scholarly journals Effects of operational parameters of process UV radiation/hydrogen peroxide on decolorization of anthraquinone textile dye

2012 ◽  
Vol 66 (4) ◽  
pp. 479-486
Author(s):  
Miljana Radovic ◽  
Jelena Mitrovic ◽  
Danijela Bojic ◽  
Milos Kostic ◽  
Radomir Ljupkovic ◽  
...  

The photodegradation of textile dye Reactive Blue 19, an anionic anthraquinone dye of reactive class, was investigated using UV radiation in the presence of H2O2 in UV reactor with low-pressure mercury lamps, with maximum energy output at the wavelength 254 nm. The effects of experimental variables, namely initial pH, initial dye concentration and concentration of peroxide were studied. The change of concentration of RB19 was followed by UV/vis spectrophotometric measurement of absorbance at 592 nm. The increase of the initial pH resulted in the efficiency increase of dye decolorization. The total decolorization was achieved in about 15 min. Results show that with the increase of dye concentration from 10 to 100 mg dm-3 the efficiency of process decreases. With the increase of the initial concentration of H2O2 from 10 to 30 mmol dm-3, the decolorization rate constant increased from 0.083 to 0.120 min1, with the decrease of process rate at the concentrations above. The highest decolorization rates were achieved at peroxide concentration of approx. 30 mmol dm-3, above which decolorization was inhibited by scavenging effect of peroxide. This study shows that UV/H2O2 process is promising treatment for dye RB 19 degradation in water and wastewater.

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2532 ◽  
Author(s):  
Md. Nahid Pervez ◽  
Felix Y. Telegin ◽  
Yingjie Cai ◽  
Dongsheng Xia ◽  
Tiziano Zarra ◽  
...  

In this study, a Fenton-activated persulfate (Fe2+/PS) system was introduced for the efficient degradation of Mordant Blue 9 (MB 9) as a textile dye in an aqueous solution. Results showed that the degradation of MB 9 was markedly influenced by operational parameters, such as initial pH, PS concentration, Fe2+ concentration, and initial dye concentration. Optimal reaction conditions were then determined. Inorganic anions, such as Cl− and HCO3−, enhanced the degradation efficiency of MB 9 under optimal conditions. Addition of HCO3− reduced the degradation performance of MB 9, whereas the addition of Cl− increased the degradation percentage of MB 9. In addition, quenching experiments were conducted using methanol and tert-butyl alcohol as scavengers, and methanol was identified as an effective scavenger. Thus, the degradation of MB 9 was attributed to S O 4 • − and •OH radicals. The degradation and mineralization efficiency of MB 9 was significantly reduced using the conventional Fenton process i.e., Fe2+/ hydrogen peroxide (HP) because of the formation of a Fe complex during degradation. Meanwhile, the Fe2+/persulfate (PS) system improved the degradation and mineralization performance.


Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2870 ◽  
Author(s):  
Jingjing Xue ◽  
Reza Ahmadian ◽  
Roger Falconer

Marine renewable energy, including tidal renewable energy, is one of the less exploited sources of energy that could contribute to energy demand, while reducing greenhouse gas emissions. Amongst several proposals to build tidal range structure (TRS), a tidal lagoon has been proposed for construction in Swansea Bay, in the South West of the UK, but this scheme was recently rejected by the UK government due to the high electricity costs. This decision makes the optimisation of such schemes more important for the future. This study proposes various novel approaches by breaking the operation into small components to optimise the operation of TRS using a widely used 0-D modelling methodology. The approach results in a minimum 10% increase in energy output, without the inclusion of pumping, in comparison to the maximum energy output using a similar operation for all tides. This increase in energy will be approximately 25% more when pumping is included. The optimised operation schemes are used to simulate the lagoon operation using a 2-D model and the differences between the results are highlighted.


2013 ◽  
Vol 69 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Sakthivel Pitchaimuthu ◽  
Ponnusamy Velusamy

An attempt has been made to enhance the photocatalytic activity of CeO2 for visible light assisted decoloration of methylene blue (MB) dye in aqueous solutions by β-cyclodextrin (β-CD). The inclusion complexation patterns between host and guest (i.e., β-CD and MB) have been confirmed with UV–visible spectral data. The interaction between CeO2 and β-CD has also been characterized by field emission scanning electron microscopy analysis. The photocatalytic activity of the catalyst under visible light was investigated by measuring the photodegradation of MB in aqueous solution. The effects of key operational parameters such as initial dye concentration, initial pH, CeO2 concentration as well as illumination time on the decolorization extents were investigated. Among the processing parameters, the pH of the reaction solution played an important role in tuning the photocatalytic activity of CeO2. The maximum photodecoloration rate was achieved at basic pH (pH 11). Under the optimum operational conditions, approximately 99.6% dye removal was achieved within 120 min. The observed results indicate that the decolorization of the MB followed a pseudo-first order kinetics.


2011 ◽  
Vol 6 (1) ◽  
Author(s):  
M. Behbahani ◽  
M.R. Alavi Moghaddam ◽  
M. Arami

The aim of this study is to examine the effect of operational parameters on fluoride removal using electrocoagulation method. For this purpose, various operational parameters including initial pH, initial fluoride concentration, applied current, reaction time, electrode connection mode, anode material, electrolyte salt, electrolyte concentration, number of electrodes and interelectrode distance were investigated. The highest defluoridation efficiency achieved at initial pH 6. In the case of initial fluoride concentration, maximum removal efficiency (98.5%) obtained at concentration of 25mg/l. The increase of applied current and reaction time improved defluoridation efficiency up to 99%. The difference of fluoride removal efficiencies between monopolar and bipolar series and monopolar parallel were significant, especially at reaction time of 5 min. When aluminum used as anode material, higher removal efficiency (98.5%) achieved compared to that of iron anode (67.7%). The best electrolyte salt was NaCl with the maximum defluoridation efficiency of 98.5% compared to KNO3 and Na2SO4. The increase of NaCl had no effect on defluoridation efficiency. Number of electrodes had little effect on the amounts of Al3+ ions released in the solution and as a result defluoridation efficiency. Almost the same fluoride removal efficiency obtained for different interelectrode distances.


