scholarly journals Solar photocatalytic degradation of azo dye Reactive Black 5 in aqueous suspension of TiO2

2011 ◽  
Vol 1 (4) ◽  
pp. 202-207 ◽  
Author(s):  
Soon-An Ong ◽  
Ohm Mar Min ◽  
Li-Ngee Ho ◽  
Yee-Shian Wong ◽  
Fahmi Muhammad Ridwan
Keyword(s):  
Photocatalytic Degradation ◽  
Acidic Solution ◽  
Aqueous Suspension ◽  
Solar Irradiation ◽  
Air Sparging ◽  
Reactive Black 5 ◽  
Treatment Technology ◽  
Sunlight Irradiation ◽  
Solar Light Irradiation ◽  
Degradation Of Pollutants

Photocatalytic degradation of pollutants under solar light irradiation is an economically viable process and a very promising clean wastewater treatment technology. The aim of this study is to evaluate photocatalytic degradation of Reactive Black 5 (RB5) under natural sunlight irradiation with TiO2 as photocatalyst. The effects of initial concentration of RB5, dosage of TiO2, with/without solar irradiation, with/without air sparging and pH solution were examined. The decolorization rate improved with a higher dosage of TiO2, with sunlight irradiation and air sparging, and under acidic solution. The photocatalytic process not only decolorized the RB5 but also mineralized the intermediate products completely.

scholarly journals Photocatalytic Degradation of Monolinuron and Linuron in an Aqueous Suspension of Titanium Dioxide Under Simulated Solar Irradiation

2007 ◽  
Vol 20 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Razika Zouaghi ◽  
Abdennour Zertal ◽  
Bernard David ◽  
Sylvie Guittonneau
Keyword(s):  
Photocatalytic Degradation ◽  
Degradation Rate ◽  
Ph Value ◽  
Degradation Kinetics ◽  
Aqueous Suspension ◽  
Operating Conditions ◽  
Solar Irradiation ◽  
Point Of Zero Charge ◽  
Degradation Rates ◽  
Simulated Solar Irradiation

Abstract The photocatalytic degradation of two phenylurea herbicides, monolinuron (MLN) and linuron (LN), was investigated in an aqueous suspension of TiO2 using simulated solar irradiation. The objective of the study was to compare their photocatalytic reactivity and to assess the influence of various parameters such as initial pesticide concentration, catalyst concentration and photonic flux on the photocatalytic degradation rate of MLN and LN. A comparative study of the photocatalytic degradation kinetics of both herbicides showed that these two compounds have a comparable reactivity with TiO2/simulated sun light. Under the operating conditions of this study, the photocatalytic degradation of MLN and LN followed pseudo first-order decay kinetics. The kobs values indicated an inverse dependence on the initial herbicide concentration and were fitted to the Langmuir-Hinshelwood equation. Photocatalytic degradation rates increased with TiO2 dosage, but overdoses did not necessarily increase the photocatalytic efficiency. The degradation rate of MLN increased with radiant flux until an optimum at 580 W m‑2 was reached and then decreased. Under these conditions, an electron-hole recombination was favored. Finally, the photocatalytic degradation rate depended on pH, where an optimum was found at a pH value close to the pH of the point of zero charge (pH = 6).

Solar Synthesis of Limonene Epoxide

2017 ◽  
Author(s):  
Rosaria Ciriminna ◽  
Francesco Parrino ◽  
Claudio De Pasquale ◽  
Leonardo Palmisano ◽  
Mario Pagliaro
Keyword(s):  
Optical Properties ◽  
Energy Transfer ◽  
Green Synthesis ◽  
Photocatalytic Degradation ◽  
Industrial Production ◽  
Thermoplastic Polymer ◽  
Selective Catalyst ◽  
Solar Light Irradiation ◽  
Limonene Oxide ◽  
Degradation Of Pollutants

The silylation of crystalline titania P25, commonly used for photocatalytic degradation of pollutants, results in an exceptionally selective catalyst for the aerobic limonene epoxidation to 1,2-limonene oxide under solar light irradiation. The hypothesized mechanism involves the singlet oxygen generated through energy transfer from the excited TiO<sub>2</sub> to adsorbed O<sub>2</sub> molecules. The reaction product is the valued precursor of bio-based poly(limonene carbonate), a thermoplastic polymer of superior thermal and optical properties whose industrial production is in need of an efficient green synthesis of limonene oxide.

