Removal of 4-Nitrophenol and Organic Dyes from Aqueous Solution Using Ag/ZnO Nanocomposite Prepared by Euphorbia peplus L. Extract (original) (raw)
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The Effect of Using Synthesis Zeolite 4A as Coating-Pigment on Physical Properties of Paper
JOURNAL OF WOOD AND FOREST SCIENCE AND TECHNOLOGY, 2017
Background and objective: Utilizing coated papers depend on the selection and proper usage of the paper ultimate coverage structure. Since pigment forms 80 to 95 percent of the weight of the cover, clearly the type and characteristics of the ingredients, play an important role in the cover structure, light characteristics and the quality of printing. Zeolite is one of the substances that have recently entered the field of research in connection with coating. The aim of this study was to investigate the effects of 4A synthetic zeolite as pigment, on the physical characteristics of the coated papers with synthetic zeolite pigments in pure form and in combination with precipitated calcium carbonate and kaolinite. Material and Methods: Requirements for this study 75 grams printing paper produced by mill Kayvta Finland, 14 and 30 grams of coating weight were considered on one side of the paper, and different calendaring conditions (70 and 90 centigrade temperature) were also considered for the samples. Some of the physical characteristics of the coated papers were considered like thickness, surface roughness, gloss, gloss variation, opacity, brightness, light scattering coefficient, whiteness and yellowness. Results: One of the very important factors, for the consumers of coated papers is the low level of yellowish. Using zeolite makes this factor to decrease dramatically and also coated papers with zeolite benefit a high whiteness as the white papers coated with calcium carbonate. Brightness of the paper coated with zeolite is higher than the papers coated with calcium carbonate and calendaring caused a little reduction of the brightness. Before calendaring, papers coated with calcium carbonate have the highest scattering coefficient and also after calendaring, has the highest amount of light scattering coefficient despite large reduction in the amount of light scattering coefficient. And as a result of this, they have a high opacity. The results also showed that adding a small amount of calcium carbonate and kaolinite to zeolites improves light scattering coefficient and opacity of the papers. The results showed that paper coated with zeolite has a small amount of gloss. Calendaring increases the gloss of all the treatments and this increase is more evident in calcium carbonate and kaolinite. Adding calcium carbonate and kaolinite to zeolites improves the gloss of the papers coated with them and it seems that because of hardness of zeolites comparing to other pigments it is better to apply more pressure for calendaring than the pressure that was used in this research. Conclusion: In summary, it can be said that 4A zeolite can be a good alternative for precipitated calcium carbonate and kaolinite, because of its unique physical characteristics. And the most ideal condition for using synthetized zeolite and reducing the amount of its deficits is to combine it with calcium carbonate and kaolinite.
Ni(II) Removal from Aqueous Solutions using Nanostructured Sorbent MCM-41 Modified by Zncl 2
2015
In this study, MCM-41 was prepared via hydrothermal method in presence of ethanol as a cosolvent and co-surfactant in alkaline media. Inorganic sorbent ZnCl 2-MCM-41 was synthesized via covalent grafting method by dispersion of samples into pure toluene for solid state interaction between silanol groups of MCM-41 surface and ZnCl 2 particles. Samples were characterized by nitrogen adsorption analysis, XRD, BET surface area, and FTIR spectrometry. MCM-41 BET surface area measured was 1099 m 2 /g, which was later reduced to 602 m 2 /g after incorporation of ZnCl 2 particles onto MCM-41 surface. Effect of different experimental conditions such as solution temperature, pH, contact time, and initial concentration of Ni (II) ions were investigated on the amount of nickel adsorption. For experimental data, the Langmuir isotherm showed a better fit than Freundlich isotherm, which indicates that nickel adsorption onto inorganic sorbent was homogeneous and monolayer. At optimum conditions, maximum adsorption capacity of Ni (II) by sorbent obtained was 303 mg/g according to Langmuir isotherm. Pseudo-second order model predicted kinetic of nickel adsorption onto synthesized sorbent better than other models. Free energy was 9.8 kJ/mol determined by Dubinin-Radushkevich model, which confirms chemical nature of nickel adsorption onto synthesized sorbent.
