Decolorization Of Dye Pollutants By Fenton-Like Oxidation Process Using Zeolite And Natural Clay Based Catalysts

The decolorization of Acid Red 1 (ARl) and Reactive Blue 4 (RB4) dye by the Fenton-like oxidation process using zeolite and natural based catalysts in batch system were studied. Fe-zeolite Y type (Fe-ZYT), Fe-natural zeolite (Fe-NZ), Fe-ball clay (Fe-BC), and Fe-Kuala Kangsar clay (Fe-KKC) were successfully prepared via impregnation method. The prepared catalysts were characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Xray powder diffraction (XRD), Nitrogen adsorption/desorption and Energy Disperse X-ray (EDX). Penyahwamaan bagi dua jenis bahan pencelup iaitu Acid Red 1 (ARl) dan Reactive Blue 4 (RB4) melalui proses pengoksidaan jenis Fenton menggunakan mangkin zeolit dan bahan semulajadi berasaskan tanah liat dalam sistem berkelompok dikaji. Pemangkin ini berjaya dihasilkan menggunakan teknik peranakan. Pencirian mangkin telah dijalankan menggunakan kaedah mikroskopi electron pengimbas (SEM), spektroskopi inframerah transformasi Fourier (FTIR), penjerapan/penyahjerapan nitrogen dan penyerakan tenaga x-ray (EDX)

Catalytic Co-Pyrolysis Of Sugarcane Bagasse And Waste Plastics Using Zeolite And Hydroxyapatite Based Catalyst For High Quality Pyrolysis Oil In A Fixed-Bed Reactor

Depletion of natural resources, massive demand for petroleum, and environmental concern have motivated studies on renewable fuel from biomass conversion. This study aims to investigate the co-pyrolysis and catalytic co-pyrolysis of sugarcane bagasse (SCB) with high-density polyethylene (HDPE) or polyethylene terephthalate (PET) in a slow-heating fixed-bed reactor over faujasite type zeolite (FAU-EAFS) and hydroxyapatite-zeolite (HAP-ZE) catalysts prepared from electric arc furnace slag. In co-pyrolysis process, the effects of reaction temperature (400-700 ℃) and biomass-to-plastic ratio (100:0-0:100) on the products yields, chemical compositions as well as synergistic effect were investigated. The optimum liquid yield of 63.69 wt% was achieved at 600 °C and 60:40 SCB: HDPE ratio in co-pyrolysis of SCB and HDPE while 60.94 wt% of liquid yield was achieved at 600 °C and 40:60 SCB: PET ratio in co-pyrolysis of SCB and PET. In catalytic co-pyrolysis section, the effects of reaction temperature (400-700 ℃), catalyst-to-feedstock ratio (1:10-1:2) and biomass-to-plastic ratio (100:0-0:100) on the product yields and chemical compositions were investigated. The maximum pyrolysis oil yield of 68.56 wt% and 71.01 wt% were obtained under catalytic co-pyrolysis of SCB and HDPE over FAU-EAFS and HAP-ZE, respectively. The catalytic co-pyrolysis of SCB and PET over FAU-EAFS and HAP-ZE, produced maximum pyrolysis oil yield of 42.95 wt% and 45.64 wt%, respectively. The catalytic co-pyrolysis of SCB and HDPE promoted the production of hydrocarbon and alcohol while the catalytic co-pyrolysis of SCB and PET enhanced the aromatic and acid production. Compared to HAP-ZE, the FAU-EAFS showed better performance in the production of hydrocarbon and aromatic during catalytic co-pyrolysis of SCB with HDPE or PET, due to its strong acidity and larger pore size which enhanced cracking and deoxygenation reactions and diffusion efficiency of pyrolysis vapors into the catalyst pore. Thermal pyrolysis, co-pyrolysis and catalytic co-pyrolysis behaviour of SCB and HDPE were determined using thermogravimetric analysis while the kinetic parameters were calculated via Coats-Redfern method. In the second region, where the decomposition of cellulose and hemicellulose are dominant, the best correlation for HDPE can be described by first order chemical reaction mechanism, whereas the other reaction samples are controlled by diffusion model. Meanwhile, in the third region, where the interaction between SCB and HDPE took place, all of the reactions samples followed the order of reaction mechanisms. An addition of FAU-EAFS and HAP-ZE catalysts resulted in lower activation energy in the second region during co-pyrolysis of SCB and HDPE

