Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2) production can reduce the carbon footprint associated with transportation of water,waste,and energy carrier.This study...Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2) production can reduce the carbon footprint associated with transportation of water,waste,and energy carrier.This study reports Ir-doped NiFe_(2)O_(4)(NFI,~5 at%Ir)spinel layer with TiO_(2) overlayer(NFI/TiO_(2)),as a scalable heterojunction anode for direct electrolysis of wastewater with circumneutral pH in a single-compartment cell.In dilute(0.1 M)NaCl solutions,the NFI/TiO_(2) marks superior activity and selectivity for chlorine evolution reaction,outperforming the benchmark IrO_(2).Robust operation in near-neutral pH was confirmed.Electroanalyses including operando X-ray absorption spectroscopy unveiled crucial roles of TiO_(2) which serves both as the primary site for Cl−chemisorption and a protective layer for NFI as an ohmic contact.Galvanostatic electrolysis of NH4+-laden synthetic wastewater demonstrated that NFI/TiO_(2)not only achieves quasi-stoichiometric NH_(4)^(+)-to-N_(2)conversion,but also enhances H_(2)generation efficiency with minimal competing reactions such as reduction of dissolved oxygen and reactive chlorine.The scaled-up WEC with NFI/TiO_(2)was demonstrated for electrolysis of toilet wastewater.展开更多
A total of 14 halophilic hydrocarbon-degrading strains were isolated from crude oil-contaminated sites,using petroleum as the sole carbon and energy source.Among these,four highly efficient strains were selected to cr...A total of 14 halophilic hydrocarbon-degrading strains were isolated from crude oil-contaminated sites,using petroleum as the sole carbon and energy source.Among these,four highly efficient strains were selected to create the mixed bacterial agent XH-1.These four strains were identified through 16S rRNA gene-based sequencing as belonging to Acinetobacter,Bacillus paramycoides,Rhodococcus sp.,and Enterobacter sp.,respectively.The optimal cultivation time for the mixed consortium XH-1 was found to be 48 h,and a nitrogen-phosphorus molar ratio of 10:1 was determined to be beneficial for crude oil degradation.XH-1 showed notable crude oil degradation even at a salinity of up to 30 g/L,with little inhibition observed at sulfide concentrations as high as 150 mg/L and initial oil concentrations of 500 mg/L.Gas chromatography analysis revealed that XH-1 was able to efficiently degrade C9–C29 n-alkanes.Moreover,a bio-contact oxidation reactor enhanced by XH-1 showed promising results in treating oilfield wastewater.These findings suggest that XH-1 can be applied for the treatment of oilfield wastewater.展开更多
Macroporous weak basic anion exchanger （D301R） was used to remove organic substances from drilling wastewater. The effect of pH, temperature and contact time on adsorption behavior was investigated in batch experime...Macroporous weak basic anion exchanger （D301R） was used to remove organic substances from drilling wastewater. The effect of pH, temperature and contact time on adsorption behavior was investigated in batch experiments, which indicated that the COD （Chemical Oxygen Demand） removal ratio of drilling wastewater was approximately 90%, and the COD of treated wastewater was below 70 mg/L under appropriate operating conditions. A mixed liquor of NaOH and NaCI was selected as desorbent because of its better elution performance. The results of column dynamic adsorption and regeneration showed that the COD of wastewater could be efficiently removed by D301R resin, and the resin was easily regenerated by the selected desorbent.展开更多
It is essential to prepare highly-efficiency reproducible adsorbent for purifying industrial dye wastewater. In this work, biscuit with a layered porous structure as a template is applied to prepare a photocatalytic r...It is essential to prepare highly-efficiency reproducible adsorbent for purifying industrial dye wastewater. In this work, biscuit with a layered porous structure as a template is applied to prepare a photocatalytic recyclable adsorbent of BiFeO3/Carbon nanocomposites for purifying simulative industrial dye wastewater. It is found that the structure of the prepared BiFeO3/Carbon nanocomposite is related to the natural structure of the biscuit, annealing temperatures and immersing times, demonstrated by XRD, TEM, UV-Vis and adsorptive activities. Kinetics data shows that the adsorption rate of the adsorbent to the dye is rapid and fitted well with the pseudo-second-order model, that more than 80% of dyes can be removed in the beginning 30 min. The adsorption isotherm can be perfectly described by the Langmuir model as well. It can be seen from the adsorption data that the adsorption performance can reach over 90% at pH ? 2–12, which can imply its universal utilization. The prepared BiFeO_3/Carbon nanocomposites have also displayed excellent capacities(over 90% within 30 min) for adsorption of seven different dyes and their mixed one. According to the five times photocatalytic reproducible experiments, it is proved that BiFeO_3/Carbon nanocomposites show the excellent stability and reproduction for purifying simulative industrial dyes, even the sample have been placed for one year. These research results indicate that the adsorbent BiFeO_3/Carbon can be a suitable material used in treating industrial dye wastewater potentially.展开更多
Nitrobenzene-containing industrial wastewater was degraded in the presence of ozone coupled with H2O2 by high gravity technology. The effect of high gravity factor, H2O2 concentration, pH value, liquid flow-rate, and ...Nitrobenzene-containing industrial wastewater was degraded in the presence of ozone coupled with H2O2 by high gravity technology. The effect of high gravity factor, H2O2 concentration, pH value, liquid flow-rate, and reaction time on the efficiency for removal of nitrobenzene was investigated. The experimental results show that the high gravity technology enhances the ozone utilization efficiency with O3/H202 showing synergistic effect. The degradation efficiency in terms of the COD removal rate and nitrobenzene removal rate reached 45.8% and 50.4%, respectively, under the following reaction conditions, viz.： a high gravity factor of 66.54, a pH value of 9, a H2O2/O3 molar ratio of 1：1, a liquid flow rate of 140 L/h, an ozone concentration of 40 rag/L, a H2O2 multiple dosing mode of 6 mL/h, and a reaction time of 4 h. Compared with the performance of conventional stirred aeration mixers, the high gravity technology could increase the COD and nitrobenzene removal rate related with the nitrobenzene-containing wastewater by 22.9% and 23.3%, respectively.展开更多
