In this study,we present a self-driven photoelectrocatalytic(SD-PEC)system that effectively treats complex uranium-bearing wastewaters for both uranium recovery and organic matter decomposition while generating power....In this study,we present a self-driven photoelectrocatalytic(SD-PEC)system that effectively treats complex uranium-bearing wastewaters for both uranium recovery and organic matter decomposition while generating power.The system utilizes a titanium dioxide nanorod array(TNR)photoelectrode coupled with a silicon solar cell to optimize electron transport,while the cathode is composed of a carbon fiber coated with carboxylated carbon nanotubes(CCNT/CF),which efficiently reduce UO_(2)^(2+).The results demonstrate significant removal efficiency of uranium(complete removal in 25 min at a rate constant of~0.248 min^(-1)),as well as substantial degradation of organic impurities.Furthermore,the system generates sufficient power output to light an LED lamp and exhibits superior performance under various complex wastewater conditions,including simulated seawater and real uranium tailings wastewater.These findings underscore the potential of the SD-PEC system as a versatile approach for sustainable treatment and energy recovery of radioactive wastewater.The significance of this research extends to global environmental challenges,offering an innovative solution for managing radioactive wastewater while simultaneously contributing to renewable energy generation.展开更多
Hydrogenotrophic denitrification is promising for tertiary nitrogen removal from municipal wastewater. To reveal the influence of residual organics in municipal wastewater on hydrogenotrophic denitrifiers, we adopted ...Hydrogenotrophic denitrification is promising for tertiary nitrogen removal from municipal wastewater. To reveal the influence of residual organics in municipal wastewater on hydrogenotrophic denitrifiers, we adopted high-throughput 16 S r RNA gene amplicon sequencing to examine microbial communities in hydrogenotrophic denitrification enrichments. Using effluent from a municipal wastewater treatment plant as water source, COD,nitrate and p H were controlled the same except for a gradient of biodegradable carbon（i.e., primary effluent（PE）, secondary effluent（SE）, or combined primary and secondary effluent（CE））. Inorganic synthetic water（IW） was used as a control. Hydrogenophaga, a major facultative autotroph, accounted for 17.1%, 5.3%, 32.7% and 12.9% of the sequences in PE, CE,SE and IW, respectively, implicating that Hydrogenophaga grew well with or without organics.Thauera, which contains likely obligate autotrophic denitrifiers, appeared to be the most dominant genera（23.6%） in IW and accounted for 2.5%, 4.6% and 8.9% in PE, CE and SE,respectively. Thermomonas, which is related to heterotrophic denitrification, accounted for 4.2% and 7.9% in PE and CE fed with a higher content of labile organics, respectively.In contrast, Thermomonas was not detected in IW and accounted for only 0.6% in SE. Our results suggest that Thermomonas are more competitive than Thauera in hydrogenotrophic denitrification with biodegradable organics. Moreover, facultative autotrophic denitrifiers,Hydrogenophaga, are accommodating to residual organic in effluent wastewater, thus we propose that hydrogenotrophic denitrification is amenable for tertiary nitrogen removal.展开更多
Interactions between microwaves and certain catalysts can lead to efficient, energy-directed convergence of a relatively dispersed microwave field onto the reactive sites of the catalyst,which produces thermal or disc...Interactions between microwaves and certain catalysts can lead to efficient, energy-directed convergence of a relatively dispersed microwave field onto the reactive sites of the catalyst,which produces thermal or discharge effects around the catalyst. These interactions form"high-energy sites"(HeS) that promote energy efficient utilization and enhanced in situ degradation of organic pollutants. This article focuses on the processes occurring between microwaves and absorbing catalysts, and presents a critical review of microwave-absorbing mechanisms. This article also discusses aqueous phase applications of relevant catalysts(ironbased, carbon-based, soft magnetic, rare earth, and other types) and microwaves, special effects caused by the dimensions and structures of catalytic materials, and the optimization and design of relevant reactors for microwave-assisted catalysis of wastewater. The results of this study demonstrate that microwave-assisted catalysis can effectively enhance the degradation rate of organic compounds in an aqueous phase and has potential applications to a variety of engineering fields such as microwave-assisted pyrolysis, pollutant removal,material synthesis, and water treatment.展开更多
Five negatively charged organic compounds with different structures, sodium methane sulfonate(MS), sodium benzene sulfonate(BS), sodium 6-hydroxynaphthalene-2-sulfonate(NSS), sodium dodecyl sulfate(SDS), and sodium do...Five negatively charged organic compounds with different structures, sodium methane sulfonate(MS), sodium benzene sulfonate(BS), sodium 6-hydroxynaphthalene-2-sulfonate(NSS), sodium dodecyl sulfate(SDS), and sodium dodecyl benzene sulfonate(SDBS), were used to examine the fouling of an anion exchange membrane(AEM) in electrodialysis(ED),to explore the effect of molecular characteristics on the fouling behavior on the AEM and changes in the surface and electrochemical properties of the AEM. Results indicated that the fouling degree of the AEM by the different organics followed the order:SDBS > SDS > NSS > BS > MS. SDBS and SDS formed a dense fouling layer on the surface of the AEM, which was the main factor in the much more severe membrane fouling, and completely restricted the transmembrane ion migration. The other three organics caused fouling of the AEM by adsorption on the surface and/or accumulation in the interlayer of the AEM, and exhibited almost no influence on the transmembrane ion migration. It was also concluded that the organics with benzene rings caused more severe fouling of the AEM due to the stronger affinity interaction and steric effect between the organics and the AEM compared with organics with aliphatic chains.展开更多
