Feizollah Dinarvand; Nematollah Jaafarzadeh; Mehdi Ahmadi Moghadam; Mohammad Bagher Miranzadeh; Nezam Mirzaei
Abstract
Introduction and Aims: Compounds containing dye are toxic, carcinogenic and mutagenic for aquatic organisms and lead to mutagenicity, carcinogenicity, and dysfunction of human beings’ kidney, liver, brain, reproductive system and central nervous system. Advanced oxidation processes can remove pollutants ...
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Introduction and Aims: Compounds containing dye are toxic, carcinogenic and mutagenic for aquatic organisms and lead to mutagenicity, carcinogenicity, and dysfunction of human beings’ kidney, liver, brain, reproductive system and central nervous system. Advanced oxidation processes can remove pollutants faster than other processes due to active hydroxyl radical production. This study was aimed at investigating feasibility of dye removal using UVA/TiO2 process.Materials and methods: This study was done in a batch reactor and the effects of initial dye concentrations, TiO2 nanoparticles dosage, time, pH and interference compounds on efficiency of dye degradation was investigated. The Daphnia Magna as bioassay test and biodegradability index (BOD5/COD rate) were used for detoxification assessment.Results: The D.Y 50 dye effluent degradation at pH 2, 20 mg/l initial dye concentration and 1 g/l TiO2 catalyst was (lnC0/C= 1.4), (lnC0/C= 3) and (lnC0/C= 2.9) respectively. Dye removal rate by 50 mg/l COD concentration was (88%), Daphnia Magna mortality rate after maximum contact time (96 h) decreased from 96.7% to 43.3% and biodegradability index increased from 0.25 to 0.68.
Jyoti A. Agashe; Dipak R. Tope; sachin S Kushare; Ashok V Borhade
Abstract
Nanocrystalline UV light induced composite CeO2:SiO2 with high surface area and low band gap energy were prepared in order to assess its photocatalytic degradation capacity of target pollutant (mixture of dyes). The complete mineralization of target dye pollutants (30 ppm) occurred within 150 min. when ...
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Nanocrystalline UV light induced composite CeO2:SiO2 with high surface area and low band gap energy were prepared in order to assess its photocatalytic degradation capacity of target pollutant (mixture of dyes). The complete mineralization of target dye pollutants (30 ppm) occurred within 150 min. when CeO2:SiO2 catalyst with optimum loading 0.4 g was used. Overall, the present system is economical, reproducible and highly efficient. Further the comparative study on photocatalytic efficiency of SiO2 and CeO2 was compared with composite CeO2:SiO2. The effect of various operational parameters used in degradation like concentration of dye, amount of photocatalyst and various catalyst has been studied on the rate of reaction. The recyclability of the photocatalyst, CeO2:SiO2 was performed up to four runs. The photodegradation of waste water pollutants was occurred nearly 96 % using CeO2:SiO2 nanoparticles. The removal of waste water pollutants was confirmed by UV spectrophotometer by diminishing the absorbance to zero within 120 min using CeO2:SiO2 nanoparticles. The synthesized catalyst was characterized by various analytical investigative techniques like UV-DRS, FTIR, XRD, SEM, TEM and BET.
PARMESHWAR LAL MEENA; Ajay Kumar Surela; Krishna Poswal
Abstract
Here in the present study, we report the synthesis of ZnO nanoparticles, ZnO/CuO(3%), ZnO/CuO(5%), and ZnO/CuO(10%), nanocomposites using simple precipitation method with variation of CuO content and the activities of prepared samples were investigated for degradation of Brilliant Cresyl Blue (BCB) dye ...
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Here in the present study, we report the synthesis of ZnO nanoparticles, ZnO/CuO(3%), ZnO/CuO(5%), and ZnO/CuO(10%), nanocomposites using simple precipitation method with variation of CuO content and the activities of prepared samples were investigated for degradation of Brilliant Cresyl Blue (BCB) dye under visible light conditions in aqueous solutions. The structural, morphology, optical and compositional characteristics of fabricated samples were characterized by using Fourier Transform Infra-Red (FTIR) Spectroscopy, Field Emission Scanning Electron Microscopy combine electron dispersive spectroscopy (FESEM-EDS) and UV-vis spectroscopy. FESEM images show that ZnO nanoparticles are polygon like shape structure while ZnO/CuO have polygon and sheet shape structures. XRD patterns reflect the high crystalinity and purity of samples. The optical band gap values determined from optical absorption method indicate that band gap energy decreased with increase of CuO content in ZnO. The catalytic efficiency of the ZnO/CuO hybrid nanocomposite was observed to be higher than the ZnO nanoparticles under similar reaction conditions, 97.30% of Brilliant Cresyl Blue (BCB) dye was degraded after 100 min of irradiation of visible light radiation using the ZnO/CuO(5%) hybrid nanocomposite. The higher efficiency of ZnO/CuO compare to ZnO may be due to increased surface area and decreased band gap energy. The kinetic study of the photoctalytic degradation displayed that hybrid ZnO/CuO degrdaded dye with high rate constant k (34.88x10-3 min -1) compare to ZnO (k, 7.00x10-3 min-1). The optimization of reaction conditions of photodegradation process were attained by the variation in reaction factors such as pH, dye concentration, catalyst amount, and reaction time.
Shirish Sadashiv Pingale; Shobha Vasant Rupanar; Manohar Chaskar
Abstract
The present study reports one step green synthesis of silver nanoparticles using Gymnema sylvestre aqueous extract at room temperature and their usage in the photodegradation of methyl orange dye. The silver nanoparticles are synthesized using an aqueous extract of stem and root of Gymnema sylvestre. ...
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The present study reports one step green synthesis of silver nanoparticles using Gymnema sylvestre aqueous extract at room temperature and their usage in the photodegradation of methyl orange dye. The silver nanoparticles are synthesized using an aqueous extract of stem and root of Gymnema sylvestre. UV-Visible spectral analysis showed absorbance peak at 430 nm with special reference to the excitation of surfaces plasmon vibration by silver nanoparticles. FT-IR analysis of nanoparticles reveals the presence of molecular functional groups such as amides, phenolic compounds, and carboxylic acid. These phytochemicals act capping and stabilizing agents for silver nanoparticles. EDAX elemental analysis shows the presence of silver as the main element in synthesized nanoparticles. The average crystalline size of silver nanoparticles was found to be 25.3 nm and 9.97 nm for Stem-AgNPs and Root-AgNPs respectively by Scherer formula. XRD patterns also suggest the occurrence of crystalline silver ions. Further, photocatalytic degradation of methyl orange was measured spectrophotometrically by using silver nanoparticles as nanocatalyst under solar light effect. The results revealed that biosynthesized silver nanoparticles using G. sylvestyre was found to be notable in degrading methyl orange dye under the influence of sunlight.