The pulsed high-voltage discharge is a new advanced oxidation technology for water treatment. Methyl Orange （MO） dye wastewater was chosen as the target object. Some investigations were conducted on MO decoloration ...The pulsed high-voltage discharge is a new advanced oxidation technology for water treatment. Methyl Orange （MO） dye wastewater was chosen as the target object. Some investigations were conducted on MO decoloration including the discharge characteristics of the multi-needle reactor, parameter optimization, and the degradation mechanism. The following results were obtained. The color group of the azo dye MO was effectively decomposed by water surface plasma. The decoloration rate was promoted with the increase of treatment time, peak voltage, and pulse frequency. When the initial conductivity was 1700 μS/cm, the decoloration rate was the highest. The optimum distance between the needle electrodes and the water surface was 1 mm, the distance between the grounding electrode and the water surface was 28 mm, and the number of needle electrodes and spacing between needles were 24 and 7.5 mm, respectively. The decoloration rate of MO was affected by the gas in the reactor and varied in the order oxygen 〉 air〉 argon 〉 nitrogen, and the energy yield obtained in this investigation was 0.45 g/kWh.展开更多
In the paper, a hybrid gas–liquid dielectric barrier discharge(DBD) plasma system was set up to treat a methylene blue(MB) solution. The effects of the change of the carrier gas, the gas bubbling rate and different k...In the paper, a hybrid gas–liquid dielectric barrier discharge(DBD) plasma system was set up to treat a methylene blue(MB) solution. The effects of the change of the carrier gas, the gas bubbling rate and different kinds of scavenger addition, including sodium carbonate(Na_2CO_3),para benzoquinone(p-BQ), triethylenediamine and sodium dihydrogen phosphate(NaH_2PO_4),on the MB decoloration were reviewed to clarify the critical active species for the dye decoloration in the DBD plasma system. The obtained results show that higher decoloration of the MB solution could be achieved when O2 was used as the carrier gas, which could be 100% after 20 min discharge treatment, and the result confirmed the crucial effect of O_3 in the MB decoloration. Based on the experiments of the scavenger addition, it could be concluded that O_2·^- and ~1O_2 were two other important reactive oxygen species(ROS) for the MB decoloration.The results of the higher chemical oxygen demand removal and faster disappearance of the characteristic peak of the MB from the UV–vis analysis under O_2 bubbling conditions also proved the critical effect of the ROS formed by O_2 on the MB decoloration.展开更多
In this paper we report the results of our experimental work conducted to decoloration of a well-known highly toxic Amaranth dye by electrochemical and photoelectrochemical methods. Throughout this investigation were ...In this paper we report the results of our experimental work conducted to decoloration of a well-known highly toxic Amaranth dye by electrochemical and photoelectrochemical methods. Throughout this investigation were used two different Dimensional Stable Anode (DSA) electrodes, namely, IrO2-Ru2O-SnO2-TiO2/Ti and Ru2O-SnO2-TiO2/Ti. The experimental results show that IrO2-Ru2O-SnO2-TiO2/Ti electrode has higher performance on amaranth decoloration than Ru2O-SnO2-TiO2/Ti electrode, but with the disadvantage of higher energy consumption. For higher degradation of Amaranth dye with both DSA electrodes, the process was carried out via photoelectrochemical method. Our experimental results clearly shown the decrease in absorbance of all UV-Vis peaks due to the mineralization of the azo dye;also, it was noteworthy photoelectrochemical process consumes less energy under the same experimental conditions than electrochemical process. The IrO2-Ru2O-SnO2-TiO2/Ti electrode reaches a higher degradation degree of Amaranth solutions than Ru2O-SnO2-TiO2/Ti electrode using a photoelectrochemical technique.展开更多
To optimize alkaline method for extracting proteins from tea residue(TR), the effect of extraction conditions on tea protein extraction rate(TPER) was investigated. Single factor experiment showed the extraction tempe...To optimize alkaline method for extracting proteins from tea residue(TR), the effect of extraction conditions on tea protein extraction rate(TPER) was investigated. Single factor experiment showed the extraction temperature 80 °C, extraction time 100 min, p H value 13 and liquid–solid ratio 40:1 as the optimal extraction conditions. The orthogonal test revealed that the maximum TPER reached 29.71% under the following optimal combination of conditions: extraction temperature 70 °C, extraction time 60 min, p H 12 and liquid–solid ratio 50:1. For optimizing the purification of tea residue proteins, isoelectric point precipitation(p I), ammonium sulfate precipitation(a S) and isoelectric point plus ammonium sulfate precipitation(i PAS) were compared. The result showed that the highest protein precipitation rate(PPR) was 89.70% which was generated by using i PAS. Furthermore, powdered activated carbon was chosen as the most suitable decolorant for the extracted proteins.展开更多
This paper describes the effects of temperature on the complex intermediate processes from the precursor to the fully-crystallized anatase TiO2 nanoparticles in hydrothermal synthesis. The anatase TiO2 nanoparticles w...This paper describes the effects of temperature on the complex intermediate processes from the precursor to the fully-crystallized anatase TiO2 nanoparticles in hydrothermal synthesis. The anatase TiO2 nanoparticles were synthesized in a wide temperature range below 230°C. The composition, morphology, and methylene blue (MB) decoloration characteristics of the obtained products were investigated by X-ray diffraction, Fourier transform infrared spectroscope, X-ray photoelectron spectroscope, and scanning and transmission electron microscope. The dehydrating polycondensation of Ti(IV)-hydrates and the decomposition of (NH4)2Ti3O7 intermediates with the temperature increase lead to the direct formation of anatase TiO2 nanoparticles under the hydrothermal environments. The strong MB decoloration of the hydrothermal products obtained at the low (≤130°C) and high (≥180°C) temperatures are attributed to the adsorption of Ti(IV)-hydrates and the photocatalysis of anatase TiO2 nanoparticles, respectively.展开更多
