Displaying publications 1 - 20 of 35 in total

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  1. Carbonated ground granulated blast furnace slag stabilising brown kaolin
    Mohammed AMA, Mohd Yunus NZ, Hezmi MA, A Rashid AS, Horpibulsuk S
    Environ Sci Pollut Res Int, 2021 Oct;28(40):57308-57320.
    PMID: 34086175 DOI: 10.1007/s11356-021-14718-4
    Proposals have been made by several researchers to conduct the sequestration of carbon dioxide (CO2) through calcium and magnesium-rich materials. From these materials, ground granulated blast furnace slag (GGBS) containing 5% magnesium and 45% calcium is seen to be a good candidate and is available to sequester CO2. This study intends to ascertain the ability to absorb CO2, sequester it, and increase treated kaolin strength with different content of GGBS under various carbonation periods with varying CO2 pressure. The impacts of carbonated GGBS on the mechanical attributes of soil were examined by conducting the unconfined compressive strength (UCS) test, and microstructure analysis was conducted to identify the changes in the structure and Crestline phase. Stationary carbonation in a triaxial test with pure CO2 was conducted to accelerate the carbonation process. The outcome indicates that the strength rises as the carbonation period rises. Likewise, UCS rises as the CO2 pressure rises from 100 to 200 kPa. It could be concluded that augmentation of the strength is because of carbonated calcium and magnesium products which stuff the soil voids. Changes occur on the microstructure level due to carbonation as well.
    Matched MeSH terms: Kaolin*
  2. Kaolin pneumoconiosis
    CUMMINS GE, AUN YS, DAVIES TA
    Med J Malaya, 1958 Jun;12(4):613-7.
    PMID: 13577154
    Matched MeSH terms: Kaolin*
  3. Investigation on the effect of sintering temperature on kaolin hollow fibre membrane for dye filtration
    Mohtor NH, Othman MHD, Ismail AF, Rahman MA, Jaafar J, Hashim NA
    Environ Sci Pollut Res Int, 2017 Jul;24(19):15905-15917.
    PMID: 28620856 DOI: 10.1007/s11356-017-9341-6
    Despite its extraordinary price, ceramic membrane can still be able to surpass polymeric membrane in the applications that require high temperature and pressure conditions, as well as harsh chemical environment. In order to alleviate the high cost of ceramic material that still becomes one of the major factors that contributes to the high production cost of ceramic membrane, various attempts have been made to use low cost ceramic materials as alternatives to well-known expensive ceramic materials such as alumina, silica, and zirconia in the fabrication of ceramic membrane. Thus, local Malaysian kaolin has been chosen as the ceramic material in this study for the preparation of kaolin hollow fibre membrane since it is inexpensive and naturally abundant in Malaysia. Due to the fact that the sintering process plays a prominent role in obtaining the desired morphology, properties, and performances of prepared ceramic membrane, the aim of this work was to study the effect of different sintering temperatures applied (ranging from 1200 to 1500 °C) in the preparation of kaolin hollow fibre membrane via dry/wet phase inversion-based spinning technique and sintering process. The morphology and properties of membrane were then characterised by SEM, AFM, FTIR, XRD, and three-point bending test, while the performances of membrane were investigated by conducting water permeation and Reactive Black 5 (RB5) dye rejection tests. From the experimental results obtained, the sintering temperature of 1400 °C could be selected as the optimum sintering temperature in preparing the kaolin hollow fibre membrane with the dense sponge-like structure of separation layer that resulted in the good mechanical strength of 70 MPa with the appreciable water permeation of 75 L/h m(2) bar and RB5 rejection of 68%.
    Matched MeSH terms: Kaolin*
  4. Impact of Bacillus species on Fe reduction of kaolin in bioleaching: surface, structural, and chemical studies
    Yong SN, Lee WS, Chieng S, Lim S, Kuan SH
    Appl Microbiol Biotechnol, 2023 Aug;107(15):4789-4801.
