Showing 13 results for Dye
Gh Ghanizadeh, Gh Asgari,
Volume 2, Issue 2 (9-2009)
Abstract
Backgrounds and Objectives: Dyes are organic materials with complex structures, toxic, carcinogenic, teratogenic,nonbiodegredable properties and!the most!important pollutants of textile industrial wastewaters. The goal of this study was to survey the feasibility application of bone char (BC) as a sorbent for the of methylene blue (MB) from synthetic wastewater.The sub goals of the research!were to determine!the adsorption isotherm, !effects of primary concentration of dye, adsorbent!dose, contact!time, and pH for the adsorption of MB with BC.
Materials and Methods: BC was prepared under laboratory conditions by using of electrical furnace at 400°C for 2h. The prepared BC was crushed and pulverized by standard ASTM sieves with range of 10-16mesh(1.18-2mm).The chemical composition and solid structure of BC was analyzed using X-ray diffraction(XRD) and scanning electronic microscopy (SEM). Measurement of the surface area was carried out by N2 gas via BET isotherm and Belsorb software. The concentration of dye was measured by photometric!method (663nm).
Results: Predominant!compositionof BC is calcium hydroxyl apatite (Ca5 (PO4)3OH with 14m2/g surface area. The results of this study showed that increasing of primary concentration of dye, adsorbent dose and pH (5 to12) would lead to increasing of adsorption/removal of MB dye.Equilibration of dye adsorption was reached at lapse of 2h andoptimum pH for adsorption of MB with BC found in the rage of 8.5-12.Adsorption of MB witht BC complies witht freundlich isotherm(R2:0.99).
Conclusion: Bone char is a cheap component that can be used as an adsorbent in water and wastewater treatment. Based on optimum pH of 8.5-12 found for the removal of MB and the fact that many of textile!industrial wastewaters have an alkaline pH, this adsorbent can be!used for the removal of dyes from these wastewaters.
A.r Yazdanbakhsh, A Sheikh Mohammadi, M Sardar, H Mohammadi, M Zarabi,
Volume 2, Issue 4 (3-2010)
Abstract
Backgrounds and Objectives: A great part of organic compounds cause more pollution in natural waters meet, are chemical dye material. Azo dyes have more usage in different industries. Azo dyes not only give undesirable dye to the water but also have mutation potential and carcinogenesis effects in human and cause the production of toxic substances in water environments.The purpose of this study is investigation of iron powder, hydrogen peroxide and iron powder-hydrogen peroxide processes in removal of acid yellow 36 dye from aqueous solutions.
Materials and Methods: This study was conducted in laboratory scale. At this experiment synthetic solution was made from acid yellow 36 dye, and the removal of acid yellow 36 dye was studied by iron powder, hydrogen peroxide and iron powder- hydrogen peroxide processes .Also effect of dye concentration, pH solution, hydrogen peroxide concentration, iron powder concentration and the time of contact on decolorization, were evaluated.
Results: The results showed that iron powder - hydrogen peroxide process, compared to two other process has high decolorization power. Removal efficacy of iron powder-hydrogen peroxide process with H2O2 =23.33 ml / L, pH =3, iron powder 2000 mg/L and 60 minute ,was about 97.9%
Conclusion:In general this investigation showed that , this method (Iron powder-hydrogen peroxide process) has high efficiency for removal of Azo dyes. But application this method in the industry, should be economically evaluated.
H. Asilian, G.r Moussavi, M. Mahmoudi,
Volume 3, Issue 1 (4-2010)
Abstract
Backgrounds and Objectives:Much attention has been recently paid on using waste materials as adsorbents for removal of contaminants from water and wastewater. A new low cost waste was examined for its capacity to adsorb RR198, an azo reactive model dye, from an aqueous solution.
Materials andMethods: The waste was dried, powdered and characterized before being used as an adsorbent. The effects of pH (3-10), adsorbent dose (0.2-3 g), dye concentration and contact time on the adsorption efficiency were investigated. Equilibrium study data were modeled using Langmuir and Freundlich models.