Porous silver-modified ZnO microrods photocatalysts were synthesized through direct thermal decomposition of the Ag-doped zinctartrate precursor,which was prepared by homogeneous precipitation method at 80 °C for...Porous silver-modified ZnO microrods photocatalysts were synthesized through direct thermal decomposition of the Ag-doped zinctartrate precursor,which was prepared by homogeneous precipitation method at 80 °C for 2 h.The obtained samples were characterized by XRD,FTIR,TG？DTA and UV-VIS absorption spectroscopy.The photocatalytic activity of the as-prepared porous Ag/ZnO microrods was tested with the photocatalytic degradation of methyl orange.The results indicate that doping Ag greatly improves the photocatalytic efficiency of ZnO and 3% Ag-doped（mole fraction） ZnO porous microrod photocatalyst exhibits the highest photocatalytic decolorization efficiency,leading to as much as 80% reduction of MO concentration in 120 min.Moreover,the 3% Ag-doped porous microrods also possess higher photocatalytic activity under the real sunlight irradiation.展开更多
[Objective] To screen out a microbial flocculant with good decolorization effect on methyl orange wastewater,and study the effect of different cultural conditions on decolorization effect of methyl orange.[Method] Abs...[Objective] To screen out a microbial flocculant with good decolorization effect on methyl orange wastewater,and study the effect of different cultural conditions on decolorization effect of methyl orange.[Method] Absorbance of methyl orange solution before and after decolorization was determined by spectrophotometer,and the decolorization rate was calculated to compare the effects of different cultural conditions on removal rate of methyl orange.[Result]An optimal actinomycete stain（F-1-2） was screened out,and the best cultural condition was as follows：with sucrose as carbon source and NaNO3 as nitrogen source,cultured in constant temperature oscillator at 150 r/min,30℃ for 72 h.Under the optimal condition,the removal rate against methyl orange could reach 68.4%.[Conclusion]Different culture conditions have great impact on decolorization effect of strain.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
Lignin isolated from enzymatic hydrolyzed corn-stalks (EH-lignin) is a renewable natural polymer noted for its versatility and applicability in a vari-ety of uses. Graft copolymerization of EH-lignin with acrylamide (...Lignin isolated from enzymatic hydrolyzed corn-stalks (EH-lignin) is a renewable natural polymer noted for its versatility and applicability in a vari-ety of uses. Graft copolymerization of EH-lignin with acrylamide (AM) and the application of this copolymer as a flocculant in dye wastewater treatment were studied in this article. The influ-ences of some factors on yield of copolymer and the grafting ratio were investigated and the structure of EH-lignin/AM graft copolymer was characterized by FT-IR. According to the yield and the grafting ratio, the optimum conditions for graft copolymerization were as follows: initiator K2S2O8-Na2S2O3 with a quantity 3 wt% of EH-lignin, mass ratio of AM to EH-lignin was 2~3, reaction time 4h and temperature at 50℃. It was found that the absorption capacity of graft copolymer to two azo-dyes was enhanced with the increase of grafting ratio. Furthermore, the residue concen-tration of EH-lignin/AM graft copolymer remained in the supernatant after flocculation was much lower than that of pure EH-lignin.展开更多
A crystalline sapphire （Al2O3） boule （Ф10 × 80mm^3） grown by the temperature gradient technique （TGT） is a bit colored due to carbon volatilization from the graphite heater at high temperatures and the abs...A crystalline sapphire （Al2O3） boule （Ф10 × 80mm^3） grown by the temperature gradient technique （TGT） is a bit colored due to carbon volatilization from the graphite heater at high temperatures and the absorption of transitional metal inclusions in the raw material. The sapphire becomes colorless and transparent after decolorization and decarbonization in successive annealings in air and hydrogen at high temperatures. The quality, optical transmissivity,and homogeneity of the sapphire are remarkably improved.展开更多
According to the design principle of the central composite experimental,the method of response surface analysis with three factors and three levels was adopted based on one factor test.A second-order quadratic equatio...According to the design principle of the central composite experimental,the method of response surface analysis with three factors and three levels was adopted based on one factor test.A second-order quadratic equation for photocatalysis of Procion Red MX-5B was built.Response surface and contour were graphed with the decoloration rate of Procion Red MX-5B as the response value.Based on the analysis of the response surface plots and their corresponding contour plots,effects of pH value,irradiation time and catalyst loading were explored.By using this new method,the optimum decoloration condition was obtained as follows:pH value,1.3;irradiation time,49.9 min;catalyst loading,0.57 g/L.In the optimization,R-Squared and Adj R-Squared correlation coefficients for quadratic model were evaluated quite satisfactorily as 0.9310 and 0.8620,respectively.Under the optimum conditions established,the performance of 99.47% for color removal was experimentally reached.It was found that all factors considered have an important effect on the decolorization efficiency of Procion Red MX-5B.By the ANOVA analysis and model confirmation the optimal solution obtained using RSM was experimentally validated and credible with preferable instructional ability for experiments.展开更多
