THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURAL AND FORESTRY HA THI NGOC EVALUATION ON THE PHOTOCATALYTIC DECOMPOSE OF TOLUENE USING LED ULTRAVIOLET LIGHT BACHELOR THESIS Study Mode : Full-time Major : Environmental Science and Management Faculty : International Programs Office Batch : 2014 - 2018 Thai Nguyen, 25/09/2018 h Thai Nguyen University of Agriculture and Forestry Degree Program Bachelor of Environmental Science and Management Student name Ha Thi Ngoc Student ID DTN1453170024 Thesis Title Evaluation on the photocatalytic decompose of toluene using LED ultraviolet light UVA Supervisor(s) 1. Sue-Min Chang 2. Nguyen Huu Tho Supervisor’signature Abstract: Environmental cleanup by the photocatalytic degradation of pollutants using TiO2 was proposed. Key features of the technology include rapid response to visible light and rapid recycling of the magnetic nanofibers with an outside magnet.
Specially, if irradiated TiO2 with the light have energy matching its bandgap, semiconducting TiO2 at anatase form generates photocurrent in a photoelectron chemical system. When irradiation the UV light, the electron-hole pairs in TiO2 will be generated. Whereas, from this advantage, photocatalysis now using to degrade nonbiodegradable toxic contaminants into their nontoxic degradation products. The results shows that, the high development of the TiO2 surface result in the ratio of surface to high volume creates favorable conditions for the transfer of charge in the redox holes and redox reduction and priority to increase the activity of photocatalytic.
i h Keywords Photocatalytic, photocatalysis, toluene, ultraviolet, UVA. Number of pages 32 Date of submission 25/9/2018 ii h ACKNOWLEDGMENT No success is associated with the relief of more or less, directly or indirectly, of others. From the beginning of my studies at the university, I have received a lot of help from teachers and friends. I would like to sincerely thank the teachers in the Faculty of International Program, Thai Nguyen University of Agriculture and Forestry who have been passionate in imparting knowledge during their years of study here.
With the knowledge acquired during the learning process is not only the basis for the research process but also valuable jewelry to my life in a firm and confident. Deepest appriciation to the kind and helpfu adviser, Prof. Sue Min Chang of Institue of Environmental Engineering National Chiao Tung University, Taiwan which serve my greates inspiration; for giving me the opportunity to be a member of Environmental Nanomaterial Lab; for suggesting the ideas and assistance as the author conducted my research study. Sincerest thank to Dr.
Nguyen Huu Tho Office of Research and International Affairs of Thai Nguyen University of Agriculture and Forestry. Thanks for his guidance and interest in helping me to the complete of this thesis. Ever grateful to Staff of Environmental Nanomaterial Laboratory of National Chiao Tung University for providing equipment to conduct my research; for sharing knowlegde and happy memories along my journey in Taiwan. Harvesting is done over a period of 4 months.
Initially went into the field of science research, my knowledge is limited, so inevitably left many shortcomings. I hope to receive the comments of teachers so that my knowledge in this field is more complete. Student Ha Thi Ngoc ~ ii ~ h TABLE OF CONTENTS LIST OF ABBREVIATIONS .v LIST OF FIGURE .1 Toluene and its application. MATERIALS AND METHODOLOGY .1 Synthesis TiO2 and Fe-TiO2 .1 Surface doping Fe .2 Test the degradation rate of toluene by using 3 samples of powder produced.4 Investigate the effective way to let the degradation process go faster.1 Result of synthesis photocatalyst.2 Product of synthesized TiO2.3 Product of doped iron(Fe) .1 Results of photocatalyst by deposition .2 Results of different conditions.
Results of different light intensity .5 Results of different concentration .24 PART 5: Discussion and Conclusion .30 ~ iv ~ h LIST OF ABBREVIATIONS VOCs : Volatile Organic Compounds PCO : Photocatalytic oxidation EPA : Environmental Protection Agency GC : Gas Chromatography machine AC : Active Carbon IPA : Isopropalnol HTOPs: Highly Toxic Organic Pollutants CB : Conduction Band SPF : Sun Protection Factor VB : Valence Band WBS : Wide Band-gap Semiconductor ~v~ h LIST OF FIGURE Figure 1. Toluene chemical structure .4 Figure 2: Photo catalyst oxidation process. Schematic image for the kinetic and thermodynamic control polymerization of TiO6 octahedral units as the nucleation of anatase and rutile in TiO2.10 Figure 4: Photocatalyst was irradiated using UVA LED 370nm .20 Figure 5: Commercial photocatalyst P25 powder .21 Figure 6: TiO2 powder made in laboratory .21 Figure 7: Fe-TiO2 powder made in laboratory .22 Figure 8: Product of iron doping on TiO2 using filter paper .22 Figure 9: Environment condition affect to the degradation of toluene.23 Figure 10: Light irradiation at different distance to the photocatalyst .24 Figure 11: Different concentration degradation through the time. Research rationale Toluene is the popular solvents in daily life, contributing to the development of society.
Toluene is a very important raw material in the industry, as well as a good organic solvent, but it also has serious effects on the body and the environment. Humans are both responsible for the toluene pollution in their living environment and are the primary victims of exposure in the manufacturing sector. However, because of its importance, people still use a lot of toluene in the manufacturing sector. Understanding the toxicity of toluene is necessary to take preventive measures in the produce and create of toluene.
So in this essay toluene was chosen as the object of study, review. Because of the benefits in minimizing of Highly Toxic Organic Pollutants (HTOPs), photocatalytic properties of titania are studied in depth in wastewater treatment (Shen, 2016). Toluene was discovered by P. Walter in 1037 when he developed coal gas from resin.