Results: The characterization analysis indicated that itwas composedmainly of ferric hydroxide. The powder had a BET and average pore size of 107 m2/g and 4.5 nm, respectively. The results showed that dye removal was highest at a solution pH of 7 to 8 and a powder dose of 2 g/L. The RR198 removal percentage decreased from 100& to 43& at 140 min contact time when the concentration of dye was increased from 25 mg/L to 100 mg/L, at optimum pH and dosage. The Langmuir equation provided the best fit for the experimental data. The maximum adsorption capacity was calculated to be 34.4 mg/g.
Conclusion: According to the obtained results, the water coagulation waste sludge appears to be a suitable low cost and effcient adsorbent for removing reactive azo dyes from waste streams.
M.t Ghaneian, M.h Ehrampoush, Gh Ghanizadeh, M Dehvary, M Abootoraby, T Jasemizad,
Volume 3, Issue 2 (7-2010)
Abstract
BackgroundandObjectives: Dyes are organic compoundswith complex structures,which due to toxicity, carcinogenicity and nonbiodegredabity, this type of pollutants is one of the most important pollutants of the environment. The goal of this researchwas to study the feasibility of the application of solar irradiation in presence of potassium persulfate (K2S2O8) for the removal of Reactive blue19 (RB19) from synthetic wastewater.
Materials and Methods:This research wascarri edoutin laboratory scalewith using of 200ml volume of batchphotoreactor.The effectsofoperatingparameters suchas concentrationofK2S2O8,pH,photoexposure time and preliminary concentrations of dye on decolorization have been evaluated.Different concentrations of pollutant inwastewaterwere prepared by solution of variousmasses of RB19 on tapwater. The reactors were exposedwith natural solar irradiation as aUVAsource from11 amto 14 pm.Themaximumabsorbtion wave length of this dye (!max) was determined by spectrophotometer (Unico, 2100). The measurement of dye concentrations was determined with using of standard curve and its best line equation
Results:Analysis of absorbtion spectra showed that the !max of RB19 is 592 nm. The average intensity of the UVA irradiated from solar system was 54.6 µW/Cm2. The results of decolorization process showed that 38.2%of this dye can be removed within 3 hr in the presence of potassium persulfate and decreasing of pH leads to the elevation of dye removal efficiency. Based on these findings, the efficiency of dye removal with 3h photoexposure time and pH ranges of 4,6 and 8 were found to be 98.2 88.5 and 78.5%, respectively.Also, the results showed that increasing of K2S2O8 dosage leads to elevation of dye removal efficiency in 3h photoexposure time and K2S2O8 dosages within 1-5mmol/L, with the removal efficiency of 75,86,92,95 and 98.5%, respectively.Analysis of data indicates that the kinetic of the removal of RB19 with this process is a first order reaction which its rate constant is 0.01min-1.
Conclusion: Due to the operation problems presented in heterogeneous photocatalitical processes such as catalysts separation and high costs of operation and maintenance of these processes caused by manmade sources of irradiations homogeneous photocatalitical process with using of potassium persulfate associated with natural solar irradiation can be used as a suitable process for the removal of dyes from textile industries wastewaters.
M.r Samarghandi, M Noori Sepehr, M Zarrabi, M Norouzi, F Amraie,
Volume 3, Issue 4 (1-2011)
Abstract
Backgrounds and Objectives: Treatment of colored wastewater is one of the important challenges of environmental engineers. Adsorption process is a key option for removal of organic matter from wastewater. The aim of present work was to investigate pumice stone as an adsorbent for removal of Acid Black 1 from aqueous solution.
Materials and Methods: Removal of Acid Black 1 by pumice stone was investigated. Acid Hyrdo Chloric(HCL) 1 N was used to increse adsorbent porosity. Various parameters such as pH, initial dye concentration and contact time were studied.
Results: Results showed that removal of Acid Black 1 was increased by increasing of contact time and initial dyeconcentration although it was decreased by increasing of pH. Experimental data was best fitted to Longmuir isotherm model (r2>0.98). Study of diffusion model revealed that intraparticle diffusion is rate-controlling step in removal of Acid Black 1 by pumice stone.
Conclusion : The results indicated that pumice stone was a dominant adsorbent for Acid Black 1 removal.
