Intensified Photocatalytic Degradation of Solophenyl Scarlet BNLE in Simulated Textile Effluents Using TiO2 Supported on Cellulosic Tissue

Author(s):  
Ikram Rouibah ◽  
Hichem Zeghioud ◽  
Nabila Khellaf ◽  
Amine ASSADI Aymen ◽  
Hédi Benmansour ◽  
...  

AbstractThe Heterogeneous photocatalysis, increasingly used in effluent purification, is attracting more and more attention by the development of new photocatalytic materials based on semiconductors deposited on various supports. In this work, TiO2 supported on cellulosic fiber was prepared and characterized by different analytical techniques such as X-ray Photoelectron Spectrometry and Brunauer-Emmett-Teller surface area. Its photocatalytic activity was investigated for the degradation of Solophenyl Scarlet BNLE (SS), an organic pollutant present in textile effluents. Several conditions were investigated such as adsorption under UV and visible irradiation, catalyst recyclability, the simulated effluent pH and the presence of H2O2 as an oxidant agent. Results showed that under UV light, the removal of SS decreased significantly with increasing initial dye concentration. For an initial concentration of 5 mg/L, SS degradation was reached more than 95 % after 2 hours of treatment (neutral pH, T = 20 °C). The supported TiO2 on cellulose remains effective over four cycles of dye treatment. In the presence of H2O2, the degradation process was inhibited with increasing the molar ratio [H2O2]/[SS]0 from 5 to 30. The kinetic modeling showed that the removal of this pollutant followed a pseudo-first-order model (Langmuir-Hinshelwood) with a regression coefficient (R2) value of 0.984.

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 117
Author(s):  
Zahir Muhammad ◽  
Farman Ali ◽  
Muhammad Sajjad ◽  
Nisar Ali ◽  
Muhammad Bilal ◽  
...  

Degradation of organic dyes and their byproducts by heterogeneous photocatalysts is an essential process, as these dyes can be potentially discharged in wastewater and threaten aquatic and xerophyte life. Therefore, their complete mineralization into nontoxic components (water and salt) is necessary through the process of heterogeneous photocatalysis. In this study, Zr/CrO2 (Zirconium-doped chromium IV oxide) nanocomposite-based photocatalysts with different compositions (1, 3, 5, 7 & 9 wt.%) were prepared by an environmentally friendly, solid-state reaction at room temperature. The as-prepared samples were calcined under air at 450 °C in a furnace for a specific period of time. The synthesis of Zr/CrO2 photocatalysts was confirmed by various techniques, including XRD, SEM, EDX, FT-IR, UV-Vis, and BET. The photocatalytic properties of all samples were tested towards the degradation of methylene blue and methyl orange organic dyes under UV light. The results revealed a concentration-dependent photocatalytic activity of photocatalysts, which increased the amount of dopant (up to 5 wt.%). However, the degradation efficiency of the catalysts decreased upon further increasing the amount of dopant due to the recombination of holes and photoexcited electrons.


Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 855
Author(s):  
Ahmed Amine Azzaz ◽  
Salah Jellali ◽  
Nasser Ben Harharah Hamed ◽  
Atef El Jery ◽  
Lotfi Khezami ◽  
...  

In the present study, methylene blue (MB) removal from aqueous solutions via the photocatalytic process using TiO2 as a catalyst in the presence of external ultra-violet light (UV) was investigated. The results of adsorption in the absence of UV radiation showed that adsorption reached an equilibrium state at 60 min. The experimental kinetic data were found to be well fitted by the pseudo-second-order model. Furthermore, the isotherm study suggested that dye uptake by TiO2 is a chemisorption process with a maximum retention capacity of 34.0 mg/g. The photodegradation of MB was then assessed under various experimental conditions. The related data showed that dye mineralization decreased when dye concentrations were increased and was favored at high pH values and low salt concentrations. The simultaneous presence of organic and inorganic pollution (Zinc) was also evaluated. The effect of the molar ratio Zn2+/MB+ in the solution at different pH values and NaCl concentrations was also monitored. The corresponding experimental results showed that at low values of Zn2+ in the solution (30 mg/L), the kinetic of the MB removal became faster until reaching an optimum at Zn2+/MB+ concentrations of 60/60 mg/L; it then slowed down for higher concentrations. The solutions’ carbon contents were measured during the degradation process and showed total mineralization after about 5 h for the optimal Zn2+/MB+ condition.