Azo-dyes photocatalytic degradation in aqueous suspension of TiO2 under solar irradiation

Chemosphere ◽  
2002 ◽  
Vol 49 (10) ◽  
pp. 1223-1230 ◽  
Author(s):  
Vincenzo Augugliaro ◽  
Claudio Baiocchi ◽  
Alessandra Bianco Prevot ◽  
Elisa Garcı́a-López ◽  
Vittorio Loddo ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Azo Dyes ◽  
Aqueous Suspension ◽  
Solar Irradiation

scholarly journals Photo-Transformation of Effluent Organic Matter by ZnO-Based Sunlight Irradiation

2020 ◽  
Vol 10 (24) ◽  
pp. 9002
Author(s):  
Thao Thi Nguyen ◽  
Seong Nam Nam ◽  
Jeill Oh
Keyword(s):  
Organic Matter ◽  
Photocatalytic Degradation ◽  
Removal Efficiency ◽  
Treatment Plant ◽  
Wastewater Effluent ◽  
Solar Irradiation ◽  
Effluent Organic Matter ◽  
Sunlight Irradiation ◽  
Vis Spectroscopy ◽  
The Impact

This study investigated the impact of effluent organic matter (EfOM) from wastewater effluent on the properties of organic matter in receiving water and the efficiency of its removal using photocatalysis. The organic matter is characterized using fluorescence excitation-emission matrices coupled with parallel factor analysis (EEM-PARAFAC), UV-Vis spectroscopy, and dissolved organic carbon (DOC) measurements. The experiments are conducted with water samples that were collected from upstream waters (used as a source of dissolved organic matter (DOM)), wastewater effluent (a source of EfOM), and waters downstream of a wastewater treatment plant, and with upstream water and wastewater effluent being mixed at different ratios in the lab (DOM/EfOM). EEM-PARAFAC analysis identifies three components: a humic-like component (C1), a tyrosine-like component (C2), and a terrestrial-like humic component (C3). When compared to DOM, EfOM has a higher specific ultraviolet absorbance at 254 nm (SUVA254), a higher fluorescence index (FI), and more abundant humic-like components. As the EfOM contribution increased, an increase in both humic-like components and a simultaneous decrease in the protein-like components are observed. The photocatalytic degradation of the organic matter using simulated solar irradiation with ZnO as a catalyst is examined. The removal efficiency of photocatalysis is calculated using the DOC, UV absorbance at 254 nm (UV254), and the maximum fluorescence intensity (Fmax) of the PARAFAC components. After 120 min of irradiation, the removal efficiency of photocatalysis differs between the DOM, EfOM, and EfOM-impacted samples due to the change in the properties of the organic matter in the source water. The photocatalytic degradation of organic matter follows pseudo-first-order kinetics, with the DOC and UV254 exhibiting a lower removal efficiency with the increasing contribution of EfOM, which indicated that EfOM has a potentially negative impact on the performance of drinking water treatment. The removal of PARAFAC components follows the order C3 > C1 > C2, indicating that humic-like components are preferentially removed when compared to protein-like components under sunlight irradiation.

scholarly journals Optimization of Alachlor Photocatalytic Degradation with Nano-TiO2 in Water under Solar Illumination: Reaction Pathway and Mineralization