Zeolite membranes offer outstanding potentials in separation of many molecular mixtures due to their molecular sieving selectivity and the high thermal and mechanical stability that allow them to operate at harsh cond...Zeolite membranes offer outstanding potentials in separation of many molecular mixtures due to their molecular sieving selectivity and the high thermal and mechanical stability that allow them to operate at harsh conditions.Development of durable and high separation performance membranes with lower fabrication and operation cost are highly demanded for industrial applications. Zeolite T membrane possesses good acid-resistance with excellent hydrophilic properties as compared to NaA zeolite membrane and can be extended to industrial organic dehydrations under an acidic environment. In the present review the research advances in development of zeolite T membranes for the dehydration of organic mixtures in acidic conditions are summarized. Especially the low temperature synthesis, and epitaxial growth of the zeolite membrane with high performance are well addressed, besides emphasis is particularly placed on ensemble synthesis of hollow fiber zeolite T membrane module and its future prospects for industrial separations.展开更多
It is particularly important to comprehensively assess the biotoxicity variation of industrial wastewater along the treatment process for ensuring the water environment security.However,intensive studies on the biotox...It is particularly important to comprehensively assess the biotoxicity variation of industrial wastewater along the treatment process for ensuring the water environment security.However,intensive studies on the biotoxicity reduction of industrial wastewater are still limited.In this study,the toxic organics removal and biotoxicity reduction of coal chemical wastewater(CCW)along a novel full-scale treatment process based on the pretreatment process-anaerobic process-biological enhanced(BE)process-anoxic/oxic(A/O)process-advanced treatment process was evaluated.This process performed great removal efficiency of COD,total phenol,NH_(4)^(+)-N and total nitrogen.And the biotoxicity variation along the treatment units was analyzed from the perspective of acute biotoxicity,genotixicity and oxidative damage.The results indicated that the effluent of pretreatment process presented relatively high acute biotoxicity to Tetrahymena thermophila.But the acute biotoxicity was significantly reduced in BE-A/O process.And the genotoxicity and oxidative damage to Tetrahymena thermophila were significantly decreased after advanced treatment.The polar organics in CCW were identified as the main biotoxicity contributors.Phenols were positively correlated with acute biotoxicity,while the nitrogenous heterocyclic compounds and polycyclic aromatic hydrocarbons were positively correlated with genotoxicity.Although the biotoxicity was effectively reduced in the novel full-scale treatment process,the effluent still performed potential biotoxicity,which need to be further explored in order to reduce environmental risk.展开更多
Chlorine dioxide(ClO_(2))disinfection usually does not produce halogenated disinfection byproducts,but the formation of the inorganic by-product chlorite(ClO^(–)_(2))is a serious consideration.In this study,the ClO^(...Chlorine dioxide(ClO_(2))disinfection usually does not produce halogenated disinfection byproducts,but the formation of the inorganic by-product chlorite(ClO^(–)_(2))is a serious consideration.In this study,the ClO^(–)_(2)formation rule in the ClO_(2)disinfection of drinking water was investigated in the presence of three representative reductive inorganics and four natural organic matters(NOMs),respectively.Fe^(2+)and S^(2–)mainly reduced ClO_(2)to ClO^(–)_(2)at low concentrations.When ClO_(2)was consumed,the ClO^(–)_(2)would be further reduced by Fe^(2+)and S^(2–),leading to the decrease of ClO^(–)_(2).The reaction efficiency of Mn^(2+)with ClO_(2)was lower than that of Fe^(2+)and S^(2–).It might be the case that Mn O 2 generated by the reaction between Mn^(2+)and ClO_(2)had adsorption and catalytic oxidation on Mn^(2+).However,Mn^(2+)would not reduce ClO^(–)_(2).Among the four NOMs,humic acid and fulvic acid reacted with ClO_(2)actively,followed by bovine serum albumin,while sodium alginate had almost no reaction with ClO_(2).The maximum ClO^(–)_(2)yields of reductive inorganics(70%)was higher than that of NOM(around 60%).The lower the concentration of reductive substances,the more ClO^(–)_(2)could be produced by per unit concentration of reductive substances.The results of the actual water samples showed that both reductive inorganics and NOM played an important role in the formation of ClO^(–)_(2)in disinfection.展开更多
Hydrogen peroxide(H_(2)O_(2))in situ electrosynthesis by O_(2)reduction reaction is a promising alternative to the conventional Fenton treatment of refractory wastewater.However,O_(2)mass transfer limitation,cathodic ...Hydrogen peroxide(H_(2)O_(2))in situ electrosynthesis by O_(2)reduction reaction is a promising alternative to the conventional Fenton treatment of refractory wastewater.However,O_(2)mass transfer limitation,cathodic catalyst selectivity,and electron transfer in O_(2)reduction remain major engineering obstacles.Here,we have proposed a systematic solution for efficient H_(2)O_(2)generation and its electro-Fenton(EF)application for refractory organic degradation based on the fabrication of a novel ZrO_(2)/CMK-3/PTFE cathode,in which polytetrafluoroethylene(PTFE)acted as a hydrophobic modifier to strengthen the O_(2)mass transfer,ZrO_(2)was adopted as a hydrophilic modifier to enhance the electron transfer of O_(2)reduction,and mesoporous carbon CMK-3 was utilized as a catalyst substrate to provide catalytic active sites.Moreover,feasible mass transfer of O_(2)from the hydrophobic to the hydrophilic layer was designed to increase the contact between O_(2)and the reaction interface.The H_(2)O_(2)yield of the ZrO_(2)/CMK-3/PTFE cathode was significantly improved by approximately 7.56 times compared to that of the co nventional gas diffusion cathode under the same conditions.The H_(2)O_(2)generation rate and Faraday efficiency reached125.98 mg·cm^(-2)·h^(-1)(normalized to 5674.04 mmol·g^(-1)·h^(-1)by catalyst loading)and 78.24%at-1.3 V versus standard hydrogen electrode(current density of-252 mA·cm^(-2)),respectively.The high H_(2)O_(2)yield ensured that sufficient OH was produced for excellent EF performance,resulting in a degradation efficiency of over 96%for refractory organics.This study offers a novel engineering solution for the efficient treatment of refractory wastewater using EF technology based on in situ high-yield H_(2)O_(2)electrosynthesis.展开更多