    PMID: 37314456 DOI: 10.1007/s00253-023-12622-0
    Conventional techniques to remove Fe impurities in kaolin typically involve high environmental impact and cost. Alternative methods have been focused on the use of bioleaching where Fe in kaolin is reduced with microorganisms. Early results established a noticeable effect of the bacteria on the redox state of Fe, but knowledge gaps persist such as details on the bacterial-kaolin interactions during attachment of bacteria onto kaolin surface, the metabolites produced by bacteria, and changes in Fe(II)/Fe(III) ion equilibria in solution. To bridge these gaps, this study was conducted to determine the detailed physicochemical changes in bacteria and kaolin during bioleaching through surface, structural, and chemical analysis. Bioleaching experiments were conducted for 10 days where each of the three Bacillus sp. was put in contact (at 9 × 108 CFU) with 20 g of kaolin powder using 200 mL of 10 g/L glucose solution. All samples treated with bacteria showed increasing trends in Fe(III) reduction up until day 6 or 8 followed by a slight decrease towards the end of the ten-day period. Examination of scanning electron microscope (SEM) images suggests that bacterial activity damaged the edges of kaolin particles during bioleaching. Ion chromatography (IC) results showed that during bioleaching, Bacillus sp. produced organic acids such as lactic acid, formic acid, malic acid, acetic acid, and succinic acid. EDS analysis of kaolin before and after bioleaching showed Fe removal efficiencies of up to 65.3%. Analyses of color properties of kaolin before and after bioleaching showed an improvement in whiteness index of up to 13.6%. KEY POINTS: • Dissolution of iron oxides by Bacillus species proven with phenanthroline analysis. • Organic acid type and concentration unique to species detected during bioleaching. • Whiteness index of kaolin is improved after bioleaching.
    Matched MeSH terms: Kaolin/metabolism
  5. Fulltext Elucidation of Gram-Positive Bacterial Iron(III) Reduction for Kaolinite Clay Refinement
    Jing H, Liu Z, Kuan SH, Chieng S, Ho CL
    Molecules, 2021 May 21;26(11).
    PMID: 34064160 DOI: 10.3390/molecules26113084
    Recently, microbial-based iron reduction has been considered as a viable alternative to typical chemical-based treatments. The iron reduction is an important process in kaolin refining, where iron-bearing impurities in kaolin clay affects the whiteness, refractory properties, and its commercial value. In recent years, Gram-negative bacteria has been in the center stage of iron reduction research, whereas little is known about the potential use of Gram-positive bacteria to refine kaolin clay. In this study, we investigated the ferric reducing capabilities of five microbes by manipulating the microbial growth conditions. Out of the five, we discovered that Bacillus cereus and Staphylococcus aureus outperformed the other microbes under nitrogen-rich media. Through the biochemical changes and the microbial behavior, we mapped the hypothetical pathway leading to the iron reduction cellular properties, and found that the iron reduction properties of these Gram-positive bacteria rely heavily on the media composition. The media composition results in increased basification of the media that is a prerequisite for the cellular reduction of ferric ions. Further, these changes impact the formation of biofilm, suggesting that the cellular interaction for the iron(III)oxide reduction is not solely reliant on the formation of biofilms. This article reveals the potential development of Gram-positive microbes in facilitating the microbial-based removal of metal contaminants from clays or ores. Further studies to elucidate the corresponding pathways would be crucial for the further development of the field.
    Matched MeSH terms: Kaolin/metabolism*
  6. Flocculation behavior and mechanism of bioflocculant produced by Aspergillus flavus
    Aljuboori AHR, Idris A, Al-Joubory HHR, Uemura Y, Ibn Abubakar BSU
    J Environ Manage, 2015 Mar 01;150:466-471.
    PMID: 25560664 DOI: 10.1016/j.jenvman.2014.12.035
    In this study, the flocculation behavior and mechanism of a cation-independent bioflocculant IH-7 produced by Aspergillus flavus were investigated. Results showed 91.6% was the lowest flocculating rate recorded by IH-7 (0.5 mg L(-1)) at pH range 4-8. Moreover, IH-7 showed better flocculation performance than polyaluminum chloride (PAC) at a wide range of flocculant concentration (0.06-25 mg L(-1)), temperature (5-45 °C) and salinity (10-60% w/w). The current study found that cation addition did not significantly enhance the flocculating rate and IH-7 is a positively charged bioflocculant. These findings suggest that charge neutralization is the main flocculation mechanism of IH-7 bioflocculant. IH-7 was significantly used to flocculate different types of suspended solids such as activated carbons, kaolin clays, soil solids and yeast cells.
    Matched MeSH terms: Kaolin/chemistry*
  7. Statistical optimization and modeling for color removal and COD reduction of reactive blue 19 dye by mesoporous chitosan-epichlorohydrin/kaolin clay composite
    Jawad AH, Abdulhameed AS, Malek NNA, ALOthman ZA
    Int J Biol Macromol, 2020 Dec 01;164:4218-4230.
    PMID: 32861784 DOI: 10.1016/j.ijbiomac.2020.08.201
    In current research work, chitosan (Chi) was subjected to subsequent physical and chemical modifications by incorporating kaolin clay (KA) into its polymeric structure, and crosslinking process with a covalent cross-linker namely epichlorohydrin (ECH) respectively. The final product of crosslinked chitosan-epichlorohydrin/kaolin (Chi-ECH/KA) composite was successfully applied for color removal and chemical oxygen demand (COD) reduction of textile dye namely reactive blue 19 dye (RB19) from aqueous environment. The influence of pertinent parameters, i.e. A: Chi-ECH/KA dose (0.02-0.1 g), B: pH (4-10), and C: time (5-30 min) on the RB19 color removal and COD reduction were statistically optimized by using response surface methodology with Box-Behnken design (RSM-BBD). The experimental data of the adsorption kinetic and the adsorption isotherm demonstrated a better fitness to pseudo-second order model and Langmuir isotherm model respectively. Excellent absorption ability of 560.9 mg/g was recorded for Chi-ECH/KA composite. The calculated thermodynamic functions clarified that the RB19 adsorption process was endothermic and spontaneous in nature. The mechanism of RB19 adsorption onto the Chi-ECH/KA may include electrostatic interactions, hydrogen bonding, Yoshida H-bonding, and n-π interactions. This study introduces Chi-ECH/KA composite as an eco-friendly, potential and multi-function composite bio adsorbent for removal of textile dye and COD reduction from aqueous environment.
    Matched MeSH terms: Kaolin/chemistry*
  8. Synthesis of nanostructured titanium dioxide layer onto kaolin hollow fibre membrane via hydrothermal method for decolourisation of reactive black 5
    Mohtor NH, Othman MHD, Bakar SA, Kurniawan TA, Dzinun H, Norddin MNAM, et al.
    Chemosphere, 2018 Oct;208:595-605.
    PMID: 29890498 DOI: 10.1016/j.chemosphere.2018.05.159
    Hydrothermal method has been proven to be an effective method to synthesise the nanostructured titanium dioxide (TiO2) with good morphology and uniform distribution at low temperature. Despite of employing a well-known and commonly used glass substrate as the support to hydrothermally synthesise the nanostructured TiO2, this study emphasised on the application of kaolin hollow fibre membrane as the support for the fabrication of kaolin/TiO2 nanorods (TNR) membrane. By varying the hydrothermal reaction times (2 h, 6 h, and 10 h), the different morphology, distribution, and properties of TiO2 nanorods on kaolin support were observed by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscope (AFM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). It was found that the well-dispersed of TiO2 nanorods have improved the surface affinity of kaolin/TNR membrane towards water, allowing kaolin/TNR membrane prepared from 10 h of hydrothermal reaction to exhibit the highest water permeation of 165 L/h.m2.bar. In addition, this prepared membrane also showed the highest photocatalytic activity of 80.3% in the decolourisation of reactive black 5 (RB5) under UV irradiation. On top of that, the kaolin/TNR membrane prepared from 10 h of hydrothermal reaction also exhibited a good resistance towards photocorrosion, enabling the reuse of this membrane for three consecutive cycles of photocatalytic degradation of RB5 without showing significant reduction in photocatalytic efficiency towards the decolourisation of RB5.
    Matched MeSH terms: Kaolin/chemistry*
  9. Fulltext Flow behaviour and viscoelasticity of polypropylene-kaolin composites extruded at different temperatures
    Nor Azura Abdul Rahim, Zulkifli Mohamad Ariff, Azlan Ariffin
    Pertanika Journal of Science & Technology, 2011;19(2):383-388.
    MyJurnal
    A study of kaolin addition in polypropylene (PP-kaolin) melt was carried out to characterize its flow behaviour and viscoelasticity at different temperatures. The compound of 20 wt% kaolin was prepared by melt mixing using two roll-mill heated at 185°C, while the compounded composites were put through a single screw extruder to evaluate its melt flow properties. The prepared PPKaolin composites exhibited a shear thinning behaviour and appeared to be strongly dependent on temperature. Moreover, it was also found that the power law index was constantly increased as the temperature increased. Meanwhile, a similar trend was observed for swelling ratio, whereby it also increased with increasing temperature. It was also observed that changes in the die temperatures would result in the formation of obvious bubble like surface morphology, and it became more prominent when the temperature was lowered.
    Matched MeSH terms: Kaolin
  10. Application of antimicrobial active packaging film made of semolina flour, nano zinc oxide and nano-kaolin to maintain the quality of low-moisture mozzarella cheese during low-temperature storage
    Jafarzadeh S, Rhim JW, Alias AK, Ariffin F, