scholarly journals Degradation of Direct Blue 1 through Heterogeneous Photocatalysis with TiO2 Irradiated with E-Beam

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1181
Author(s):  
Elvia Gallegos ◽  
Florinella Muñoz Bisesti ◽  
Katherine Vaca-Escobar ◽  
Cristian Santacruz ◽  
Lenys Fernández ◽  
...  

Most dyes used in the textile industry are chemically stable and poorly biodegradable, therefore, they are persistent in the environment and difficult to degrade by conventional methods. An alternative treatment for this kind of substance is heterogeneous photocatalysis using TiO2, so, in this work, it is proposed to degrade Direct Blue 1 (DB1) using microparticulate TiO2 irradiated with e-beam at three different doses: 5, 10 and 20 kGy (J/kg). The DB1 degradation was implemented in a batch reactor (DB1 initial concentration = 50 mg L−1, pH 2.5, TiO2 concentration = 200 mg L−1). We have demonstrated that the photocatalytic power of TiO2, when irradiated with e-beam (5, 10, 20 kGy), varies slightly, with minor effects on photodegradation performance. However, the dose of 10 kGy showed a slightly better result, according to the DB1 photodegradation rate constant. Adsorption process was not affected by irradiation; its isotherm was fitted to Freundlich’s mathematical model. The DB1 photodegradation rate constants, after one hour of treatment, were: 0.0661 and 0.0742 min−1 for irradiated (10 kGy) and nonirradiated TiO2, respectively. The degradation rate constant has an increase of 12.3% for irradiated TiO2. Finally, there was no evidence of mineralization in the degradation process after 60 min of treatment. According to the results, the irradiation of microparticulate TiO2 with e-beam (10 kGy) slightly improves the photodegradation rate constant of DB1.

2007 ◽  
Vol 61 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Dusan Mijin ◽  
Mirko Jugurdzija ◽  
Petar Jovancic

Synthetic dyes are widely used in the textile industry. Dye pollutants from the textile industry are an important source of environmental contamination. The majority of these dyes are toxic, mostly non-biodegradable and also resistant to decomposition by physico-chemical methods. Among new oxidation methods or "advanced oxidation processes", heterogeneous photocatalysis appears as an emerging destructive technology leading to the total mineralization of many organic pollutants. CI Basic Yellow 28 (BY28), commonly used as a textile dye, could be photocatalytically degraded using TiU2 as catalyst under sunlight. The effect of some parameters such as the initial catalyst concentration, initial dye concentration, initial NaCl and Na2CO3 concentrations, pH, H2O2 and type of catalyst on the degradation rate of BY28 was examined in details. The presence of NaCl and Na2CO3 led to inhibition of the photodegradation process. The highest photodegradation rate was observed at high pH, while the rate was the lowest at low pH. Increase of the initial H2O2 concentration increased the initial BY28 photodegradation efficiency. ZnO was a better catalyst than TiO2 at low dye concentrations.


2015 ◽  
Vol 15 (3) ◽  
pp. 533-540
Author(s):  
Jong Kyu Kim ◽  
Luiza Cintra Campos

Metaldehyde is best known as the main constituent of slug pellets. This organic compound has been found in relatively high levels in both surface and underground water. While many water treatment processes do not work with metaldehyde degradation, a photocatalytic degradation process has been proved to have a significant effect on metaldehyde stability. Nanosized ZnO/laponite composite (NZLC) was used as a photocatalyst in this investigation of metaldehyde degradation. The reactions were carried out in a ultraviolet C (UVC) lamp fitted batch reactor by considering the following parameters: initial metaldehyde concentration, pH of solution, and light intensity. A comparison of degradation efficiency between photolysis, photocatalysis, and adsorptive ability on NZLC indicated that the latter had the highest efficiency. Furthermore, higher metaldehyde degradation was observed as the initial concentration decreased. However, the fastest metaldehyde degradation rate in heterogeneous photocatalysis was obtained when pH values were greater than 7.0. Consequently, the findings suggest that the removal of metaldehyde by adsorption and photocatalytic degradation using NZLC under UV irradiation was a hybrid reaction process (i.e. photolysis, adsorption, and photocatalysis).


