301)the National Natural Science Foundation of China(Nos.42173063 and 42377251)+1 种基金the Youth Innovation Promotion Association CAS(No.2020200)the Fundamental Research Funds for the Central Universities.
文摘In sulfidic anoxic environments,iron sulfides are widespread solid phases that play an important role in the arsenic(As)biogeochemical cycle.This work investigated the transformation process of FeS-As coprecipitates,the concurrent behavior,and the speciation of associated As under anoxic conditions.The results showed that FeS-As coprecipitates could convert to greigite and pyrite.The transformation degree of the produced solid phases was dependent upon the pH conditions and initial As species.These results showed that the As mobilization was closely associated with the solid phase transformation.The solid phase transformationwent from disordered mackinawite to crystallinemackinawite,then greigite and finally pyrite.The As in the coprecipitates underwent a process of release,fixation,and release again.Both reduction of As(Ⅴ)and oxidation of As(Ⅲ)were observed in the aqueous and solid phases during reactions.Our study may have important implications for further understanding of As behavior and Fe/S cycling thatmay occur under an anoxic environment more comprehensively.
基金supported financially by the“Xing Liao Talents Program”Project(No.XLYC1902051)the National Natural Science Foundation of China(No.22076018)+1 种基金the Fundamental Research Funds for the Central Universities(No.DUT19LAB10)the Key Laboratory of Industrial Ecology and Environmental Engineering,China Ministry of Education,and the State Key Laboratory of Catalysis in DICP(No.N-20-06)。
文摘Volatile organic compounds(VOCs)are a crucial kind of pollutants in the environment due to their obvious features of severe toxicity,high volatility,and poor degradability.It is particularly urgent to control the emission of VOCs due to the persistent increase of concentration and the stringent regulations.In China,clear directions and requirements for reduction of VOCs have been given in the“national plan on environmental improvement for the 13th Five-Year Plan period”.Therefore,the development of efficient technologies for removal and recovery of VOCs is of great significance.Recovery technologies are favored by researchers due to their advantages in both recycling VOCs and reducing carbon emissions.Among them,adsorption and membrane separation processes have been extensively studied due to their remarkable industrial prospects.This overview was to provide an up-to-date progress of adsorption and membrane separation for removal and recovery of VOCs.Firstly,adsorption and membrane separation were found to be the research hotspots through bibliometric analysis.Then,a comprehensive understanding of their mechanisms,factors,and current application statuses was discussed.Finally,the challenges and perspectives in this emerging field were briefly highlighted.
基金supported by the National Basic Research Program (973) of China (No. 2007CB407302)the New Century Excellent Talent Program of the Ministry of Education of China (2010)the Fundamental Research Funds for the Central Universities of China (No.DUT11ZD108)
文摘This work was designed to explore the characteristics of photodegradation of herbicides in the copper-polluted water body. The results showed that Cu（Ⅱ） alone could induce a photo Fenton-like reaction to enhance the degradation of atrazine, in which hydroxyl radical （.OH） was a main active species. Humic acids restrained atrazine degradation, nevertheless, when introducing Cu（Ⅱ）, the photodegradation was accelerated, in which singlet oxygen （102） replaced -OH acting as the prevailing species. A feasible mechanism for the photochemical process was also proposed, which is helpful for better understanding the environmental photochemistry of atrazine in the copper-polluted water.
文摘Thermal decomposition of polylactic acid （PLA） was studied in the presence of pine wood sawdust （PS）, walnut shell （WS）, corncob （CC） in order to understand the pyrolytic behavior of these components occurring in waste. A thermogravimetric analyzer （TGA） was applied for monitoring the mass loss profiles under heating rate of 10℃·min^-1. Results obtained from this comprehensive investigation indicated that PLA was decomposed in the temperature range 300 -372℃, whereas the thermal degradation temperature of biomass is 183-462℃. The difference of mass loss （AW） between experimental and theoretical ones, calculated as algebraic sums of those from each separated component, is about 17%-46% at 300-400℃. These experimental results indicated a significant synergistic effect during PLA and biomass copyrolysis. Moreover, a kinetic analysis was performed to fit thermogravimetric data, the global processes being considered as one to two consecutive reactions. A reasonable fit to the experimental data was obtained for all materials and their blends.