Complex organics are now commonly found in meteorites,comets,asteroids,planetary satellites and interplanetary dust particles.The chemical composition and possible origin of these organics are presented.Specifically,w...Complex organics are now commonly found in meteorites,comets,asteroids,planetary satellites and interplanetary dust particles.The chemical composition and possible origin of these organics are presented.Specifically,we discuss the possible link between Solar System organics and the complex organics synthesized during the late stages of stellar evolution.Implications of extraterrestrial organics on the origin of life on Earth and the possibility of existence of primordial organics on Earth are also discussed.展开更多
This study was carried out for gathering qualitative information about the potential of photocatalytic oxidation for the removal of trace organics (analysed by gas chromatography coupled to mass spectrometry, GC/MS) f...This study was carried out for gathering qualitative information about the potential of photocatalytic oxidation for the removal of trace organics (analysed by gas chromatography coupled to mass spectrometry, GC/MS) from biologically pretreated greywater to make it suitable for high quality reuse applications like groundwater recharge. Additionally, fractions of bulk organics (humic substances, building blocks, and low molecular weight organic acids) were quantified by liquid chromatography with organic carbon detection. Biologically pretreated greywater was subjected to photocatalytic oxidation in open stirred vessel reactors with UV lamps positioned over the reactors. UV doses of 0, 5, and 15 Wh·L-1 and TiO2 P25 photocatalyst concentrations of 1, 5, 10, and 20 g·L-1 were investigated. Photocatalysis experiments with a 15 Wh·L-1 UV dose were also conducted in the presence of 1 g·L-1 powdered activated carbon. Subsequent to mere contact of the photocatalyst to biologically pretreated greywater without UV, GC/MS did not indicate a substantial removal of trace organics, while humic substances were increasingly adsorbed by increasing photocatalyst concentration. A UV dose of 15 Wh·L-1 and TiO2 concentrations > 5 g·L-1 were favorable conditions for photocatalytic oxidation resulting in the removal of most of the trace organics, especially chlorinated phosphate flame retardants. Also humic substances were efficiently removed under these conditions. Photocatalytic oxidation is thus a promising process for advanced greywater treatment prior to groundwater recharge. Addition of powdered activated carbon did not improve trace and bulk organics removal by photocatalysis with a UV dose of 15 Wh·L-1 and with photocatalyst concentrations > 5 g·L-1.展开更多
The vapor phase organics (VPOs) in the air of Beijing, Langfang and Tianjin were detected by a capillary gas chromatography and GC/MS during the winter and the summer separately. The tentatively identified compounds i...The vapor phase organics (VPOs) in the air of Beijing, Langfang and Tianjin were detected by a capillary gas chromatography and GC/MS during the winter and the summer separately. The tentatively identified compounds include alkanes, cyclic hydrocarbons, alkenes, aromatics, acids, alcohols, aldehydes, ketones, esters, halocarbons and so on. The numbers of VPOs found are 118 in Beijing, 83 in Lang-fang and 65 in Tianjin in the winter, and 56, 39 and 72 in the summer respectively. Based on the data of some representative compounds determined quantitatively by GC and GC/MS, a profile of organic pollution in the air of the three cities is presented.展开更多
Since the discovery of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in the process of municipal solid waste incineration(MSWI),a large number of researches have been conducted to reveal their formation ...Since the discovery of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in the process of municipal solid waste incineration(MSWI),a large number of researches have been conducted to reveal their formation mechanisms and emission characteristics.As one of national priority control pollutants,chlorinated organics are inclined to transfer into PCDD/Fs in the heterogeneously catalyzed process,which has been considered to be one of great challenges in environmental catalysis.However,so far direct evidences to support such a conversion process are insufficient,and the reaction mechanisms are lack of exploration.This study investigated the catalytic elimination of chlorobenzene(CBz)over a range of industrially applied active species including Pt,Ru,V,Ce and Mn oxides,and explored their reaction byproducts,chlorine adsorption/desorption behaviors and PCDD/F formations.We found that all of these species could generate the PCDD/Fs,amongst which,Mn species were the most active for PCDD/F formation.Approximately 140 ng I-TEQg-1 PCDD/Fs were detected on the Mn-CNT surface after ageing at250℃for 30 h.Even using the dichloromethane(DCM)as a precursor,significant PCDD/Fs were still detected.The Ru and V species were shown to generate much less polychlorinated byproducts and PCDD/Fs,owning to their sufficiently high abilities in Cl desorption,which were through the semi-Deacon and Br(?)nsted H reactions,respectively.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
Recently,a novel 2-electron oxygen reduction reaction(ORR)based electro-oxidation(EO)system was developed,which utilizes a H_(2)O_(2)generation cathode instead of H_(2)evolution cathode.A Ti-based Ni-Sb co-doped SnO_(...Recently,a novel 2-electron oxygen reduction reaction(ORR)based electro-oxidation(EO)system was developed,which utilizes a H_(2)O_(2)generation cathode instead of H_(2)evolution cathode.A Ti-based Ni-Sb co-doped SnO_(2)(Ti/NATO)anode was selected for efficient degradation of refractory organics and O_(3)production.The synergistic reaction of O3/H_(2)O_(2)further accelerated the generation of hydroxyl radicals(·OH)in the ORR-EO system.However,the catalytic activity and long-term effectiveness of the Ti/NATO anode limited the large-scale application of the ORR-EO process.In this study,a blue TiO_(2)nanotube array(blue-TiO_(2)-NTA)inter-layer was introduced into the fabrication process between the Ti substrate and NATO catalyst layer.Compared to the Ti/NATO anode,the Ti/blue-TiO_(2)-NTA/NATO anode achieved higher efficiency of organic removal and O_(3)generation.Additionally,the accelerated lifetime of the Ti/blue-TiO_(2)-NTA/NATO anode was increased by 7 times compared to the Ti/NATO anode.When combined with CNTs-C/PTFE air cathode in ORR-EO system,all anodic oxidation and O_(3)/H_(2)O_(2)processes achieved higher•OH production.Over 92%of TOC in leachate bio-effluent was effectively eliminated with a relatively low energy cost of 45 kWh/t.展开更多