2021 ◽  
Vol 16 (3) ◽  
pp. 673-685
Author(s):  
D. Hadj Bachir ◽  
Hocine Boutoumi ◽  
H. Khalaf ◽  
Pierre Eloy ◽  
J. Schnee ◽  
...  

TiO2 pillared clay was prepared by intercalation of titan polyoxocation into interlamelar space of an Algerian montmorillonite and used for the photocatalytic degradation of the linuron herbicide as a target pollutant in aqueous solution. The TiO2 pillared montmorillonite (Mont-TiO2) was characterized by X-ray photoelectron spectroscopy (XPS), X-Ray diffraction (XRD), X-Ray fluorescence (XRF), scanning electronic microscopy (SEM), thermogravimetry and differential thermal analysis (TG-DTA), Fourier transformed infra-red (FT-IR), specific area and porosity determinations. This physicochemical characterization pointed to successful TiO2 pillaring of the clay. The prepared material has porous structure and exhibit a good thermal stability as indicated by its surface area after calcination by microwave. The effects of operating parameters such as catalyst loading, initial pH of the solution and the pollutant concentration on the photocatalytic efficiency and COD removal  were evaluated. Under initial pH of the solution around seven, pollutant concentration of 10 mg/L and 2.5 g/L of catalyst at room temperature, the degradation efficiency and COD removal of linuron was best then the other operating conditions. It was observed that operational parameters play a major role in the photocatalytic degradation process. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 


2018 ◽  
Vol 7 (3.18) ◽  
pp. 11
Author(s):  
Musse Mohamud Ahmed ◽  
Mohammad Kamrul Hasan ◽  
Mohammad Shafiq

The main purpose of this paper is to present a novel idea that is based on design and development of an automatic solar tracker system that tracks the Sun's energy for maximum energy output achievement. In this paper, a novel automatic solar tracking system has been developed for small-scale solar energy system. The hardware part and programming part have been concurrently developed in order for the solar tracking system to be possible for it to operate accurately. Arduino Uno R3, Sensor Shield V4 Digital Analog Module, LDR (Light Dependent Resistor), MPU-6050 6DOF 3 Axis Gyroscope has been used for tracking the angular sun movement as shown in Fig. 1. Accelerometer, High-Efficiency Solar Panel, and Tower Pro MG90S Servo Motor have been used for the hardware part. High-level programming language has been embedded in the hardware to operate the tracking system effectively. The tracking system has shown significant improvement of energy delivery to solar panel comparing to the conventional method. All the results will be shown in the full paper. There are three contributions the research presented in this paper which are, i.e. perfect tracking system, the comparison between the static and tracking system and the development of Gyroscope angular movement system which tracks the angular movement of the sun along with another tracking system.  


2020 ◽  
Vol 82 (9) ◽  
pp. 1961-1970
Author(s):  
Yu Gao ◽  
Shibo Cong ◽  
Yulun He ◽  
Donglei Zou ◽  
Yuzhi Liu ◽  
...  

Abstract Among the different antibiotics, tetracycline hydrochloride (TCH) is one of the most commonly used. In this study, the activated sodium persulfate (SPS) process induced by microwave (MW) energy was used to treat TCH. The effect of different operational parameters of MW/SPS-treated TCH, such as SPS concentration, TCH concentration, initial pH, and MW power, was investigated. The concentration changes of TCH were determined using a spectrophotometer. The results of radical scavenger experiments indicated that the sulfate radical () was stronger than the hydroxyl radical (·OH). On the basis of high performance liquid chromatography–mass spectrometry (HPLC–MS) analysis, a possible degradation pathway of TCH was proposed. This research indicates that the MW/SPS system is a promising prospect for the treatment of TCH.


2016 ◽  
Vol 74 (9) ◽  
pp. 1999-2009 ◽  
Author(s):  
Sayed Mohammad Bagher Hosseini ◽  
Narges Fallah ◽  
Sayed Javid Royaee

This study evaluates the advanced oxidation process for decolorization of real textile dyeing wastewater containing azo and disperse dye by TiO2 and UV radiation. Among effective parameters on the photocatalytic process, effects of three operational parameters (TiO2 concentration, initial pH and aeration flow rate) were examined with response surface methodology. The F-value (136.75) and p-value <0.0001 imply that the model is significant. The ‘Pred R-Squared’ of 0.95 is in reasonable agreement with the ‘Adj R-Squared’ of 0.98, which confirms the adaptability of this model. From the quadratic models developed for degradation and subsequent analysis of variance (ANOVA) test using Design Expert software, the concentration of catalyst was found to be the most influential factor, while all the other factors were also significant. To achieve maximum dye removal, optimum conditions were found at TiO2 concentration of 3 g L−1, initial pH of 7 and aeration flow rate of 1.50 L min−1. Under the conditions stated, the percentages of dye and chemical oxygen demand removal were 98.50% and 91.50%, respectively. Furthermore, the mineralization test showed that total organic compounds removal was 91.50% during optimum conditions.


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