基金supported by the National Key Scientific and Technology Project for Water Pollution Treatment of China(No.2012ZX07202006)the National Natural Science Foundation of China(No.21477014)
文摘The coupled effects of nitrogen source and methane monooxygenase（MMO） on the growth and poly-β-hydroxybutyrate（PHB） accumulation capacity of methanotrophs were explored.The ammonia-supplied methanotrophs expressing soluble MMO（s MMO） grew at the highest rate, while N2-fixing bacteria expressing particulate MMO（p MMO） grew at the lowest rate. Further study showed that more hydroxylamine and nitrite was formed by ammonia-supplied bacteria containing p MMO, which might cause their slightly lower growth rate. The highest PHB content（51.0%） was obtained under nitrogen-limiting conditions with the inoculation of nitrate-supplied bacteria containing p MMO. Ammoniasupplied bacteria also accumulated a higher content of PHB（45.2%） with the expression of p MMO, while N2-fixing bacteria containing p MMO only showed low PHB production capacity（32.1%）. The maximal PHB contents of bacteria expressing s MMO were low, with no significant change under different nitrogen source conditions. The low MMO activity,low cell growth rate and low PHB production capacity of methanotrophs continuously cultivated with N2 with the expression of p MMO were greatly improved in the cyclic NO3-N2 cultivation regime, indicating that long-term deficiency of nitrogen sources was detrimental to the activity of methanotrophs expressing pMMO.
基金supported by the National Natural Science Foundation of China(Nos.31970107 and 51508068)the Fundamental Research Funds for the Central Universities(No.DUT19JC17)the Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.QAK201943)。
文摘Nitrogen-containing organic pollutants(quinoline,pyridine and indole)are widely distributed in coking wastewater,and bioaugmentation with specific microorganisms may enhance the removal of these recalcitrant pollutants.The bioaugmented system(group B)was constructed through inoculation of two aromatics-degrading bacteria,Comamonas sp.Z1(quinoline degrader)and Acinetobacter sp.JW(indole degrader),into the activated sludge for treatment of quinoline,indole and pyridine,and the non-bioaugmented activated sludge was used as the control(group C).Both groups maintained high efficiencies(>94%)for removal of nitrogen-containing organic pollutants and chemical oxygen demand(COD)during the long-term operation,and group B was highly effective at the starting period and the operation stage fed with raw wastewater.High-throughput sequencing analysis indicated that nitrogen-containing organic pollutants could shape the microbial community structure,and communities of bioaugmented group B were clearly separated from those of non-bioaugmented group C as observed in non-metric multidimensional scaling(NMDS)plot.Although the inoculants did not remain their dominance in group B,bioaugmentation could induce the formation of effective microbial community,and the indigenous microbes might play the key role in removal of nitrogen-containing organic pollutants,including Dokdonella,Comamonas and Pseudoxanthomonas.Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt)analysis suggested that bioaugmentation could facilitate the enrichment of functional genes related to xenobiotics biodegradation and metabolism,probably leading to the improved performance in group B.This study indicated that bioaugmentation could promote the removal of nitrogen-containing organic pollutants,which should be an effective strategy for wastewater treatment.