To investigate feasibility of pathogen free industrial organics with higher agronomic value, the industrial organic wastes were subjected to vermistabilization. The body of earthworm work as ＂biofilter＂ and they can...To investigate feasibility of pathogen free industrial organics with higher agronomic value, the industrial organic wastes were subjected to vermistabilization. The body of earthworm work as ＂biofilter＂ and they can ＂purify＂ and also ＂disinfect＂ and ＂detoxify＂ municipal and industrial organics. The microbiomics of gut and cast of earthworm （Eisenia foetida Savigny） and their association with vermistabilization was studied to determine the microbial quantification in reactors （industrial organics）. Worm were reared in five reactors viz. Sewage sludge （SS）, Paper mill industry sludge （PS）, Vegetable processing industry （VP）, Tannery waste （TW） and Meat process industrial sludge （MP） for ninety days. The microbial load （Salmonella, Shigella, Escherichia, Mycobacterium, Streptococcus） in gut and cast, biomass, recovery of cast in different reactors were determined, periodically. The microbiomics of worms gut revealed the removal of Salmonella （12-18 × 10^8±0.02 to 0-4 × 10^3 ＋ 0.05 CFU/g）, Shigella （14-23 × 10^8 ± 0.04 to 0-4 × 10^3 ± 0.05 CFU/g）, Escherichia （4-16 × 10^8 ± 0.02 to 0-4 × 10^2 ± 0.05 CFU/g）, Mycobacterium （3-16 × 10^8 ± 0.02 to 0-3 × 10^2 ± 0.05 CFU/g）, Streptococcus （6-16 × 10^8 ± 0.02 to 0-4 × 10^3 ± 0.05 CFU/g） during stabilization of industrial organics. Similarly, reduction in pathogens Salmonella （12-19 × 10^8 ± 0.02 to 0-8 ×10^3 ± 0.05 CFU/g）, Shigella （7-20× 10^8 ± 0.04 to 0-2 ×10^3 ± 0.05 CFU/g）, Escherichia （2-20 × 10^8 ± 0.02 to 0.0-2 × 10^3 ± 0.05）, Mycobacterium （1-8 × 10^8 ±0.05 to 0.0-5 × 10^2 ± 0.05 CFU/g）, Streptococcus （8-18 × 10^8 ± 0.02 to 0-7 × 10^3 ± 0.05 CFU/g） in castings of industrial organics indicates the selective nature of feeding of worm. This amply demonstrates that these pathogens have been eliminated as they entered in food chain of worms. However, it may not be possible to remove pathogens completely, but at least worms change the ＂microbial make-up＂ of industrial organics to make it harmless to the soil and enable its use as a nutritive organic fertilizer.展开更多
In order to improve the engineering properties oforganic soil, a new stabilization agent is developed by theaddition of phosphor gypsum and calcium aluminate cement.The artificial organic soil is applied in the study ...In order to improve the engineering properties oforganic soil, a new stabilization agent is developed by theaddition of phosphor gypsum and calcium aluminate cement.The artificial organic soil is applied in the study and a series oflaboratory tests were carried out to explore new stabilizationagents and determine the optimal dosage. Unconfinedcompressive strength （UCS） and the pH value of soil poresolution were measured. The influence of organic content,agent composition and curing time on the UCS of sampleswere also researched. The test results show that the UCS ofstabilized organic soils by a new agent achieves approximately800 and 1 200 kPa at 28 and 90 d curing time, respectively.The pH test results show that a high alkaline environment is anecessary and not a sufficient condition for high strength. Thestrength of stabilized soil is related to the hydration product ofstabilization agent. The mechanism of strength formation wasalso explored by X-ray diffraction （XRD）, mercury intrusionporosimetry （MIP） and scanning electron microscope （SEM）tests. A large amount of ettringite is produced to fill the largepores of organic soils, which contribute to the high UCS valueof stabilized organic soils. The new agent can solidify theorganic soil successfully as well as provide a new approach totreat the organic soil.展开更多
Constructing a Z-scheme is a significant approach to improve the separation of photogene rated carriers for effective organic pollutant degradation.Herein,a BiVO4/ZnIn2S4(BZ) Z-scheme composite was successfully synthe...Constructing a Z-scheme is a significant approach to improve the separation of photogene rated carriers for effective organic pollutant degradation.Herein,a BiVO4/ZnIn2S4(BZ) Z-scheme composite was successfully synthesized,and applied to photodegrade methyl orange(MO) irradiated by a LED lamp.Anchoring the BiVO4 on the ZnIn2S4 nanoparticles promoted the separation of photogenerated electronholes and broadened the light response range.The detailed characterizations,including surface morphology,elements valence state,and photocurrent performance,demonstrated that the enhanced separation of photogenerated carriers was the pivotal reason for the enhanced photocatalysis reaction.Benefiting from the excellent photocatalytic characteristics,the 5% mass ratio of BZ composite presented the highest MO degradation rate of 0.00997 min^-1,which was 1.9 and 10.3 times greater than the virgin ZnIn2S4 and BiVO4,respectively.Furthermore,the BZ hybrid materials indicated a well photo-stability in the four recycling tests.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52170083,51808143)the Science and Technology Innovation Program of Hunan Province(No.2022RC1125)the Hunan Provincial Natural Science Foundation of China(No.2021JJ20007)。
文摘In this study,we present a self-driven photoelectrocatalytic(SD-PEC)system that effectively treats complex uranium-bearing wastewaters for both uranium recovery and organic matter decomposition while generating power.The system utilizes a titanium dioxide nanorod array(TNR)photoelectrode coupled with a silicon solar cell to optimize electron transport,while the cathode is composed of a carbon fiber coated with carboxylated carbon nanotubes(CCNT/CF),which efficiently reduce UO_(2)^(2+).The results demonstrate significant removal efficiency of uranium(complete removal in 25 min at a rate constant of~0.248 min^(-1)),as well as substantial degradation of organic impurities.Furthermore,the system generates sufficient power output to light an LED lamp and exhibits superior performance under various complex wastewater conditions,including simulated seawater and real uranium tailings wastewater.These findings underscore the potential of the SD-PEC system as a versatile approach for sustainable treatment and energy recovery of radioactive wastewater.The significance of this research extends to global environmental challenges,offering an innovative solution for managing radioactive wastewater while simultaneously contributing to renewable energy generation.