The strain No. 2 which was isolated from the soil through enrichment culture was used as the experimental material. It was cultured in liquid medium to research decolorizing effect to Rose Bengal and soluble color pas...The strain No. 2 which was isolated from the soil through enrichment culture was used as the experimental material. It was cultured in liquid medium to research decolorizing effect to Rose Bengal and soluble color paste under the different conditions of different media,carbon sources,nitrogen sources,initial pH values and culture temperatures. The results revealed that the optimum decolorizing conditions were using bean juice medium and PDA medium as the minimal medium,sucrose as the carbon source,and ammonium nitrate as the nitrogen source,initial pH 6.0-8.0. In addition,the strain was primarily identified as Aspergillus flavus according to its morphous and ITS sequence analysis.展开更多
A coagulation/flocculation process using the composite flocculant polyaluminum chloride-epichlorohydrin dimethylamine （PAC- EPI-DMA） was employed for the treatment of an anionic azo dye （Reactive Brilliant Red K-2B...A coagulation/flocculation process using the composite flocculant polyaluminum chloride-epichlorohydrin dimethylamine （PAC- EPI-DMA） was employed for the treatment of an anionic azo dye （Reactive Brilliant Red K-2BP dye）. The effect of viscosity 01）, basicity （B = [OH]/[Al]） and organic content （Wp） on the flocculation performance as well as the mechanism of PAC-EPI-DMA flocculant were investigated. The η was the key factor affecting the dye removal efficiency of PAC-EPI-DMA. PAC-EPI-DMA with an intermediate η （2400 mPa.sec） gave higher decolorization efficiency by adsorption bridging and charge neutralization due to the co-effect of PAC and EPI-DMA polymers. The Wp of the composite flocculant was a minor important factor for the flocculation. The adsorption bridging of PAC-EPI-DMA with η of 300 or 4300 mPa.sec played an important role with the increase of Wp, whereas the charge neutralization of them was weaker with the increase of Wp. There was interaction between Wp and B on the removal of reactive dye. The composite flocculant with intermediate viscosity and organic content was effective for the treatment of reactive dyeing wastewater, which could achieve high reactive dye removal efficiency with low organic dosage.展开更多
To achieve effective decolorization of reactive dyes,laccase immobilization was investigated.Laccase 0.2%(m/V)(Denilite IIS) was trapped in beads of alginate/gelatin blent with polyethylene glycol(PEG),and then the su...To achieve effective decolorization of reactive dyes,laccase immobilization was investigated.Laccase 0.2%(m/V)(Denilite IIS) was trapped in beads of alginate/gelatin blent with polyethylene glycol(PEG),and then the supporters were activated by cross-linking with glutaraldehyde.The results of repeated batch decolorization showed that gelatin and appropriate concentration of glutaraldehyde accelerated the decolorization of Reactive Red B-3BF(RRB);PEG had a positive effect on enzyme stability and led to an inc...展开更多
Green macroalga Caulerpa lentillifera was found to have reasonable adsorption capacity for basic dyes, Astrazon Blue FGRL （AB）, Astrazon Red GTLN （AR）, and Astrazon Golden Yellow GL-E （AY）. The initial dye conce...Green macroalga Caulerpa lentillifera was found to have reasonable adsorption capacity for basic dyes, Astrazon Blue FGRL （AB）, Astrazon Red GTLN （AR）, and Astrazon Golden Yellow GL-E （AY）. The initial dye concentration was in the range of 100-1,800 mg/L. The dried algal sorbent was ground and sieved into 3 sizes： S （0.1-0.84 mm）, M （0.84-2.0 mm）, and L sizes （larger than 2.0 mm）. For all conditions examined in this work （at 25℃ in batch systems）, the adsorption reached equilibrium within the first hour. The kinetic data corresponded well with the pseudo second order kinetic model where the rate constant, k2, decreased as the sorbent size increased for all dyes. The adsorption isotherms followed both Langmuir and Freundlich models. Among three sorbent sizes, S size gave the highest adsorption capacity followed by M and L sizes. A reduction of sorbent size increased the specific surface area for mass transfer, and also increased the total pore volume, thus providing more active sites for adsorption. The adsorption of AB was adversely influenced by the protonation of algal surface at low pH. On the other hand, the adsorption of AR and AY could be due to weak electrostatic interaction, which was not significantly affected by pH. Increasing salinity of the system caused a decrease in adsorption capacity possibly due to the competition between Na^＋ and the dye cations for the binding sites on algal surface. Moreover, an increase in salinity generated a compressed electrical double layer on the algal surface which exerted repulsive force, retarding the adsorption of positive charged molecules such as the basic dyes.展开更多
Pseudomonas otitidis WL-13, which has a high capacity to decolorize triphenylmethane dyes, was isolated from activated sludge obtained from a wastewater treatment plant of a dyeing industry. This strain exhibited a re...Pseudomonas otitidis WL-13, which has a high capacity to decolorize triphenylmethane dyes, was isolated from activated sludge obtained from a wastewater treatment plant of a dyeing industry. This strain exhibited a remarkable color-removal capability when tested against several triphenylmethane dyes under both shaking and static conditions at high concentrations of dyes. More than 95% of Malachite Green and Brilliant Green was removed within 12 h at 500 μmol/L dye concentration under shaking conditions. Crystal Violet lost about 13% of its color under the same conditions tested. The rate of decolorization increased when the M9 medium was supplemented with yeast extract. The optimum pH and temperature for color removal were 7-9 and 35-40℃, respectively. The observed changes in the visible spectra and the inspection of bacterial growth indicated the color-removal by the adsorption of dye to the cells during incubation with strains.展开更多