基金supported by the Specialized Research Fund for Sanjin Scholars Program of Shanxi Province(201707)Key Research&Development Plan of Shanxi Province(201903D321059)+2 种基金Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(20200004)Transformation and Cultivation Projects of Scientific and Technological Achievements in Universities of Shanxi Province Institutions(2020CG040)the China National Key Project of Science and Technology “Major Science and Technology Program for Water Pollution Control and Treatment”(2018ZX07601001)。
文摘This study investigated catalytic decomposition and mass transfer of aqueous ozone promoted by Fe-MnCu/γ-Al_(2)O_(3)(Cat)in a rotating packed bed(RPB)for the first time.The results showed that the value of the overall decomposition rate constant of ozone(K_(c))and overall volumetric mass transfer coefficient(K_(L)a)are 4.28×10^(-3) s^(-1) and 11.60×10^(-3) s^(-1) respectively at an initial pH of 6,βof 40,Co3(g)of 60 mg·L^(-1)and Q_(L) of 85 L·h^(-1) in deionized water,respectively.Meanwhile,the K_(c) and K_(L)a values of Fenhe water are0.88×10^(-3) s^(-1) and 2.51×10^(-3) s^(-1) lower than deionized water,respectively.In addition,the K_(c) and K_(L)a values in deionized water for the Cat/O_(3)-RPB system are 44.86%and 47.41%higher than that for the Cat/O_(3)-BR(bubbling reactor)system,respectively,indicating that the high gravity technology can facilitate the decomposition and mass transfer of ozone in heterogeneous catalytic ozonation and provide some insights into the industrial wastewater.
基金supported by the National Natural Science Foundation of China(Nos.31970107,51508068)the Fundamental Research Funds for the Central Universities(No.DUT19JC17)support from the Undergraduate Innovation and En-trepreneurship Training Program in Dalian University of Technology。
文摘Estuarine wetland is the transitional interface linking terrestrial with marine ecosystems,and wetland microbes are crucial to the biogeochemical cycles of nutrients.The soil samples were collected in four seasons(spring,S1;summer,S2;autumn,S3;and winter,S4)from Suaeda wetland of Shuangtaizi River estuary,Northeast China,and the variations of bacterial community were evaluated by high-throughput sequencing.Soil properties presented a significant seasonal change,including p H,carbon(C)and total nitrogen(TN),and the microbial diversity,richness and structure also differed with seasons.Canonical correspondence analysis(CCA)and Mantel tests implied that soil p H,C and TN were the key factors structuring the microbial community.Gillisia(belonging to Bacteroidetes)and Woeseia(affiliating with Gammaproteobacteria)were the two primary components in the rhizosphere soils,displaying opposite variations with seasons.Based on PICRUSt(Phylogenetic Investigation of Communities by Reconstruction of Unobserved States)prediction,the xenobiotics biodegradation related genes exhibited a seasonal decline,while the majority of biomarker genes involved in nitrogen cycle showed an ascending trend.These findings could advance the understanding of rhizosphere microbiota of Suaeda in estuarine wetland.
文摘The effects of various quinone compounds on the decolorization rates of sulfonated azo dyes by Sphingomonas xenophaga QYY were investigated.The results showed that anthraquinone-2-sulfonate(AQS)was the most effective redox mediator and AQS reduction was the rate-limited step of AQS-mediated decolorization of sulfonated azo dyes.Based on AQS biological toxicity tests,it was assumed that AQS might enter the cells and kill them.In the cytoplasmic extracts from strain QYY,AQS more effectively increased decolorization rates of sulfonated azo dyes than other quinone compounds.In addition,we found a NADH/FMN-dependent AQS reductase using nondenaturing polyacrylamide gel electrophoresis(Native-PAGE).