基金supported by the National Natural Science Foundation of China (No. 51408028)the Fundamental Research Funds for the Central Universities (No. 2015JBM063) in China
文摘Hydrogenotrophic denitrification is promising for tertiary nitrogen removal from municipal wastewater. To reveal the influence of residual organics in municipal wastewater on hydrogenotrophic denitrifiers, we adopted high-throughput 16 S r RNA gene amplicon sequencing to examine microbial communities in hydrogenotrophic denitrification enrichments. Using effluent from a municipal wastewater treatment plant as water source, COD,nitrate and p H were controlled the same except for a gradient of biodegradable carbon（i.e., primary effluent（PE）, secondary effluent（SE）, or combined primary and secondary effluent（CE））. Inorganic synthetic water（IW） was used as a control. Hydrogenophaga, a major facultative autotroph, accounted for 17.1%, 5.3%, 32.7% and 12.9% of the sequences in PE, CE,SE and IW, respectively, implicating that Hydrogenophaga grew well with or without organics.Thauera, which contains likely obligate autotrophic denitrifiers, appeared to be the most dominant genera（23.6%） in IW and accounted for 2.5%, 4.6% and 8.9% in PE, CE and SE,respectively. Thermomonas, which is related to heterotrophic denitrification, accounted for 4.2% and 7.9% in PE and CE fed with a higher content of labile organics, respectively.In contrast, Thermomonas was not detected in IW and accounted for only 0.6% in SE. Our results suggest that Thermomonas are more competitive than Thauera in hydrogenotrophic denitrification with biodegradable organics. Moreover, facultative autotrophic denitrifiers,Hydrogenophaga, are accommodating to residual organic in effluent wastewater, thus we propose that hydrogenotrophic denitrification is amenable for tertiary nitrogen removal.
基金the support of the Natural Science Foundation of Shandong Province(No.ZR2018MEE030)the National Natural Science Foundation of China(Nos.51506116,51576118,51376112)+1 种基金the Young Scholars Program of Shandong University(No.2016WLJH37)the Fundamental Research Funds of Shandong University(No.2016JC004)
文摘Interactions between microwaves and certain catalysts can lead to efficient, energy-directed convergence of a relatively dispersed microwave field onto the reactive sites of the catalyst,which produces thermal or discharge effects around the catalyst. These interactions form"high-energy sites"(HeS) that promote energy efficient utilization and enhanced in situ degradation of organic pollutants. This article focuses on the processes occurring between microwaves and absorbing catalysts, and presents a critical review of microwave-absorbing mechanisms. This article also discusses aqueous phase applications of relevant catalysts(ironbased, carbon-based, soft magnetic, rare earth, and other types) and microwaves, special effects caused by the dimensions and structures of catalytic materials, and the optimization and design of relevant reactors for microwave-assisted catalysis of wastewater. The results of this study demonstrate that microwave-assisted catalysis can effectively enhance the degradation rate of organic compounds in an aqueous phase and has potential applications to a variety of engineering fields such as microwave-assisted pyrolysis, pollutant removal,material synthesis, and water treatment.
基金supported by the National Natural Science Foundation of China(Nos.51878645 and 51425405)the Science and Technology Open Cooperation Project of Henan Province(No.172106000076)+2 种基金the Beijing Natural Science Foundation(No.8132047)the Major Science and Technology Program for Water Pollution Control and Treatment(Nos.2014ZX07201-011 and 2014ZX07510-001)financial support from the China Scholarship Council
文摘Five negatively charged organic compounds with different structures, sodium methane sulfonate(MS), sodium benzene sulfonate(BS), sodium 6-hydroxynaphthalene-2-sulfonate(NSS), sodium dodecyl sulfate(SDS), and sodium dodecyl benzene sulfonate(SDBS), were used to examine the fouling of an anion exchange membrane(AEM) in electrodialysis(ED),to explore the effect of molecular characteristics on the fouling behavior on the AEM and changes in the surface and electrochemical properties of the AEM. Results indicated that the fouling degree of the AEM by the different organics followed the order:SDBS > SDS > NSS > BS > MS. SDBS and SDS formed a dense fouling layer on the surface of the AEM, which was the main factor in the much more severe membrane fouling, and completely restricted the transmembrane ion migration. The other three organics caused fouling of the AEM by adsorption on the surface and/or accumulation in the interlayer of the AEM, and exhibited almost no influence on the transmembrane ion migration. It was also concluded that the organics with benzene rings caused more severe fouling of the AEM due to the stronger affinity interaction and steric effect between the organics and the AEM compared with organics with aliphatic chains.