P Bahmani, R Rezaei Kalantary, M Gholami, A Jonidi Jafari, Z Javadi,
Volume 3, Issue 4 (1-2011)
Abstract
Backgrounds and Objectives: Reactive dyestuff has potential of toxicity, carcinogenesis and mutagenesis for mammals and aquatic organisms. The current physical and chemical methods such as adsorption, coagulation, precipitation, filtration and ... can been used for removing of dyestuff. Biological treatment which is effective and economic for decontamination of dyestuff wastewaters was preferred because of limitation and difficulty of physicochemical methods. In order to investigate the trend of pollution reduction of color compounds, ability of Remazol Black-B dyestuff removal from aqueous medium by bacterial consortium under anoxic conditions was studied.
Materials and Methods: The mix culture of bacteria from textile industries activated sludge was enriched in luria broth medium containing RB-B dyestuff as a carbon source. Then biodegradation was assessed in 4 batch reactors. Microbial population of bacterial and decolorization quantities of samples were detected by MPN and UV-Vis spectrophotometer.
Results: Decolorization efficiency by the bacterial consortium was obtained more than 99% for 50 and 250 mg/L concentrations in 72 and 144 h (3 and 6 days) respectively, while for the initial concentration of 500 mg/L was 98.1in 240 h (10 days) of biodegradation period. Dyestuff reduction rate after completed removal was about 0.69, 1.74,2 mg/L/h for initial concentration of 50, 250, 500 mg/L respectively.
Conclusion: Results showed that Alcaligenes denitrificans and Alcaligenes xylosoxidans bacteria
which were isolated from activated sludge have good potential of RB-B dyestuff removal and this removal is depending on primary concentration of dye. Removal efficiency increased as primary concentration went up.
M Manshouri, A Yazdanbakhsh, M Sardar, A Sheykh Mohammadi,
Volume 3, Issue 4 (1-2011)
Abstract
Backgrounds and Objectives: Reactive dyestuff has potential of toxicity, carcinogenesis and mutagenesis for mammals and aquatic organisms. The current physical and chemical methods such as adsorption, coagulation, precipitation, filtration and ... can been used for removing of dyestuff. Biological treatment which is effective and economic for decontamination of dyestuff wastewaters was preferred because of limitation and difficulty of physicochemical methods. In order to investigate the trend of pollution reduction of color compounds, ability of Remazol Black-B dyestuff removal from aqueous medium by bacterial consortium under anoxic conditions was studied.
Materials and Methods: The mix culture of bacteria from textile industries activated sludge was enriched in luria broth medium containing RB-B dyestuff as a carbon source. Then biodegradation was assessed in 4 batch reactors. Microbial population of bacterial and decolorization quantities of samples were detected by MPN and UV-Vis spectrophotometer.
Results: Decolorization efficiency by the bacterial consortium was obtained more than 99% for 50 and 250 mg/L concentrations in 72 and 144 h (3 and 6 days) respectively, while for the initial concentration of 500 mg/L was 98.1in 240 h (10 days) of biodegradation period. Dyestuff reduction rate after completed removal was about 0.69, 1.74,2 mg/L/h for initial concentration of 50, 250, 500 mg/L respectively.
Conclusion: Results showed that Alcaligenes denitrificans and Alcaligenes xylosoxidans bacteria
which were isolated from activated sludge have good potential of RB-B dyestuff removal and this removal is depending on primary concentration of dye. Removal efficiency increased as primary concentration went up.
A Dalvand, A Jonidi Jafari, M Gholami, A Ameri, N.m Mahmoodi,
Volume 4, Issue 1 (5-2011)
Abstract
Background and Objectives: Discharge of textile colored wastewater industries without providing enough treatment in water bodies, is harmful for human and aquatic organisms and poses serious damages to the environment. Most of conventional wastewater treatment methods don't have enough efficiency to remove textile dyes from colored wastewater thus in this research the efficiency of electrocoagulation treatment process with aluminum electrodes for treatment of a synthetic wastewater containing C.I. Reactive Red 198 in batch reactor was studied.
Material and Methods: The experiment conducted in a Plexiglas reactor with a working volume of 2L that equipped with 4 aluminum electrodes. The effects of operating parameters such as voltage, time of reaction, initial dye concentration and interelectrode distance on the color removal efficiency, electrical energy consumption and electrode consumption were investigated.
Results: in the optimum operational condition electrocoagulation, is able to remove color and COD as high as 99.1 and 84.3% in aluminum electrode in 75 minutes at 20 volt and 2 cm interelectrode distance, respectively. Under this condition, operating cost was 2986 rails per cubic meter of treated wastewater. Increase in the interelectrode distance and initial dye concentration,lead to the decrease in efficiency of dye and COD removal.While as the voltage and time of reaction increased, energy consumption, electrode consumption, final pH and color removal, increased too.
