China,as the world’s largest producer and consumer of synthetic textiles,faces sustainability challenges in the synthetic textile dyeing and finishing sector.The greenhouse gas(GHG)emission profiles and potential mit...China,as the world’s largest producer and consumer of synthetic textiles,faces sustainability challenges in the synthetic textile dyeing and finishing sector.The greenhouse gas(GHG)emission profiles and potential mitigation pathways for this sector require further classification.This study analyzed the GHG emissions from the synthetic textile dyeing and finishing process of eight representative life cycle assessment(LCA)cases.To explore the potential for emission mitigation,four mitigation strategies were developed,resulting in the formulation of 11 scenarios.The average GHG emissions per kilogram of synthetic textiles from the dyeing and finishing process were 3.06 kg CO_(2)equivalent(eq)(ranging from 1.83 to 5.34 kg CO_(2)eq),primarily contributed by the dyeing unit and resulting from energy consumption(steam and electricity).The scenario analysis suggested that in the business-as-usual scenario,GHG emissions from the dyeing and finishing sector could reach 17.79 Mt CO_(2)eq by the year of 2060.Emission mitigation potentials across scenarios ranged from 35.72%to 71.65%.In the most optimistic scenario,emissions could be reduced to as low as 5.04 Mt CO_(2)eq by the year of 2060.These findings provide valuable insights to identify key mitigation pathways for the synthetic textile dyeing and finishing sector.展开更多
Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ ...Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ measurements performed at a mountain site(1690 m a.s.l.)in southern China,we investigated the formation of NOCs in the cloud droplets and the cloud-free particles,based on their mixing state information of NOCscontaining particles by single particle mass spectrometry.The relative abundance of NOCs in the cloud-free particles was significantly higher than those in cloud residual(cloud RES)particles.NOCs were highly correlated with carbonyl compounds(including glyoxalate and methylglyoxal)in the cloud-free particles,however,limited correlation was observed for cloud RES particles.Analysis of their mixing state and temporal variations highlights that NOCs was mainly formed from the carbonyl compounds and ammonium in the cloud-free particles,rather than in the cloud RES particles.The results support that the formation of NOCs from carbonyl compounds is facilitated in concentrated solutions in wet aerosols,rather than cloud droplets.In addition,we have identified the transport of biomass burning particles that facilitate the formation of NOCs,and that the observed NOCs is most likely contributed to the light absorption.These findings have implications for the evaluation of NOCs formation and their contribution to light absorption.展开更多
Peroxyacetyl nitrate （PAN）, as a major secondary pollutant, has gained increasing worldwide attentions, but relevant studies in China are still quite limited. During winter of 2015 to summer of 2016, the ambient lev...Peroxyacetyl nitrate （PAN）, as a major secondary pollutant, has gained increasing worldwide attentions, but relevant studies in China are still quite limited. During winter of 2015 to summer of 2016, the ambient levels of PAN were measured continuously by an automatic gas chromatograph equipped with an electron capture detector （GC-ECD） analyzer at an urban site in Jinan （China）, with related parameters including concentrations of 03, NO, NO2, PM2.5, HONO, the photolysis rate constant of NO2 and meteorological factors observed concurrently. The mean and maximum values of PAN concentration were （1.89 ± 1.42） and 9.61 ppbv respectively in winter, and （2.54 ± 1.44） and 13.47 ppbv respectively in summer. Unusually high levels of PAN were observed during severe haze episodes in winter, and the formation mechanisms of them were emphatically discussed, Study showed that high levels of PAN in winter were mainly caused by local accumulation and strong photochemical reactions during haze episodes, while mass transport played only a minor role. Accelerated photochemical reactions （compared to winter days without haze） during haze episodes were deduced by the higher concentrations but shorter lifetimes of pAN, which was further supported by the sufficient solar radiation in the photolysis band along with the high concentrations of precursors （NO2, VOCs） and HONO during haze episodes. In addition, significant PAN accumulation during calm weather of haze episodes was verified by meteorological data.展开更多
There is an urgent need for developing cost-effective methods for the treatment of perfluorooctanoic acid(PFOA)due to its global emergence and potential risks.In this study,taking surface-defective BiOCl as an example...There is an urgent need for developing cost-effective methods for the treatment of perfluorooctanoic acid(PFOA)due to its global emergence and potential risks.In this study,taking surface-defective BiOCl as an example,a strategy of surface oxygen vacancy modulation was used to promote the photocatalytic defluorination efficiency of PFOA under simulated sunlight irradiation.The defective BiOCl was fabricated by a fast microwave solvothermal method,which was found to induce more surface oxygen vacancies than conventional solvothermal and precipitation methods.As a result,the asprepared BiOCl showed significantly enhanced defluorination efficiency,which was 2.7 and33.8 times higher than that of BiOCl fabricated by conventional solvothermal and precipitation methods,respectively.Mechanistic studies indicated that the defluorination of PFOA follows a direct hole(h^+)oxidation pathway with the aid of·OH,while the oxygen vacancies not only promote charge separation but also facilitate the intimate contact between the photocatalyst surface and PFOA by coordinating with its terminal carboxylate group in a bidentate or bridging mode.This work will provide a general strategy of oxygen vacancy modulation by microwave-assisted methods for efficient photocatalytic defluorination of PFOA in the environment using sunlight as the energy source.展开更多
Photocatalytic degradation of gaseous pollutants on Bi-based semiconductors under solar lightirradiation has attracted significant attention.However,their application in gaseous straight-chainalkane purification is st...Photocatalytic degradation of gaseous pollutants on Bi-based semiconductors under solar lightirradiation has attracted significant attention.However,their application in gaseous straight-chainalkane purification is still rare.Here,a series of Bi/BiOBr composites were solvothermally synthe-sized and applied in solar-light-driven photocatalytic degradation of gaseous n-hexane.The charac-terization results revealed that both increasing number of functional groups of alcohol solvent(from methanol and ethylene glycol to glycerol)and solvothermal temperature(from 160 and 180to 200℃)facilitated the in-situ formation of metallic Bi nanospheres on BiOBr nanoplates withexposed(110)facets.Meanwhile,chemical bonding between Bi and BiOBr was observed on theseexposed facets that resulted in the formation of surface oxygen vacancy.Furthermore,the synergis-tic effect of optimum surface oxygen vacancy on exposed(110)facets led to a high visible light re-sponse,narrow band gap,great photocurrent,low recombination rate of the charge carriers,andstrong·O2-and h*formation,all of which resulted in the highest removal efficiency of 97.4%within120 min of 15 ppmv of n-hexane on Bi/BiOBr.Our findings efficiently broaden the application ofBi-based photocatalysis technology in the purification of gaseous straight-chain pollutants emittedby the petrochemical industry.展开更多