基金Supported by the Fundamental Research Funds of Panjin Industrial Technology Institute(PJYJY2016A004)the National Natural Science Foundation of China(No.21776032)+2 种基金Natural Science Foundation of Anhui Province(1808085QB51)the Key Research and Development Plan of Anhui Province(1804a09020072)the Natural Science Research Project of Anhui Colleges and Universities(KJ2017A397)
文摘Zeolite membranes offer outstanding potentials in separation of many molecular mixtures due to their molecular sieving selectivity and the high thermal and mechanical stability that allow them to operate at harsh conditions.Development of durable and high separation performance membranes with lower fabrication and operation cost are highly demanded for industrial applications. Zeolite T membrane possesses good acid-resistance with excellent hydrophilic properties as compared to NaA zeolite membrane and can be extended to industrial organic dehydrations under an acidic environment. In the present review the research advances in development of zeolite T membranes for the dehydration of organic mixtures in acidic conditions are summarized. Especially the low temperature synthesis, and epitaxial growth of the zeolite membrane with high performance are well addressed, besides emphasis is particularly placed on ensemble synthesis of hollow fiber zeolite T membrane module and its future prospects for industrial separations.
基金supported by the Natural Science Foundation of Shandong Province,China(No.ZR2021QE227)the Natural Science Foundation of Shandong Province,China(No.ZR2021QE272)+1 种基金the Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.ES202120)the Taishan Scholars Program of Shandong Province,China(No.tsqn201812091)。
文摘It is particularly important to comprehensively assess the biotoxicity variation of industrial wastewater along the treatment process for ensuring the water environment security.However,intensive studies on the biotoxicity reduction of industrial wastewater are still limited.In this study,the toxic organics removal and biotoxicity reduction of coal chemical wastewater(CCW)along a novel full-scale treatment process based on the pretreatment process-anaerobic process-biological enhanced(BE)process-anoxic/oxic(A/O)process-advanced treatment process was evaluated.This process performed great removal efficiency of COD,total phenol,NH_(4)^(+)-N and total nitrogen.And the biotoxicity variation along the treatment units was analyzed from the perspective of acute biotoxicity,genotixicity and oxidative damage.The results indicated that the effluent of pretreatment process presented relatively high acute biotoxicity to Tetrahymena thermophila.But the acute biotoxicity was significantly reduced in BE-A/O process.And the genotoxicity and oxidative damage to Tetrahymena thermophila were significantly decreased after advanced treatment.The polar organics in CCW were identified as the main biotoxicity contributors.Phenols were positively correlated with acute biotoxicity,while the nitrogenous heterocyclic compounds and polycyclic aromatic hydrocarbons were positively correlated with genotoxicity.Although the biotoxicity was effectively reduced in the novel full-scale treatment process,the effluent still performed potential biotoxicity,which need to be further explored in order to reduce environmental risk.
基金supported by the National Key Research and Development Program of China(No.2018YFD0900805)the Practice Innovation Program of Postgraduates in Jiangsu Province(No.SJCX20_0306)。
文摘Chlorine dioxide(ClO_(2))disinfection usually does not produce halogenated disinfection byproducts,but the formation of the inorganic by-product chlorite(ClO^(–)_(2))is a serious consideration.In this study,the ClO^(–)_(2)formation rule in the ClO_(2)disinfection of drinking water was investigated in the presence of three representative reductive inorganics and four natural organic matters(NOMs),respectively.Fe^(2+)and S^(2–)mainly reduced ClO_(2)to ClO^(–)_(2)at low concentrations.When ClO_(2)was consumed,the ClO^(–)_(2)would be further reduced by Fe^(2+)and S^(2–),leading to the decrease of ClO^(–)_(2).The reaction efficiency of Mn^(2+)with ClO_(2)was lower than that of Fe^(2+)and S^(2–).It might be the case that Mn O 2 generated by the reaction between Mn^(2+)and ClO_(2)had adsorption and catalytic oxidation on Mn^(2+).However,Mn^(2+)would not reduce ClO^(–)_(2).Among the four NOMs,humic acid and fulvic acid reacted with ClO_(2)actively,followed by bovine serum albumin,while sodium alginate had almost no reaction with ClO_(2).The maximum ClO^(–)_(2)yields of reductive inorganics(70%)was higher than that of NOM(around 60%).The lower the concentration of reductive substances,the more ClO^(–)_(2)could be produced by per unit concentration of reductive substances.The results of the actual water samples showed that both reductive inorganics and NOM played an important role in the formation of ClO^(–)_(2)in disinfection.
基金National Natural Science Foundation of China(22176125,52200103 and22178220)China Postdoctoral Science Foundation(2022 M722081 and 2021 M692064)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Center for Advanced Electronic Materials and Devices and the instrumental Analysis Center,School of Environmental Science and Engineering,Shanghai Jiao Tong University for support。
文摘Hydrogen peroxide(H_(2)O_(2))in situ electrosynthesis by O_(2)reduction reaction is a promising alternative to the conventional Fenton treatment of refractory wastewater.However,O_(2)mass transfer limitation,cathodic catalyst selectivity,and electron transfer in O_(2)reduction remain major engineering obstacles.Here,we have proposed a systematic solution for efficient H_(2)O_(2)generation and its electro-Fenton(EF)application for refractory organic degradation based on the fabrication of a novel ZrO_(2)/CMK-3/PTFE cathode,in which polytetrafluoroethylene(PTFE)acted as a hydrophobic modifier to strengthen the O_(2)mass transfer,ZrO_(2)was adopted as a hydrophilic modifier to enhance the electron transfer of O_(2)reduction,and mesoporous carbon CMK-3 was utilized as a catalyst substrate to provide catalytic active sites.Moreover,feasible mass transfer of O_(2)from the hydrophobic to the hydrophilic layer was designed to increase the contact between O_(2)and the reaction interface.The H_(2)O_(2)yield of the ZrO_(2)/CMK-3/PTFE cathode was significantly improved by approximately 7.56 times compared to that of the co nventional gas diffusion cathode under the same conditions.The H_(2)O_(2)generation rate and Faraday efficiency reached125.98 mg·cm^(-2)·h^(-1)(normalized to 5674.04 mmol·g^(-1)·h^(-1)by catalyst loading)and 78.24%at-1.3 V versus standard hydrogen electrode(current density of-252 mA·cm^(-2)),respectively.The high H_(2)O_(2)yield ensured that sufficient OH was produced for excellent EF performance,resulting in a degradation efficiency of over 96%for refractory organics.This study offers a novel engineering solution for the efficient treatment of refractory wastewater using EF technology based on in situ high-yield H_(2)O_(2)electrosynthesis.