2018 ◽  
Vol 1 (1) ◽  
pp. 141-153 ◽  
Author(s):  
Md. Molla ◽  
Mai Furukawa ◽  
Ikki Tateishi ◽  
Hideyuki Katsumata ◽  
Satoshi Kaneco
Keyword(s):  
Photocatalytic Degradation ◽  
Reaction Pathway ◽  
Irradiation Time ◽  
Low Cost ◽  
Solar Irradiation ◽  
Order Kinetic ◽  
Operational Parameters ◽  
Sunlight Irradiation ◽  
Kinetics Of ◽  
Sunlight Intensity

In the present study, the photocatalytic degradation of alachlor was investigated using TiO2 under sunlight irradiation. The effects of some operational parameters, such as photocatalyst concentration, temperature, pH, sunlight intensity and irradiation time, were optimized. The kinetics of photodegradation was found to follow a pseudo-first-order kinetic law, and the rate constant at optimal condition is 0.245 min−1. The activation energy (Ea) is 6.4 kJ/mol. The alachlor mineralization can be completed under sunlight irradiation after 10 h. The formations of chloride, nitrate and ammonium ions are observed during the photocatalytic degradation. The eight photoproducts were identified by the GC–MS technique. The photodegradation reaction pathways are proposed based on the evidence of the detected photoproducts and the calculated frontier electron densities of the alachlor structure. The photocatalytic degradation treatment for the alachlor wastewater under solar irradiation is simple, convenient and low cost.

scholarly journals OVAT DEGRADATION ANALYSIS OF METHYLENE BLUE USING RICE HUSK ASH (AGRO-WASTE) BASED CATALYST IN SOLAR IRRADIATION

2021 ◽  
Vol 36 (2) ◽  
pp. 1-9
Author(s):  
O.O Okeniyi ◽  
O.A Adekunle ◽  
O. A AJAYI ◽  
T.K BELLO ◽  
S.O Okeniyi ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Active Sites ◽  
Irradiation Time ◽  
Industrial Applications ◽  
Solar Irradiation ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
Sunlight Irradiation ◽  
The One

This study investigated the degradation of methylene blue dye with ZnO-CuO/RHA, a synthesised agro waste-based photocatalyst under solar irradiation at ambient temperature. Preliminary screening of the methylene blue degradation facilitated the selection of the best ZnO-CuO/RHA combination. The photocatalytic degradation was done by taking varying weights of catalyst in 100 mL of dissolved 10-30 ppm MB solutions. The sample was magnetically stirred at 500 rpm in darkness before being exposed to sunlight irradiation. The suspension was magnetically stirred continuously and 5 ml was withdrawn intermittently, centrifuged and analysed with UV-Vis spectrophotometer. The effect of catalyst dosage, initial concentration and irradiation time on the photodegradation were studied using the one-variable-at-a-time method. The result showed that the degradation percentages of the catalyst with 1, 2, 3, 4, and 5 wt. % of RHA were 80.31%, 88.23%, 99.94%, 91.06 % and 81.12% respectively after 180 minutes. These results showed that degradation percentage was directly proportional to the irradiation time up to 3 wt. % thereafter, there was a decline in the percentage degradation. Hence, as the irradiation time increases, there was a significant increase in the degradation of methylene blue dye. ZnO-CuO/RHA catalyst was found to possess a higher photocatalytic activity in the presence of sunlight in comparison to bare ZnO-CuO since using RHA as a base for ZnO-CuO increased the surface area resulting in more active sites under visible light irradiation. ZnO-CuO/RHA may serve as an efficient-photocatalyst for industrial applications with excellent prospects. Keywords: Photocatalytic degradation, Sunlight irradiation, One-variable-at-a-time

Solar Synthesis of Limonene Epoxide

2017 ◽  
Author(s):  
Rosaria Ciriminna ◽  
Francesco Parrino ◽  
Claudio De Pasquale ◽  
Leonardo Palmisano ◽  
Mario Pagliaro
Keyword(s):  
Optical Properties ◽  
Energy Transfer ◽  
Green Synthesis ◽  
Photocatalytic Degradation ◽  
Industrial Production ◽  
Thermoplastic Polymer ◽  
Selective Catalyst ◽  
Solar Light Irradiation ◽  
Limonene Oxide ◽  
Degradation Of Pollutants