Conclusion: electrocoagulation process by aluminum electrode is an efficient and suitable method for reactive dye removal from colored wastewater.
E Hoseinzadeh, A.r Rahmani,
Volume 4, Issue 4 (3-2012)
Abstract
Background and Objectives: The disposal of waste tires has become an increasingly important issue worldwide in recent years. Tires not only take up large amounts of valuable landfill space, but also create fire hazards and provide a refuge for disease- carrying creatures. The goal of this study was to produce activated carbon from scrap tires .Adsorption of Acid Black1 (AB1) in aqueous solution as a pollutant by the activated carbon was also investigated.
Materials and Methods: Activated carbon was prepared from scrap vehicle tires using a thermo-chemical activation method. The chemical composition and solid structure of prepared activated carbon were analyzed using Scanning Electron Microscopy (SEM) coupled with energy dispersive spectrometry (EDS) and Nitrogen Sas. Micro pore volumes of the sample were determined by the application of the BET and BJH.
Results: Predominant composition of prepared activated carbon was C (83.274%) and with area surface of 44.226 and 35.747 m2/gr observed by BET and BJH methods, respectively. Mean pore diameter was 52 nm. The result of this study showed that increasing of initial dye concentration and pH would lead to decrease of adsorption/removal of dye but by increasing of sorbent dosage and contact time, adsorption/removal of dye increased.
Conclusion: As the results of present study it can be concluded that the production of the activated carbon from scrap tires, can provide a two-fold environmental and economic benefit a recycling path is created for scrap tires of vehicles, and a new suitable adsorbent is produced for pollutants removal.
Mohammad Malakootian, Mahdi Asadi, Amir Hossein Mahvi,
Volume 5, Issue 4 (2-2013)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Synthetic dyes represent one of the largest groups of
pollutants in wastewater of dying industries. Discharging these wastewaters
into receiving streams not only affects the aesthetic but also reduces
photosynthetic activity. Electrochemical advanced oxidation processes such as
Electro-Fenton process are low operational and have high mineralization degree
of pollutants. In this study, we investigated affective factors in this process
to determine the optimum conditions for dye and COD removal from aqueous
solutions containing Reactive Blue 19 dye.
Materials and Methods: Synthetic samples containing Reactive Blue 19 dye were prepared by dissolving
dye powder in double distilled water. and the the solution prepared was
transferred into pilot electrochemical cell having two anode and cathode
electrode made of iron and carbon. Electro-Fenton process was began by adding
of Fe
2+ ions and establishing electrical potential difference. After
testing and at specified time intervals, each sample was collected from the
pilot cell, and process performance was evaluated through measuring dye
concentration and COD.
Results: Based on the
results obtained, optimum conditions of Electro-Fenton process for dye and COD
removal was determined. Accordingly, potential difference of 20 volt for dye
concentration up to 100 mg/L and potential difference of 30 volt for dye
concentration of more than 200 mg/L, reaction time 60 minutes, 0.5 mg/L of Fe
2+ concentration and suitable pH for the maximum dye removal efficiency equaled 4
respectively. Under such conditions, the dye and COD removal was 100 and 95%
respectively.
Conclusion: Based on
the results obtained, it was revealed that Electro-Fenton process has
significant ability in not only dye removal but also in COD removal.
Accordingly, it was found that the effective parameters in Electro-Fenton
process for removal Reactive Blue19 dye are electric potential difference,
concentration of iron ions and electrolysis time.