DOAJ (DOAJ: Directory of Open Access Journals), 2014
Introduction:Cadmium is a heavy metal with high toxicity and is best known as a carcinogen element. For protecting human health and environment it is necessary to remove excess Cadmium from industrial wastewater before discharging it to surface and ground water. In this study the efficiency of Zinc Oxides Nanoparticles in Cadmium removal from aqueous solution was evaluated. Methods: This is a laboratory experimental study. Adsorption tests were performed in a batch reactor in a laboratory scale using zinc oxide nanoparticles and the effect of initial cadmium concentrations, adsorbent dose, pH, and contact time on the removal efficiency was studied. Theresidual cadmium concentration in the solutionwas determined using flame atomic absorption spectroscopy Varian AA20 made in Australia. Finally for designing graphs, we used Excel software. Results:The results indicated that the adsorption process is affected by different parameters such as initial pollutant concentrations, adsorbent dose, pH, and contact time and Cadmiumremoval efficiency increases with increasing adsorbent dose and reaction time and decreases with increasing initial concentration of Cadmium. Therefore, it is observed that by raising the initial Cadmium concentration, the adsorption rate increases. The maximum efficiency of adsorptionin pH=7amounted to 89.6%. Conclusion:It is concluded that Zinc Oxide nanoparticles have proper efficiency in removal of Cadmium from aqueous solutions and can be used in the treatment of wastewater that contains ion Cadmium.However, its efficiency is deeply dependent on ion strength and the interaction of other metals in wastewater.
Journal of Advanced Materials In Engineering, 2016
Bio-inspired silver nanoparticles were synthesized with the aid of a novel method, using leaves of the plant Nigella sativa. After drying the leaves in air, they were first sweltered in boiling distilled water and the liquid was filtered subsequently. The result was the brothused to reduce solutions including various concentrations of silver nitrate in a proper amount of pH. The displayed UV-visible spectra identified formation of silver nanoparticles whenever the colorless initial acclimated mixture turned brown. The centrifuged powder samples were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (FESEM) and energy dispersive X-ray diffraction analysis (EDX) methods. The results clearly revealed that the final particles of precipitated powder are high purity agglomerates of silver nanoparticles. Besides, the effects of various amounts of the silver salt on particle size of nano silver were studied, using a particle size analyzer. FTIR results also indicated the role of different functional groups in the synthetic process.
2016
Introduction: Azo groups of dyes used widely for coloring yarn. Methylene blue is one of this group's dyes therefore with benzene rings in its structure caused the toxicity and its persistence in the environment. So that the its deficiency of proper treatment can cause the irreparable damage to the environment. One of the ways to removal these dyes from natural sources are absorbed by the absorbent. So the aim of this study is Kinetic and isotherm study of methylene blue adsorption by powdered pumice from the aquatic environment. Methods: Adsorption process was investigated in vitro at neutral pH, a constant concentration of dye and adsorbent dosage. The residual concentration of the dye solution through adsorption was measured at a wavelength nm 665 by using a spectrophotometer (Cary 50 manufacturers of Perkin Elmer). In order to understand how to adsorption, obtained data were fitted with Langmuir, Freundlich, Temkin, Harikens-jura and Dubinin-Radushkevich isotherms and Pseudo-first-order, Pesedo-second-order, Intraparticle diffusion and Elovich Kinetics. Results: Results showed that in the between of five isotherm models, the adsorption process is most obeyed of Harikens-jura isotherm (R 2 =0.9914). Also the adsorption process has appropriate obeyed of both Langmuir and Freundlich isotherms (R 2 =0.9633 and R 2 =0.9365) and it is means that the adsorption process occurs in a mono-layer and multi-layer. The low of mean free energy (E= 0.323 KJ/mol) in Dubinin-Radushkevich showed that the physical absorption process is dominant adsorption. Also adsorption process is obeyed of pseudo-second-order model. Conclusion: According to the results, can say Methylene blue adsorption multi-layer is most occurs than mono-layer and the pumice is the effectiveness adsorbent for removal methylene blue dye (RL=0.2).