The photodegradation of gaseous dichloromethane （DCM） by a vacuum ultraviolet （VUV） light in a spiral reactor was investigated with different reaction media and initial concentrations. Through the combination of d...The photodegradation of gaseous dichloromethane （DCM） by a vacuum ultraviolet （VUV） light in a spiral reactor was investigated with different reaction media and initial concentrations. Through the combination of direct photolysis, O3 oxidation and HO. oxidation, DCM was ultimately mineralized into inorganic compounds （such as HC1, CO2, H20, etc.） in the air with relative humidity （RH） of 75%-85%. During the photodegradation process, some small organic acids （including formic acid, acetic acid） were also detected and the intermediates were more soluble than DCM, providing a possibility for its combination with subsequent biodegradation. Based on the detected intermediates and the confirmed radicals, a photodegradation pathway of DCM by VUV was proposed. With RH 75%- 80% air as the reaction medium, the DCM removal followed the second-order kinetic model at inlet concentration of 100-1000 mg/m3. Kinetic analysis showed that the reaction media affected the kinetic constants of DCM conversion by a large extent, and RH 80% air could cause a much lower half-life for its conversion. Such results supported the possibility that VUV photodegradation could be used not only for the mineralization of DCM but also as a pretreatment before biodegradation.展开更多
A series of europium-doped titanium dioxide (TiO 2) fluorescent nano-material s prepared by sol-gel method is presented. The phase structure and crystalline sizes of TiO 2∶Eu, which is doped with different europiu...A series of europium-doped titanium dioxide (TiO 2) fluorescent nano-material s prepared by sol-gel method is presented. The phase structure and crystalline sizes of TiO 2∶Eu, which is doped with different europium content and then he at-treated at different temperature, were investigated by XRD,TG,DTA and TEM. The results show that europium could be introduced into TiO 2 under high temper ature and it can suppress the structural phase transition from anatase to rutile and the crystal growth of TiO 2 in TiO 2∶Eu nano-materials. The fluorescenc e spectra were examined by fluorescence spectrophotometer, and the results show that the fluorescence intensity is the strongest when europium content is 2.68%( mole fraction) and the heat-treated temperature is 700 ℃. From the measurement results of the fluorescence lifetimes, it can be seen that the fluorescence lifetime c ould be prolonged when europium is incorporated in TiO 2.展开更多
The COVID-19 pandemic has raised awareness about various environmental issues,includ-ing PM_(2.5) pollution.Here,PM_(2.5) pollution during the COVID-19 lockdown was traced and an-alyzed to clarify the sources and fact...The COVID-19 pandemic has raised awareness about various environmental issues,includ-ing PM_(2.5) pollution.Here,PM_(2.5) pollution during the COVID-19 lockdown was traced and an-alyzed to clarify the sources and factors influencing PM_(2.5) in Guangzhou,with an emphasis on heavy pollution.The lockdown led to large reductions in industrial and traffic emissions,which significantly reduced PM_(2.5) concentrations in Guangzhou.Interestingly,the trend of PM_(2.5) concentrations was not consistent with traffic and industrial emissions,as minimum concentrations were observed in the fourth period(3/01-3/31,22.45 μg/m^(3))of the lockdown.However,the concentrations of other gaseous pollutants,e.g.,SO_(2),NO_(2) and CO,were corre-lated with industrial and traffic emissions,and the lowest values were noticed in the sec-ond period(1/24-2/0_(3))of the lockdown.Meteorological correlation analysis revealed that the decreased PM_(2.5) concentrations during COVID-19 can be mainly attributed to decreased in-dustrial and traffic emissions rather than meteorological conditions.When meteorological factors were included in the PM_(2.5) composition and backward trajectory analyses,we found that long-distance transportation and secondary pollution offset the reduction of primary emissions in the second and third stages of the pandemic.Notably,industrial PM_(2.5) emis-sions from western,southern and southeastern Guangzhou play an important role in the formation of heavy pollution events.Our results not only verify the importance of control-ling traffic and industrial emissions,but also provide targets for further improvements in PM_(2.5) pollution.展开更多
Pathogenic microbes with antibiotic resistance can thrive on municipal solid waste as nutrients and be aerosolized and transported to vicinities during waste disposal processes.However,the characterization of pathogen...Pathogenic microbes with antibiotic resistance can thrive on municipal solid waste as nutrients and be aerosolized and transported to vicinities during waste disposal processes.However,the characterization of pathogenic bioaerosols and assessment of their exposure risks are lacking.Herein,particle size,concentration,activity,antibiotic resistance,and pathogenicity of airborne microorganisms were assessed in different sectors of a typical landfill.Results showed that active sector in downwind direction has the highest bioaerosol level(1234 CFU/m3),while residential area has the highest activity(14.82 mg/L).Botanical deodorizer from mist cannon can effectively remove bioaerosol.Most bioaerosols can be inhaled into respiratory system till bronchi with sizes ranging from 2.1−3.3 and 3.3−4.7μm.Pathogenic bacteria(Bacilli,Bacillus,and Burkholderia-Paraburkholderia)and allergenic fungi(Aspergillus,Cladosporium,and Curvularia)prevailed in landfill.Although high abundance of microbial volatile organic compounds(mVOCs)producing bioaerosols were detected,these mVOCs contributed little to odor issues in landfill.Notably,surrounding areas have higher levels of antibiotic-resistance genes(ARGs)than inner landfill with tetC,acrB,acrF,mdtF,and bacA as dominant ones.Most ARGs were significantly correlated with bacterial community,while environmental parameters mainly influenced fungal prevalence.These findings can assist in reducing and preventing respiratory allergy or infection risks in occupational environments relating to waste management.展开更多
Geothermal water of Xi＇an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. 5180 and 5D data of geopressured thermal water＇in Xi＇an and Xianyang, combined with data from ...Geothermal water of Xi＇an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. 5180 and 5D data of geopressured thermal water＇in Xi＇an and Xianyang, combined with data from the perimeter of the basin, are analyzed to study features of hydrogen and oxygen shifts. The results show that ^18O exchange of geothermal water at the perimeter of the basin and in the non-geopressured thermal water in the center of the basin is not evident, while in most of the geopressured thermal water in the central basin, in cities such as Xi＇an and Xianyang, significant oxygen exchange had taken place as well as hydrogen exchange, suggesting that isotope exchanges would slowly move the geothermal water system towards equilibrium. Thermal water reservoirs in the central basin have passed through significant water-rock reactions. Moreover, the geothermal reservoir of Xianyang city is relatively much more enclosed than that of Xi＇an city. It has been observed that the more enclosed the geological environment of geothermal water is, the more obvious the oxygen shifts are. With the increasing of the depth, residence time, total amounts of dissolute solids and temperatures of geothermal waters, the oxygen exchange accelerates.展开更多