The silylation of crystalline titania P25, commonly used for photocatalytic degradation of pollutants, results in an exceptionally selective catalyst for the aerobic limonene epoxidation to 1,2-limonene oxide under solar light irradiation. The hypothesized mechanism involves the singlet oxygen generated through energy transfer from the excited TiO<sub>2</sub> to adsorbed O<sub>2</sub> molecules. The reaction product is the valued precursor of bio-based poly(limonene carbonate), a thermoplastic polymer of superior thermal and optical properties whose industrial production is in need of an efficient green synthesis of limonene oxide.

Photocatalytic partial oxidation of limonene to 1,2 limonene oxide

2018 ◽  
Vol 54 (8) ◽  
pp. 1008-1011 ◽  
Author(s):  
Rosaria Ciriminna ◽  
Francesco Parrino ◽  
Claudio De Pasquale ◽  
Leonardo Palmisano ◽  
Mario Pagliaro
Keyword(s):  
Photocatalytic Degradation ◽  
Partial Oxidation ◽  
Light Irradiation ◽  
Solar Light ◽  
Selective Catalyst ◽  
Solar Light Irradiation ◽  
Limonene Oxide ◽  
Degradation Of Pollutants

The silylation of crystalline TiO2 P25, commonly used for photocatalytic degradation of pollutants, results in an exceptionally selective catalyst for the aerobic limonene epoxidation to 1,2-limonene oxide under solar light irradiation.

scholarly journals Recent Achievements in Development of TiO2-Based Composite Photocatalytic Materials for Solar Driven Water Purification and Water Splitting

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1338 ◽  
Author(s):  
Klara Perović ◽  
Francis M. dela Rosa ◽  
Marin Kovačić ◽  
Hrvoje Kušić ◽  
Urška Lavrenčič Štangar ◽  
...  
Keyword(s):  
Water Treatment ◽  
Transition Metal ◽  
Photocatalytic Degradation ◽  
Water Splitting ◽  
Water Purification ◽  
Degradation Mechanism ◽  
Living Environment ◽  
Solar Irradiation ◽  
Metal Chalcogenides ◽  
Photocatalytic Water Splitting

Clean water and the increased use of renewable energy are considered to be two of the main goals in the effort to achieve a sustainable living environment. The fulfillment of these goals may include the use of solar-driven photocatalytic processes that are found to be quite effective in water purification, as well as hydrogen generation. H2 production by water splitting and photocatalytic degradation of organic pollutants in water both rely on the formation of electron/hole (e−/h+) pairs at a semiconducting material upon its excitation by light with sufficient photon energy. Most of the photocatalytic studies involve the use of TiO2 and well-suited model compounds, either as sacrificial agents or pollutants. However, the wider application of this technology requires the harvesting of a broader spectrum of solar irradiation and the suppression of the recombination of photogenerated charge carriers. These limitations can be overcome by the use of different strategies, among which the focus is put on the creation of heterojunctions with another narrow bandgap semiconductor, which can provide high response in the visible light region. In this review paper, we report the most recent advances in the application of TiO2 based heterojunction (semiconductor-semiconductor) composites for photocatalytic water treatment and water splitting. This review article is subdivided into two major parts, namely Photocatalytic water treatment and Photocatalytic water splitting, to give a thorough examination of all achieved progress. The first part provides an overview on photocatalytic degradation mechanism principles, followed by the most recent applications for photocatalytic degradation and mineralization of contaminants of emerging concern (CEC), such as pharmaceuticals and pesticides with a critical insight into removal mechanism, while the second part focuses on fabrication of TiO2-based heterojunctions with carbon-based materials, transition metal oxides, transition metal chalcogenides, and multiple composites that were made of three or more semiconductor materials for photocatalytic water splitting.

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