基金supported by a grant from the Natural Science and Engineering Research Council of Canada
文摘Complex organics are now commonly found in meteorites,comets,asteroids,planetary satellites and interplanetary dust particles.The chemical composition and possible origin of these organics are presented.Specifically,we discuss the possible link between Solar System organics and the complex organics synthesized during the late stages of stellar evolution.Implications of extraterrestrial organics on the origin of life on Earth and the possibility of existence of primordial organics on Earth are also discussed.
文摘This study was carried out for gathering qualitative information about the potential of photocatalytic oxidation for the removal of trace organics (analysed by gas chromatography coupled to mass spectrometry, GC/MS) from biologically pretreated greywater to make it suitable for high quality reuse applications like groundwater recharge. Additionally, fractions of bulk organics (humic substances, building blocks, and low molecular weight organic acids) were quantified by liquid chromatography with organic carbon detection. Biologically pretreated greywater was subjected to photocatalytic oxidation in open stirred vessel reactors with UV lamps positioned over the reactors. UV doses of 0, 5, and 15 Wh·L-1 and TiO2 P25 photocatalyst concentrations of 1, 5, 10, and 20 g·L-1 were investigated. Photocatalysis experiments with a 15 Wh·L-1 UV dose were also conducted in the presence of 1 g·L-1 powdered activated carbon. Subsequent to mere contact of the photocatalyst to biologically pretreated greywater without UV, GC/MS did not indicate a substantial removal of trace organics, while humic substances were increasingly adsorbed by increasing photocatalyst concentration. A UV dose of 15 Wh·L-1 and TiO2 concentrations > 5 g·L-1 were favorable conditions for photocatalytic oxidation resulting in the removal of most of the trace organics, especially chlorinated phosphate flame retardants. Also humic substances were efficiently removed under these conditions. Photocatalytic oxidation is thus a promising process for advanced greywater treatment prior to groundwater recharge. Addition of powdered activated carbon did not improve trace and bulk organics removal by photocatalysis with a UV dose of 15 Wh·L-1 and with photocatalyst concentrations > 5 g·L-1.
文摘The vapor phase organics (VPOs) in the air of Beijing, Langfang and Tianjin were detected by a capillary gas chromatography and GC/MS during the winter and the summer separately. The tentatively identified compounds include alkanes, cyclic hydrocarbons, alkenes, aromatics, acids, alcohols, aldehydes, ketones, esters, halocarbons and so on. The numbers of VPOs found are 118 in Beijing, 83 in Lang-fang and 65 in Tianjin in the winter, and 56, 39 and 72 in the summer respectively. Based on the data of some representative compounds determined quantitatively by GC and GC/MS, a profile of organic pollution in the air of the three cities is presented.
基金financially supported by the National Natural Science Foundation of China(Nos.21777140,21922607)the Outstanding Youth Project of Zhejiang Natural Science Foundation(No.LR19E080004)。
文摘Since the discovery of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in the process of municipal solid waste incineration(MSWI),a large number of researches have been conducted to reveal their formation mechanisms and emission characteristics.As one of national priority control pollutants,chlorinated organics are inclined to transfer into PCDD/Fs in the heterogeneously catalyzed process,which has been considered to be one of great challenges in environmental catalysis.However,so far direct evidences to support such a conversion process are insufficient,and the reaction mechanisms are lack of exploration.This study investigated the catalytic elimination of chlorobenzene(CBz)over a range of industrially applied active species including Pt,Ru,V,Ce and Mn oxides,and explored their reaction byproducts,chlorine adsorption/desorption behaviors and PCDD/F formations.We found that all of these species could generate the PCDD/Fs,amongst which,Mn species were the most active for PCDD/F formation.Approximately 140 ng I-TEQg-1 PCDD/Fs were detected on the Mn-CNT surface after ageing at250℃for 30 h.Even using the dichloromethane(DCM)as a precursor,significant PCDD/Fs were still detected.The Ru and V species were shown to generate much less polychlorinated byproducts and PCDD/Fs,owning to their sufficiently high abilities in Cl desorption,which were through the semi-Deacon and Br(?)nsted H reactions,respectively.
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supported by grants from the National Natural Science Foundation of China(No.52070008).