Nanometer-size zero-valent iron(NZVI)is an efficient reducing agent,but its surface is easily passivated with an oxide layer,leading to reaction inefficiency.In our study,oxalate(OA)was introduced into this heterogene...Nanometer-size zero-valent iron(NZVI)is an efficient reducing agent,but its surface is easily passivated with an oxide layer,leading to reaction inefficiency.In our study,oxalate(OA)was introduced into this heterogeneous system of NZVI,which could form ferrioxalate complexes with the NZVI surface-bound Fe3+and dissolved Fe3+in the solution.Photolysis of ferrioxalate complexes can facilitate the generation of Fe2+from Fe3+and CO_(2)·-radical,both species have strong reduction capacity.Hence,a"photo-oxalate-Fe(0)"system through sunlight induction was established,which not only prohibited the formation of a surface passivation layer,but also displayed a synergetic mechanism of ferrioxalate photolysis to enhance reduction,exhibiting remarkably higher degradation activity(several times faster)toward the model pollutant Cr(Ⅵ)than the mechanism with NZVI alone.Factor tests suggested that both NZVI dosage and OA content markedly affected the reduction rate.Low pH was beneficial to the reduction efficiency.Moreover,recyclability experiment showed that the reduction rate decreased from 0.21706 to 0.03977 min-1 after three cycles of reuse due to the NZVI losing reaction activity generally,but the system still maintained considerable reduction capacity.Finally,a mechanism was revealed whereby NZVI would transform to Fe oxides after the exhaustion of its reductive power,and the photolysis of ferrioxalate to promote the cycling of iron species played the predominant role in providing extra reduction ability.These features confirm that introduction of OA into Cr(Ⅵ)reduction by NZVI through sunlight induction is advantageous and promising.展开更多
Increasing attention has been paid to the air pollution more recently. Smog chamber has been proved as a necessary and effective tool to study atmospheric processes, including photochemical smog and haze formation. A ...Increasing attention has been paid to the air pollution more recently. Smog chamber has been proved as a necessary and effective tool to study atmospheric processes, including photochemical smog and haze formation. A novel smog chamber was designed to study the atmospheric photochemical reaction mechanism of typical volatile organic compounds(VOCs) as well as the aging of aerosols. The smog chamber system includes an enclosure equipped with black lights as the light source, two parallel reactors(2 m^3 of each) with separate control of light source and temperature, with a series of coupled instruments for online monitoring of gas phase and particle phase reactants and products. Chamber characterization, including air source stability, effective light intensity, temperature stability, as well as gas phase and particle phase wall losses, were carried out before further research. The results showed that our smog chamber systems developed by other domestic and international groups. It was also observed that the wall loss of aromatic VOCs varied with different functional groups as well as the isomerism. The results of preliminary simulation experiment from styrene-NO_x demonstrated that the chamber can be well utilized to simulate gas-particle conversion progresses in the atmosphere.展开更多
Polychlorinated biphenyls(PCBs) and organochlorine pesticides(OCPs) are typical persistent organic pollutants(POPs),which have high toxicity,bioaccumulation and long-distance transfer capability.Daily variation,source...Polychlorinated biphenyls(PCBs) and organochlorine pesticides(OCPs) are typical persistent organic pollutants(POPs),which have high toxicity,bioaccumulation and long-distance transfer capability.Daily variation,sources of PcBs and OcPs in PM2.5 are rarely explored in polluted rural area.Here,the sources and health risks of the PcBs and OcPs were evaluated for 48 PM2.5 samples collected in winter 2017 in Wangdu,a heavy polluted rural area in the North China Plain.The average diurnal and nocturnal concentrations of E18 PCBs and∑15OCPs were 1.74-24.37 and 1.77-100.49,11.67-408.81 and 16.89-865.60 pg/m3,respectively.Hexa-CBs and penta-CBs accounted for higher proportions(29.0% and 33.6%) of clean and polluted samples,respectively.Hexachlorobenzene(HCB) was the dominant contributor to OCPs with an average concentration of 116.17 pg/m3.Hexachlorocyclohexane(EHCHs) and dichlorodiphenyltrichloroethane(EDDTs) were the other two main classes in OCPs with the average concentrations of 4.33 and 15.89 pg/m3,respectively.β-HCH and p,p’-DDE were the main degradation products of HCHs and DDTs,respectively.The principal component analysis and characteristic ratio method indicated both waste incineration and industrial activities were the main sources of PCBs,contributing 76.8% and 12.7%,respectively.The loadings of OCPs were attributed to their application characteristics and the characteristic ratio method reflected a current or past use of OCPs.Health risk assessment showed that the respiratory exposure quantity of doxin-like PCBs(DL-PCBs) and the lifetime cancer risk from airborne OCPs exposure was negligible,while the other exposure modes may pose a risk to human bodies.展开更多
Thermodynamic equilibrium calculations were performed to reveal effects of interactions among Cl,S,P and other minerals on Cu migration.Our results showed that HCl(g),SO2(g)and(P2O5)2(g)were released from the sewage s...Thermodynamic equilibrium calculations were performed to reveal effects of interactions among Cl,S,P and other minerals on Cu migration.Our results showed that HCl(g),SO2(g)and(P2O5)2(g)were released from the sewage sludge co-incineration.Cl was found to weaken adsorption of Cu by Al2O3,CaO and Fe2O3,while S de-layed reactions of Fe2O3 and Al2O3 with Cu,with P having no effect on reactions between the minerals and Cu.Among the coupled systems ofCl,S and P,the co-existences of Cl and S,and Cl,S and P were determined to inhibit Cu volatilization,and the co-existence of Cl and P had an enhancing effect Cu migration was affected only by S in the S and P system.With the SiO2,CaO and Al2O3 system,both Cl alone and Cl and P led to failed reactions be-tween the minerals and Cu.In the systems of S,S and Cl,S and P,and S,Cl and P,the migration behavior of Cu was mainly affected by S at low temperatures and by Cl at high temperatures,whereas P had no effect on Cu mi-gration during the entire nrocess.展开更多
Given the high abundance of water in the atmosphere,the reaction of Criegee intermediates(CIs)with(H_(2)O)_(2) is considered to be the predominant removal pathway for CIs.However,recent experimental findings reported ...Given the high abundance of water in the atmosphere,the reaction of Criegee intermediates(CIs)with(H_(2)O)_(2) is considered to be the predominant removal pathway for CIs.However,recent experimental findings reported that the reactions of CIs with organic acids and carbonyls are faster than expected.At the same time,the interface behavior between CIs and carbonyls has not been reported so far.Here,the gas-phase and air-water interface behavior between Criegee intermediates and HCHO were explored by adopting high-level quantum chemical calculations and Born-Oppenheimer molecular dynamics(BOMD)simulations.Quantum chemical calculations evidence that the gas-phase reactions of CIs+HCHO are submerged energy or low energy barriers processes.The rate ratios speculate that the HCHO could be not only a significant tropospheric scavenger of CIs,but also an inhibitor in the oxidizing ability of CIs on SO_(x) in dry and highly polluted areas with abundant HCHO concentration.The reactions of CH_(2)OO with HCHO at the droplet’s surface follow a loop structure mechanism to produce i)SOZ(■),ii)BHMP(HOCH_(2)OOCH_(2)OH),and iii)HMHP(HOCH_(2)OOH).Considering the harsh reaction conditions between CIs and HCHO at the interface(i.e.,the two molecules must be sufficiently close to each other),the hydration of CIs is still their main atmospheric loss pathway.These results could help us get a better interpretation of the underlying CIs-aldehydes chemical processes in the global polluted urban atmospheres.展开更多