Some problems including low treatment capacity,agglomeration and clogging phenomena,and short working life,limit the application of pre-treatment methods involving zero-valent iron （ZVI）.In this article,ZVI was froz...Some problems including low treatment capacity,agglomeration and clogging phenomena,and short working life,limit the application of pre-treatment methods involving zero-valent iron （ZVI）.In this article,ZVI was frozen in an amorphous state through a melt-spinning technique,and the decolorization effect of amorphous ZVI on Acid Orange II solution was investigated under varied conditions of experimental variables such as reaction temperature,ribbon dosage,and initial pH.Batch experiments suggested that the decolorization rate was enhanced with the increase of reaction temperature and ribbon dosage,but decreased with increasing initial solution pH.Kinetic analyses indicated that the decolorization process followed a first order exponential kinetic model,and the surface-normalized decolorization rate could reach 2.09 L/（m^2 ·min） at room temperature,which was about ten times larger than any previously reported under similar conditions.Recycling experiments also proved that the ribbons could be reused at least four times without obvious decay of decolorization rate and efficiency.This study suggests a tremendous application potential for amorphous ZVI in remediation of groundwater or wastewater contaminated with azo dyes.展开更多
The effects of chloride anion （Cl-） （up to 1.0 mol/L） on the decolorization of a model compound,azo dye Acid Orange 7 （AO7）,by sulfate radical （SO4-） based-peroxydisulfate （PS） or peroxymonosulfate （PMS） o...The effects of chloride anion （Cl-） （up to 1.0 mol/L） on the decolorization of a model compound,azo dye Acid Orange 7 （AO7）,by sulfate radical （SO4-） based-peroxydisulfate （PS） or peroxymonosulfate （PMS） oxidation under various activated conditions （UV 254 nm /PS,Thermal （70°C/PS,UV 254 nm /PMS,Co 2＋ /PMS） were investigated.Methanol and NH4 ＋ were used as quenching reagents to determine the contributions of active chlorine species （dichloride radical （Cl2-.） and hypochlorous acid （HClO））.The results indicated that the effects of Cl- on the reaction mechanism were different under various activated conditions.For UV/PS and Thermal/PS,the inhibition tendency became more clear as the Cl- concentration increased,probably due to the reaction between Cl- and SO4-.and the generation of Cl2-.or HClO.For UV/PMS,Cl- did not exhibit inhibition when the concentration was below 0.1 mol/L.As Cl- concentration reached to 1.0 mol/L,the decolorization rate of AO7 was,however,accelerated,possibly because PMS directly reacts with Cl- to form HClO.For Co2＋ /PMS,Cl- exhibited a significant inhibiting effect even at low concentration （ 0.01 mol/L）.When Cl- concentration exceeded 0.1 mol/L,the activation of PMS by Co 2＋ was almost completely inhibited.Under this condition,HClO maybe played a major role in decolorization of AO7.The results implicated that chloride ion is an important factor in SO4-.-based degradation of organic contamination in chloride-containing water.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
The capability of decolorization for commercial dyes by Coriolus versicolor fermentation broth containing laccase with or without immobilized mycelium was evaluated. With cell free fermentation broth containing l...The capability of decolorization for commercial dyes by Coriolus versicolor fermentation broth containing laccase with or without immobilized mycelium was evaluated. With cell free fermentation broth containing laccase, high decolorization ratio was achieved for acid orange 7, but not for the other dyes concerned. The immobilized mycelium was proved to be more efficient than the cell free system. All the four dyestuffs studied were found being decolourized with certain extent by immobilized mycelium. The repeated batch decolorization was carried out with satisfactory results. The experimental data showed that the continuous decolorization of wastewater from a printing and dyeing industry was possible by using the self immobilized C. Versicolor.展开更多
基金supported by the National Natural Science Foundation of China (No. 10875019)the Fundamental Research Funds for the Central Universities
文摘The pulsed high-voltage discharge is a new advanced oxidation technology for water treatment. Methyl Orange （MO） dye wastewater was chosen as the target object. Some investigations were conducted on MO decoloration including the discharge characteristics of the multi-needle reactor, parameter optimization, and the degradation mechanism. The following results were obtained. The color group of the azo dye MO was effectively decomposed by water surface plasma. The decoloration rate was promoted with the increase of treatment time, peak voltage, and pulse frequency. When the initial conductivity was 1700 μS/cm, the decoloration rate was the highest. The optimum distance between the needle electrodes and the water surface was 1 mm, the distance between the grounding electrode and the water surface was 28 mm, and the number of needle electrodes and spacing between needles were 24 and 7.5 mm, respectively. The decoloration rate of MO was affected by the gas in the reactor and varied in the order oxygen 〉 air〉 argon 〉 nitrogen, and the energy yield obtained in this investigation was 0.45 g/kWh.