文摘Recently,a novel 2-electron oxygen reduction reaction(ORR)based electro-oxidation(EO)system was developed,which utilizes a H_(2)O_(2)generation cathode instead of H_(2)evolution cathode.A Ti-based Ni-Sb co-doped SnO_(2)(Ti/NATO)anode was selected for efficient degradation of refractory organics and O_(3)production.The synergistic reaction of O3/H_(2)O_(2)further accelerated the generation of hydroxyl radicals(·OH)in the ORR-EO system.However,the catalytic activity and long-term effectiveness of the Ti/NATO anode limited the large-scale application of the ORR-EO process.In this study,a blue TiO_(2)nanotube array(blue-TiO_(2)-NTA)inter-layer was introduced into the fabrication process between the Ti substrate and NATO catalyst layer.Compared to the Ti/NATO anode,the Ti/blue-TiO_(2)-NTA/NATO anode achieved higher efficiency of organic removal and O_(3)generation.Additionally,the accelerated lifetime of the Ti/blue-TiO_(2)-NTA/NATO anode was increased by 7 times compared to the Ti/NATO anode.When combined with CNTs-C/PTFE air cathode in ORR-EO system,all anodic oxidation and O_(3)/H_(2)O_(2)processes achieved higher•OH production.Over 92%of TOC in leachate bio-effluent was effectively eliminated with a relatively low energy cost of 45 kWh/t.
文摘To investigate feasibility of pathogen free industrial organics with higher agronomic value, the industrial organic wastes were subjected to vermistabilization. The body of earthworm work as ＂biofilter＂ and they can ＂purify＂ and also ＂disinfect＂ and ＂detoxify＂ municipal and industrial organics. The microbiomics of gut and cast of earthworm （Eisenia foetida Savigny） and their association with vermistabilization was studied to determine the microbial quantification in reactors （industrial organics）. Worm were reared in five reactors viz. Sewage sludge （SS）, Paper mill industry sludge （PS）, Vegetable processing industry （VP）, Tannery waste （TW） and Meat process industrial sludge （MP） for ninety days. The microbial load （Salmonella, Shigella, Escherichia, Mycobacterium, Streptococcus） in gut and cast, biomass, recovery of cast in different reactors were determined, periodically. The microbiomics of worms gut revealed the removal of Salmonella （12-18 × 10^8±0.02 to 0-4 × 10^3 ＋ 0.05 CFU/g）, Shigella （14-23 × 10^8 ± 0.04 to 0-4 × 10^3 ± 0.05 CFU/g）, Escherichia （4-16 × 10^8 ± 0.02 to 0-4 × 10^2 ± 0.05 CFU/g）, Mycobacterium （3-16 × 10^8 ± 0.02 to 0-3 × 10^2 ± 0.05 CFU/g）, Streptococcus （6-16 × 10^8 ± 0.02 to 0-4 × 10^3 ± 0.05 CFU/g） during stabilization of industrial organics. Similarly, reduction in pathogens Salmonella （12-19 × 10^8 ± 0.02 to 0-8 ×10^3 ± 0.05 CFU/g）, Shigella （7-20× 10^8 ± 0.04 to 0-2 ×10^3 ± 0.05 CFU/g）, Escherichia （2-20 × 10^8 ± 0.02 to 0.0-2 × 10^3 ± 0.05）, Mycobacterium （1-8 × 10^8 ±0.05 to 0.0-5 × 10^2 ± 0.05 CFU/g）, Streptococcus （8-18 × 10^8 ± 0.02 to 0-7 × 10^3 ± 0.05 CFU/g） in castings of industrial organics indicates the selective nature of feeding of worm. This amply demonstrates that these pathogens have been eliminated as they entered in food chain of worms. However, it may not be possible to remove pathogens completely, but at least worms change the ＂microbial make-up＂ of industrial organics to make it harmless to the soil and enable its use as a nutritive organic fertilizer.
基金The National Natural Science Foundation of Chin(No.51578148)the Project of China Communications Construction(No.2015-ZJKJ-26)the Fundamental Research Funds for the Centra Universities,the Scientific Innovation Research of College Graduates in Jiangsu Province(No.SJLX15_0062)
文摘In order to improve the engineering properties oforganic soil, a new stabilization agent is developed by theaddition of phosphor gypsum and calcium aluminate cement.The artificial organic soil is applied in the study and a series oflaboratory tests were carried out to explore new stabilizationagents and determine the optimal dosage. Unconfinedcompressive strength （UCS） and the pH value of soil poresolution were measured. The influence of organic content,agent composition and curing time on the UCS of sampleswere also researched. The test results show that the UCS ofstabilized organic soils by a new agent achieves approximately800 and 1 200 kPa at 28 and 90 d curing time, respectively.The pH test results show that a high alkaline environment is anecessary and not a sufficient condition for high strength. Thestrength of stabilized soil is related to the hydration product ofstabilization agent. The mechanism of strength formation wasalso explored by X-ray diffraction （XRD）, mercury intrusionporosimetry （MIP） and scanning electron microscope （SEM）tests. A large amount of ettringite is produced to fill the largepores of organic soils, which contribute to the high UCS valueof stabilized organic soils. The new agent can solidify theorganic soil successfully as well as provide a new approach totreat the organic soil.
基金financial supports from the National Natural Science Foundation of China(Nos.51908485 and 51608468)the China Postdoctoral Science Foundation(No.2019T120194)the University Science and Technology Program Project of Hebei Provincial Department of Education(No.QN2018258)。
文摘Constructing a Z-scheme is a significant approach to improve the separation of photogene rated carriers for effective organic pollutant degradation.Herein,a BiVO4/ZnIn2S4(BZ) Z-scheme composite was successfully synthesized,and applied to photodegrade methyl orange(MO) irradiated by a LED lamp.Anchoring the BiVO4 on the ZnIn2S4 nanoparticles promoted the separation of photogenerated electronholes and broadened the light response range.The detailed characterizations,including surface morphology,elements valence state,and photocurrent performance,demonstrated that the enhanced separation of photogenerated carriers was the pivotal reason for the enhanced photocatalysis reaction.Benefiting from the excellent photocatalytic characteristics,the 5% mass ratio of BZ composite presented the highest MO degradation rate of 0.00997 min^-1,which was 1.9 and 10.3 times greater than the virgin ZnIn2S4 and BiVO4,respectively.Furthermore,the BZ hybrid materials indicated a well photo-stability in the four recycling tests.