The α-pinene ozonolysis under the different environmental conditions were observed in a smog chamber. The second-order rate constant （k） was determined to be （7.25 ± 0.06） x 10^-17 cm^3/（molecule.sec） unde...The α-pinene ozonolysis under the different environmental conditions were observed in a smog chamber. The second-order rate constant （k） was determined to be （7.25 ± 0.06） x 10^-17 cm^3/（molecule.sec） under 20% of relative humidity （RH） and room temperature. RH showed a marked influence on the α-pinene ozonolysis. The value of k increased with KH increase, which was 1.6 times faster at RH = 80% than that at RH = 20%. Additionally, the value of k apparently changed in the presence of the aerosol particles. The diesel soot increased the k value. The fly ash prohibited the reaction, however, H2SO4-treated fly ash promoted the reaction. The information of products gained using FT-IR and SPAMS showed that pinonic acid, 10-hydroxy-pinonic acid and pinic acid could be generated during the α- pinene ozonolysis. Water molecules could take part in the formation of the products, and play a vital role in the degradation of α-pinene. The atmospheric residence time calculation showed that the ozonolysis in the atmosphere is an important way of the α-pinene consumption as compared to that reacted with OH during daytime. The results suggested that the degradation of α-pinene via the ozonization in the atmosphere may be affected greatly by RH, as well as the presence of aerosol particles. The ozonolysis reaction may be an important way of the a-pinene consumption during daytime.展开更多
High efficient removal of antibiotics during nutriments recovery for biomass production poses a major technical challenge for photosynthetic microbial biofilm-based wastewater treatment since antibiotics are always co...High efficient removal of antibiotics during nutriments recovery for biomass production poses a major technical challenge for photosynthetic microbial biofilm-based wastewater treatment since antibiotics are always co-exist with nutriments in wastewater and resist biodegradation due to their strong biotoxicity and recalcitrance.In this study,we make a first attempt to enhance metronidazole(MNZ)removal from wastewater using electrochemistry-activated binary-species photosynthetic biofilm of Rhodopseudomonas Palustris(R.Palustris)and Chlorella vulgaris(C.vulgaris)by cultivating them under different applied potentials.The results showed that application of external potentials of-0.3,0 and 0.2 V led to 11,33 and 26-fold acceleration in MNZ removal,respectively,as compared to that of potential free.The extent of enhancement in MNZ removal was positively correlated to the intensities of photosynthetic current produced under different externally applied potentials.The binary-species photoelectrogenic biofilm exhibited 18 and 6-fold higher MNZ removal rate than that of single-species of C.vulgaris and R.Palustris,respectively,due to the enhanced metabolic interaction between them.Application of an external potential of 0V significantly promoted the accumulation of tryptophan and tyrosine-like compounds as well as humic acid in ex-tracellular polymeric substance,whose concentrations were 7.4,7.1 and 2.0-fold higher than those produced at potential free,contributing to accelerated adsorption and reductive and photosensitive degradation of MNZ.展开更多
Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bat...Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bath. An electrolyte cell which was constructed by the cathode of porous nickel foam and the anode of Ti/RuO2 was used. During electrolysis, the nickel ion was electrodeposited at the cathode and the oxidation of the organics in the hath was conducted at the anode. The current （i） , time （t） , temperature （T） and pH of the solution affected the recovery efficiency of nickel with constant potential electrolysis. With the optimum experimental conditions of pH=7.6, i = 0.45 A. T = 65℃ andt = 2 h, the concentration of nickel ion was reduced from 2.09 g/L to 0. 053 g/L and the recovery rate of nickel, the current efficiency and the consumed energy wer 97.5%, 17. 1%, 12.2 kWh/kg Ni, respectively. Meanwhile, total organic carbon （TOC） of the bath was reduced from 5 800 mg/L to 152.5 mg/L and the removal efficiency of TOC was 97.3%. The recovery rate of nickel could keep to about 97% when eleetrodeposit was used to recover nickel for 40 hours in a laboratol.w batch reactor containing the spent bath. Dull nickel containing phosphorus was obtained on the cathode.展开更多
Research on pollution characteristics and toxicities of emerging polycyclic aromatic sulfur heterocycles(PASHs) in PM_(2.5) has not been reported due to the lack of analytical method with the needed performance.In the...Research on pollution characteristics and toxicities of emerging polycyclic aromatic sulfur heterocycles(PASHs) in PM_(2.5) has not been reported due to the lack of analytical method with the needed performance.In the present study,a novel method for the determination of 14 PASHs in PM_(2.5) was developed using atmospheric pressure gas chro matography-tandem mass spectrometry(APGC-MS/MS).Atmospheric pressure chemical ionization was operated with multiple reaction monitoring in positive ionization mode.High sensitivity(method detection limit <1.673 pg/m^(3)),acceptable re coveries(67.6%-120.8%) and precisions(RSD of 2.2%-15.4%) were obtained.The method was successfully applied for analyzing PASHs in 10 PM_(2.5) samples collected from Taiyuan,a typical industrial city in China,in 2016,The total concentrations were from 929 pg/m^(3) to 14,593 pg/m^(3).The determined levels indicated that further investigations on environmental fate and toxicities of PM_(2.5)-bound PASHs may be needed.展开更多
As the rapid development of industrial economy,massiveconsumption of fossil energy leads to increasingly seriousenvironmental pollution.Thus.it is highly obliged to developgreen,efficient and robust technologies for f...As the rapid development of industrial economy,massiveconsumption of fossil energy leads to increasingly seriousenvironmental pollution.Thus.it is highly obliged to developgreen,efficient and robust technologies for fuel production andpollution remediation.Semiconductor-based photocatalysiscould realize the production of fuel chemicals,selectivetransformation/degradation of organic pollutants and eveninactivation of microorganisms by using the solar-to-chemicalenergy conversion hence possesses scientific significance andgreat application potential.Besides,multidisciplinarilyinvolving semiconductor physics.catalysis and surface science,photocatalysis has become one of the most attractive andpioneering research fields all over the world.展开更多
基金Shanghai Municipal Natural Science Foundation,China(No.23ZR1402300)Fundamental Research Funds for the Central Universities,China(Nos.2232022G-11 and 2232023G-11)。
文摘China,as the world’s largest producer and consumer of synthetic textiles,faces sustainability challenges in the synthetic textile dyeing and finishing sector.The greenhouse gas(GHG)emission profiles and potential mitigation pathways for this sector require further classification.This study analyzed the GHG emissions from the synthetic textile dyeing and finishing process of eight representative life cycle assessment(LCA)cases.To explore the potential for emission mitigation,four mitigation strategies were developed,resulting in the formulation of 11 scenarios.The average GHG emissions per kilogram of synthetic textiles from the dyeing and finishing process were 3.06 kg CO_(2)equivalent(eq)(ranging from 1.83 to 5.34 kg CO_(2)eq),primarily contributed by the dyeing unit and resulting from energy consumption(steam and electricity).The scenario analysis suggested that in the business-as-usual scenario,GHG emissions from the dyeing and finishing sector could reach 17.79 Mt CO_(2)eq by the year of 2060.Emission mitigation potentials across scenarios ranged from 35.72%to 71.65%.In the most optimistic scenario,emissions could be reduced to as low as 5.04 Mt CO_(2)eq by the year of 2060.These findings provide valuable insights to identify key mitigation pathways for the synthetic textile dyeing and finishing sector.