Performance of Olive Pit Ash's in Nitrate Removal from the Aqueous Solutions
2014
Nitrate ion in drinking water has been found to have a significant effect against health human. Nitrate is an acute toxic; it can be reduced to nitrite in the stomach when it can lead to have blue baby diseases in infants. This research is directed towards to elucidate the nitrate removal efficiency by kernel ashes of olive in water supply. Methods: This experimental study was conducted in a batch laboratory scale. The batch flow experiments for nitrate removal were undertaken to investigate the effects of the different parameters such as: initial concentrations of nitrate solution (50, 100, 150 mg/l), initial pH (3,5,7,9), detention time (15,30,60,120,180 min), and weight of adsorbent(.04, .06. .08 gr). Nitrate concentrations were measured by standard method using a spectrophotometer at two wavelengths 220 and 275 nm. Results: The Results obtained showed that the removal efficiency increases when the time and adsorbent dose is increased. By decreasing of pH value and the initial concentration of nitrate, the removal efficiency would be increased significantly. Investigation of the effect of nitrate initial concentration showed that increasing initial concentration of nitrate from 50 to 150 mg/l and without changing absorbent dose would lead to decrease in the absorption efficiency from 88% to 48% but the absorption capacity (qe) increased from 8.31 to 14.3. Moreover the maximum absorption took Place at 60 min of the first reaction. Conclusion: Nitrate removal by olive kernel ashes are considered as effective and appropriate method compared with other absorbents and the process is more efficient at acidic pH.
مهندسی بهداشت محیط, 2019
Background and Objective: In this research, the performance of coagulation and flocculation process for the removal of pollutants from raw wastewater as well as anaerobic unit effluent of biological treatment of textile dyeing factory wastewater treatment plant was investigated. Methods: For this purpose, the Jar test unit as a batch reactor, FeCl3, PAC, and Alum as coagulants, and two polyelectrolytes, namely, Zetafloc 7563 and Megafloc 3045PWG as cationic and anionic flocculants were used and the effect of coagulant dosage and type as well as flocculant type on removal of COD, turbidity and color were investigated in two stages. Findings: The results of coagulation and flocculation experiments on raw wastewater showed that Alum at concentration of 40 mg/L was the most effective coagulant with COD, turbidity and color removal efficiency of 73.1±1.5%, 93.7% and 71.7%, respectively. However, the results of coagulation and flocculation experiments on the effluent from biological anaerobic treatment unit showed that the highest percentage of COD and turbidity removal were 52.2±2.6% and 99.1%, respectively that corresponds to PAC with concentration of 2000 mg/L. Additionally, the COD removal efficiency of FeCl3 coagulant at concentration of 400 mg/L was 52.2±3.5%. The difference in the results of the two stages was due to the change in the nature of the pollutants after exposure to biological treatment and different pH of the wastewater used in these stages. Discussion and Conclusion: A general review of the results showed that use of physicochemical treatment applying only coagulation and flocculation process could not reduce the pollutants present in the dyeing wastewater for reuse, while this method could be considered as a pretreatment or one of the secondary treatment steps and post treatment.
2016
Introduction: Carwash are industries that consume large amounts of water and results wastewater that have different type of pollutents(detergents, oil and grease, metals, etc.). Enough treatment of carwash wastewater is important and could be protect surface and ground water. Therefore, in this study ozonation process was used for carwash wastewater that generated from washing the cars in Yazd. Method: The study was conducted on a laboratory scale. Samples were collected from a carwash unit. In a cylindrical pilot packed reactor (with height=1 m and internal diameter=5 cm) with plastic bed, removal rate of COD and anionic surfactants determined by method digestion and Standard chloroform extraction, respectively during the ozonation process with Two Ozone doses (0.7 and 1.1 mg per minute), 3 reaction time (30, 60 and 90 minute) and three pH (7, 9 and 11) were used. Results: The results showed that removal efficiency of COD and anionic surfactants increases with increasing pH and reaction time. At pH =11 and after a reaction time of 90 minutes for an ozone dose of 1.1 mg/min, removal efficiency of COD and anionic surfactants was %68.57 and %77.71, respectively. Conclusion: The results showed that the ozonation process in packed bed rector has significant ability to remove COD and anionic surfactants from carwash wastewater. But this process alone cannot remove organic content of carwash wastewater completely. The ozonation process can be combined with other methods as appropriate and safe method for treating carwash wastewater.