Reactive black 5 dye decolorization by heterogeneous Fenton-like reaction using Fe-clamshell catalyst / Wan Zuraida Wan Kamis and Hamizura Hassan

Fenton reaction wastewater treatment process is known to be very effective in the removal of many hazardous organic pollutants and dyestuff from water. The Fenton reaction causes dissociation of the oxidant with the formation of highly reactive hydroxyl radicals that attack and destroy the organic pollutants. However, the homogeneous Fenton process has significant disadvantages such as the generation of iron hydroxide sludge and limited range of pH. Heterogeneous Fenton is an alternative solution to overcome these limitations. Selection of catalyst support is important during the preparation of heterogeneous Fenton-like catalyst. At present, the catalyst supports include organic (such as C-Nafion and resin) and inorganic materials (such as HY zeolite, C fabrics and pillared clays). In heterogeneous solid catalyst, the iron species is "immobilized" on the solid supports or within the structure and in the pore/interlayer of the catalyst. The clam is a bi-valve mollusk of the clams family that digs in the sand. Salt-water clams are widely popular for eating purposes but the shells are considered as waste. Being inexpensive and abundant, the clam shell represents an attractive supports for iron immobilization. Therefore this study focuses on the development of heterogeneous catalysts from the low cost material, which is the clam shell. The efficiency of the heterogeneous catalyst will be tested on decolorization of model real textile wastewater that is Reactive Black 5 (RB5) by making use of a Fenton-like process. This catalyst (Fe-clamshell) will be prepared by impregnation method in which iron ion act as catalyst is attached on the supported catalyst (clamshell). The prepared catalyst is characterized by using Fourier Transform Infrared (FTIR). The effect of different reaction parameters such as different ion loading on supported catalyst, catalyst dosage, initial pH, and initial concentration of hydrogen peroxide and dye on the decolorization of RB5 will be assessed. It is expected that Fe-clamshell catalyst possess a potential to treat RB5 solution and this could give an added value since it is natural, abundant, low cost and environmentally friendly

Decolourization of methyl orange in UV assisted fenton-like reaction using Fe-MKSF catalyst / Nur Hidayati Abdullah

In this work, two types montmorillonite clay (MKSF and MK10) were applied as catalyst support in heterogeneous UV assisted Fenton-like reaction. MKSF was chosen for the iron immobilization based on catalytic activity performance. Fe-supported montmorillonite KSF (Fe-MKSF) exhibited both increment in surface area, 175.208 m2 /g and pore volume, 0.3536 cm3 /g compared to the pristine MKSF as a result of incorporation of iron species onto MKSF matrix. The reactivity of Fe-MKSF was further tested on the effect of UV irradiation. Fe-MKSF exhibited 99% of methyl orange (MO) removal within 45 min of reaction under UVC illumination but it takes more than 120 min under UVA illumination. These findings proved Fe-MKSF as a promising alternative catalyst in decolourization of recalcitrant contaminant in wastewater

Fe-Kuala Kangsar clay as heterogeneous catalyst for fenton-like decolorization of dyeing wastewater / Hamizura Hassan and Wan Zuraida Wan Kamis