基金supported by the National Key Research and Development Program of China(No.2022YFC3701103)the National Natural Science Foundation of China(No.42222705)+1 种基金the Youth Innovation Promotion Association CAS(No.2021354)Guangdong Foundation for Program of Science and Technology Research(No.2023B1212060049).
文摘Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ measurements performed at a mountain site(1690 m a.s.l.)in southern China,we investigated the formation of NOCs in the cloud droplets and the cloud-free particles,based on their mixing state information of NOCscontaining particles by single particle mass spectrometry.The relative abundance of NOCs in the cloud-free particles was significantly higher than those in cloud residual(cloud RES)particles.NOCs were highly correlated with carbonyl compounds(including glyoxalate and methylglyoxal)in the cloud-free particles,however,limited correlation was observed for cloud RES particles.Analysis of their mixing state and temporal variations highlights that NOCs was mainly formed from the carbonyl compounds and ammonium in the cloud-free particles,rather than in the cloud RES particles.The results support that the formation of NOCs from carbonyl compounds is facilitated in concentrated solutions in wet aerosols,rather than cloud droplets.In addition,we have identified the transport of biomass burning particles that facilitate the formation of NOCs,and that the observed NOCs is most likely contributed to the light absorption.These findings have implications for the evaluation of NOCs formation and their contribution to light absorption.
基金supported by the National Key R&D Program of China(No.2016YFC0202700)the National Natural Science Foundation of China(Nos.41375126,21527814,91743202)the H2020 Marie Sklodowska-Curie Actions(No.H2020-MSCARISE-2015-690958)
文摘Peroxyacetyl nitrate （PAN）, as a major secondary pollutant, has gained increasing worldwide attentions, but relevant studies in China are still quite limited. During winter of 2015 to summer of 2016, the ambient levels of PAN were measured continuously by an automatic gas chromatograph equipped with an electron capture detector （GC-ECD） analyzer at an urban site in Jinan （China）, with related parameters including concentrations of 03, NO, NO2, PM2.5, HONO, the photolysis rate constant of NO2 and meteorological factors observed concurrently. The mean and maximum values of PAN concentration were （1.89 ± 1.42） and 9.61 ppbv respectively in winter, and （2.54 ± 1.44） and 13.47 ppbv respectively in summer. Unusually high levels of PAN were observed during severe haze episodes in winter, and the formation mechanisms of them were emphatically discussed, Study showed that high levels of PAN in winter were mainly caused by local accumulation and strong photochemical reactions during haze episodes, while mass transport played only a minor role. Accelerated photochemical reactions （compared to winter days without haze） during haze episodes were deduced by the higher concentrations but shorter lifetimes of pAN, which was further supported by the sufficient solar radiation in the photolysis band along with the high concentrations of precursors （NO2, VOCs） and HONO during haze episodes. In addition, significant PAN accumulation during calm weather of haze episodes was verified by meteorological data.
基金supported by the National Natural Science Foundation of China (Nos. 21607028, 41425015 and 41573086)the Research Grant Council of Hong Kong Special Administrative Region (SAR) Government (No. GRF14100115)+3 种基金Science and Technology Project of Guangdong Province, China (No. 2017A050506049)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (No. 2017BT01Z032)Innovation Team Project of Guangdong Provincial Department of Education (No. 2017KCXTD012)Leading Scientific, Technical and Innovation Talents of Guangdong Special Support Program (No. 2016TX03Z094)
文摘There is an urgent need for developing cost-effective methods for the treatment of perfluorooctanoic acid(PFOA)due to its global emergence and potential risks.In this study,taking surface-defective BiOCl as an example,a strategy of surface oxygen vacancy modulation was used to promote the photocatalytic defluorination efficiency of PFOA under simulated sunlight irradiation.The defective BiOCl was fabricated by a fast microwave solvothermal method,which was found to induce more surface oxygen vacancies than conventional solvothermal and precipitation methods.As a result,the asprepared BiOCl showed significantly enhanced defluorination efficiency,which was 2.7 and33.8 times higher than that of BiOCl fabricated by conventional solvothermal and precipitation methods,respectively.Mechanistic studies indicated that the defluorination of PFOA follows a direct hole(h^+)oxidation pathway with the aid of·OH,while the oxygen vacancies not only promote charge separation but also facilitate the intimate contact between the photocatalyst surface and PFOA by coordinating with its terminal carboxylate group in a bidentate or bridging mode.This work will provide a general strategy of oxygen vacancy modulation by microwave-assisted methods for efficient photocatalytic defluorination of PFOA in the environment using sunlight as the energy source.
文摘Photocatalytic degradation of gaseous pollutants on Bi-based semiconductors under solar lightirradiation has attracted significant attention.However,their application in gaseous straight-chainalkane purification is still rare.Here,a series of Bi/BiOBr composites were solvothermally synthe-sized and applied in solar-light-driven photocatalytic degradation of gaseous n-hexane.The charac-terization results revealed that both increasing number of functional groups of alcohol solvent(from methanol and ethylene glycol to glycerol)and solvothermal temperature(from 160 and 180to 200℃)facilitated the in-situ formation of metallic Bi nanospheres on BiOBr nanoplates withexposed(110)facets.Meanwhile,chemical bonding between Bi and BiOBr was observed on theseexposed facets that resulted in the formation of surface oxygen vacancy.Furthermore,the synergis-tic effect of optimum surface oxygen vacancy on exposed(110)facets led to a high visible light re-sponse,narrow band gap,great photocurrent,low recombination rate of the charge carriers,andstrong·O2-and h*formation,all of which resulted in the highest removal efficiency of 97.4%within120 min of 15 ppmv of n-hexane on Bi/BiOBr.Our findings efficiently broaden the application ofBi-based photocatalysis technology in the purification of gaseous straight-chain pollutants emittedby the petrochemical industry.