基金supported by the National Key Research and Development Program of China(2016YFD0300901)the Fundamental Research Funds for Central Nonprofit Scientific Institutions of China(1610132019035,1610132020023 and 1610132020024)the Natural Science Foundation of Jiangxi Province,China(20192BAB203022)。
文摘Understanding the impact of biological activities on the soil phosphorus(P)distribution under long-term fertilizer application can facilitate better soil P fertility management.Therefore,the primary objectives of this study were to investigate the effect of long-term(since 1981)fertilizer application on the soil P fractions and microbial community and to evaluate correlations between the microbial community structure and P distribution.The following treatments were implemented in a long-term field trial:no fertilization(CK),inorganic N and K(NK),inorganic P and K(PK),inorganic N,P and K(NPK)and manure+NPK(MNPK)fertilization.The study showed that the soil pH,soil organic carbon and total and available N and P concentrations were considerably higher in the MNPK treatment than in the CK treatment.The soil microbial biomass C,N and P concentrations were also significantly higher in the MNPK treatment than in the CK treatment.Among fertilization treatments,theβ-1,4-glucosidase,α-1,4-glucosidase,urease,acid phosphatase and phosphodiesterase activities were the highest in the MNPK treatment.Compared to inorganic fertilization,the MNPK treatment increased the labile soil P fractions and decreased the residual soil P concentration.Continuous fertilization significantly affected the soil microbial composition.The total phospholipid fatty acid(PLFA)concentrations in the NK,PK,NPK and MNPK treatments were 23.3,43.1,48.7 and 87.7%higher,respectively,than in the CK treatment.A significant correlation was observed between the microbial community and soil P fractions.Moreover,the aggregated boosted tree(ABT)model showed that among the various soil biochemical properties,the total PLFA concentration was the factor that most influenced the active P pool,accounting for 35.4%of the relative influence of all soil biochemical properties examined.These findings reveal that combined manure and inorganic fertilizer application is a better approach than applying inorganic fertilizer alone for sustaining long-term P fertility by mediating soil biological activity.
基金supported financially by the Program for New Century Excellent Talents in University (NCET-09-0256)the Fundamental Research Funds for the Central Universities (DUT13LK27)the National Nature Science Foundation of China (No.21377016)
文摘CO and formaldehyde(HCHO)oxidation reactions were investigated over mesoporous Ag/Co3O4 catalysts prepared by one-pot(OP)and impregnation(IM)methods.It was found that the one-pot method was superior to the impregnation method for synthesizing Ag/Co3O4 catalysts with high activity for both reactions.It was also found that the catalytic behavior of mesoporous Co3O4 and Ag/Co3O4 catalysts for the both reactions was different.And the addition of silver on mesoporous Co3O4 did not always enhance the catalytic activity of final catalyst for CO oxidation at room temperature(20 C),but could significantly improve the catalytic activity of final catalyst for HCHO oxidation at low temperature(90 C).The high surface area,uniform pore structure and the pretty good dispersion degree of the silver particle should be responsible for the excellent low-temperature CO oxidation activity.However,for HCHO oxidation,the addition of silver played an important role in the activity enhancement.And the silver particle size and the reducibility of Co3O4 should be indispensable for the high activity of HCHO oxidation at low temperature.
基金financially supported by the National Key Research and Development Program of China(2016YFD0300901 and 2017YFD0800101)the Fundamental Research Funds for Central Non-profit Scientific Institution,China(161032019035,1610132020022 and 1610132020023)。
文摘Soil organic carbon(SOC)and nitrogen(N)are two of the most important indicators for agricultural productivity.The primary objective of this study was to investigate the changes in SOC and N in the deep soil profile(up to 100 cm)and their relationships with crop productivity under the influence of long-term(since 1990)fertilization in the wheat-maize cropping system.Treatments included CK(control),NP(inorganic N and phosphorus(P)fertilizers),NPK(inorganic N,P and potassium fertilizers),NPKM(NPK plus manure),and M(manure).Crop yield and the properties of topsoil were measured yearly from 2001 to 2009.C and N contents were measured at five different depths in 2001 and 2009.The results showed that wheat and maize yields decreased between 2001 and 2009 under the inorganic fertilizer(NP and NPK)treatments.The average yield between 2001 and 2009 under the NP,NPK,NPKM,and M treatments(compared with the CK treatment)increased by 38,115,383,and 381%,respectively,for wheat and 348,891,2738,and 1845%,respectively,for maize.Different long-term fertilization treatments significantly changed coarse free particulate(cf POC),fine free particulate(ff POC),intramicroaggregate particulate(i POC),and mineral-associated(m SOC)organic carbon fractions.In the experimental years of 2001 and 2009,soil fractions occurred in the following order for all treatments:m SOC>cf POC>i POC>ff POC.All fractions were higher under the manure application treatments than under the inorganic fertilization treatments.Compared to the inorganic fertilization treatments,manure input enhanced the stocks of SOC and total N in the surface layer(0–20 cm)but decreased SOC and N in the deep soil layer(80–100 cm).This reveals the efficiency of manure in increasing yield productivity and decreasing risk of vertical loss of nutrients,especially N,compared to inorganic fertilization treatments.The findings provide opportunities for understanding deep soil C and N dynamics,which could help mitigate climate change impact on agricultural production and maintain soil health.