2019 ◽  
Vol 292 ◽  
pp. 01063
Author(s):  
Lubomír Macků

An alternative method of determining exothermic reactor model parameters which include first order reaction rate constant is described in this paper. The method is based on known in reactor temperature development and is suitable for processes with changing quality of input substances. This method allows us to evaluate the reaction substances composition change and is also capable of the reaction rate constant (parameters of the Arrhenius equation) determination. Method can be used in exothermic batch or semi- batch reactors running processes based on the first order reaction. An example of such process is given here and the problem is shown on its mathematical model with the help of simulations.


2010 ◽  
Vol 62 (11) ◽  
pp. 2579-2589 ◽  
Author(s):  
Koji Tani ◽  
Yoshihiko Matsui ◽  
Kentaro Narita ◽  
Koichi Ohno ◽  
Taku Matsushita

We quantitatively evaluated the factors that affect the concentrations of rice-farming pesticides (an herbicide and a fungicide) in river water by a sensitivity analysis using a diffuse pollution hydrologic model. Pesticide degradation and adsorption in paddy soil affected concentrations of the herbicide pretilachlor but did not affect concentrations of the fungicide isoprothiolane. We attributed this difference to the timing of pesticide application in relation to irrigation and drainage of the rice paddy fields. The herbicide was applied more than a month before water drainage of the fields and runoff was gradual over a long period of time, whereas the fungicide was applied shortly before drainage and runoff was rapid. However, the effects of degradability-in-water on the herbicide and fungicide concentrations were similar, with concentrations decreasing only when the rate constant of degradation in water was large. We also evaluated the effects of intermittent irrigation methods (irrigation/artificial drainage or irrigation/percolation) on pesticide concentrations in river water. The runoff of the fungicide, which is applied near or in the period of intermittent irrigation, notably decreased when the method of irrigation/artificial drainage was changed to irrigation/percolation. In a sensitivity analysis evaluating the synergy effect of degradation and adsorbability in soil, the degradation rate constant in soil greatly affected pesticide concentration when the adsorption coefficient was small but did not affect pesticide concentration when the adsorption coefficient was large. The pesticide concentration in the river water substantially decreased when either or both the degradation rate constant in soil and adsorption coefficient was large.


2018 ◽  
Vol 67 ◽  
pp. 01012 ◽  
Author(s):  
Nelson Saksono ◽  
Dwiputra Muhammad Zairin ◽  
Fikri Averous

Remazol Brilliant Blue is a dye waste mostly generated by the textile industry and can be very dangerous to the environment. Plasma electrolysis is a method that can produce hydroxyl radicals in large quantities in order to degrade the dye compounds. This study aims to test the ability of plasma electrolysis method to degrade Remazol Brilliant Blue wastewater using NaCl as electrolyte, with the addition of Fe2+ ion and air injection. Before the degradation process was carried out, permanganometric test was performed to see the production of hydroxyl radicals with the variations of electrolyte concentration and voltage. The degradation process were investigated more specifically by looking at the effect of Fe2+ ion concentration and the initial concentration of Remazol Brilliant Blue. Remazol Brilliant Blue degradation reached 98.5% in 30 minutes where the initial concentration of Remazol Brilliant Blue is 100 ppm, voltage of 750 V, NaCl concentration 0.03 M,with the addition of 40 ppm Fe2+ ion and air injection. The results show that plasma electrolysis with NaCl as electrolyte using air injection has a good potential in degrading dye wastewater in the environment.


2018 ◽  
Vol 67 ◽  
pp. 03031
Author(s):  
Tulus Sukreni ◽  
Nadya Saarah Amelinda ◽  
Nelson Saksono ◽  
Setijo Bismo

This research determined the optimum concentration of Fe2+ to degrade waste textile dye by Contact Glow Discharge Electrolysis (CGDE) method with air injection. The addition of Fe2+ ions can increase the degradation rate of the dye waste due to the radical catalytic conversion of H2O2 producing OH radicals that play a significant role in the degradation process. Remazol Red was used as a dye synthetic dye which was degraded using a batch reactor equipped with continuous cooling water. Experimental results showed that waste concentrations of 100, 200, 300 and 400 ppm obtained the optimum Fe2+ concentration at 10, 20, 30 and 40 ppm, respectively. The higher concentration of dye waste indicated the higher the Fe2+ ion requirement to decrease the textile dye waste.