Dyes in wastewater can create aesthetic problems, limit the possible use of water and obstruct the light penetration and oxygen transfer into water bodies, hence affecting the aquatic life. The Fenton process has long-established credibility in the field of environmental remediation for nonbiodegradable pollutants. However, the overall efficiency of homogeneous Fenton is limited with significant disadvantages like generated iron hydroxide sludge and tight range of pH. Heterogeneous Fenton emerged as an interesting ways to overcome these limitations by the usage of Fenton-like heterogeneous catalyst. In heterogeneous solid catalyst, the iron species is "immobilized" on the solid supports or within the structure and in the pore/interlayer of the catalyst. Being inexpensive and widely available, clays represents an attractive supports for iron immobilization. Therefore this study focuses on the development of heterogeneous catalysts from the low cost material, which is Kuala Kangsar clay. The efficiency of this heterogeneous catalyst will be tested on decolorization of model real textile wastewater that is Reactive Black 5 (RB5) by making use of a Fenton-like process. This catalyst (Fe-Kuala Kangsar clay) will be prepared by impregnation method in which iron ion act as catalyst is attached on the supported catalyst (Kuala Kangsar clay). The prepared catalyst is characterized by using Scanning Electron Microscope (SEM), Brunauer Emmett-Teller (BET), Fourier Transform Infrared (FTIR), Elemental chemical analysis (EDX), and X-Ray diffraction (XRD). The effect of different reaction parameters such as different ion loading on supported catalyst, catalyst dosage, initial pH, and initial concentration of hydrogen peroxide and dye on the decolorization of RB5 will be assessed. It is expected that Fe- Kuala Kangsar clay catalyst possess a potential to treat RB 5 solution and this could give an added value since it is natural, abundant, low cost and environmentally friendly

Optimisation of silicone-based dielectric elastomer transducers by means of block copolymers – synthesis and compounding

Emerging artificial muscle technology has developed from metal-based robotics to softtype robotics made from soft matter. Research into artificial muscle technology based on soft matter has been conducted mainly in order to mimic soft and robust human muscle. In this regard, dielectric elastomers have been studied. Their actuation occurs when Maxwell stress exceeds elastic stress in the presence of an electrical field, resulting in contraction in thickness and planar expansion in the area. As well as an actuator, dielectric elastomers can be used as generators and sensors. As a dielectric elastomer, silicones have been used extensively in many applications, due to favourable properties such as thermal stability, non-conductivity, high gas permeability and low toxicity. However, silicones have a low dielectric constant and thereby low energy density. In order to enhance actuation performance, it is the aim of this research to develop silicone elastomers with a high dielectric constant and high electrical breakdown strength, as well as a low Young’s modulus. In this Ph.D. thesis, two methods were developed to enhance silicone properties such as the dielectric constant and electrical breakdown strength. The first method was devised to enhance the dielectric constant of silicone elastomers through the use of a polydimethylsiloxane-polyethyleneglycol (PDMS-PEG) copolymer, in order to obtain an elastomer with high electrical energy. PDMS-PEG copolymers were synthesised and blended in commercial silicone and subsequently cross-linked. The relative permittivity of cross-linked silicone with 5 wt% of PDMS-PEG copolymers increased by nearly 50%, without compromising dielectric loss and mechanical properties, compared to the commercial silicone elastomer. The second investigated method involved enhancing the electrical breakdown strength of silicone by using an aromatic voltage stabiliser. Here, polyphenylmethylsiloxane (PPMS), which contained aromatic voltage stabilisers, was bonded covalently to PDMS through a hydrosilylation reaction obtaining PDMS-PPMS copolymers. The synthesised copolymers were subsequently cross-linked with a vinyl cross-linker. The obtained cross-linked PDMS-PPMS copolymers were inherently soft and robust with increased electrical breakdown strength (21%) compared to the reference elastomer without an aromatic voltage stabiliser. The conducting polymer was developed through the use of a multi-walled carbon nanotube (MWCNT) in a PDMS-PEG matrix as a compliant electrode of dielectric elastomers. The conductive PDMS-PEG copolymer was incorporated with surface-treated MWCNT, in order to obtain highly conductive elastomer. The prepared sample with 4 parts per hundred rubber (phr) MWCNT was soft and the resulting conductivity of the cross-linked PDMS-PEG copolymer with the addition of MWCNT was high, at 10-2 S cm-1, nearly equivalent to a commonly used commercial conducting polymer. In this thesis, the elastomer and electrode system is referred to as a ‘dielectrielastome