基金National Natural Science Foundation of China (No. 21876070)Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment for their support of this work。
文摘In the paper, a hybrid gas–liquid dielectric barrier discharge(DBD) plasma system was set up to treat a methylene blue(MB) solution. The effects of the change of the carrier gas, the gas bubbling rate and different kinds of scavenger addition, including sodium carbonate(Na_2CO_3),para benzoquinone(p-BQ), triethylenediamine and sodium dihydrogen phosphate(NaH_2PO_4),on the MB decoloration were reviewed to clarify the critical active species for the dye decoloration in the DBD plasma system. The obtained results show that higher decoloration of the MB solution could be achieved when O2 was used as the carrier gas, which could be 100% after 20 min discharge treatment, and the result confirmed the crucial effect of O_3 in the MB decoloration. Based on the experiments of the scavenger addition, it could be concluded that O_2·^- and ~1O_2 were two other important reactive oxygen species(ROS) for the MB decoloration.The results of the higher chemical oxygen demand removal and faster disappearance of the characteristic peak of the MB from the UV–vis analysis under O_2 bubbling conditions also proved the critical effect of the ROS formed by O_2 on the MB decoloration.
文摘In this paper we report the results of our experimental work conducted to decoloration of a well-known highly toxic Amaranth dye by electrochemical and photoelectrochemical methods. Throughout this investigation were used two different Dimensional Stable Anode (DSA) electrodes, namely, IrO2-Ru2O-SnO2-TiO2/Ti and Ru2O-SnO2-TiO2/Ti. The experimental results show that IrO2-Ru2O-SnO2-TiO2/Ti electrode has higher performance on amaranth decoloration than Ru2O-SnO2-TiO2/Ti electrode, but with the disadvantage of higher energy consumption. For higher degradation of Amaranth dye with both DSA electrodes, the process was carried out via photoelectrochemical method. Our experimental results clearly shown the decrease in absorbance of all UV-Vis peaks due to the mineralization of the azo dye;also, it was noteworthy photoelectrochemical process consumes less energy under the same experimental conditions than electrochemical process. The IrO2-Ru2O-SnO2-TiO2/Ti electrode reaches a higher degradation degree of Amaranth solutions than Ru2O-SnO2-TiO2/Ti electrode using a photoelectrochemical technique.
基金supported by the Earmarked Fund for Modern Agro-industry Technology Research System (CARS-23)Jiangsu Provincial Agricultural Project (SXGC[2015]018)+1 种基金Fudiyingcai Talent Project of Jurong (2014)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘To optimize alkaline method for extracting proteins from tea residue(TR), the effect of extraction conditions on tea protein extraction rate(TPER) was investigated. Single factor experiment showed the extraction temperature 80 °C, extraction time 100 min, p H value 13 and liquid–solid ratio 40:1 as the optimal extraction conditions. The orthogonal test revealed that the maximum TPER reached 29.71% under the following optimal combination of conditions: extraction temperature 70 °C, extraction time 60 min, p H 12 and liquid–solid ratio 50:1. For optimizing the purification of tea residue proteins, isoelectric point precipitation(p I), ammonium sulfate precipitation(a S) and isoelectric point plus ammonium sulfate precipitation(i PAS) were compared. The result showed that the highest protein precipitation rate(PPR) was 89.70% which was generated by using i PAS. Furthermore, powdered activated carbon was chosen as the most suitable decolorant for the extracted proteins.
