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

Adsorption mechanism of reactive dyes onto modified coal-fired bottom ash: equilibrium and thermodynamics study / Hawaiah Imam Maarof, Norhaslinda Nasuha and Nor Aida Zubir

Adsorption has been recognized to be a promising process to remove colours from aqueous solution (Xue, et al., 2009). Utilizing of agricultural and industrial wastes as adsorbents had been explored by many researchers. However, the study of coal-fired bottom ash as adsorbent for dye adsorption is scanty reported by researcher. In fact, the influence of complex properties of coal-fired bottom ash to the adsorption system have not yet been explored in detailed. Therefore, the study on the adsorption mechanism of dye onto coal-fired bottom ash as well as modified coal-fired bottom ash is needed in improving its capability of dyes adsorption process. The physical and chemical properties of an adsorbent serve significant effects to the adsorption process. Chemical properties include the degree of ionization of the adsorbent surface, the types of functional group which are present on the adsorbent and degree to which these properties may changed by contact with the solution (Bernardin, 1985). Some adsorbents have affinity for H+ and OH' ions, which will directly affect the solution pH, solubility and adsorption capacity. The mechanism might vary from reversible to strong chemical interaction with the presence of active functional groups on the adsorbent surface (Bernardin, 1985). In this study, the equilibrium and thermodynamics studies will be carried out on specific pair of reactive dye-bottom ash and modified coal-fired bottom ash system

Physico-chemical properties of zinc partially substituted magnetite nanoparticles

In this work, a series of zinc partially substituted magnetite nanoparticles (FeZnO, 0 ≤ x ≤ 0.4), were synthesised through a facile precipitation-oxidation method. The partial substitution of zinc into the magnetite (FeO) structure was confirmed by the collective findings of nitrogen sorption, XRD and TG-DTG analysis. It was found that the partial substitution of zinc slightly changed the textural properties of the resultant FeZnxO nanoparticles. From the XRD analysis, there was no visible formation of secondary phase or impurity peaks in the nanoparticles. These findings indicated the partial substitution of zinc into the FeO crystal structure with a good dispersion within the FeO matrix

sulfonated polystyrene pore-filled electrolytes membranes by electrons induced grafting of styrene into PVDF films: thermal stability and structural investigation

There is considerable interest currently in pore-filled electrolyte membranes (Mika et al., 1995, Yamaguchi et al., 2003). These membranes have a variety of potential applications such as temperature and pH (ionic strength) sensors (Childs et al., 2002), dialysis (Stachera et al., 1998), proton exchange membrane (Bae and Kim., 2003, Yamaguchi et al., 2003;) and so on. Efforts have been made in order to study and correlate the performance of such membranes with the grafting yield in these systems

Electrochemical Removal of Copper Ion Using Coconut Shell Activated Carbon

In this work, coconut shell activated carbon (CSAC) electrode was evaluated to remove copper ion via electrochemical processes. CSAC electrode and graphite were applied as the cathode and the anode, respectively. The reusability of the electrode, the effects of initial pH, applied voltage and initial concentration were studied. The electrochemical process was carried out for 3 h of treatment time, and the electrodes (anode and cathode) were separated by 1 cm. The results revealed that CSAC is proven as a reusable electrode to remove copper ion, up to 99% of removal efficiency from an initial concentration of 50 ppm after it had been used three times. From the observation, the removal efficiency was optimum at an initial pH of 4.33 (without any initial pH adjustment). The applied voltage at 8 V showed a higher removal efficiency of copper ion compared to at 5 V

Identification of chrysotile in brake pads and linings from Malaysian vehicles and heavy vehicles by using Polarized Light Microscope (PLM)

Exposure to types of asbestos such as chrysotile and crocidolite increases respiratory disease risks such as lung cancer, mesothelioma, and asbestosis. Nevertheless, asbestos products banning in Malaysia is only limited to crocidolite as per stated in OSHA (Prohibition of Use of Substance) Order 1999, though other types are highly suspected to be found in asbestos-containing materials (ACM) like brake pads and linings. This study ascertains the presence of asbestos fibres, particularly chrysotile, in brake pads and linings used in Malaysia's vehicle and heavy vehicle sector. Seven different brake pads; three from vehicle brands, and four from heavy vehicle brands were collected by bulk sampling approaches from the market and field. Dust fibres were extracted using slow grinding method and analysed under Polarized Light Microscope (PLM). The fibre characteristics such as colour, morphology, pleochroism, extinction, and dispersion staining technique were examined, referring the National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods (NMAM) 9002. Additionally, the observed samples also were verified by an accredited lab to support the authenticity of the outcome. From the analysis and lab results, chrysotile fibres were consistently detected in all brake pad samples, fulfilling the fibre characteristics and positive elongation signs

Effect of Sintering Temperature on the Morphology and Mechanical Properties of PTFE Membranes as a Base Substrate for Proton Exchange Membrane

This paper reports the development of PTFE membranes as the base substrates for producing proton exchange membrane by using radiation-grafting technique. An aqueous dispersion of PTFE, which includes sodium benzoate, is cast in order to form suitable membranes. The casting was done by using a pneumatically controlled flat sheet membrane-casting machine. The membrane is then sintered to fuse the polymer particles and cooled. After cooling process, the salt crystals are leached from the membrane by dissolution in hot bath to leave a microporous structure, which is suitable for such uses as a filtration membrane or as a base substrate for radiation grafted membrane in PEMFC. The effects of sintering temperature on the membrane morphology and tensile strength were investigated at 350oC and 385oC by using scanning electron microscopy (SEM) and EX 20, respectively. The pore size and total void space are significantly smaller at higher sintering temperature employed with an average pore diameter of 11.78 nm. The tensile strength and tensile strain of sintered PTFE membrane at 385oC are approximately 19.02 + 1.46 MPa and 351.04 + 23.13 %, respectively. These results were indicated at 385oC, which represents significant improvements in tensile strength and tensile strain, which are nearly twice those at 350oC

Optimisation of graphene oxide-iron oxide nanocomposite in heterogeneous Fenton-like oxidation of Acid Orange 7

Well-dispersed iron oxide nanoparticles supported onto graphene oxide sheets (i.e. GO-Fe3O4 nanocomposite) were synthesised and used as heterogeneous Fenton-like catalyst for the degradation of Acid Orange 7 dye (AO7). The reaction was systematically investigated under various experimental conditions such as nanocomposite dosage, pH, temperature, oxidant and dye concentrations. Best results showed a fast 80% degradation in ∼20 min, whilst ∼98% of AO7 was successfully removed after 180 min of reaction time. The degradation kinetics of AO7 was most influenced by pH and temperature, and can be described by a pseudo-first-order reaction following the Langmuir-Hinshelwood mechanism. Analysis of the spent nanocomposite suggested that the phase of iron oxide nanoparticles remained unchanged whilst minor pore volume losses occurred via carbon deposition and/or re-stacking of GO sheets