Effects of modern instructional technology (MIT) on critical thinking skills of students in agriculture vocational courses in Nigeria

The recent development in modern instruction technology (MIT) methods and equipment warranted for studies to examine their effects on students, teachers, and the education system in general. This study examines the effects of MIT on students’ critical thinking skills in Agriculture vocational courses in Nigeria. The methods and equipment used were identified, and the effect of teachers’ usage behaviour was assessed. A survey approach was adopted, using questionnaires for data collection. The descriptive, correlations and multiple regressions were carried out using SPSS. The result of this study indicates that the most commonly used equipment is electronic whiteboard, while the least are electronic tablets and laptops. Cooperative learning is the most commonly used methods while games and online instruction are the least. There is a moderate positive correlation between MIT methods and the students’ critical thinking skill, but a very weak positive correlation between MIT equipment and students’ critical thinking skill. There is statistically significant contribution of methods to student’s critical thinking, but insignificant method usage behaviour. Therefore, it is concluded that government should incorporate the provision and effective utilisation of MIT equipment and methods in the national education policy. School managements should emphasise the use of MIT methods and review curriculum to improve teachers’ skills in MIT usage. Teachers should utilise the available MIT equipment and method along with their skills for an effective delivery of lessons. Similarly, the students should be encouraged to appreciate the available methods and the equipment, and use them effectively

Contribution @ l' tude physico-chimique de la catalyse par transfert de phase solide-liquide

SIGLEBSE B226354K / UCL - Université Catholique de LouvainBEBelgiu

Formation of a Nanorod-Assembled TiO₂ Actinomorphic-Flower-like Microsphere Film via Ta Doping Using a Facile Solution Immersion Method for Humidity Sensing

This study fabricated tantalum (Ta)-doped titanium dioxide with a unique nanorod-assembled actinomorphic-flower-like microsphere structured film. The Ta-doped TiO2 actinomorphic-flower-like microsphere (TAFM) was fabricated via the solution immersion method in a Schott bottle with a home-made improvised clamp. The samples were characterised using FESEM, HRTEM, XRD, Raman, XPS, and Hall effect measurements for their structural and electrical properties. Compared to the undoped sample, the rutile-phased TAFM sample had finer nanorods with an average 42 nm diameter assembled to form microsphere-like structures. It also had higher oxygen vacancy sites, electron concentration, and mobility. In addition, a reversed double-beam photoacoustic spectroscopy measurement was performed for TAFM, revealing that the sample had a high electron trap density of up to 2.5 μmolg−1. The TAFM showed promising results when employed as the resistive-type sensing film for a humidity sensor, with the highest sensor response of 53,909% obtained at 3 at.% Ta doping. Adding rGO to 3 at.% TAFM further improved the sensor response to 232,152%

Formation of a Nanorod-Assembled TiO2 ActinomorphicFlower-like Microsphere Film via Ta Doping Using a Facile Solution Immersion Method for Humidity Sensing

This study fabricated tantalum (Ta)-doped titanium dioxide with a unique nanorodassembled actinomorphic-flower-like microsphere structured film. The Ta-doped TiO2 actinomorphicflower-like microsphere (TAFM) was fabricated via the solution immersion method in a Schott bottle with a home-made improvised clamp. The samples were characterised using FESEM, HRTEM, XRD, Raman, XPS, and Hall effect measurements for their structural and electrical properties. Compared to the undoped sample, the rutile-phased TAFM sample had finer nanorods with an average 42 nm diameter assembled to form microsphere-like structures. It also had higher oxygen vacancy sites, electron concentration, and mobility. In addition, a reversed double-beam photoacoustic spectroscopy measurement was performed for TAFM, revealing that the sample had a high electron trap density of up to 2.5 µmolg1. The TAFM showed promising results when employed as the resistive-type sensing film for a humidity sensor, with the highest sensor response of 53,909% obtained at 3 at.% Ta doping. Adding rGO to 3 at.% TAFM further improved the sensor response to 232,152