基金the support and funding from Innovation Technology Foundation from Hong Kong SAR.
文摘Fresh TiO2 was found to possess a strong germicidal activity even without UV irradiation. Live Yeast （Saccharomyces cerevisiae） cells in contact with fresh TiO2 were found deformed and dead after 15min contact. The cause of germicidal activity was discussed from the observed cell deformation, lysis and increased absorption at 1680 cm^-1 in FT-IR spectra of the affected cells, which proved the oxidizing effect of fresh TiO2 to cells. The deformation caused by the stretching of cell wail and pressure built-up inside the cell, led to cell burst and release of intracellular materials. The degree of cell deformation was found positively related with the wetting property of TiO2. Cells are negatively charged, for Gram-negative cell （thinner ceil wail）, a higher germicidal effect was observed than Gram-positive cells. The germicidal effect of TiO2 gradually decreased after exposure to air at room temperature, as the wetting property decreased. This kind of germicidal activity was more effective compared to other germicidal process such as UVA/TiO2 or Ag＋. This shed light on designing new germicidal material either maintained by visible light irradiation, or by oxidation effect generated by reactive oxygen species.
基金Supported by the National Natural Science Foundation of China(No.21107136)the International Foundation for Science(No.F/5230-1)
文摘Glutathione S-transferases （GSTs） are phase II enzymes that facilitate the detoxification of xenobioties and play important roles in antioxidant defense. We investigated the expression patterns of seven Venerupis philippinarum GSTs （VpGSTs） and four Mytilus galloprovincialis GSTs （MgGSTs） following exposure to BDE-47. Differential expressions of the seven VpGSTs and four MgGSTs transcripts were observed, with differences between the hepatopancreas and gills. Among these GSTs, the sigma classes （VpGSTS1, VpGSTS2, VpGSTS3, MgGST1, and MgGST3） were highly expressed in response to BDE-47 exposure, demonstrating their potential as molecular biomarkers for environmental biomonitoring studies. We obtained the three-dimensional crystal structures of VpGSTs and MgGSTs by homologous modeling. A model to elucidate the binding interactions between the ligands and receptors was defined by molecular docking, Hydrophobic and n were the most often observed interactions between BDE-47 and the GSTs.
基金supported by the National Natural Science Foundation of China (Nos. 21437001 and 21407019)Open Project of State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (No. QA201617)
文摘Nanoporous carbons（NPCs） derived from metal–organic frameworks（MOFs） are attracting increasing attention in many areas by virtue of their high specific surface area, large pore volume and unique porosity. The present work reports the preparation of an NPC with high surface area（1731 m^2/g） and pore volume（1.68 cm^3/g） by direct carbonization of MOF-5. We examined the adsorption of three typical contaminants from aqueous solutions, i.e., sulfamethoxazole（SMX）,bisphenol A（BPA） and methyl orange（MO）, by using the as-prepared NPC. The results demonstrated that NPC could adsorb the contaminants effectively, with adsorption capacity（qm） of 625 mg/g（SMX）, 757 mg/g（BPA） and 872 mg/g（MO）, respectively. These values were approximately 1.0-3.2 times higher than those obtained for single-walled carbon nanotubes（SWCNTs） and commercial powder active carbon（PAC） under the same conditions. With its high surface area and unique meso/macropore structure, the enhanced adsorption of NPC most likely originates from the cooperative interaction of a pore-filling mechanism, electrostatic interaction,and hydrogen bonding. In particular, the p H value has a crucial impact on adsorption, suggesting the significant contribution of electrostatic interaction between NPC and the contaminants. This study provides a proof-of-concept demonstration of MOF-derived nanoporous carbons as effective adsorbents of contaminants for water treatment.