1995 ◽  
Vol 50 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Andreas Karst ◽  
Burkhardt Broschk ◽  
Joseph Grobe ◽  
Duc Le Van

Reaction of the cyclotetraphosphane (PCF3)4 or of a mixture of (PCF3)4 and (PCF3)5 with 2,3-dimethyl-1,3-butadiene or isoprene at 25 °C leads to the [4 + 2]-cycloadducts of bis(trifluoromethyl) diphosphene and the phospholene derivatives 2a and 2b, respectively, in the molar ratio diphosphinine/phospholene = 1/2. The analogous reactions of the cycloarsanes (AsCF3)4,5 give the Diels/Alder compounds 4 and 5 of bis(trifluoromethyl)diarsene in 90% yield without arsolene formation. Cyclopentadiene, 1,3-cyclohexadiene and cis or trans piperylene do not react with (AsCF3)4,5, up to temperatures of 60 °C. However, the corresponding [4 + 2]-cycloadducts 6 - 8 are produced by irradiation of the reaction mixture with UV light. The novel phospholenes 2a and 2b as well as the diarsinines 4 - 8 have been characterized by spectroscopic data (MS, NMR, IR). 2a was coordinated as a phosphane ligand to the pentacarbonylchromium fragment by reaction with the photochemically generated complex Cr(CO)5 · THF to afford the new compound (3).


1999 ◽  
Vol 40 (1) ◽  
pp. 183-190 ◽  
Author(s):  
N. H. Ince ◽  
G. Tezcanlı

Treatability of textile dye-bath effluents by advanced oxidation with Fenton and Fenton-like reagents (FeII/H2O2 and FeIII/H2O2), in the presence and absence of UV light was investigated, using a reactive azo-dye (Procion Red HE7B), and typical dye bath constituents. Under the experimental conditions employed, it was found that with 20 min UV irradiation, complete color removal and 79% total organic carbon degradation is possible, when the system is operated at pH=3, and with a H2O2/Fe(II) molar ratio of 20:1. The increased dissolved solids content of the treated solution implies the necessity of an appropriate membrane system to make the effluent reusable in the dye/wash processes.


2018 ◽  
Vol 80 (2) ◽  
Author(s):  
Klinsmann Cheong Lee Khang ◽  
Mohd Hayrie Mohd Hatta ◽  
Siew Ling Lee ◽  
Leny Yuliati

A series of mesoporous ZnO/TiO2 composites were successfully synthesized using cetyltrimethylammonium bromide surfactant. The composites of different Zn:Ti molar ratios (0.5:1, 0.75:1, and 1:1) were prepared by impregnating ZnO onto mesoporous TiO2. XRD results verified co-existence of both anatase TiO2 and hexagonal wurtzite ZnO in the ZnO/TiO2 composites. Based on the Tauc plots, all the composites showed almost the same band gap energy of approximately 3.21 eV. The fourier transform infrared spectroscopy results successful covering of ZnO on the surface of the TiO2 as the hydrophilicity property of TiO2 decreased remarkably with the loading of ZnO in the composites. N2 adsorption-desorption isotherms of the samples exhibited type-IV isotherm with a hysteresis loop. The Barrett-Joyner-Halenda pore size distribution revealed that the average pore size of the composites was around 3.6 nm, indicating the formation of mesopores dominantly in the samples. The photocatalytic removal of phenol over the samples under UV light irradiation after 3 h decreased in the order: ZnO/TiO2 composites > anatase TiO2 (with surfactant) > anatase TiO2 (without surfactant) > ZnO. The composite with Zn:Ti molar ratio of 0.75:1 has achieved the highest photocatalytic activity of 36.5% in the removal of phenol under UV light irradiation for 3 h.