Hence, in the present work, to study the application of photocatalyst for degradation of toluene, and evaluate the toluene degradation of this material in comparison with difference condition. The nanotechnology concept has evolved since its future application to the present location is a research innovation with wide applications in many aspects of science. Research’s Objective - Evaluate the capability of P25, TiO2 powder, Fe/TiO2 in the degradation of toluene. - Examine photocatalytic activity under the UVA light source - Assess these condition has effect on the degradation of toluene.
Literature review about toluene, its adverse effects on ecosystem and human health. Synthesis and investigate the characteristics of materials to the degradation of toluene. Compare the photocatalytic activity differences type of photocatalysts to ward toluene degradation. Research’s Scope The sample of toluene and photocatalyst were prepared in Environmental Nanomaterial Laboratory, Chiao Tung University, Taiwan.
The experimental process was done in the laboratory. Toluene Volatile compounds that exist in the atmosphere, such as toluene, are very noticeable because they cause side effects on human health as well as the environment (Beydoun et al., 1999; Bernstein et al. Research shows that regular exposure to toluene easily leads to neurological complications, such as memory loss and muscle growth, as well as some degree of hearing loss and color vision (Peral et al., 1997; Neubert et al. EPA (Environmental Protection Agency) reported that toluene was found in well water, surface water, or soil and its relative vapors are also present in air.
Because of its usage in consumed products, the concentrations of toluene in indoor air may surpass those in outdoor air. Indoor toluene levels from consumer products and outdoor levels due to car or gasoline emissions, are estimated to be an average absorbed dose of 300 µg/day. Toluene plays an important role as the starting material in the explosive industry and is used as a solvent. The maximum toluene concentration is within the current allowed level of about 200 parts per million part of air.
But there is little evidence to be able to maintain the validity of this concentration always within the maximum allowable limit.Air quality control remains one of the most important issues in environmental science and technology research. Photocatalytic oxidation (PCO) processes have been studied to a high degree to control air quality when the target compounds are CO, NO, volatile organic compounds (VOC) and bioaerosol in an enclosed environment PCO is valuable for controlling these compounds, especially in ~3~ h their depressive conditions. To remove VOC from polluted air, TiO2 catalysts are popular because of their high activity, safety and low cost. The visual oxidation of organic compounds including aromatic compounds on TiO2 catalysts irradiated at close range has been elucidated.
The toluene name is derived from the toluol name, which stands for "TOL" - the balsamic resin of South America. Toluene is a transparent liquid, low viscosity. Toluene is water-insoluble liquid, it can melt completely with most organic solvents such as alcohol, ether, ketone .Toluene is a flammable and predominantly used as an industrial feedstock and a solvent. Toluene chemical structure The toluene molecule consists of two parts: the benzene ring and the ankyl ring.
So its properties include the aroma of the benzene ring and the satiety of the base. However, the nature of the benzene ring and the alkyl base is altered by the relative influence between the two. The basic reaction of toluene is the substitution reaction SE plus in the benzene ring, reaction SR , Oxidation at methyl base. Application of toluene Toluene is an aromatic hydrocarbon that is widely used in the industry, often ~4~ h as a substitute for benzene: Toluene is used primarily in applications requiring solubility and the highest volatility.1 Toluene and its application.
As in the manufacture of synthetic resins, automotive paints, interior paint and marine paint, toluene is highly soluble, so it is used in the production process of adhesives and binders. Toluene is also used as a diluent and as a component in detergents, in the manufacture of benzene and in the manufacture of dyes, textiles, and many other industries.2 Toluene toxicity • If exposed to toluene for a long time, cancer may develop. • Eye contact: Stimulating, but does not affect the eye membrane. • Skin contact: Frequent or prolonged contact may be irritated and inflamed.
Short and irregular contact with liquids will not cause serious irritation, which occurs when evaporation occurs. Skin contact may cause severe dermatitis. • Inhalation (respiratory system): High evaporation content (greater than about 1000 ppm) causes eye and respiratory irritation, can cause headaches, drowsiness, unconsciousness, affecting the nerve center , brain damage and can cause death. • Ingestion (digestive system): A small amount enters the abdomen or causes or damages the human lungs, which cause death.
TiO2 photocatalysis Titanium dioxide (TiO2) is a semiconductor and is famous as an anti-ultraviolet (UV) catalyst in oxidizing photos of organic matter and inactivating bacteria, algae and viruses. ~5~ h By absorbing the energy of light, titanium oxide changes from the insulating property to a conductor, so it is thought to be an optical semiconductor. This happens because the excited electrons move from the valence band to the conduction band and create holes in the valence band. The excited electrons react with oxygen in the atmosphere to form superoxide anions, the holes continue to react with atmospheric moisture to produce hdroxyl radicals.
These types of active oxygen readily react, oxidize and decompose organic matter Figure 2: Photo catalyst oxidation process With an angle of contact with water of 5 ° or below, the surface of titanium oxide exhibits super permeability when exposed to light. Under the light irradiation, the electron-hole pairs are formed once again, the superfluidity is a straightforward result of the formation of oxygen vacancies due to the interaction of the holes with the ~6~ h oxygen atoms in the lattice. Such holes form a hydrophilic area, and because water is readily adsorbed there, super-permeable products are generally. Advanced oxidation processes (AOP) with UV irradiation and titanium photocatalytic titanium (TiO2) are improving their ability to accept conveniently as an effective wastewater treatment.
A comprehensive review of UV-TiO2 catalyst oxidation was conducted with insight into the relevant equipment, TiO2 catalysts, irradiation sources, and reactor types, comparisons among Effective mode of TiO2 application as surface immobilization or as system suspension.