基金supported by the Ministry of Science and Technology of China (Grant No. 2010CB631004)the Fundamental Research Funds for the Central Universities (Grant Nos. 1112021302, 1106021343, 1116021301)+1 种基金the PAPD and National Natural Science Foundation of China (Grant Nos. 50831004, 11004098, 51171078)the research fund of Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province (Grant No. AE201015)
文摘This paper describes the effects of temperature on the complex intermediate processes from the precursor to the fully-crystallized anatase TiO2 nanoparticles in hydrothermal synthesis. The anatase TiO2 nanoparticles were synthesized in a wide temperature range below 230°C. The composition, morphology, and methylene blue (MB) decoloration characteristics of the obtained products were investigated by X-ray diffraction, Fourier transform infrared spectroscope, X-ray photoelectron spectroscope, and scanning and transmission electron microscope. The dehydrating polycondensation of Ti(IV)-hydrates and the decomposition of (NH4)2Ti3O7 intermediates with the temperature increase lead to the direct formation of anatase TiO2 nanoparticles under the hydrothermal environments. The strong MB decoloration of the hydrothermal products obtained at the low (≤130°C) and high (≥180°C) temperatures are attributed to the adsorption of Ti(IV)-hydrates and the photocatalysis of anatase TiO2 nanoparticles, respectively.
基金Project (20907001) supported by the National Natural Science Foundation of ChinaProject (KJ2010A336) supported by the University Natural Science Research Project of Anhui Province,ChinaProject (KJ2009A010Z) supported by the Educational Commission of Anhui Province,China
文摘Porous silver-modified ZnO microrods photocatalysts were synthesized through direct thermal decomposition of the Ag-doped zinctartrate precursor,which was prepared by homogeneous precipitation method at 80 °C for 2 h.The obtained samples were characterized by XRD,FTIR,TG？DTA and UV-VIS absorption spectroscopy.The photocatalytic activity of the as-prepared porous Ag/ZnO microrods was tested with the photocatalytic degradation of methyl orange.The results indicate that doping Ag greatly improves the photocatalytic efficiency of ZnO and 3% Ag-doped（mole fraction） ZnO porous microrod photocatalyst exhibits the highest photocatalytic decolorization efficiency,leading to as much as 80% reduction of MO concentration in 120 min.Moreover,the 3% Ag-doped porous microrods also possess higher photocatalytic activity under the real sunlight irradiation.
基金Supported by National Natural Science Foundation of China(51064011)Jiangxi Education Science " Twelfth Five-year" Planning Program (10YB335)Science Foundation for Youths of Jiangxi Educational Committee (GJJ09599)~~
文摘[Objective] To screen out a microbial flocculant with good decolorization effect on methyl orange wastewater,and study the effect of different cultural conditions on decolorization effect of methyl orange.[Method] Absorbance of methyl orange solution before and after decolorization was determined by spectrophotometer,and the decolorization rate was calculated to compare the effects of different cultural conditions on removal rate of methyl orange.[Result]An optimal actinomycete stain（F-1-2） was screened out,and the best cultural condition was as follows：with sucrose as carbon source and NaNO3 as nitrogen source,cultured in constant temperature oscillator at 150 r/min,30℃ for 72 h.Under the optimal condition,the removal rate against methyl orange could reach 68.4%.[Conclusion]Different culture conditions have great impact on decolorization effect of strain.
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.
文摘Lignin isolated from enzymatic hydrolyzed corn-stalks (EH-lignin) is a renewable natural polymer noted for its versatility and applicability in a vari-ety of uses. Graft copolymerization of EH-lignin with acrylamide (AM) and the application of this copolymer as a flocculant in dye wastewater treatment were studied in this article. The influ-ences of some factors on yield of copolymer and the grafting ratio were investigated and the structure of EH-lignin/AM graft copolymer was characterized by FT-IR. According to the yield and the grafting ratio, the optimum conditions for graft copolymerization were as follows: initiator K2S2O8-Na2S2O3 with a quantity 3 wt% of EH-lignin, mass ratio of AM to EH-lignin was 2~3, reaction time 4h and temperature at 50℃. It was found that the absorption capacity of graft copolymer to two azo-dyes was enhanced with the increase of grafting ratio. Furthermore, the residue concen-tration of EH-lignin/AM graft copolymer remained in the supernatant after flocculation was much lower than that of pure EH-lignin.