M Panbehkar Bishe, B Ayati,
Volume 7, Issue 1 (7-2014)
Abstract
Background and Objective: Most of the dyes used in the textile industries can be toxic and carcinogenic. One of the suitable technologies to remove them is advanced oxidation processes. The main purpose of this study was to investigate the positive effect of adding oxidant Na2S2O8 to the photocatalytic process using TiO2 nano-particles immobilized on concrete and UV radiation for removal of Direct Blue71 dye. Materials and Methods: Concrete was covered by 40 g/m2 of TiO2 nanoparticles using SSP method. After selecting suitable oxidant concentration and optimum pH, initial dye concentration, UV irradiation intensity, and time, the efficiency and rate of dye removal and breaking amounts of benzene rings and COD variation were investigated in two systems of UV/TiO2 and UV/TiO2/Na2S2O8. Results: In UV/TiO2 system, 50.48 percent dye removal was observed at initial dye concentration of 100 ppm, pH 9, and 90 Watt UV lamp after 55 minutes and for UV/TiO2/Na2S2O8 system, initial dye concentration of 200 ppm, pH 6.9, and 0.24 g/L oxidant under the same abovementioned conditions resulted in 88.65 percent dye removal. Conclusion: Oxidant addition increased the dye removal efficiency and decreased total time for complete decolorization indicating the positive effect of oxidant on photocatalytic process in dye removal.
M Bijari, H Younesi, N Bahramifar,
Volume 10, Issue 4 (3-2018)
Abstract
Background and Objective: Reactive dyes are the newest dyes in textile industry. They may cause environmental problems. The aim of this study was to remove Reactive Black 5 (RB5) in aqueous solutions with activated carbon that was made from grape wood.
Materials and Methods: The activated carbon was synthesized by potassium carbonate with impragnation ratios of 1:0.25 at different temperatures (600,650,700,750,800,850,900)°C. Experiments on dye adsorption were done under the same conditions including pH of 2, adsorbent dose of 0.025 g/L, initial dye concentration of 250 mg/L, volume of 100 mL, and contact time of 120 min. Then, the absorption RB5 in a bathc mode was done using the optimized activated carbon. The trends of pH, absorbent dose, initial concentration, temperature, retention time, parametrs were studied. The BET and SEM techniques were used to characterize the activated carboon. Finally, the equilibrium, synthetic and thermodynamic studies were done for RB5.
Results: The results showed that the activated carbon sample that was synthesized under the imprenation ratio of 1:0.25 and temperature of 900 oC had a surface area 1670 m2/g. Moreover, the total pore volume was 1.134 cm3/g and 68% of the total pore size were within mesoporous zone. The highest adsorption capacity was observed at the optimum condition. The optimum condition with the maximum adsorption capacity for RB5 was pH of 2, adsorbent dose of 0.035 g/L and temperature 45 °C. According to the equilibrium test results RB5 followed the Freundlich model. of the kinetic adsorption results showed that RB5 showed a pseudo-second-order kinetic model. According to the thermodynamic studies, it seems that RB5 absorption process was an endothermic, non-spontaneous and physical sorption process.
Conclusion: The study showed that the produced-activated carbon from grape wood had a great potentioal for removing RB5 from aqueous solutions.
Mohamad Javad Zoqi,
Volume 14, Issue 3 (12-2021)
Abstract
Background and Objective: The most used dyes in textile industries are Azo Group dyes. Azo dyes have complex aromatic compounds, low chemical and biodegradable stability. Due to these properties, treatment of this type of wastewater by conventional methods will not meet environmental standards. The advanced oxidation process has been widely used to treat organic matter from wastewater. In this study, dye purification of azo dye Reactive Red 195 by UV/H2O2 process was investigated. Moreover, the parameters affecting this process have also been determined.
Materials and Methods: In this study, dye treatment was conducted in the presence of different concentrations of hydrogen peroxide, and at different retention time, temperature and pH values in a continuous photoreactor equipped with UV lamps. Using central composite design and response surface methodology (RSM), effects of various concentrations of hydrogen peroxide, retention time, temperature, and pH on the color and COD removal were studied in the range of 0–2%, 60-240 min, 25-80 oC, and 3-10, respectively.
Results: The results showed that the concentration of hydrogen peroxide and retention time were the most influential parameters on color and COD removal. Color removal significantly enhanced by increasing retention time and H2O2 concentration to 200 min and 1.2%, respectively. pH increase had positive effect on color removal. There were increases in the rate of color and COD removal as the temperature went up to 50 oC. However, temperature of 80 oC negatively impacted AOP process. According to RSM, the optimum factor levels were achieved at 1.28%, 240 min, 49 oC and 10 for concentrations of hydrogen peroxide, reaction time, temperature, and pH, respectively.
Conclusion: According to the result, UV/H2O2 proved to be capable of degrading Reactive Red 195. Almost all the azo dye color destroyed after 209 min while 87.52 % of the COD was removed after 240 min of irradiation.