基金supported by the National Natural Science Foundation of China (No. 20976165,21207115)the Ph.D.Programs Foundation of Ministry of Education of China(No. 20093317110003)the Zhejiang Provincial Funds for Distinguished Young Scientists (No. R5090230)
文摘The photodegradation of gaseous dichloromethane （DCM） by a vacuum ultraviolet （VUV） light in a spiral reactor was investigated with different reaction media and initial concentrations. Through the combination of direct photolysis, O3 oxidation and HO. oxidation, DCM was ultimately mineralized into inorganic compounds （such as HC1, CO2, H20, etc.） in the air with relative humidity （RH） of 75%-85%. During the photodegradation process, some small organic acids （including formic acid, acetic acid） were also detected and the intermediates were more soluble than DCM, providing a possibility for its combination with subsequent biodegradation. Based on the detected intermediates and the confirmed radicals, a photodegradation pathway of DCM by VUV was proposed. With RH 75%- 80% air as the reaction medium, the DCM removal followed the second-order kinetic model at inlet concentration of 100-1000 mg/m3. Kinetic analysis showed that the reaction media affected the kinetic constants of DCM conversion by a large extent, and RH 80% air could cause a much lower half-life for its conversion. Such results supported the possibility that VUV photodegradation could be used not only for the mineralization of DCM but also as a pretreatment before biodegradation.
文摘A series of europium-doped titanium dioxide (TiO 2) fluorescent nano-material s prepared by sol-gel method is presented. The phase structure and crystalline sizes of TiO 2∶Eu, which is doped with different europium content and then he at-treated at different temperature, were investigated by XRD,TG,DTA and TEM. The results show that europium could be introduced into TiO 2 under high temper ature and it can suppress the structural phase transition from anatase to rutile and the crystal growth of TiO 2 in TiO 2∶Eu nano-materials. The fluorescenc e spectra were examined by fluorescence spectrophotometer, and the results show that the fluorescence intensity is the strongest when europium content is 2.68%( mole fraction) and the heat-treated temperature is 700 ℃. From the measurement results of the fluorescence lifetimes, it can be seen that the fluorescence lifetime c ould be prolonged when europium is incorporated in TiO 2.
基金This work was supported by the National Natural Science Foundation of China(Nos.21806025 and 91843301)the Natural Science Foundation of Guangdong Province(No.2019A1515011294)+1 种基金the Science and Technology Planning Project of Guangdong Province(No.2020B1212030008)the National Key Research and Development Project(No.2019YFC1804604).
文摘The COVID-19 pandemic has raised awareness about various environmental issues,includ-ing PM_(2.5) pollution.Here,PM_(2.5) pollution during the COVID-19 lockdown was traced and an-alyzed to clarify the sources and factors influencing PM_(2.5) in Guangzhou,with an emphasis on heavy pollution.The lockdown led to large reductions in industrial and traffic emissions,which significantly reduced PM_(2.5) concentrations in Guangzhou.Interestingly,the trend of PM_(2.5) concentrations was not consistent with traffic and industrial emissions,as minimum concentrations were observed in the fourth period(3/01-3/31,22.45 μg/m^(3))of the lockdown.However,the concentrations of other gaseous pollutants,e.g.,SO_(2),NO_(2) and CO,were corre-lated with industrial and traffic emissions,and the lowest values were noticed in the sec-ond period(1/24-2/0_(3))of the lockdown.Meteorological correlation analysis revealed that the decreased PM_(2.5) concentrations during COVID-19 can be mainly attributed to decreased in-dustrial and traffic emissions rather than meteorological conditions.When meteorological factors were included in the PM_(2.5) composition and backward trajectory analyses,we found that long-distance transportation and secondary pollution offset the reduction of primary emissions in the second and third stages of the pandemic.Notably,industrial PM_(2.5) emis-sions from western,southern and southeastern Guangzhou play an important role in the formation of heavy pollution events.Our results not only verify the importance of control-ling traffic and industrial emissions,but also provide targets for further improvements in PM_(2.5) pollution.
基金This work was supported by the National Natural Science Foundation of China(Nos.U1901210,41877363,42130611,and 42177410)the Science and Technology Project of Guangdong Province,China(No.2021A0505030070)+2 种基金the Natural Science Foundation of Guangdong Province(No.2019A1515010599)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z032)the Young S&T Talent Training Program of Guangdong Provincial Association,China(No.2022QNRC23).
文摘Pathogenic microbes with antibiotic resistance can thrive on municipal solid waste as nutrients and be aerosolized and transported to vicinities during waste disposal processes.However,the characterization of pathogenic bioaerosols and assessment of their exposure risks are lacking.Herein,particle size,concentration,activity,antibiotic resistance,and pathogenicity of airborne microorganisms were assessed in different sectors of a typical landfill.Results showed that active sector in downwind direction has the highest bioaerosol level(1234 CFU/m3),while residential area has the highest activity(14.82 mg/L).Botanical deodorizer from mist cannon can effectively remove bioaerosol.Most bioaerosols can be inhaled into respiratory system till bronchi with sizes ranging from 2.1−3.3 and 3.3−4.7μm.Pathogenic bacteria(Bacilli,Bacillus,and Burkholderia-Paraburkholderia)and allergenic fungi(Aspergillus,Cladosporium,and Curvularia)prevailed in landfill.Although high abundance of microbial volatile organic compounds(mVOCs)producing bioaerosols were detected,these mVOCs contributed little to odor issues in landfill.Notably,surrounding areas have higher levels of antibiotic-resistance genes(ARGs)than inner landfill with tetC,acrB,acrF,mdtF,and bacA as dominant ones.Most ARGs were significantly correlated with bacterial community,while environmental parameters mainly influenced fungal prevalence.These findings can assist in reducing and preventing respiratory allergy or infection risks in occupational environments relating to waste management.
基金Projects 1212010535416 supported by the Geological Investigation Bureau of China2005D03 by the Shaanxi Natural Science Foundation
文摘Geothermal water of Xi＇an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. 5180 and 5D data of geopressured thermal water＇in Xi＇an and Xianyang, combined with data from the perimeter of the basin, are analyzed to study features of hydrogen and oxygen shifts. The results show that ^18O exchange of geothermal water at the perimeter of the basin and in the non-geopressured thermal water in the center of the basin is not evident, while in most of the geopressured thermal water in the central basin, in cities such as Xi＇an and Xianyang, significant oxygen exchange had taken place as well as hydrogen exchange, suggesting that isotope exchanges would slowly move the geothermal water system towards equilibrium. Thermal water reservoirs in the central basin have passed through significant water-rock reactions. Moreover, the geothermal reservoir of Xianyang city is relatively much more enclosed than that of Xi＇an city. It has been observed that the more enclosed the geological environment of geothermal water is, the more obvious the oxygen shifts are. With the increasing of the depth, residence time, total amounts of dissolute solids and temperatures of geothermal waters, the oxygen exchange accelerates.