文摘A crystalline sapphire （Al2O3） boule （Ф10 × 80mm^3） grown by the temperature gradient technique （TGT） is a bit colored due to carbon volatilization from the graphite heater at high temperatures and the absorption of transitional metal inclusions in the raw material. The sapphire becomes colorless and transparent after decolorization and decarbonization in successive annealings in air and hydrogen at high temperatures. The quality, optical transmissivity,and homogeneity of the sapphire are remarkably improved.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 51078100)the National Creative Research Groups granted by NSFC(Grant No. 50821002)+1 种基金Excellent Youth Foundation of Heilongjiang Scientific Committee(Grant No. JC2010-03)State Key Laboratory of Urban Water Resource and Environment(Grant No. 2010DX11)
文摘According to the design principle of the central composite experimental,the method of response surface analysis with three factors and three levels was adopted based on one factor test.A second-order quadratic equation for photocatalysis of Procion Red MX-5B was built.Response surface and contour were graphed with the decoloration rate of Procion Red MX-5B as the response value.Based on the analysis of the response surface plots and their corresponding contour plots,effects of pH value,irradiation time and catalyst loading were explored.By using this new method,the optimum decoloration condition was obtained as follows:pH value,1.3;irradiation time,49.9 min;catalyst loading,0.57 g/L.In the optimization,R-Squared and Adj R-Squared correlation coefficients for quadratic model were evaluated quite satisfactorily as 0.9310 and 0.8620,respectively.Under the optimum conditions established,the performance of 99.47% for color removal was experimentally reached.It was found that all factors considered have an important effect on the decolorization efficiency of Procion Red MX-5B.By the ANOVA analysis and model confirmation the optimal solution obtained using RSM was experimentally validated and credible with preferable instructional ability for experiments.
基金Supported by National Science &Technology Pillar Program in the Eleventh Five-year Plan Period ( NO. 2008BADC4B08 )International Science and Technology Cooperation Project of Ministry of Science and Technology of China (NO. 2010DFA62510)Post-graduate Innovation Fund (NO. 54040108003)~~
文摘The strain No. 2 which was isolated from the soil through enrichment culture was used as the experimental material. It was cultured in liquid medium to research decolorizing effect to Rose Bengal and soluble color paste under the different conditions of different media,carbon sources,nitrogen sources,initial pH values and culture temperatures. The results revealed that the optimum decolorizing conditions were using bean juice medium and PDA medium as the minimal medium,sucrose as the carbon source,and ammonium nitrate as the nitrogen source,initial pH 6.0-8.0. In addition,the strain was primarily identified as Aspergillus flavus according to its morphous and ITS sequence analysis.
基金supported by the National Natural Science Foundation of China (No. 50578089,21077066)the Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period (No. 2006BAJ08B05-2)+2 种基金the Scientific Technology Research and Development Program of Shandong of China (No. 2009GG10006003 2010GZX20605)the Natural Science Foundation of Shandong Province of China (No. ZR2010BM014)
文摘A coagulation/flocculation process using the composite flocculant polyaluminum chloride-epichlorohydrin dimethylamine （PAC- EPI-DMA） was employed for the treatment of an anionic azo dye （Reactive Brilliant Red K-2BP dye）. The effect of viscosity 01）, basicity （B = [OH]/[Al]） and organic content （Wp） on the flocculation performance as well as the mechanism of PAC-EPI-DMA flocculant were investigated. The η was the key factor affecting the dye removal efficiency of PAC-EPI-DMA. PAC-EPI-DMA with an intermediate η （2400 mPa.sec） gave higher decolorization efficiency by adsorption bridging and charge neutralization due to the co-effect of PAC and EPI-DMA polymers. The Wp of the composite flocculant was a minor important factor for the flocculation. The adsorption bridging of PAC-EPI-DMA with η of 300 or 4300 mPa.sec played an important role with the increase of Wp, whereas the charge neutralization of them was weaker with the increase of Wp. There was interaction between Wp and B on the removal of reactive dye. The composite flocculant with intermediate viscosity and organic content was effective for the treatment of reactive dyeing wastewater, which could achieve high reactive dye removal efficiency with low organic dosage.
基金supported by the National Hi-Tech Research and Development Program(863)of China(No.2007AA02Z218)the Open Project Program of Key Lab-oratory of Eco-Textiles,Jiangnan University,Ministry of Education,China(No.KLET0625) the Youth Fundof Jiangnan University(No.2006LQN002).
文摘To achieve effective decolorization of reactive dyes,laccase immobilization was investigated.Laccase 0.2%(m/V)(Denilite IIS) was trapped in beads of alginate/gelatin blent with polyethylene glycol(PEG),and then the supporters were activated by cross-linking with glutaraldehyde.The results of repeated batch decolorization showed that gelatin and appropriate concentration of glutaraldehyde accelerated the decolorization of Reactive Red B-3BF(RRB);PEG had a positive effect on enzyme stability and led to an inc...
文摘Green macroalga Caulerpa lentillifera was found to have reasonable adsorption capacity for basic dyes, Astrazon Blue FGRL （AB）, Astrazon Red GTLN （AR）, and Astrazon Golden Yellow GL-E （AY）. The initial dye concentration was in the range of 100-1,800 mg/L. The dried algal sorbent was ground and sieved into 3 sizes： S （0.1-0.84 mm）, M （0.84-2.0 mm）, and L sizes （larger than 2.0 mm）. For all conditions examined in this work （at 25℃ in batch systems）, the adsorption reached equilibrium within the first hour. The kinetic data corresponded well with the pseudo second order kinetic model where the rate constant, k2, decreased as the sorbent size increased for all dyes. The adsorption isotherms followed both Langmuir and Freundlich models. Among three sorbent sizes, S size gave the highest adsorption capacity followed by M and L sizes. A reduction of sorbent size increased the specific surface area for mass transfer, and also increased the total pore volume, thus providing more active sites for adsorption. The adsorption of AB was adversely influenced by the protonation of algal surface at low pH. On the other hand, the adsorption of AR and AY could be due to weak electrostatic interaction, which was not significantly affected by pH. Increasing salinity of the system caused a decrease in adsorption capacity possibly due to the competition between Na^＋ and the dye cations for the binding sites on algal surface. Moreover, an increase in salinity generated a compressed electrical double layer on the algal surface which exerted repulsive force, retarding the adsorption of positive charged molecules such as the basic dyes.