基金supported by the National Natural Science Foundation of China(No.50608011)the 39th Postdoctoral Funds of China.
文摘A novel biphenyl-degrading bacterial strain LA-4 was isolated from activated sludge.It was identified as Dyella ginsengisoli according to phylogenetic similarity of 16S rRNA gene sequence.This isolate could utilize biphenyl as sole source of carbon and energy,which degraded over 95 mg/L biphenyl within 36 h.The major metabolites formed from biphenyl,such as 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid(HOPDA)and benzoic acid,were identified by LC-MS.The crude cell extract of strain LA-4 exhibited the activity of 2,3-dihydroxybiphenyl 1,2-dioxygenase(2,3-DHBD)and the kinetic parameters Km was 26.48μmol/L and Vmax was 8.12 U/mg protein.A conserved region of the biphenyl dioxygenase gene bphA1 of strain LA-4 was amplified by PCR and confirmed by DNA sequencing.
文摘The reference values of serum perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) concentrations were evaluated based on the human blood samples collected from Kashi, Xinjiang. And human serum samples of family members from Liaoning were evaluated for levels of PFOS and PFOA with the purpose to compare exposure pathways for family members. Among the 110 blood specimens from Kashi, the detection frequency of PFOS and PFOA was 93% and 6%, respectively. Reference values of serum PFOS, evaluated as the 90th percentiles of the concentrations, were determined to be 6.44 μg/L. Significant positive correlations were observed for serum levels of PFOS and PFOA among family members in Liaoning. Specially, stronger correlation between mother and offspring was observed than that between father and offspring. And stronger correlation of serum PFOS and PFOA levels was observed among fam- ily members in rural areas than those in big and small-medium cities. Difference in the association of serum PFOS and PFOA level among family members suggested that exposure in the outdoor and working environment of different oc- cupations should be evaluated. Present study provides reference values for exposure assessment in China and potential pathways of human exposure to PFOS and PFOA.
基金the financial support from the National Natural Scientific Foundation of China(No.52000020)the National Natural Scientific Foundation of China(No.21876022)。
文摘Considering that cathode of microbial electrochemical system(MES)is a good electrons source for methane production via direct/indirect electron transfer to electroactive microorganisms,and that Fe(0)is also a confirmed electron donor for some electroactive microorganisms through metal-microbe direct electron transfer(DET),Fe(0)-cathode was equipped into an MES digester to enhance cathodic methane production.The results of this study indicated that the potential DET participator,Clostridium possibly obtained electrons directly from Fe(0)-cathode via metal-microbe electrons transfer,then transferred electrons directly to the definite DET participators,Methanosarcina/Methanothrix via microbemicrobe electrons transfer for CH_(4)production.In addition,Methanobacterium is another specially enriched methanogen on Fe(0)-cathode,which might obtain electrons directly from Fe(0)-cathode to produce CH_(4) via metal/electrode-microbe DET.The increment of conductivity of cathodic sludge in Fe(0)-cathode MES digester(R1)further confirmed the enrichment of electroactive microorganisms participating in DET process.As a consequence,a higher CH_(4) production(1205–1508 m L/d)and chemical oxygen demand(COD)removal(79.0%-93.8%)were achieved in R1 compared with graphite-cathode MES digester(R2,720–1090 m L/d and 63.6%-85.6%)and the conventional anaerobic digester(R3,384–428 m L/d and 35.2%-41.0%).In addition,energy efficiency calculated indicated that the output energy of CH_(4) production was 8.16 folds of electricity input in Fe(0)-cathode MES digester.