A unique cyclonic static microbubble flotation column was developed for oily wastewater separation.The separation effciency was found to be highly dependent on gas holdup and bubble size distribution.By changing the c...A unique cyclonic static microbubble flotation column was developed for oily wastewater separation.The separation effciency was found to be highly dependent on gas holdup and bubble size distribution.By changing the circulation pressure,gas flow rate,frother concentration,the effect of operation parameters on gas holdup and oil removal effciency were attained.A mathematical modeling between the kinetic constant and the gas holdup was established for oily water separation process.The results show that higher gas holdup and smaller microbubble sizes are benefcial to improve oil removal effciency.展开更多
Treatment of drilling wastewater from a sulfonated drilling mud system in the Shengli Oilfield, East China, was studied. The wastewater was deeply treated by a chemical coagulationcentrifugal separation-ozone catalyti...Treatment of drilling wastewater from a sulfonated drilling mud system in the Shengli Oilfield, East China, was studied. The wastewater was deeply treated by a chemical coagulationcentrifugal separation-ozone catalytic oxidation combined process. The factors （i.e. pH value, chemical dosage, reaction time, etc.） influencing the treatment effect were investigated, and pH = 7 was determined as optimal for the coagulation; polymeric aluminum chloride （PAC） was selected as the optimal coagulant with a dosage of 18 g/L; cationic polyacrylamide （CPAM） with molecular weight of 8 million was selected as the optimal coagulant aid with an optimum dosage of 8 mg/L; and the optimal condition of catalytic ozonation was found to be a pH of 12 and an oxidation time of 40 min. The results showed that the combined treatment process was effective. The oil content and suspended solids content of the effluent reached the first class discharge standard according to China＇s standard GB 8978-1996 （Integrated Wastewater Discharge Standard） and the chemical oxygen demand （COD） decreased to 195 mg/L from 2.34×10^4 mg/L after coagulation process and ozone oxidation at pH = 12 for 40 min.展开更多
A novel high gravity electrochemical reactor with multi-concentric cylindrical electrodes was used in the electrochemical treatment of 5 000 mg/L phenol-containing wastewater at a petrochemical plant, which can operat...A novel high gravity electrochemical reactor with multi-concentric cylindrical electrodes was used in the electrochemical treatment of 5 000 mg/L phenol-containing wastewater at a petrochemical plant, which can operate continuously and process in a large scale. The results show that the high gravity technology used in electrochemical treatment of phenol-containing wastewater can shorten the electrolysis time, decrease the electrolysis voltage, and reduce the energy consumption. The COD removal efficiency was high in the high-gravity field, and reached up to about 48%, which was about 2 times the value achieved in the normal gravity field at a processing capacity of 6 L, a high gravity factor of 80, a voltage of 12 V, an electrolysis time of 40 min, and a wastewater flowrate of 80 L/h.展开更多
Wastewater, which involves easy-soluble reactive dyes, especially non-degradable dyes, is very difficult to decolor efficiently by normal processes such as coagulation process and biological treatment. The high chroma...Wastewater, which involves easy-soluble reactive dyes, especially non-degradable dyes, is very difficult to decolor efficiently by normal processes such as coagulation process and biological treatment. The high chromaticity se- riously hinders the reuse of reactive dye waste water. In this paper, a new method by bentonite adsorption and coagulation (PAC) is employed for removing color from synthetic dye waste water which contains reactive red K-2G, K-RN blue, K-GR blue, X-3B red, K-GN orange, KB-3G yellow, K-2BP red, K-RN yellow and K-6G yellow. Bentonite pre- treated by 4% CTMAB and milled to 160 order screen is proven to the best decoloring agent. For a 100 mL reactive red K-2G sample (CODcr 400 mg/L, 25 000 chromaticity color), 0.5 g bentonite pretreated and 2.5 mL PAC is enough to decolor wastewater up to 99.92% and the sediment time is short. Non-degradable dyes such as active red X-3B and K-GN orange are declored completely as well. Raw sewage (low chromaticity color) is decolored completely at a ben-tonite dosage of 0.001g. More researches prove the high practical value of this process.展开更多
Water pollution is an increasingly serious environmental problem because many pollutants have carcinogenic effects on humans and aquatic organisms.Metal organic framework(MOF),made up of metal ions and multifunctional...Water pollution is an increasingly serious environmental problem because many pollutants have carcinogenic effects on humans and aquatic organisms.Metal organic framework(MOF),made up of metal ions and multifunctional organic ligands,has been one of the most concerned materials because of its adjustable and regular pore structure.MOFs have always shown attractive advantages in membrane separation and adsorption technologies,among which water-stable MOFs are particularly prominent in wastewater treatment(WWT)applications.This review systematically summarizes the application of MOF membranes in membrane filtration,membrane pervaporation and membrane distillation.Also,the adsorption mechanisms of heavy metals,dyes and antibacterials in wastewater have been concluded.In order to tap the full application potential of pristine MOFs in sustainable wastewater treatment,current challenges are discussed in detail and future research directions are proposed.展开更多
A new type of device,a dissolved-air flotation column,was developed for separation of oily wastewater. The unique design idea of the dissolved-air flotation column is the combined use of dissolved-air flotation and co...A new type of device,a dissolved-air flotation column,was developed for separation of oily wastewater. The unique design idea of the dissolved-air flotation column is the combined use of dissolved-air flotation and column flotation. The dissolved air release occurred within the column separation system. As a potential application the column was investigated for its performance in separating emulsified oil droplets in oily wastewater. A high separation efficiency was obtained in a series of tests. The aeration performance of the bubble generator used in the dissolved-air flotation column was also studied in particular.展开更多
A hybrid gas/liquid pulsed discharge plasma reactor using a porous ceramic tube is proposed for dye wastewater treatment. High voltage pulsed discharge plasma was generated in the gas phase and simultaneously the plas...A hybrid gas/liquid pulsed discharge plasma reactor using a porous ceramic tube is proposed for dye wastewater treatment. High voltage pulsed discharge plasma was generated in the gas phase and simultaneously the plasma channel was permeated through the tiny holes of the ceramic tube into the water phase accompanied by gas bubbles. The porous ceramic tube not only separated the gas phase and liquid phase but also offered an effective plasma spreading channel. The effects of the peak pulse voltage, additive gas varieties, gas bubbling rate, solution conductivity and TiO2 addition were investigated. The results showed that this reactor was effective for dye wastewater treatment. The decoloration efficiency of Acid Orange II was enhanced with an increase in the power supplied. Under the studied conditions, 97% of Acid Orange II in aqueous solution was effectively decolored with additive oxygen gas, which was 51% higher than that with argon gas, and the increasing 02 bubbling rate also benefited the decoloration of dye wastewater. Water conductivity had a small effect on the level of decoloration. Catalysis of TiO2 could be induced by the pulsed discharge plasma and addition of TiO2 aided the decoloration of Acid Orange II.展开更多
The pyromellitic dianhydride（PMDA） crosslinked poly（vinyl alcohol）（PVA） was coated on top of the PAN ultrafiltration membrane to form a PVA/PAN composite PV membranes for wastewater desalination. The composite m...The pyromellitic dianhydride（PMDA） crosslinked poly（vinyl alcohol）（PVA） was coated on top of the PAN ultrafiltration membrane to form a PVA/PAN composite PV membranes for wastewater desalination. The composite membranes have high application value in industrial wastewater treatment. By varying the membrane fabrication parameters including the weight percent（wt%） of the PMDA, the crosslink temperature and duration, membrane with the best desalination performance was obtained. The composite membrane with a 2-lm-thick PVA selective layer containing 20 wt% of PMDA and being crosslinked at 100 °C for 2 h showed the highest Na Cl rejection of 99.98% with a water flux of 32.26 L/（m^2 h）at 70 °C using the 35,000 ppm Na Cl aqueous solution as feed. FTIR spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis and scanning electron microscope have been used to characterize the structures and properties of both the crosslinked PVA dense films and PVA/PAN composite membranes. The effects of the concentrations of PMDA,the crosslinking time and temperature to the membrane water contact angle, swelling degree, salt rejection and water flux were systematically studied.展开更多
It is of great importance to explore a creative route to improve the degradation e ciency of organic pollutants in wastewater.Herein,we construct a unique hybrid system by combining self-powered triboelectric nanogene...It is of great importance to explore a creative route to improve the degradation e ciency of organic pollutants in wastewater.Herein,we construct a unique hybrid system by combining self-powered triboelectric nanogenerator(TENG)with carbon dots-TiO_(2)sheets doped three-dimensional graphene oxide photocatalyst(3 DGA@CDs-TNs),which can significantly enhance the degradation e ciency of brilliant green(BG)and direct blue 5 B(DB)owing to the powerful interaction of TENG and 3 DGA@CDs-TNs photocatalyst.The power output of TENG can be applied for wastewater purification directly,which exhibits a selfpowered electrocatalytic technology.Furthermore,the results also verify that TENG can replace conventional electric catalyst to remove pollutants e ectively from wastewater without any consumption.Subsequently,the unstable fragments and the plausible removal pathways of the two pollutants are proposed.Our work sheds light on the development of e cient and sustainable TENG/photocatalyst system,opening up new opportunities and possibilities for comprehensive utilization of random energy.展开更多
Electrical discharge treatments of synthetic dyeing wastewater were carried out with two different systems： underwater pulsed electrical discharge （UPED） and underwater dielectric barrier discharge （UDBD）. Reacti...Electrical discharge treatments of synthetic dyeing wastewater were carried out with two different systems： underwater pulsed electrical discharge （UPED） and underwater dielectric barrier discharge （UDBD）. Reactive Blue 4 （RB4） and Acid Red 4 （AR4） were used as model contaminants for the synthetic wastewater. The performance of the aforementioned systems was compared with respect to the chromaticity removal and the energy requirement. The results showed that the present electrical discharge systems were very effective for degradation of the dyes. The dependences of the dye degradation rate on treatment time, initial dye concentration, electrical energy, and the type of working gas including air, 02, and N2 were examined. The change in the initial dye concentration did not largely affect the degradation of either RB4 or AR4. The energy delivered to the UPED system was only partially utilized for generating reactive species capable of degrading the dyes, leading to higher energy requirement than the UDBD system. Among the working gases, the best performance was observed with O2. As the degradation proceeded, the concentration of total dissolved solids and the solution conductivity kept increasing while pH showed a decreasing trend, revealing that the dyes were effectively mineralized.展开更多
A wastewater treatment system was established by means of pulsed dielectric barrier discharge（DBD）. The main advantage of this system is that the wastewater is employed as one of the electrodes for the degradation o...A wastewater treatment system was established by means of pulsed dielectric barrier discharge（DBD）. The main advantage of this system is that the wastewater is employed as one of the electrodes for the degradation of rhodamine B, which makes use of the high conductivity and lessenes its negative influence on the discharge process. At the same time, the reactive species like ozone and ultraviolet（UV） light generated by the DBD can be utilized for the treatment of wastewater. The effects of some factors like conductivity, peak pulse voltage, discharge frequency and pH values were investigated. The results show that the combination of these reactive species could enhance the degradation of the dye while the ozone played the most important role in the process. The degradation efficiency was enhanced with the increase of energy supplied. The reduction in the concentration of rhodamine B was much more effective with high solution conductivity;under the highest conductivity condition, the degradation rate could rise to 99%.展开更多
Novel Mn–Fe–Mg-and Mn–Fe–Ce-loaded alumina（Mn–Fe–Mg/Al2O3 and Mn–Fe–Ce/Al2O3） were developed to catalytically ozonate reverse osmosis concentrates generated from petroleum refinery wastewaters（PRW-ROC）. Hi...Novel Mn–Fe–Mg-and Mn–Fe–Ce-loaded alumina（Mn–Fe–Mg/Al2O3 and Mn–Fe–Ce/Al2O3） were developed to catalytically ozonate reverse osmosis concentrates generated from petroleum refinery wastewaters（PRW-ROC）. Highly dispersed 100–300-nm deposits of composite multivalent metal oxides of Mn（Mn^2＋）, Mn^3＋,and Mn^4＋, Fe（Fe^2＋）and Fe^3＋ and Mg（Mg^2＋）, or Ce（Ce^4＋） were achieved on Al2O3 supports. The developed Mn–Fe–Mg/Al2O3 and Mn–Fe–Ce/Al2O3 exhibited higher catalytic activity during the ozonation of PRW-ROC than Mn–Fe/Al2O3, Mn/Al2O-3, Fe/Al2O3, and Al2O3. Chemical oxygen demand removal by Mn–Fe–Mg/Al2O3-or Mn–Fe–Ce/Al2O3-catalyzed ozonation increased by 23.9% and23.2%, respectively, in comparison with single ozonation.Mn–Fe–Mg/Al2O3 and Mn–Fe–Ce/Al2O3 notably promoted áOH generation and áOH-mediated oxidation. This study demonstrated the potential use of composite metal oxide-loaded Al2O3 in advanced treatment of bio-recalcitrant wastewaters.展开更多
The physicochemical processes of dielectric barrier discharge （DBD） such as insitu formation of chemically active species and emission of ultraviolet （UV）/visible light were utilized for the treatment of a simulat...The physicochemical processes of dielectric barrier discharge （DBD） such as insitu formation of chemically active species and emission of ultraviolet （UV）/visible light were utilized for the treatment of a simulated wastewater formed with Acid Red 4 as the model organic contaminant. The chemically active species （mostly ozone） produced in the DBD reactor were well distributed in the wastewater using a porous gas diffuser, thereby increasing the gas-liquid contact area. For the purpose of making the best use of the light emission, a titanium oxide-based photocatalyst was incorporated in the wastewater treating system. The experimental parameters chosen were the voltage applied to the DBD reactor, the initial pH of the wastewater, and the concentration of hydrogen peroxide added to the wastewater. The results have clearly shown that the present system capable of degrading organic contaminants in two ways （photocatalysis and ozonation） may be a promising wastewater treatment technology.展开更多
Banana peel-derived porous carbon(BPPC) was prepared from banana peel and used as an adsorbent for methyl orange(MO) wastewater removal. BPPC-MO50 is a N,S-doped BPPC obtained via secondary carbonization. The BPPC-MO5...Banana peel-derived porous carbon(BPPC) was prepared from banana peel and used as an adsorbent for methyl orange(MO) wastewater removal. BPPC-MO50 is a N,S-doped BPPC obtained via secondary carbonization. The BPPC-MO50 exhibited a high specific surface area of1774.3 m^2/g. Heteroatom-doped porous carbon(PC) was successfully synthesized from the BPPC absorbed MO at high temperature and used for oxygen reduction. The BPPC-MO50 displayed the highest ORR onset potential among all carbon-based electrocatalysts, i.e., 0.93 V vs.reversible hydrogen electrode(RHE). This is the first report to describe porous carbon-activated materials from agriculture and forestry waste that is used for adsorption of dyes from wastewater via an enhanced heteroatom(N,S) content. These results may contribute to the sustainable development of dye wastewater treatment by transforming saturated PC into an effective material and has potential applications in fuel cells or as energy sources.展开更多
The zero valent iron/granular active carbon(ZVI/GAC) micro-electrolysis enhanced by ultrasound(US) coupled with hydrogen peroxide(H_2O_2) was investigated for the deep degradation of nitrobenzene-containing wastewater...The zero valent iron/granular active carbon(ZVI/GAC) micro-electrolysis enhanced by ultrasound(US) coupled with hydrogen peroxide(H_2O_2) was investigated for the deep degradation of nitrobenzene-containing wastewater. The results of scanning electron microscopy-energy dispersive X-rays analysis(SEM-EDS) demonstrated that continuously accelerated regeneration of ZVI and GAC in situ by US could improve the process for converting nitrobenzene(NB) to aniline(AN). H_2O_2 was decomposed catalytically by the byproduct Fe^(2+) ions generated in the micro-electrolysis process to hydroxyl radicals and the organic pollutants in the wastewater were finally mineralized to CO2 and H2O. Effects of the ZVI dosage, the ZVI/GAC mass ratio, the initial pH value and the H_2O_2 dosage on the efficiency for degradation of NB were studied in these experiments. The optimal operating conditions covered a ZVI dosage of 15 g/L, a ZVI/GAC mass ratio of 1:2,an initial pH value of 3 and a H_2O_2 dosage of 4 mL. In this case, the NB removal efficiency reached 97.72% and the total organic carbon(TOC) removal efficiency reached 73.42% at a NB concentration of 300 mg/L. The reduction of NB by USZVI/GAC followed the pseudo-first-order kinetics model, and the pseudo-first-order rate constants were given at different initial pH values. The reaction intermediates such as AN, benzoquinonimine, p-benzoquinone, p-nitrophenol and other organic acids were detected and a probable pathway for NB degradation has been proposed.展开更多
基金supported by the National Research Foundation of Korea(NRF)grants(2022R1A2C4001228,2022M3H4A4097524,2022M3I3A1082499,and 2021M3I3A1084818)the Technology Innovation Program(20026415)of the Ministry of Trade,Industry&Energy(MOTIE,Korea)the supports from Nanopac for fabrication of scaled-up reactor.
文摘Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2) production can reduce the carbon footprint associated with transportation of water,waste,and energy carrier.This study reports Ir-doped NiFe_(2)O_(4)(NFI,~5 at%Ir)spinel layer with TiO_(2) overlayer(NFI/TiO_(2)),as a scalable heterojunction anode for direct electrolysis of wastewater with circumneutral pH in a single-compartment cell.In dilute(0.1 M)NaCl solutions,the NFI/TiO_(2) marks superior activity and selectivity for chlorine evolution reaction,outperforming the benchmark IrO_(2).Robust operation in near-neutral pH was confirmed.Electroanalyses including operando X-ray absorption spectroscopy unveiled crucial roles of TiO_(2) which serves both as the primary site for Cl−chemisorption and a protective layer for NFI as an ohmic contact.Galvanostatic electrolysis of NH4+-laden synthetic wastewater demonstrated that NFI/TiO_(2)not only achieves quasi-stoichiometric NH_(4)^(+)-to-N_(2)conversion,but also enhances H_(2)generation efficiency with minimal competing reactions such as reduction of dissolved oxygen and reactive chlorine.The scaled-up WEC with NFI/TiO_(2)was demonstrated for electrolysis of toilet wastewater.
基金the Shandong Provincial Natural Science Foundation(No.ZR2019MEE038,ZR202110260011)the Fundamental Research Funds for the Central Universities(No.19CX02038A)。
文摘A total of 14 halophilic hydrocarbon-degrading strains were isolated from crude oil-contaminated sites,using petroleum as the sole carbon and energy source.Among these,four highly efficient strains were selected to create the mixed bacterial agent XH-1.These four strains were identified through 16S rRNA gene-based sequencing as belonging to Acinetobacter,Bacillus paramycoides,Rhodococcus sp.,and Enterobacter sp.,respectively.The optimal cultivation time for the mixed consortium XH-1 was found to be 48 h,and a nitrogen-phosphorus molar ratio of 10:1 was determined to be beneficial for crude oil degradation.XH-1 showed notable crude oil degradation even at a salinity of up to 30 g/L,with little inhibition observed at sulfide concentrations as high as 150 mg/L and initial oil concentrations of 500 mg/L.Gas chromatography analysis revealed that XH-1 was able to efficiently degrade C9–C29 n-alkanes.Moreover,a bio-contact oxidation reactor enhanced by XH-1 showed promising results in treating oilfield wastewater.These findings suggest that XH-1 can be applied for the treatment of oilfield wastewater.
文摘Macroporous weak basic anion exchanger （D301R） was used to remove organic substances from drilling wastewater. The effect of pH, temperature and contact time on adsorption behavior was investigated in batch experiments, which indicated that the COD （Chemical Oxygen Demand） removal ratio of drilling wastewater was approximately 90%, and the COD of treated wastewater was below 70 mg/L under appropriate operating conditions. A mixed liquor of NaOH and NaCI was selected as desorbent because of its better elution performance. The results of column dynamic adsorption and regeneration showed that the COD of wastewater could be efficiently removed by D301R resin, and the resin was easily regenerated by the selected desorbent.
基金financial support from the NSFC project(21501052 and 91622119)the China Postdoctoral Science Foundation(2015M570304)+2 种基金Special Funding for Postdoctoral of Heilongjiang Province(LBH-TZ06019)the Science Foundation for Excellent Youth of Harbin City of China(2016RQQXJ099)UNPYSCT-2016173
文摘It is essential to prepare highly-efficiency reproducible adsorbent for purifying industrial dye wastewater. In this work, biscuit with a layered porous structure as a template is applied to prepare a photocatalytic recyclable adsorbent of BiFeO3/Carbon nanocomposites for purifying simulative industrial dye wastewater. It is found that the structure of the prepared BiFeO3/Carbon nanocomposite is related to the natural structure of the biscuit, annealing temperatures and immersing times, demonstrated by XRD, TEM, UV-Vis and adsorptive activities. Kinetics data shows that the adsorption rate of the adsorbent to the dye is rapid and fitted well with the pseudo-second-order model, that more than 80% of dyes can be removed in the beginning 30 min. The adsorption isotherm can be perfectly described by the Langmuir model as well. It can be seen from the adsorption data that the adsorption performance can reach over 90% at pH ? 2–12, which can imply its universal utilization. The prepared BiFeO_3/Carbon nanocomposites have also displayed excellent capacities(over 90% within 30 min) for adsorption of seven different dyes and their mixed one. According to the five times photocatalytic reproducible experiments, it is proved that BiFeO_3/Carbon nanocomposites show the excellent stability and reproduction for purifying simulative industrial dyes, even the sample have been placed for one year. These research results indicate that the adsorbent BiFeO_3/Carbon can be a suitable material used in treating industrial dye wastewater potentially.
基金financially supported by the National Natural Science Foundation of China(21206153)Science and Technology Development Program Fund of Taiyuan City(120164053)
文摘Nitrobenzene-containing industrial wastewater was degraded in the presence of ozone coupled with H2O2 by high gravity technology. The effect of high gravity factor, H2O2 concentration, pH value, liquid flow-rate, and reaction time on the efficiency for removal of nitrobenzene was investigated. The experimental results show that the high gravity technology enhances the ozone utilization efficiency with O3/H202 showing synergistic effect. The degradation efficiency in terms of the COD removal rate and nitrobenzene removal rate reached 45.8% and 50.4%, respectively, under the following reaction conditions, viz.： a high gravity factor of 66.54, a pH value of 9, a H2O2/O3 molar ratio of 1：1, a liquid flow rate of 140 L/h, an ozone concentration of 40 rag/L, a H2O2 multiple dosing mode of 6 mL/h, and a reaction time of 4 h. Compared with the performance of conventional stirred aeration mixers, the high gravity technology could increase the COD and nitrobenzene removal rate related with the nitrobenzene-containing wastewater by 22.9% and 23.3%, respectively.
基金the National Natural Science Foundation of China(No.51104158)the Science and Technology Fund of China University of Mining & Technology (No.2011QNB08) for the financial support
文摘A unique cyclonic static microbubble flotation column was developed for oily wastewater separation.The separation effciency was found to be highly dependent on gas holdup and bubble size distribution.By changing the circulation pressure,gas flow rate,frother concentration,the effect of operation parameters on gas holdup and oil removal effciency were attained.A mathematical modeling between the kinetic constant and the gas holdup was established for oily water separation process.The results show that higher gas holdup and smaller microbubble sizes are benefcial to improve oil removal effciency.
基金National High Technology Research and Development Program of China(No. 2013AA064301)National Natural Science Foundation of China (No. 51274210)
文摘Treatment of drilling wastewater from a sulfonated drilling mud system in the Shengli Oilfield, East China, was studied. The wastewater was deeply treated by a chemical coagulationcentrifugal separation-ozone catalytic oxidation combined process. The factors （i.e. pH value, chemical dosage, reaction time, etc.） influencing the treatment effect were investigated, and pH = 7 was determined as optimal for the coagulation; polymeric aluminum chloride （PAC） was selected as the optimal coagulant with a dosage of 18 g/L; cationic polyacrylamide （CPAM） with molecular weight of 8 million was selected as the optimal coagulant aid with an optimum dosage of 8 mg/L; and the optimal condition of catalytic ozonation was found to be a pH of 12 and an oxidation time of 40 min. The results showed that the combined treatment process was effective. The oil content and suspended solids content of the effluent reached the first class discharge standard according to China＇s standard GB 8978-1996 （Integrated Wastewater Discharge Standard） and the chemical oxygen demand （COD） decreased to 195 mg/L from 2.34×10^4 mg/L after coagulation process and ozone oxidation at pH = 12 for 40 min.
基金the Natural Science Foundation for Young Scientists of Shanxi Province, China (Grant No. 2010021007-2) for its financial support to this study
文摘A novel high gravity electrochemical reactor with multi-concentric cylindrical electrodes was used in the electrochemical treatment of 5 000 mg/L phenol-containing wastewater at a petrochemical plant, which can operate continuously and process in a large scale. The results show that the high gravity technology used in electrochemical treatment of phenol-containing wastewater can shorten the electrolysis time, decrease the electrolysis voltage, and reduce the energy consumption. The COD removal efficiency was high in the high-gravity field, and reached up to about 48%, which was about 2 times the value achieved in the normal gravity field at a processing capacity of 6 L, a high gravity factor of 80, a voltage of 12 V, an electrolysis time of 40 min, and a wastewater flowrate of 80 L/h.
文摘Wastewater, which involves easy-soluble reactive dyes, especially non-degradable dyes, is very difficult to decolor efficiently by normal processes such as coagulation process and biological treatment. The high chromaticity se- riously hinders the reuse of reactive dye waste water. In this paper, a new method by bentonite adsorption and coagulation (PAC) is employed for removing color from synthetic dye waste water which contains reactive red K-2G, K-RN blue, K-GR blue, X-3B red, K-GN orange, KB-3G yellow, K-2BP red, K-RN yellow and K-6G yellow. Bentonite pre- treated by 4% CTMAB and milled to 160 order screen is proven to the best decoloring agent. For a 100 mL reactive red K-2G sample (CODcr 400 mg/L, 25 000 chromaticity color), 0.5 g bentonite pretreated and 2.5 mL PAC is enough to decolor wastewater up to 99.92% and the sediment time is short. Non-degradable dyes such as active red X-3B and K-GN orange are declored completely as well. Raw sewage (low chromaticity color) is decolored completely at a ben-tonite dosage of 0.001g. More researches prove the high practical value of this process.
基金supported by the National Natural Science Foundation of China (NSFC-U1904215)Natural Science Foundation of Jiangsu Province (BK20200044)Changjiang scholars program of the Ministry of Education (Q2018270).
文摘Water pollution is an increasingly serious environmental problem because many pollutants have carcinogenic effects on humans and aquatic organisms.Metal organic framework(MOF),made up of metal ions and multifunctional organic ligands,has been one of the most concerned materials because of its adjustable and regular pore structure.MOFs have always shown attractive advantages in membrane separation and adsorption technologies,among which water-stable MOFs are particularly prominent in wastewater treatment(WWT)applications.This review systematically summarizes the application of MOF membranes in membrane filtration,membrane pervaporation and membrane distillation.Also,the adsorption mechanisms of heavy metals,dyes and antibacterials in wastewater have been concluded.In order to tap the full application potential of pristine MOFs in sustainable wastewater treatment,current challenges are discussed in detail and future research directions are proposed.
基金Projects 50425414 supported by thte National Fund for Distinguished Young Scholars2006A019 by the Science and Technology Fund of China University of Mining &Technology
文摘A new type of device,a dissolved-air flotation column,was developed for separation of oily wastewater. The unique design idea of the dissolved-air flotation column is the combined use of dissolved-air flotation and column flotation. The dissolved air release occurred within the column separation system. As a potential application the column was investigated for its performance in separating emulsified oil droplets in oily wastewater. A high separation efficiency was obtained in a series of tests. The aeration performance of the bubble generator used in the dissolved-air flotation column was also studied in particular.
基金supported financially by the Program for Liaoning Excellent Talents in University,China (No.2009R09)National Natural Science Foundation of China (No.40901150)863 Program of China (No.2009AA064101-4)
文摘A hybrid gas/liquid pulsed discharge plasma reactor using a porous ceramic tube is proposed for dye wastewater treatment. High voltage pulsed discharge plasma was generated in the gas phase and simultaneously the plasma channel was permeated through the tiny holes of the ceramic tube into the water phase accompanied by gas bubbles. The porous ceramic tube not only separated the gas phase and liquid phase but also offered an effective plasma spreading channel. The effects of the peak pulse voltage, additive gas varieties, gas bubbling rate, solution conductivity and TiO2 addition were investigated. The results showed that this reactor was effective for dye wastewater treatment. The decoloration efficiency of Acid Orange II was enhanced with an increase in the power supplied. Under the studied conditions, 97% of Acid Orange II in aqueous solution was effectively decolored with additive oxygen gas, which was 51% higher than that with argon gas, and the increasing 02 bubbling rate also benefited the decoloration of dye wastewater. Water conductivity had a small effect on the level of decoloration. Catalysis of TiO2 could be induced by the pulsed discharge plasma and addition of TiO2 aided the decoloration of Acid Orange II.
基金supported by the Higher Education and High-quality and World-class Universities (PY201618)the National Natural Science Foundation of China (Contract Grant Number 51373014)the National Natural Science Foundation of China (Contract Grant Number 51403012)
文摘The pyromellitic dianhydride（PMDA） crosslinked poly（vinyl alcohol）（PVA） was coated on top of the PAN ultrafiltration membrane to form a PVA/PAN composite PV membranes for wastewater desalination. The composite membranes have high application value in industrial wastewater treatment. By varying the membrane fabrication parameters including the weight percent（wt%） of the PMDA, the crosslink temperature and duration, membrane with the best desalination performance was obtained. The composite membrane with a 2-lm-thick PVA selective layer containing 20 wt% of PMDA and being crosslinked at 100 °C for 2 h showed the highest Na Cl rejection of 99.98% with a water flux of 32.26 L/（m^2 h）at 70 °C using the 35,000 ppm Na Cl aqueous solution as feed. FTIR spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis and scanning electron microscope have been used to characterize the structures and properties of both the crosslinked PVA dense films and PVA/PAN composite membranes. The effects of the concentrations of PMDA,the crosslinking time and temperature to the membrane water contact angle, swelling degree, salt rejection and water flux were systematically studied.
基金financially supported by the National Key R&D Program of China(Grant Nos.2016YFA0202704 and 2019YFA0706900)the Beijing Municipal Natural Science Foundation(Grant No.2212052)+1 种基金the China Postdoctoral Science Foundation(Grant No.2019T120390)the Jiangsu Planned Projects for Postdoctoral research funds(Grant No.2018K018A)。
文摘It is of great importance to explore a creative route to improve the degradation e ciency of organic pollutants in wastewater.Herein,we construct a unique hybrid system by combining self-powered triboelectric nanogenerator(TENG)with carbon dots-TiO_(2)sheets doped three-dimensional graphene oxide photocatalyst(3 DGA@CDs-TNs),which can significantly enhance the degradation e ciency of brilliant green(BG)and direct blue 5 B(DB)owing to the powerful interaction of TENG and 3 DGA@CDs-TNs photocatalyst.The power output of TENG can be applied for wastewater purification directly,which exhibits a selfpowered electrocatalytic technology.Furthermore,the results also verify that TENG can replace conventional electric catalyst to remove pollutants e ectively from wastewater without any consumption.Subsequently,the unstable fragments and the plausible removal pathways of the two pollutants are proposed.Our work sheds light on the development of e cient and sustainable TENG/photocatalyst system,opening up new opportunities and possibilities for comprehensive utilization of random energy.
基金supported by the Ministry of Education, Science & Technology (MEST)the National Research Foundation of Korea (NRF)
文摘Electrical discharge treatments of synthetic dyeing wastewater were carried out with two different systems： underwater pulsed electrical discharge （UPED） and underwater dielectric barrier discharge （UDBD）. Reactive Blue 4 （RB4） and Acid Red 4 （AR4） were used as model contaminants for the synthetic wastewater. The performance of the aforementioned systems was compared with respect to the chromaticity removal and the energy requirement. The results showed that the present electrical discharge systems were very effective for degradation of the dyes. The dependences of the dye degradation rate on treatment time, initial dye concentration, electrical energy, and the type of working gas including air, 02, and N2 were examined. The change in the initial dye concentration did not largely affect the degradation of either RB4 or AR4. The energy delivered to the UPED system was only partially utilized for generating reactive species capable of degrading the dyes, leading to higher energy requirement than the UDBD system. Among the working gases, the best performance was observed with O2. As the degradation proceeded, the concentration of total dissolved solids and the solution conductivity kept increasing while pH showed a decreasing trend, revealing that the dyes were effectively mineralized.
基金supported by National Natural Science Foundation of China(No.11075041)
文摘A wastewater treatment system was established by means of pulsed dielectric barrier discharge（DBD）. The main advantage of this system is that the wastewater is employed as one of the electrodes for the degradation of rhodamine B, which makes use of the high conductivity and lessenes its negative influence on the discharge process. At the same time, the reactive species like ozone and ultraviolet（UV） light generated by the DBD can be utilized for the treatment of wastewater. The effects of some factors like conductivity, peak pulse voltage, discharge frequency and pH values were investigated. The results show that the combination of these reactive species could enhance the degradation of the dye while the ozone played the most important role in the process. The degradation efficiency was enhanced with the increase of energy supplied. The reduction in the concentration of rhodamine B was much more effective with high solution conductivity;under the highest conductivity condition, the degradation rate could rise to 99%.
基金supported in part by the National Science and Technology Major Project of China (No. 2016ZX05040-003)
文摘Novel Mn–Fe–Mg-and Mn–Fe–Ce-loaded alumina（Mn–Fe–Mg/Al2O3 and Mn–Fe–Ce/Al2O3） were developed to catalytically ozonate reverse osmosis concentrates generated from petroleum refinery wastewaters（PRW-ROC）. Highly dispersed 100–300-nm deposits of composite multivalent metal oxides of Mn（Mn^2＋）, Mn^3＋,and Mn^4＋, Fe（Fe^2＋）and Fe^3＋ and Mg（Mg^2＋）, or Ce（Ce^4＋） were achieved on Al2O3 supports. The developed Mn–Fe–Mg/Al2O3 and Mn–Fe–Ce/Al2O3 exhibited higher catalytic activity during the ozonation of PRW-ROC than Mn–Fe/Al2O3, Mn/Al2O-3, Fe/Al2O3, and Al2O3. Chemical oxygen demand removal by Mn–Fe–Mg/Al2O3-or Mn–Fe–Ce/Al2O3-catalyzed ozonation increased by 23.9% and23.2%, respectively, in comparison with single ozonation.Mn–Fe–Mg/Al2O3 and Mn–Fe–Ce/Al2O3 notably promoted áOH generation and áOH-mediated oxidation. This study demonstrated the potential use of composite metal oxide-loaded Al2O3 in advanced treatment of bio-recalcitrant wastewaters.
文摘The physicochemical processes of dielectric barrier discharge （DBD） such as insitu formation of chemically active species and emission of ultraviolet （UV）/visible light were utilized for the treatment of a simulated wastewater formed with Acid Red 4 as the model organic contaminant. The chemically active species （mostly ozone） produced in the DBD reactor were well distributed in the wastewater using a porous gas diffuser, thereby increasing the gas-liquid contact area. For the purpose of making the best use of the light emission, a titanium oxide-based photocatalyst was incorporated in the wastewater treating system. The experimental parameters chosen were the voltage applied to the DBD reactor, the initial pH of the wastewater, and the concentration of hydrogen peroxide added to the wastewater. The results have clearly shown that the present system capable of degrading organic contaminants in two ways （photocatalysis and ozonation） may be a promising wastewater treatment technology.
基金supported by the Doctor Foundation of Bingtuan (No.2014BB004)National Natural Science Foundation of China (U130329)+1 种基金the Program for Changjiang Scholars, Innovative Research Team in University (No. IRT_15R46)the Program of Science and Technology Innovation Team in Bingtuan (No. 2015BD003)
文摘Banana peel-derived porous carbon(BPPC) was prepared from banana peel and used as an adsorbent for methyl orange(MO) wastewater removal. BPPC-MO50 is a N,S-doped BPPC obtained via secondary carbonization. The BPPC-MO50 exhibited a high specific surface area of1774.3 m^2/g. Heteroatom-doped porous carbon(PC) was successfully synthesized from the BPPC absorbed MO at high temperature and used for oxygen reduction. The BPPC-MO50 displayed the highest ORR onset potential among all carbon-based electrocatalysts, i.e., 0.93 V vs.reversible hydrogen electrode(RHE). This is the first report to describe porous carbon-activated materials from agriculture and forestry waste that is used for adsorption of dyes from wastewater via an enhanced heteroatom(N,S) content. These results may contribute to the sustainable development of dye wastewater treatment by transforming saturated PC into an effective material and has potential applications in fuel cells or as energy sources.
基金supported by the Natural Science Foundation of China (U1610106)the Excellent Youth Science and Technology Foundation of Province Shanxi of China (2014021007)+1 种基金the Specialized Research Fund for Sanjin Scholars Pragram of Shanxi Prouince (201707)the North University of China Fund for Distinguished Young Scholars (201701)
文摘The zero valent iron/granular active carbon(ZVI/GAC) micro-electrolysis enhanced by ultrasound(US) coupled with hydrogen peroxide(H_2O_2) was investigated for the deep degradation of nitrobenzene-containing wastewater. The results of scanning electron microscopy-energy dispersive X-rays analysis(SEM-EDS) demonstrated that continuously accelerated regeneration of ZVI and GAC in situ by US could improve the process for converting nitrobenzene(NB) to aniline(AN). H_2O_2 was decomposed catalytically by the byproduct Fe^(2+) ions generated in the micro-electrolysis process to hydroxyl radicals and the organic pollutants in the wastewater were finally mineralized to CO2 and H2O. Effects of the ZVI dosage, the ZVI/GAC mass ratio, the initial pH value and the H_2O_2 dosage on the efficiency for degradation of NB were studied in these experiments. The optimal operating conditions covered a ZVI dosage of 15 g/L, a ZVI/GAC mass ratio of 1:2,an initial pH value of 3 and a H_2O_2 dosage of 4 mL. In this case, the NB removal efficiency reached 97.72% and the total organic carbon(TOC) removal efficiency reached 73.42% at a NB concentration of 300 mg/L. The reduction of NB by USZVI/GAC followed the pseudo-first-order kinetics model, and the pseudo-first-order rate constants were given at different initial pH values. The reaction intermediates such as AN, benzoquinonimine, p-benzoquinone, p-nitrophenol and other organic acids were detected and a probable pathway for NB degradation has been proposed.