基金supported by Project funded by China Postdoctoral Science Foundation(No.2017M611533)
文摘Nanometer-size zero-valent iron(NZVI)is an efficient reducing agent,but its surface is easily passivated with an oxide layer,leading to reaction inefficiency.In our study,oxalate(OA)was introduced into this heterogeneous system of NZVI,which could form ferrioxalate complexes with the NZVI surface-bound Fe3+and dissolved Fe3+in the solution.Photolysis of ferrioxalate complexes can facilitate the generation of Fe2+from Fe3+and CO_(2)·-radical,both species have strong reduction capacity.Hence,a"photo-oxalate-Fe(0)"system through sunlight induction was established,which not only prohibited the formation of a surface passivation layer,but also displayed a synergetic mechanism of ferrioxalate photolysis to enhance reduction,exhibiting remarkably higher degradation activity(several times faster)toward the model pollutant Cr(Ⅵ)than the mechanism with NZVI alone.Factor tests suggested that both NZVI dosage and OA content markedly affected the reduction rate.Low pH was beneficial to the reduction efficiency.Moreover,recyclability experiment showed that the reduction rate decreased from 0.21706 to 0.03977 min-1 after three cycles of reuse due to the NZVI losing reaction activity generally,but the system still maintained considerable reduction capacity.Finally,a mechanism was revealed whereby NZVI would transform to Fe oxides after the exhaustion of its reductive power,and the photolysis of ferrioxalate to promote the cycling of iron species played the predominant role in providing extra reduction ability.These features confirm that introduction of OA into Cr(Ⅵ)reduction by NZVI through sunlight induction is advantageous and promising.
基金supported by the Local Innovative and Research Team Project of Guangdong Pearl River Talents Program (No. 2017BT01Z032)the National Natural Science Foundation of China (Nos. 41731279 and 41425015 )+2 种基金the Key-Area Research and Development Program of Guangdong Province (No. 2019B110206002)The Innovation Team Project of Guangdong Provincial Department of Education (No. 2017KCXTD012)Guangdong Special Branch Plan of Science and Technology for Innovation leading scientists (2016TX03Z094)。
文摘Increasing attention has been paid to the air pollution more recently. Smog chamber has been proved as a necessary and effective tool to study atmospheric processes, including photochemical smog and haze formation. A novel smog chamber was designed to study the atmospheric photochemical reaction mechanism of typical volatile organic compounds(VOCs) as well as the aging of aerosols. The smog chamber system includes an enclosure equipped with black lights as the light source, two parallel reactors(2 m^3 of each) with separate control of light source and temperature, with a series of coupled instruments for online monitoring of gas phase and particle phase reactants and products. Chamber characterization, including air source stability, effective light intensity, temperature stability, as well as gas phase and particle phase wall losses, were carried out before further research. The results showed that our smog chamber systems developed by other domestic and international groups. It was also observed that the wall loss of aromatic VOCs varied with different functional groups as well as the isomerism. The results of preliminary simulation experiment from styrene-NO_x demonstrated that the chamber can be well utilized to simulate gas-particle conversion progresses in the atmosphere.
基金supported by the National Natural Science Foundation of China(Nos.91743202,91843301,and 21806020)the National Research Program for key issues in air pollution control(Nos.DQGG0103 and DQGG0102)
文摘Polychlorinated biphenyls(PCBs) and organochlorine pesticides(OCPs) are typical persistent organic pollutants(POPs),which have high toxicity,bioaccumulation and long-distance transfer capability.Daily variation,sources of PcBs and OcPs in PM2.5 are rarely explored in polluted rural area.Here,the sources and health risks of the PcBs and OcPs were evaluated for 48 PM2.5 samples collected in winter 2017 in Wangdu,a heavy polluted rural area in the North China Plain.The average diurnal and nocturnal concentrations of E18 PCBs and∑15OCPs were 1.74-24.37 and 1.77-100.49,11.67-408.81 and 16.89-865.60 pg/m3,respectively.Hexa-CBs and penta-CBs accounted for higher proportions(29.0% and 33.6%) of clean and polluted samples,respectively.Hexachlorobenzene(HCB) was the dominant contributor to OCPs with an average concentration of 116.17 pg/m3.Hexachlorocyclohexane(EHCHs) and dichlorodiphenyltrichloroethane(EDDTs) were the other two main classes in OCPs with the average concentrations of 4.33 and 15.89 pg/m3,respectively.β-HCH and p,p’-DDE were the main degradation products of HCHs and DDTs,respectively.The principal component analysis and characteristic ratio method indicated both waste incineration and industrial activities were the main sources of PCBs,contributing 76.8% and 12.7%,respectively.The loadings of OCPs were attributed to their application characteristics and the characteristic ratio method reflected a current or past use of OCPs.Health risk assessment showed that the respiratory exposure quantity of doxin-like PCBs(DL-PCBs) and the lifetime cancer risk from airborne OCPs exposure was negligible,while the other exposure modes may pose a risk to human bodies.
基金Supported by the Science and Technology Planning Project of Guangdong Province,China(2017A050501036,2015B020235013,2015A020215033,2017B090907012)the Scientific and Technological Planning Project of Guangzhou,China(2016201604030058,201704030109)Guangdong Special Support Program for Training High Level Talents(2014TQ01Z248)
文摘Thermodynamic equilibrium calculations were performed to reveal effects of interactions among Cl,S,P and other minerals on Cu migration.Our results showed that HCl(g),SO2(g)and(P2O5)2(g)were released from the sewage sludge co-incineration.Cl was found to weaken adsorption of Cu by Al2O3,CaO and Fe2O3,while S de-layed reactions of Fe2O3 and Al2O3 with Cu,with P having no effect on reactions between the minerals and Cu.Among the coupled systems ofCl,S and P,the co-existences of Cl and S,and Cl,S and P were determined to inhibit Cu volatilization,and the co-existence of Cl and P had an enhancing effect Cu migration was affected only by S in the S and P system.With the SiO2,CaO and Al2O3 system,both Cl alone and Cl and P led to failed reactions be-tween the minerals and Cu.In the systems of S,S and Cl,S and P,and S,Cl and P,the migration behavior of Cu was mainly affected by S at low temperatures and by Cl at high temperatures,whereas P had no effect on Cu mi-gration during the entire nrocess.
基金support from the National Natural Science Foundation of China(Nos:22073059,42107109)the GHfund B(No:20210702)+2 种基金the Key Cultivation Project of Shaanxi University of Technology(No:SLG2101)the Funds of Graduate Innovation of Shaanxi University of Technology(No:SLGYCX2120)the State Key Laboratory of Biological Resources and Ecological Environment of Qinba Areas“City-School Co-Construction”Special Research Project(No:SXC-2110).