2012 ◽  
Author(s):  
Rusmidah Ali ◽  
Siti Salamah Maisoan @ Selamat

Asid amino merupakan bahan asas dalam tisu tumbuhan dan haiwan. Tirosina (Tr) salah satu jenis asid amino yang mengandungi gelang aromatik, telah dipilih sebagai sampel untuk proses degradasi dalam medium akueus. Ini bertujuan melihat kesan penggunaan mangkinfoto dalam sinaran ultralembayung (λ < 400 nm) atau cahaya matahari ke atas molekul tirosina. Kajian telah dijalankan menggunakan sistem cahaya, mangkin serbuk TiO2, hidrogen peroksida, H2O2 dan ion logam. Penambahan ion logam seperti Ni2+, Cu2+, Ag+, Mn2+, Co2+, Fe2+ dan Cd2+ dan agen pengoksidaan, iaitu hidrogen peroksida adalah untuk mendapatkan kaedah yang paling cekap. Keputusan menunjukkan penambahan H2O2 dan ion Fe2+ dan Ni2+ berjaya meningkatkan kecekapan proses degradasifoto tirosina. Ion Ni2+ memberikan keputusan terbaik berbanding ion-ion lain. Ion Cu2+, Ag+, Mn2+ dan Cd2+ merencat proses degradasi. Keputusan juga menunjukkan cahaya matahari adalah setanding dengan cahaya ultralembayung. Kepekatan H2O2 terbaik adalah 5.0 x 10-2M dan semakin banyak TiO2 digunakan semakin baik peratus degradasi tirosina. Oleh itu kaedah optimum untuk proses degradasifoto ialah Tr 2.5 x 10-4 M + TiO2 + H2O25.0 x 10-3 M + Mn+ 1.0 x 10-2 M. Proses degradasifoto dikaji menggunakan spektroskopi ultralembayung-nampak pada julat panjang gelombang 400-200 nm. Kata kunci: Tirosina; degradasifoto; serbuk TiO; akueus Amino acid is a basic component in plant or animal tissue. Tyrosine (Tr), an amino acid which contains aromatic ring, was chosen as a sample for a photodegradation process in an aqueous system. The purpose of the experiment is to study the effect of photocatalysis under UV (λ < 400 nm) or sunlight on tyrosine. The experiment was carried out by using UV light, catalyst powder (TiO2), hidrogen peroxide H2O2 and metal ions system. The addition of oxidising agent H2O2 and metal ions such as Ni2+, Cu2+, Ag+, Mn2+, Co2+, Fe2+ and Cd2+ were used in order to achieve the most efficient system. Results showed that the system with added H2O2 and metal ions such as Ni2+ and Fe2+ had successfully enhanced the process of the tyrosine photodegradation. Other metal ions system such as Cu2+, Ag+, Mn2+ and Cd2+ were found to inhibit the degradation process. The results also showed that sunlight was comparable to ultraviolet light. The best H2O2 concentration was 5.0 x 10-2 M and the percentage of tyrosine degradation increased with the addition of more TiO2) by mass. Therefore, the optimum condition for tyrosine photodegradation process was in Tr 2.5 x 10-4 M + TiO2 + H2O2 5.0 x 10-3 M + H2O2 1.0 x 10-2 M. The dissappearance of tyrosine in the photo degradation process was monitored by UV-visible spectroscopy between 400-200 nm. Key words: Tyrosine; photodegradation; TiO2 powder; akueus


2018 ◽  
Vol 233 (6) ◽  
pp. 411-419 ◽  
Author(s):  
Dan Zhao ◽  
Cong-Kui Nie ◽  
Ye Tian ◽  
Bao-Zhong Liu ◽  
Yun-Chang Fan ◽  
...  