2020 ◽  
Vol 1008 ◽  
pp. 97-103
Author(s):  
Mahmoud Samy ◽  
Mona G. Ibrahim ◽  
Mohamed Gar Alalm ◽  
Manabu Fujii

Methylene blue (MB) is one of the commonly used dyes in the textile industry and can be used as a model pollutant for the textile industry wastewater. In this work, the photocatalytic degradation of MB by synthesized nanoparticles of lanthanum vanadate (LaVO4) was assessed. The effects of pH, initial MB concentration and catalyst dose on the removal performance of MB were investigated and measuring the optimum values of these operational conditions was performed using response surface methodology (RSM). Catalyst dose of 0.43 g/L, initial MB concentration of 5.0 mg/L, and pH of 6.86 were found to be the optimum conditions in reaction time of 60 min. A mathematical model was formed to relate the removal efficiency of MB to the aforementioned operating parameters. The removal efficiency of MB was 91% without any scavengers at a catalyst dose of 0.3 g/L, pH of 7 and initial MB concentration of 10 mg/L. The trapping experiments confirmed the participation of different reactive species in the photo-degradation process. The degradation rates of MB were 91%, 86%, 81%, 77.70% and 72% in five successive runs using LaVO4.


Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1003 ◽  
Author(s):  
Ainoa Murcia-Salvador ◽  
José A. Pellicer ◽  
María I. Fortea ◽  
Vicente M. Gómez-López ◽  
María I. Rodríguez-López ◽  
...  

The dyeing industry is one of the most polluting in the world. The adsorption of dyes by polymeric matrixes can be used to minimize the discharge of dyes into the environment. In the present study, chitosan-NaOH and β-cyclodextrin-epichlorohydrin polymers were used to remove the dye Direct Blue 78 from a wastewater model. To understand the adsorption behavior of Direct Blue 78 onto the polymers, adsorption rate and maximum adsorption capacity were calculated using kinetic tests and isotherm curves respectively. The kinetic data and mechanism of the adsorption process were analyzed by three models and the equilibrium data by three adsorption isotherms; also the different thermodynamic parameters were calculated. Results showed that the adsorption process follows pseudo-second-order kinetics in both polymers and the Langmuir isotherm best-fitted data for chitosan-NaOH polymer and the Freundlich isotherm for the β-CDs-EPI polymer. The adsorption process is exothermic in both cases and spontaneous for the β-CDs-EPI polymer to a certain temperature and not spontaneous for the chitosan-NaOH polymer and β-CDs-EPI polymer at higher temperatures. The complementary action of an advanced oxidation process eliminated >99% of the dye from water. The coupled process seems to be suitable for reducing the environmental impact of the dyeing industry.


Water SA ◽  
2018 ◽  
Vol 44 (2 April) ◽  
Author(s):  
E Miranda-Mandujano ◽  
G Moeller-Chávez ◽  
O Villegas-Rosas ◽  
Germán Buitrón ◽  
MA Garzón-Zúñiga

In this work the decolourization of Direct Blue 2 dye (DB2) using an industrial soybean waste as a source of peroxidases was studied. Temperature, pH, amount of H2O2 and concentration of dye were evaluated to determine the maximum catalytic activity of the enzyme during the dye degradation process. It was observed that a temperature of 40°C, a pH of 5 and a concentration of 40 mg/L for the dye in aqueous phase, play a significant role in the overall enzyme-mediated reaction. The maximum decolourization efficiency achieved under optimal conditions was 70% ± 4%. HPLC studies were carried out to confirm dye degradation and analyse the intermediate metabolites. The oxidation products quantified during the reaction were benzidine and 4 aminobiphenyl. Also, an increase in toxicity, determined by Vibrio fisheri, was observed after the enzymatic oxidation of the dye. Results suggest that the oxidation of DB2 with peroxidases can be recommended as a pretreatment step before a conventional treatment process.


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