基金supported by the Dong-A University Research Fund in 2007
文摘Pseudomonas otitidis WL-13, which has a high capacity to decolorize triphenylmethane dyes, was isolated from activated sludge obtained from a wastewater treatment plant of a dyeing industry. This strain exhibited a remarkable color-removal capability when tested against several triphenylmethane dyes under both shaking and static conditions at high concentrations of dyes. More than 95% of Malachite Green and Brilliant Green was removed within 12 h at 500 μmol/L dye concentration under shaking conditions. Crystal Violet lost about 13% of its color under the same conditions tested. The rate of decolorization increased when the M9 medium was supplemented with yeast extract. The optimum pH and temperature for color removal were 7-9 and 35-40℃, respectively. The observed changes in the visible spectra and the inspection of bacterial growth indicated the color-removal by the adsorption of dye to the cells during incubation with strains.
基金the financial support from the Ministry of Science and Technology of China(No. 2011CB606301)the National Natural Science Foundation of China (No. 50825402,51101156)
文摘Some problems including low treatment capacity,agglomeration and clogging phenomena,and short working life,limit the application of pre-treatment methods involving zero-valent iron （ZVI）.In this article,ZVI was frozen in an amorphous state through a melt-spinning technique,and the decolorization effect of amorphous ZVI on Acid Orange II solution was investigated under varied conditions of experimental variables such as reaction temperature,ribbon dosage,and initial pH.Batch experiments suggested that the decolorization rate was enhanced with the increase of reaction temperature and ribbon dosage,but decreased with increasing initial solution pH.Kinetic analyses indicated that the decolorization process followed a first order exponential kinetic model,and the surface-normalized decolorization rate could reach 2.09 L/（m^2 ·min） at room temperature,which was about ten times larger than any previously reported under similar conditions.Recycling experiments also proved that the ribbons could be reused at least four times without obvious decay of decolorization rate and efficiency.This study suggests a tremendous application potential for amorphous ZVI in remediation of groundwater or wastewater contaminated with azo dyes.
基金supported by the National Natural Science Foundation of China (No. 21107101)the Fundamental Research Funds for the Central Universities of China (Ocean University of China)(No.201113005)
文摘The effects of chloride anion （Cl-） （up to 1.0 mol/L） on the decolorization of a model compound,azo dye Acid Orange 7 （AO7）,by sulfate radical （SO4-） based-peroxydisulfate （PS） or peroxymonosulfate （PMS） oxidation under various activated conditions （UV 254 nm /PS,Thermal （70°C/PS,UV 254 nm /PMS,Co 2＋ /PMS） were investigated.Methanol and NH4 ＋ were used as quenching reagents to determine the contributions of active chlorine species （dichloride radical （Cl2-.） and hypochlorous acid （HClO））.The results indicated that the effects of Cl- on the reaction mechanism were different under various activated conditions.For UV/PS and Thermal/PS,the inhibition tendency became more clear as the Cl- concentration increased,probably due to the reaction between Cl- and SO4-.and the generation of Cl2-.or HClO.For UV/PMS,Cl- did not exhibit inhibition when the concentration was below 0.1 mol/L.As Cl- concentration reached to 1.0 mol/L,the decolorization rate of AO7 was,however,accelerated,possibly because PMS directly reacts with Cl- to form HClO.For Co2＋ /PMS,Cl- exhibited a significant inhibiting effect even at low concentration （ 0.01 mol/L）.When Cl- concentration exceeded 0.1 mol/L,the activation of PMS by Co 2＋ was almost completely inhibited.Under this condition,HClO maybe played a major role in decolorization of AO7.The results implicated that chloride ion is an important factor in SO4-.-based degradation of organic contamination in chloride-containing water.
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TheNationalNaturalScienceFoundationofChina (No .2 9976 0 38)
文摘The capability of decolorization for commercial dyes by Coriolus versicolor fermentation broth containing laccase with or without immobilized mycelium was evaluated. With cell free fermentation broth containing laccase, high decolorization ratio was achieved for acid orange 7, but not for the other dyes concerned. The immobilized mycelium was proved to be more efficient than the cell free system. All the four dyestuffs studied were found being decolourized with certain extent by immobilized mycelium. The repeated batch decolorization was carried out with satisfactory results. The experimental data showed that the continuous decolorization of wastewater from a printing and dyeing industry was possible by using the self immobilized C. Versicolor.