文摘Given the high abundance of water in the atmosphere,the reaction of Criegee intermediates(CIs)with(H_(2)O)_(2) is considered to be the predominant removal pathway for CIs.However,recent experimental findings reported that the reactions of CIs with organic acids and carbonyls are faster than expected.At the same time,the interface behavior between CIs and carbonyls has not been reported so far.Here,the gas-phase and air-water interface behavior between Criegee intermediates and HCHO were explored by adopting high-level quantum chemical calculations and Born-Oppenheimer molecular dynamics(BOMD)simulations.Quantum chemical calculations evidence that the gas-phase reactions of CIs+HCHO are submerged energy or low energy barriers processes.The rate ratios speculate that the HCHO could be not only a significant tropospheric scavenger of CIs,but also an inhibitor in the oxidizing ability of CIs on SO_(x) in dry and highly polluted areas with abundant HCHO concentration.The reactions of CH_(2)OO with HCHO at the droplet’s surface follow a loop structure mechanism to produce i)SOZ(■),ii)BHMP(HOCH_(2)OOCH_(2)OH),and iii)HMHP(HOCH_(2)OOH).Considering the harsh reaction conditions between CIs and HCHO at the interface(i.e.,the two molecules must be sufficiently close to each other),the hydration of CIs is still their main atmospheric loss pathway.These results could help us get a better interpretation of the underlying CIs-aldehydes chemical processes in the global polluted urban atmospheres.
基金supported by the Ministry of Science and Technology of China(Nos.2016YFC0202700,2016YFE0112200,2014BAC22B01)the National Natural Science Foundation of China(Nos.21527814,21077025)the Marie Sklodowska Curie Actions(Nos.690958-MARSU-RISE-2015)
文摘The α-pinene ozonolysis under the different environmental conditions were observed in a smog chamber. The second-order rate constant （k） was determined to be （7.25 ± 0.06） x 10^-17 cm^3/（molecule.sec） under 20% of relative humidity （RH） and room temperature. RH showed a marked influence on the α-pinene ozonolysis. The value of k increased with KH increase, which was 1.6 times faster at RH = 80% than that at RH = 20%. Additionally, the value of k apparently changed in the presence of the aerosol particles. The diesel soot increased the k value. The fly ash prohibited the reaction, however, H2SO4-treated fly ash promoted the reaction. The information of products gained using FT-IR and SPAMS showed that pinonic acid, 10-hydroxy-pinonic acid and pinic acid could be generated during the α- pinene ozonolysis. Water molecules could take part in the formation of the products, and play a vital role in the degradation of α-pinene. The atmospheric residence time calculation showed that the ozonolysis in the atmosphere is an important way of the α-pinene consumption as compared to that reacted with OH during daytime. The results suggested that the degradation of α-pinene via the ozonization in the atmosphere may be affected greatly by RH, as well as the presence of aerosol particles. The ozonolysis reaction may be an important way of the a-pinene consumption during daytime.
基金The authors thank the financial support provided by the National Natural Science Foundation of China(No.51108186)the Tip-top Scientific and Technical Innovative Youth Talents of Guangdong Special Support Program,China(No.2015TQ01Z039)the Natural Science Research Project of Higher Education Institutions of Guangdong Province(No.2015KTSCX025).
文摘High efficient removal of antibiotics during nutriments recovery for biomass production poses a major technical challenge for photosynthetic microbial biofilm-based wastewater treatment since antibiotics are always co-exist with nutriments in wastewater and resist biodegradation due to their strong biotoxicity and recalcitrance.In this study,we make a first attempt to enhance metronidazole(MNZ)removal from wastewater using electrochemistry-activated binary-species photosynthetic biofilm of Rhodopseudomonas Palustris(R.Palustris)and Chlorella vulgaris(C.vulgaris)by cultivating them under different applied potentials.The results showed that application of external potentials of-0.3,0 and 0.2 V led to 11,33 and 26-fold acceleration in MNZ removal,respectively,as compared to that of potential free.The extent of enhancement in MNZ removal was positively correlated to the intensities of photosynthetic current produced under different externally applied potentials.The binary-species photoelectrogenic biofilm exhibited 18 and 6-fold higher MNZ removal rate than that of single-species of C.vulgaris and R.Palustris,respectively,due to the enhanced metabolic interaction between them.Application of an external potential of 0V significantly promoted the accumulation of tryptophan and tyrosine-like compounds as well as humic acid in ex-tracellular polymeric substance,whose concentrations were 7.4,7.1 and 2.0-fold higher than those produced at potential free,contributing to accelerated adsorption and reductive and photosensitive degradation of MNZ.
文摘Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bath. An electrolyte cell which was constructed by the cathode of porous nickel foam and the anode of Ti/RuO2 was used. During electrolysis, the nickel ion was electrodeposited at the cathode and the oxidation of the organics in the hath was conducted at the anode. The current （i） , time （t） , temperature （T） and pH of the solution affected the recovery efficiency of nickel with constant potential electrolysis. With the optimum experimental conditions of pH=7.6, i = 0.45 A. T = 65℃ andt = 2 h, the concentration of nickel ion was reduced from 2.09 g/L to 0. 053 g/L and the recovery rate of nickel, the current efficiency and the consumed energy wer 97.5%, 17. 1%, 12.2 kWh/kg Ni, respectively. Meanwhile, total organic carbon （TOC） of the bath was reduced from 5 800 mg/L to 152.5 mg/L and the removal efficiency of TOC was 97.3%. The recovery rate of nickel could keep to about 97% when eleetrodeposit was used to recover nickel for 40 hours in a laboratol.w batch reactor containing the spent bath. Dull nickel containing phosphorus was obtained on the cathode.
基金financial support from the National Natural Science Foundation of China (Nos.91843301 and 91543202)National Key Research and Development Program Cooperation on Scientific and Technological Innovation in Hong Kong,Macao and Taiwan (No. 2017YFE0191000)。
文摘Research on pollution characteristics and toxicities of emerging polycyclic aromatic sulfur heterocycles(PASHs) in PM_(2.5) has not been reported due to the lack of analytical method with the needed performance.In the present study,a novel method for the determination of 14 PASHs in PM_(2.5) was developed using atmospheric pressure gas chro matography-tandem mass spectrometry(APGC-MS/MS).Atmospheric pressure chemical ionization was operated with multiple reaction monitoring in positive ionization mode.High sensitivity(method detection limit <1.673 pg/m^(3)),acceptable re coveries(67.6%-120.8%) and precisions(RSD of 2.2%-15.4%) were obtained.The method was successfully applied for analyzing PASHs in 10 PM_(2.5) samples collected from Taiyuan,a typical industrial city in China,in 2016,The total concentrations were from 929 pg/m^(3) to 14,593 pg/m^(3).The determined levels indicated that further investigations on environmental fate and toxicities of PM_(2.5)-bound PASHs may be needed.
文摘As the rapid development of industrial economy,massiveconsumption of fossil energy leads to increasingly seriousenvironmental pollution.Thus.it is highly obliged to developgreen,efficient and robust technologies for fuel production andpollution remediation.Semiconductor-based photocatalysiscould realize the production of fuel chemicals,selectivetransformation/degradation of organic pollutants and eveninactivation of microorganisms by using the solar-to-chemicalenergy conversion hence possesses scientific significance andgreat application potential.Besides,multidisciplinarilyinvolving semiconductor physics.catalysis and surface science,photocatalysis has become one of the most attractive andpioneering research fields all over the world.