Abstract A new borate compound K3GdB6O12 has been prepared using a high temperature flux method and structurally characterized by single crystal X-ray diffraction analysis. The structure can be described as a three-dimensional framework that is composed of [B5O10]5− groups, K+ ions and Gd3+ ions. In this structure, one crystallographic distinct site is mixed occupied by K and Gd atoms at the molar ratio of 1:1. Furthermore, Sm3+ ion was used as the activator to test primary of K3GdB6O12 to be used as a luminescent host matrix. A series of phosphors K3Gd1−xB6O12:xSm3+ were synthesized by conventional solid-state reaction. The photoluminescence properties and concentration quenching of the prepared phosphors were investigated. The results show that K3Gd1−xB6O12:xSm3+ can be efficiently excited by near-UV light. K3Gd1−xB6O12:xSm3+ might be a promising candidate for visual display and solid-state lighting as an orange emission phosphor.


2021 ◽  
Vol 1019 ◽  
pp. 194-204
Author(s):  
S. Sudhaparimala ◽  
R. Usha

Graphene, functionalized with the heteroatoms like nitrogen, oxygen and sulphur atoms has been well explored for a wide range of applications but only few reports are available on its adsorption and photocatalytic application in the degradation of chlorophenols and organic dyes. A simple and energy-efficient process to prepare graphene oxide and sulphur doped graphene oxide was developed. The micro structure and surface morphology were confirmed by the analytical techniques of Powder X-ray diffractogram (PXRD), Fourier Transformed Raman Spectroscopy (FT-Raman), Scanning Electron Microscopy. The results were suggestive of the structures suitable for screening their catalytic activity in the degradation of the highly toxic polychlorophenols and organic dyes. The adsorption and photo catalytic properties of the asprepared samples were screened for the degradation process and it was found that sulphur doped graphene oxide showed more positive results for the degradation of chlorophenols than graphene oxide. Under the given experimental conditions the decoloration of dyes were not satisfactory. Ultimately, the study provided an economical and efficient, method for tuning graphene structures for the removal of pollutants in wastewater.


2018 ◽  
Vol 13 ◽  
pp. 117739011876336 ◽  
Author(s):  
Eman Alzahrani

Fast Green (FCF) dye is commonly used in both cytology and histology applications. Previous studies have found that it can cause mutagenic and tumorigenic effects in experimental human and animal populations. It can also be a source of skin, eye, respiratory, and digestive irritation. The purpose of this study was to examine the use of thin film membranes to degrade FCF. A thin film membrane of chitosan (CS) was fabricated and subsequently filled with zinc oxide nanoparticles (ZnO) or ZnO/CuO-heterostructured nanocomposites. The CS membrane was used as a matrix, and the nanomaterials were used as photocatalysts. The prepared membranes were characterised by four analytical techniques: atomic force microscopy, scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray analyses. The photocatalytic activity of the fabricated membranes was evaluated by performing experiments in which aqueous solutions of FCF dye that contained the fabricated membrane were irradiated with solar light or UV light. The photodegradation percentage was spectrophotometrically determined by monitoring the maximum wavelengths (λmax) of FCF at 623 nm for different irradiation times. The decolourisation percentages of the dye under solar light were 57.90% and 60.23% using the CS-ZnO and CS-ZnO/CuO membranes, respectively. When UV light irradiation was employed as the source of irradiation, the photodegradation percentages of FCF were 71.45% and 91.21% using the CS-ZnO and CS-ZnO/CuO membranes, respectively. These results indicated that the best photocatalytic system for the degradation of FCF dye was CS-ZnO/CuO membrane in combination with UV light irradiation. The study also found that it was easy to separate the prepared membranes after the reaction without the need for a centrifuge or magnet. The results demonstrate the potential for CS-ZnO and CS-ZnO/CuO membranes for use as effective sorbents during the process of photodegradation of harmful dyes within waste water recycling practices.


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.


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