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
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
In order to develop a catalyst with high activity for catalytic wet oxidation (CWO) process at room temperature and atmospheric pressure, Fe2O3-CeO2-TiO2/γ-Al2O3 catalyst was prepared by consecutive impregnation me...In order to develop a catalyst with high activity for catalytic wet oxidation (CWO) process at room temperature and atmospheric pressure, Fe2O3-CeO2-TiO2/γ-Al2O3 catalyst was prepared by consecutive impregnation method and the prepared parameters were optimized. The structure of the catalyst was characterized by BET, XRF, SEM and XPS technologies, and the actual wastewater was used to investigate the catalytic activity of Fe2O3-CeO2-TiO2/γ-Al2O3 in CWO process. The experimental results showed that the prepared catalyst exhibited good catalytic activity when the doping amount of Ti was 1.0 wt% (the weight ratio of Ti to carriers), and the middle product, Fe2O3-CeO2-TiO2/γ-Al2O3, was calcined in 450℃ for 2 h. The CWO experiment for treating actual dye wastewater indicated that the COD, color and TOC of actual wastewater were decreased by 62.23%, 50.12% and 41.26% in 3 h, respectively, and the ratio of BOD5/COD was increased from 0.19 to 0.30.展开更多
Tight ceramic ultrafiltration membranes have been proven to exhibit good rejection performance for reactive dye wastewater at high temperatures because of their high thermal and chemical resistance.However,the applica...Tight ceramic ultrafiltration membranes have been proven to exhibit good rejection performance for reactive dye wastewater at high temperatures because of their high thermal and chemical resistance.However,the application of ceramic membranes for the treatment of cationic dye wastewater is challenging because of their surface charge.In this study,a ceramic membrane is modified by grafting aminosilane(KH-551)to enhance the positive charge of the membrane surface.The rejection performance of the charged modified ceramic membrane toward the methylene blue solution is significantly improved.The modification substance is bonded to the ceramic membrane surface via covalent bonding,which imparts good thermal stability.The modified ceramic membrane exhibits stable separation performance toward the methylene blue solution.Overall,this study provides valuable guidance for the adjustment of the ceramic membrane surface charge for treating industrial cationic dye wastewater.展开更多
Degradation of methylene blue (MB) was performed using the pulsed discharge process (PDP) combined with spent tea leaves (STLs). The effects of STL dosage, concentration of initial solution, and pH were analyzed...Degradation of methylene blue (MB) was performed using the pulsed discharge process (PDP) combined with spent tea leaves (STLs). The effects of STL dosage, concentration of initial solution, and pH were analyzed in the combined treatment. Results showed that the combined treatment was effective for dye wastewater degradation; when the dosage of STLs was 3.2 g/L, the degradation efficiency reached 90% after 15 rain treatment, and STLs showed a good repeatability. The degradation rate decreased with increasing initial MB concentration but not related to the solution pH in the combined treatment. Fourier-transform infrared spectra and N2 adsorption suggested that the number of acidic and basic groups in the STL surface increased after the treatment, but the surface area and pore volume remained unchanged.展开更多
Fe-doped TiO 2 coated on activated carbon (Fe-TiO 2 /AC, FTA) composites were prepared by an improved sol-gel method and characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffrac...Fe-doped TiO 2 coated on activated carbon (Fe-TiO 2 /AC, FTA) composites were prepared by an improved sol-gel method and characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, inductively coupled plasma mass spectrometry and BET surface area analysis. Obtained FTA composites were applied to the continuous treatment of dye wastewater in a dynamic reactor. The effects of Fe ion content, catalyst content, UV-lamp power and flowrate of the continuous treatment of dye wastewater on degradation efficiency were analyzed to determine the optimum operating conditions of dye wastewater degradation. Continuous photocatalytic experiments provided interesting results that FTA had a high chemical oxygen demand (COD) removal rate compared with TiO 2 , Fe doped TiO 2 (FT) and TiO 2 coated on activated carbon (TA). In particular, when using the FTA catalyst with a Fe ion content of 0.33%, the kinetic content (k = 0.0376) of COD removal was more than the sum of both TA (0.0205) and 0.33% FT (0.0166). FTA showed a high photoactivity because of a synergistic effect between Fe ions and AC on TiO 2 , which is higher than the individual effects of AC or Fe ions on TiO 2 . Additionally, for the photocatalytic degradation of dye wastewater, the optimum Fe ion content, catalyst content, UV-lamp power and flowrate were 0.33%, 6 g/L, 60 W (two lamps) and 300 mL/hr, respectively. An investigation of catalyst reuse revealed that the 0.33% FTA showed almost no deactivation in photocatalytic degradation of naturally treated wastewater.展开更多
Zero valent iron (ZVI) is expected to help create an enhanced anaerobic environment that might improve the performance of anaerobic treatment. Based on this idea, a novel ZVI packed upflow anaerobic sludge blanket ...Zero valent iron (ZVI) is expected to help create an enhanced anaerobic environment that might improve the performance of anaerobic treatment. Based on this idea, a novel ZVI packed upflow anaerobic sludge blanket (ZVI-UASB) reactor was developed to treat azo dye wastewater with variable influent quality. The results showed that the reactor was less influenced by increases of Reactive Brilliant Red X-3B concentration from 50 to 1000 mg/L and chemical oxygen demand (COD) from 1000 to 7000 mg/L in the feed than a reference UASB reactor without the ZVI. The ZVI decreased oxidation-reduction potential in the reactor by about 80 mV. Iron ion dissolution from the ZVI could buffer acidity in the reactor, the amount of which was related to the COD concentration. Fluorescence in situ hybridization test showed the abundance of methanogens in the sludge of the ZVI-UASB reactor was significantly greater than that of the reference one. Denaturing gradient gel electrophoresis showed that the ZVI increased the diversity of microbial strains responsible for high efficiency.展开更多
In order to improve the efficient decolorization of dye-containing water by biosorbent and understand the biosorption mechanism, the self-immobilization mycelial pellets were prepared using a marine-derived fungus Asp...In order to improve the efficient decolorization of dye-containing water by biosorbent and understand the biosorption mechanism, the self-immobilization mycelial pellets were prepared using a marine-derived fungus Aspergillus niger ZJUBE-1, and an azo dye, Congo red was chosen as a model dye to investigate batch decolorization efficiency by pellets. The pellets as biosorbent showed strong salt and acid tolerance in biosorption process. The results for dye adsorption showed that the biosorption process fitted well with models of pseudo-second-order kinetic and Langmuir isotherm, with a maximum adsorption capacity of 263.2 mg·g^(-1) mycelium. During 6 batches of continuous decolorization operation, the mycelial pellets could possess efficient decolorization abilities(>98.5%).The appearance of new peak in the UV–Vis spectral result indicated that the decolorization process may also contain biodegradation. The mechanism studies showed that efficient biosorption ability of pellets only relies on the active zone on the surface of the pellet, which can be enhanced by nutrition supplement or be shifted outward by a reculture process.展开更多
Hazardous dye substances discharged from the textile and dyestuff industries not only threaten local the surrounding ecosystems but are also hard to degraded.We report the preparation of process for a photocatalytic m...Hazardous dye substances discharged from the textile and dyestuff industries not only threaten local the surrounding ecosystems but are also hard to degraded.We report the preparation of process for a photocatalytic membrane device that can degrade dye pollution under visible light.This filtration membrane,with a well-organized multilayer structure,simultaneously achieves continuous and flow-through separation of degradation products.Cellulose nanofibers(CNFs)were used as a template for nanosheet C_(3)N_(4)(NS C_(3)N_(4))preparation;the performance for the photocatalytic degradation of dyes improved as the morphology changed from bulking to nanosheet.NS C3N4 was then attached to the surface of a prepared CNF membrane via vacuum filtration.This device exhibited high efficiency(the degradation rates of both Rhodamine B and Methylene blue both reached 96%),high flux(above 160 L·h^(-1)·m^(-2)·bar^(-1))and excellent stability(maintaining steady flux and high separation were maintained after 4 h).This easy-preparation,easy-scale-up,and low-cost process provides a new method of fabricating photocatalytic membrane devices for dye wastewater treatment.展开更多
The textile industry spreads globally with the challenges of its wastewater treatment,especially dyes,which are difficult to degrade.To improve coagulation-flocculation process in dye wastewater treatment,an intercala...The textile industry spreads globally with the challenges of its wastewater treatment,especially dyes,which are difficult to degrade.To improve coagulation-flocculation process in dye wastewater treatment,an intercalation process was employed to prepare a new efficient coagulant of lithium borohydride-iron oxychloride(LiBH_(4)_FeOCl) in this study.The layered crystal pristine iron oxychloride(FeOCl) material was prepared by chemical gas phase migration.LiBH4 was introduced into the layers of two dimensional(2 D) FeOCl nanosheets by a simple method of liquid phase insertion.The samples were characterized by a field emitting scanning electron microscopy(SEM),a rotating anode X-ray powder diffractometer(XRD),etc.The cationic dye was employed as the simulated pollutant.A coagulation and decolorization experimental device was built to study the coagulation performance of the new coagulant LiBH_(4)_FeOCl.It is found that the intercalation modified LiBH_(4)_FeOCl exhibits the characteristics of crystal structure,and the layered structure of FeOCl is preserved.LiBH_(4)_FeOCl,as an insoluble inorganic solid coagulant,performs well for dye pollutants of methyl red,basic yellow 1,methylene blue,rhodamine B,ethyl violet and Janus green B.The reaction rate is significantly 68% higher than the current commercial coagulants of Al_(2)(SO_(4))_(3).The mechanism analysis reveals that LiBH_(4)_FeOCl breaks and disperses rapidly in the water environment.Its negatively charged material particles can be electrostatically adsorbed with dye pollutant molecules through electrostatic action.The above collaborative actions of breaking,dispersion and electrostatic adsorption are the main coagulation mechanisms of LiBH_(4)_FeOCl.The solid inorganic coagulant of LiBH4FeOCl provides a competitive alternative for traditional inorganic salts and organic coagulants.展开更多
The dye industry produces a large amount of hazardous wastewater every day worldwide,which brings potential threaten to the global environment.As an excellent method for removal of water chroma and chemical oxygen dem...The dye industry produces a large amount of hazardous wastewater every day worldwide,which brings potential threaten to the global environment.As an excellent method for removal of water chroma and chemical oxygen demand,electrocatalytic methods are currently widely used in the treatment of dye wastewater.The selection and preparation of electrode materials and electrocatalysts play an important role on the electrocatalytic treatment.The aim of this paper is to introduce the most excellent high-efficiency electrode materials and electrocatalysts in the field of dye wastewater treatment.Many electrode materials such as metal electrode materials,boron-doped diamond anode materials and three-dimensional electrode are introduced in detail.Besides,the mechanism of electrocatalytic oxidation is summarized.The composite treatment of active electrode and electrocatalyst are extensively examined.Finally,the progress of photo-assisted electrocatalytic methods of dye wastewater and the catalysts are described.展开更多
Well-channeled porous polyethersulfone(PES) beads were synthesized and used for the immobilization of Comamonas testosteroni QYY cells for an aerobic reactor to remove quinoline, phenol, and other refractory com- po...Well-channeled porous polyethersulfone(PES) beads were synthesized and used for the immobilization of Comamonas testosteroni QYY cells for an aerobic reactor to remove quinoline, phenol, and other refractory com- pounds in accidentally-released dye wastewater supplemented with domestic wastewater. The pore size in PES beads mainly depended on the dripping time through the Water vapor cylinder. When the cylinder was 2.5 m in length, the pore size in the obtained beads was enlarged to 3 ~m, which provided an ideal surface for cells to pass through and grow inside. The reactor with the immobilized C. testosteroni QYY on PES beads resisted organic loading shock and enhanced total organic carbon(TOC) removal, which had 100% removal efficiencies of both quinoline and phenol when the volume ratio of the accidental wastewater to domestic wastewater was increased from 1:2 to 1:1, as compared with the 100% and 34.7% removal efficiencies by the reactor with immobilized C. testosteroni QYY on polyttrethane(PU) cube or the 82% and 2.4% removal efficiencies by the reactor with only the suspended C. testosteroni QYY cells, respectively. The PES beads had a specific surface area of 1843 cm2/cm3, which had immobilized (0.0244-0.003) g of C, testosteroni QYY cell dry mass/cm3, compared with the specific surface area of 564 cm2/cm3 of the PU cube with (0.0184-0.002) g of cell dry mass/cm3. The kinetic study revealed that the quinoline and phenol degradation followed zero-order reactions for all the three reactors. The PES reactor demonstrated the highest quinoline and phenol removal efficiencies. The immobilized C. testosteroni QYY on the low-cost inert PES beads demonstrated good shock resistance and was able to completely remove the toxic compounds, including phenyl carbamate, 2-nitrotoluene, and dioctyl phthalate. Therefore, the beads were ideal for large-scale accidental wastewater treatment.展开更多
A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was exc...A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was excellent, i.e. effluent COD less than 25 mg/L, BOD 5 under 5 mg/L, turbidity lower than 0 65 NTU, and colour less than 30 DT, and met with the reuse water standard of China. The removal rates of COD, BOD 5, colour, and turbidity were 92 4%, 98 4%, 74% and 98 9%, respectively. Constant flux operation mode was carried out in this study, and backwash was effective for reducing membrane fouling and maintaining constant flux. Membrane fouling had heavy impact on energy consumption. More attention should be paid on pipe selection and design for the sidestream MBR system, too.展开更多
As the characteristic pollutant, terephthalic acid(TA)was in charge of 40%—78% of the total COD of terylene artificial silk printing and dyeing wastewater(TPW-water). The studies on biodegradability of TA were conduc...As the characteristic pollutant, terephthalic acid(TA)was in charge of 40%—78% of the total COD of terylene artificial silk printing and dyeing wastewater(TPW-water). The studies on biodegradability of TA were conducted in a serial of activated sludge reactors with TPW-water. TA appeared to be readily biodegradable with removal efficiency over 96.5% under aerobic conditions, hardly biodegradable with removal efficiency below 10% under anoxic conditions and slowly biodegradable with a turnover between 31.4% and 56.0% under anaerobic conditions. TA also accounted for the majority of BOD in TPW-water. The process combined by anoxic, anaerobic and aerobic activated sludge reactor was suitable for TA degradation and TPW-water treatment. Further, the aerobic process was essentially much more effective than the anaerobic or anoxic one to degrade TA in TPW-water.展开更多
[ Object] The study aimed to discuss the decolorization on indigo dyeing wastewater by laccase from Coriolus versicolor. [ Method ] Firstly, the effects of temperature, pH, indigo concentration, HBT concentration, lac...[ Object] The study aimed to discuss the decolorization on indigo dyeing wastewater by laccase from Coriolus versicolor. [ Method ] Firstly, the effects of temperature, pH, indigo concentration, HBT concentration, laccase dosage on the decolorization of indigo dyeing wastewater by laccase/HBT, and then the synergism of laccase and acid cellulase was analyzed. [Result] Using ABTS as the substrate, the kinetic parame- ters, K,, and Vmax, were 0.318 mmol/L and 0.035 5 mmol/( L . min) respectively. The decolorization rate of indigo reached 96.5% when the lacca- se acted on indigo for 40 min with HBT as an introducer at temperature 50 ℃, pH =4.5, indigo concentration 100 mg/L, HBT concentration 0.1% and laccase dosage 100 lU/L. Due to the synergism of laccase and acid cellulase during the bio-finishing of blue jeans, the backstaining degree of blue jeans reduced by 85% when the amount of laccase added was 15 000 IU/kg. Menawhile, the synergism of the laccase and acid cellulase de- creased indigo concentration in wastewater by 83.8%. [ Conclusion ] The laccase from Coriolus versicolor had a good prospect in the bio-finishing of blue jeans and the decolorization of indigo dyeing wastewater.展开更多
Terylene artificial silk printing and dyeing wastewater(TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular slu...Terylene artificial silk printing and dyeing wastewater(TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular sludge bed(EGSB) process. The stability of the EGSB process was firstly conducted by laboratory experiment. TA ionization was the predominated factor influencing the acid-base balance of the system. High concentration of TA in wastewater resulted in sufficient buffering capacity to neutralize the volatile fatty acids(VFA) generated from substrate degradation and provided strong base for anaerobic system to resist the pH decrease below 6.5. VFA and UFA caused almost no inhibition on the anaerobic process and biogas production except that pH was below 6.35 and VFA was at its maximum value. Along with the granulating of the activated sludge, the efficiency of organic removal and production rate of biogas increased gradually and became more stable. After start-up, the efficiency of COD removal increased to 57%—64%, pH stabilized in a range of 7.99—8.04, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted in neglectable rebound of pH, and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment.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
Chitosan-TiO2 composite has been prepared by the sol-gel process. Tetrabutyl titanate( TTB) was used as a precursor to obtain nano TiO2 sol,which was then added into acid solution of chitosan to form titania network i...Chitosan-TiO2 composite has been prepared by the sol-gel process. Tetrabutyl titanate( TTB) was used as a precursor to obtain nano TiO2 sol,which was then added into acid solution of chitosan to form titania network in the matrix. SEM,TG,and Fourier transform infrared spectroscopy( FTIR) were employed to characterize morphology and structure of the Chitosan-TiO2 composite. The resulting hybrid has potential applications for the adsorption and sonolytic-degradation of organic dyes in wastewater.The result shows that the de-coloring ratio reaches 97. 2% at the optimum conditions with the help of ultrasound.展开更多
An anaerobic/oxic membrane bioreactor (A/O MBR) was used for treatment of dyeing wastewater from a woolen mill. COD and color of the wastewater were 54—473 mg/L and 40—400 dilution time (DT) respectively. The ratio ...An anaerobic/oxic membrane bioreactor (A/O MBR) was used for treatment of dyeing wastewater from a woolen mill. COD and color of the wastewater were 54—473 mg/L and 40—400 dilution time (DT) respectively. The ratio of BOD 5/COD was less than 0.13. By the A/O MBR process, the average removal of COD, BOD 5, color and turbidity was 82%, 96%, 71% and 99%, respectively. The average COD, BOD 5, color and turbidity of effluent was 37 mg/L, 0.8 mg/L, 40 DT and 0.44 NUT respectively. The effluent COD met the local standard of reuse water in Beijing, China. The average COD volume load of the anaerobic biological tank was 0.0483 kgCOD/(m 3·d) and that of the aeration tank of the MBR was 0.3589 kgCOD/(m 3·d). The sludge load of the MBR was 0.19 kgCOD/(kg·MLSS·d) on average and the maximum of that was 0.4 kgCOD/(kg·MLSS·d). The flux of the A/O membrane bioreactor could be remained at larger than 50 L/(h·m 2·0.1MPa). The results indicated that A/O membrane bioreactor has technical feasibility for treatment of woolen mill wastewater.展开更多
The oxidation ditch process is economic and efficient for wastewater treatment, but its application is limited in case where land is costly due to its large land area required. An innovative integrated oxidation ditch...The oxidation ditch process is economic and efficient for wastewater treatment, but its application is limited in case where land is costly due to its large land area required. An innovative integrated oxidation ditch with vertical circle(IODVC) system was developed to treat domestic and industrial wastewater aiming to save land area. The new system consists of a single channel divided into two ditches(the top one and the bottom one by a plate), a brush, and an innovative integral clarifier. Different from the horizontal circle of the conventional oxidation ditch, the flow of IODVC system recycles from the top zone to the bottom zone in the vertical circle as the brush is running, and then the IODVC saved land area required by about 50% compared with a conventional oxidation ditch with an intrachannel clarifier. The innovative integral clarifier is effective for separation of liquid and solids, and is preferably positioned at the opposite end of the brush in the ditch. It does not affect the hydrodynamic characteristics of the mixed liquor in the ditch, and the sludge can automatically return to the down ditch without any pump. In this study, experiments of domestic and dye wastewater treatment were carried out in bench scale and in full scale, respectively. Results clearly showed that the IODVC efficiently removed pollutants in the wastewaters, i.e., the average of COD removals for domestic and dye wastewater treatment were 95% and 90%, respectively, and that the IODVC process may provide a cost effective way for full scale dye wastewater treatment.展开更多
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 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The National Basic Research Program (973) of China (No. 2004CB418505) the Foundation for Excellent Youth of HeilongjiangProvince
文摘In order to develop a catalyst with high activity for catalytic wet oxidation (CWO) process at room temperature and atmospheric pressure, Fe2O3-CeO2-TiO2/γ-Al2O3 catalyst was prepared by consecutive impregnation method and the prepared parameters were optimized. The structure of the catalyst was characterized by BET, XRF, SEM and XPS technologies, and the actual wastewater was used to investigate the catalytic activity of Fe2O3-CeO2-TiO2/γ-Al2O3 in CWO process. The experimental results showed that the prepared catalyst exhibited good catalytic activity when the doping amount of Ti was 1.0 wt% (the weight ratio of Ti to carriers), and the middle product, Fe2O3-CeO2-TiO2/γ-Al2O3, was calcined in 450℃ for 2 h. The CWO experiment for treating actual dye wastewater indicated that the COD, color and TOC of actual wastewater were decreased by 62.23%, 50.12% and 41.26% in 3 h, respectively, and the ratio of BOD5/COD was increased from 0.19 to 0.30.
基金supported by the Project for Natural Science Research of Jiangsu Higher Education Institutions(20KJA530001)the National Natural Science Foundation of China(22078147,21808107)the Natural Science Foundation of Jiangsu Province(BK20180163)and the Research Project of National Synthetic Biotechnology Innovation Centre(TSBICIP-KJGG-002-16).
文摘Tight ceramic ultrafiltration membranes have been proven to exhibit good rejection performance for reactive dye wastewater at high temperatures because of their high thermal and chemical resistance.However,the application of ceramic membranes for the treatment of cationic dye wastewater is challenging because of their surface charge.In this study,a ceramic membrane is modified by grafting aminosilane(KH-551)to enhance the positive charge of the membrane surface.The rejection performance of the charged modified ceramic membrane toward the methylene blue solution is significantly improved.The modification substance is bonded to the ceramic membrane surface via covalent bonding,which imparts good thermal stability.The modified ceramic membrane exhibits stable separation performance toward the methylene blue solution.Overall,this study provides valuable guidance for the adjustment of the ceramic membrane surface charge for treating industrial cationic dye wastewater.
基金supported by the Science and Technology Department of Sichuan Province,China(No.2010JY0040)
文摘Degradation of methylene blue (MB) was performed using the pulsed discharge process (PDP) combined with spent tea leaves (STLs). The effects of STL dosage, concentration of initial solution, and pH were analyzed in the combined treatment. Results showed that the combined treatment was effective for dye wastewater degradation; when the dosage of STLs was 3.2 g/L, the degradation efficiency reached 90% after 15 rain treatment, and STLs showed a good repeatability. The degradation rate decreased with increasing initial MB concentration but not related to the solution pH in the combined treatment. Fourier-transform infrared spectra and N2 adsorption suggested that the number of acidic and basic groups in the STL surface increased after the treatment, but the surface area and pore volume remained unchanged.
基金supported by the National Natural Science Foundation of China (No. 50802034)the Educationaland Technological Department of Hunan Province (No.08B063)the Natural Science Foundation of Hunan Province (No. 09JJ6101)
文摘Fe-doped TiO 2 coated on activated carbon (Fe-TiO 2 /AC, FTA) composites were prepared by an improved sol-gel method and characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, inductively coupled plasma mass spectrometry and BET surface area analysis. Obtained FTA composites were applied to the continuous treatment of dye wastewater in a dynamic reactor. The effects of Fe ion content, catalyst content, UV-lamp power and flowrate of the continuous treatment of dye wastewater on degradation efficiency were analyzed to determine the optimum operating conditions of dye wastewater degradation. Continuous photocatalytic experiments provided interesting results that FTA had a high chemical oxygen demand (COD) removal rate compared with TiO 2 , Fe doped TiO 2 (FT) and TiO 2 coated on activated carbon (TA). In particular, when using the FTA catalyst with a Fe ion content of 0.33%, the kinetic content (k = 0.0376) of COD removal was more than the sum of both TA (0.0205) and 0.33% FT (0.0166). FTA showed a high photoactivity because of a synergistic effect between Fe ions and AC on TiO 2 , which is higher than the individual effects of AC or Fe ions on TiO 2 . Additionally, for the photocatalytic degradation of dye wastewater, the optimum Fe ion content, catalyst content, UV-lamp power and flowrate were 0.33%, 6 g/L, 60 W (two lamps) and 300 mL/hr, respectively. An investigation of catalyst reuse revealed that the 0.33% FTA showed almost no deactivation in photocatalytic degradation of naturally treated wastewater.
基金supported by the National Basic Research Program of China (No. 2007CB407302)the Natural Science Foundation of China (No. 21177015)+2 种基金the New Century Excellent Talent Program of the Ministry of Education of China (No. NCET-10-028)the Fundamental Research Funds for the Central Universities of China (No.DUT11ZD108)the Program for Changjiang Scholars and Innovative Research Team at the University of China(No. IRT0813)
文摘Zero valent iron (ZVI) is expected to help create an enhanced anaerobic environment that might improve the performance of anaerobic treatment. Based on this idea, a novel ZVI packed upflow anaerobic sludge blanket (ZVI-UASB) reactor was developed to treat azo dye wastewater with variable influent quality. The results showed that the reactor was less influenced by increases of Reactive Brilliant Red X-3B concentration from 50 to 1000 mg/L and chemical oxygen demand (COD) from 1000 to 7000 mg/L in the feed than a reference UASB reactor without the ZVI. The ZVI decreased oxidation-reduction potential in the reactor by about 80 mV. Iron ion dissolution from the ZVI could buffer acidity in the reactor, the amount of which was related to the COD concentration. Fluorescence in situ hybridization test showed the abundance of methanogens in the sludge of the ZVI-UASB reactor was significantly greater than that of the reference one. Denaturing gradient gel electrophoresis showed that the ZVI increased the diversity of microbial strains responsible for high efficiency.
基金Supported by the National Natural Science Foundation of China(No.21376214)
文摘In order to improve the efficient decolorization of dye-containing water by biosorbent and understand the biosorption mechanism, the self-immobilization mycelial pellets were prepared using a marine-derived fungus Aspergillus niger ZJUBE-1, and an azo dye, Congo red was chosen as a model dye to investigate batch decolorization efficiency by pellets. The pellets as biosorbent showed strong salt and acid tolerance in biosorption process. The results for dye adsorption showed that the biosorption process fitted well with models of pseudo-second-order kinetic and Langmuir isotherm, with a maximum adsorption capacity of 263.2 mg·g^(-1) mycelium. During 6 batches of continuous decolorization operation, the mycelial pellets could possess efficient decolorization abilities(>98.5%).The appearance of new peak in the UV–Vis spectral result indicated that the decolorization process may also contain biodegradation. The mechanism studies showed that efficient biosorption ability of pellets only relies on the active zone on the surface of the pellet, which can be enhanced by nutrition supplement or be shifted outward by a reculture process.
基金supported by the National Key R&D Program of China(No.2018YFC1902101)the National Natural Science Foundation of China(Nos.21908127,21838006,and 21776159)the project supported by the Foundation(No.KF201810)of Key Laboratory of Pulp and Paper Science and Technology of Ministry of Education/Shandong Province of China and Opening Project of the Key Laboratory of Bionic Engineering(Ministry of Education),Jilin University.
文摘Hazardous dye substances discharged from the textile and dyestuff industries not only threaten local the surrounding ecosystems but are also hard to degraded.We report the preparation of process for a photocatalytic membrane device that can degrade dye pollution under visible light.This filtration membrane,with a well-organized multilayer structure,simultaneously achieves continuous and flow-through separation of degradation products.Cellulose nanofibers(CNFs)were used as a template for nanosheet C_(3)N_(4)(NS C_(3)N_(4))preparation;the performance for the photocatalytic degradation of dyes improved as the morphology changed from bulking to nanosheet.NS C3N4 was then attached to the surface of a prepared CNF membrane via vacuum filtration.This device exhibited high efficiency(the degradation rates of both Rhodamine B and Methylene blue both reached 96%),high flux(above 160 L·h^(-1)·m^(-2)·bar^(-1))and excellent stability(maintaining steady flux and high separation were maintained after 4 h).This easy-preparation,easy-scale-up,and low-cost process provides a new method of fabricating photocatalytic membrane devices for dye wastewater treatment.
基金financial supports by the National Key Basic Research Program of China (No.2019YFC1906700)National Natural Science Foundation of China (Nos.21876049,51878643)University of Shanghai for Science and Technology (Grant Agreement No.ZR18PY01)。
文摘The textile industry spreads globally with the challenges of its wastewater treatment,especially dyes,which are difficult to degrade.To improve coagulation-flocculation process in dye wastewater treatment,an intercalation process was employed to prepare a new efficient coagulant of lithium borohydride-iron oxychloride(LiBH_(4)_FeOCl) in this study.The layered crystal pristine iron oxychloride(FeOCl) material was prepared by chemical gas phase migration.LiBH4 was introduced into the layers of two dimensional(2 D) FeOCl nanosheets by a simple method of liquid phase insertion.The samples were characterized by a field emitting scanning electron microscopy(SEM),a rotating anode X-ray powder diffractometer(XRD),etc.The cationic dye was employed as the simulated pollutant.A coagulation and decolorization experimental device was built to study the coagulation performance of the new coagulant LiBH_(4)_FeOCl.It is found that the intercalation modified LiBH_(4)_FeOCl exhibits the characteristics of crystal structure,and the layered structure of FeOCl is preserved.LiBH_(4)_FeOCl,as an insoluble inorganic solid coagulant,performs well for dye pollutants of methyl red,basic yellow 1,methylene blue,rhodamine B,ethyl violet and Janus green B.The reaction rate is significantly 68% higher than the current commercial coagulants of Al_(2)(SO_(4))_(3).The mechanism analysis reveals that LiBH_(4)_FeOCl breaks and disperses rapidly in the water environment.Its negatively charged material particles can be electrostatically adsorbed with dye pollutant molecules through electrostatic action.The above collaborative actions of breaking,dispersion and electrostatic adsorption are the main coagulation mechanisms of LiBH_(4)_FeOCl.The solid inorganic coagulant of LiBH4FeOCl provides a competitive alternative for traditional inorganic salts and organic coagulants.
基金supported by Nankai University&Cangzhou Bohai New Area Institute of Green Chemical Engineering Fund(Grant No.NCC2020FH11).
文摘The dye industry produces a large amount of hazardous wastewater every day worldwide,which brings potential threaten to the global environment.As an excellent method for removal of water chroma and chemical oxygen demand,electrocatalytic methods are currently widely used in the treatment of dye wastewater.The selection and preparation of electrode materials and electrocatalysts play an important role on the electrocatalytic treatment.The aim of this paper is to introduce the most excellent high-efficiency electrode materials and electrocatalysts in the field of dye wastewater treatment.Many electrode materials such as metal electrode materials,boron-doped diamond anode materials and three-dimensional electrode are introduced in detail.Besides,the mechanism of electrocatalytic oxidation is summarized.The composite treatment of active electrode and electrocatalyst are extensively examined.Finally,the progress of photo-assisted electrocatalytic methods of dye wastewater and the catalysts are described.
基金Supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China(No. 2014ZX07201-011-004), the National Natural Science Foundation of China(Nos.51578118, 51378098, 51238001, 51408110, 51508078, 51478095, 51478096), the Natural Science Foundation of Jilin Province, China(Nos.20150101072JC, 20140520151JH, 20160520023JH), the Jilm Province Education Department Science and Technology Research Project, China(No.2014B043) and the Program for New Century Excellent Talents in University of the Ministry of Education of China(No.NCET-13-0723).
文摘Well-channeled porous polyethersulfone(PES) beads were synthesized and used for the immobilization of Comamonas testosteroni QYY cells for an aerobic reactor to remove quinoline, phenol, and other refractory com- pounds in accidentally-released dye wastewater supplemented with domestic wastewater. The pore size in PES beads mainly depended on the dripping time through the Water vapor cylinder. When the cylinder was 2.5 m in length, the pore size in the obtained beads was enlarged to 3 ~m, which provided an ideal surface for cells to pass through and grow inside. The reactor with the immobilized C. testosteroni QYY on PES beads resisted organic loading shock and enhanced total organic carbon(TOC) removal, which had 100% removal efficiencies of both quinoline and phenol when the volume ratio of the accidental wastewater to domestic wastewater was increased from 1:2 to 1:1, as compared with the 100% and 34.7% removal efficiencies by the reactor with immobilized C. testosteroni QYY on polyttrethane(PU) cube or the 82% and 2.4% removal efficiencies by the reactor with only the suspended C. testosteroni QYY cells, respectively. The PES beads had a specific surface area of 1843 cm2/cm3, which had immobilized (0.0244-0.003) g of C, testosteroni QYY cell dry mass/cm3, compared with the specific surface area of 564 cm2/cm3 of the PU cube with (0.0184-0.002) g of cell dry mass/cm3. The kinetic study revealed that the quinoline and phenol degradation followed zero-order reactions for all the three reactors. The PES reactor demonstrated the highest quinoline and phenol removal efficiencies. The immobilized C. testosteroni QYY on the low-cost inert PES beads demonstrated good shock resistance and was able to completely remove the toxic compounds, including phenyl carbamate, 2-nitrotoluene, and dioctyl phthalate. Therefore, the beads were ideal for large-scale accidental wastewater treatment.
文摘A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was excellent, i.e. effluent COD less than 25 mg/L, BOD 5 under 5 mg/L, turbidity lower than 0 65 NTU, and colour less than 30 DT, and met with the reuse water standard of China. The removal rates of COD, BOD 5, colour, and turbidity were 92 4%, 98 4%, 74% and 98 9%, respectively. Constant flux operation mode was carried out in this study, and backwash was effective for reducing membrane fouling and maintaining constant flux. Membrane fouling had heavy impact on energy consumption. More attention should be paid on pipe selection and design for the sidestream MBR system, too.
文摘As the characteristic pollutant, terephthalic acid(TA)was in charge of 40%—78% of the total COD of terylene artificial silk printing and dyeing wastewater(TPW-water). The studies on biodegradability of TA were conducted in a serial of activated sludge reactors with TPW-water. TA appeared to be readily biodegradable with removal efficiency over 96.5% under aerobic conditions, hardly biodegradable with removal efficiency below 10% under anoxic conditions and slowly biodegradable with a turnover between 31.4% and 56.0% under anaerobic conditions. TA also accounted for the majority of BOD in TPW-water. The process combined by anoxic, anaerobic and aerobic activated sludge reactor was suitable for TA degradation and TPW-water treatment. Further, the aerobic process was essentially much more effective than the anaerobic or anoxic one to degrade TA in TPW-water.
基金Supported by the Foundation for Young Scholars of Educational Commission of Jiangxi Province,China (Foundation)National Natural Science Foundation of China (51064011)
文摘[ Object] The study aimed to discuss the decolorization on indigo dyeing wastewater by laccase from Coriolus versicolor. [ Method ] Firstly, the effects of temperature, pH, indigo concentration, HBT concentration, laccase dosage on the decolorization of indigo dyeing wastewater by laccase/HBT, and then the synergism of laccase and acid cellulase was analyzed. [Result] Using ABTS as the substrate, the kinetic parame- ters, K,, and Vmax, were 0.318 mmol/L and 0.035 5 mmol/( L . min) respectively. The decolorization rate of indigo reached 96.5% when the lacca- se acted on indigo for 40 min with HBT as an introducer at temperature 50 ℃, pH =4.5, indigo concentration 100 mg/L, HBT concentration 0.1% and laccase dosage 100 lU/L. Due to the synergism of laccase and acid cellulase during the bio-finishing of blue jeans, the backstaining degree of blue jeans reduced by 85% when the amount of laccase added was 15 000 IU/kg. Menawhile, the synergism of the laccase and acid cellulase de- creased indigo concentration in wastewater by 83.8%. [ Conclusion ] The laccase from Coriolus versicolor had a good prospect in the bio-finishing of blue jeans and the decolorization of indigo dyeing wastewater.
文摘Terylene artificial silk printing and dyeing wastewater(TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular sludge bed(EGSB) process. The stability of the EGSB process was firstly conducted by laboratory experiment. TA ionization was the predominated factor influencing the acid-base balance of the system. High concentration of TA in wastewater resulted in sufficient buffering capacity to neutralize the volatile fatty acids(VFA) generated from substrate degradation and provided strong base for anaerobic system to resist the pH decrease below 6.5. VFA and UFA caused almost no inhibition on the anaerobic process and biogas production except that pH was below 6.35 and VFA was at its maximum value. Along with the granulating of the activated sludge, the efficiency of organic removal and production rate of biogas increased gradually and became more stable. After start-up, the efficiency of COD removal increased to 57%—64%, pH stabilized in a range of 7.99—8.04, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted in neglectable rebound of pH, and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment.
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National Natural Science Foundations of China(Nos.50973097,21076199)
文摘Chitosan-TiO2 composite has been prepared by the sol-gel process. Tetrabutyl titanate( TTB) was used as a precursor to obtain nano TiO2 sol,which was then added into acid solution of chitosan to form titania network in the matrix. SEM,TG,and Fourier transform infrared spectroscopy( FTIR) were employed to characterize morphology and structure of the Chitosan-TiO2 composite. The resulting hybrid has potential applications for the adsorption and sonolytic-degradation of organic dyes in wastewater.The result shows that the de-coloring ratio reaches 97. 2% at the optimum conditions with the help of ultrasound.
文摘An anaerobic/oxic membrane bioreactor (A/O MBR) was used for treatment of dyeing wastewater from a woolen mill. COD and color of the wastewater were 54—473 mg/L and 40—400 dilution time (DT) respectively. The ratio of BOD 5/COD was less than 0.13. By the A/O MBR process, the average removal of COD, BOD 5, color and turbidity was 82%, 96%, 71% and 99%, respectively. The average COD, BOD 5, color and turbidity of effluent was 37 mg/L, 0.8 mg/L, 40 DT and 0.44 NUT respectively. The effluent COD met the local standard of reuse water in Beijing, China. The average COD volume load of the anaerobic biological tank was 0.0483 kgCOD/(m 3·d) and that of the aeration tank of the MBR was 0.3589 kgCOD/(m 3·d). The sludge load of the MBR was 0.19 kgCOD/(kg·MLSS·d) on average and the maximum of that was 0.4 kgCOD/(kg·MLSS·d). The flux of the A/O membrane bioreactor could be remained at larger than 50 L/(h·m 2·0.1MPa). The results indicated that A/O membrane bioreactor has technical feasibility for treatment of woolen mill wastewater.
文摘The oxidation ditch process is economic and efficient for wastewater treatment, but its application is limited in case where land is costly due to its large land area required. An innovative integrated oxidation ditch with vertical circle(IODVC) system was developed to treat domestic and industrial wastewater aiming to save land area. The new system consists of a single channel divided into two ditches(the top one and the bottom one by a plate), a brush, and an innovative integral clarifier. Different from the horizontal circle of the conventional oxidation ditch, the flow of IODVC system recycles from the top zone to the bottom zone in the vertical circle as the brush is running, and then the IODVC saved land area required by about 50% compared with a conventional oxidation ditch with an intrachannel clarifier. The innovative integral clarifier is effective for separation of liquid and solids, and is preferably positioned at the opposite end of the brush in the ditch. It does not affect the hydrodynamic characteristics of the mixed liquor in the ditch, and the sludge can automatically return to the down ditch without any pump. In this study, experiments of domestic and dye wastewater treatment were carried out in bench scale and in full scale, respectively. Results clearly showed that the IODVC efficiently removed pollutants in the wastewaters, i.e., the average of COD removals for domestic and dye wastewater treatment were 95% and 90%, respectively, and that the IODVC process may provide a cost effective way for full scale dye wastewater treatment.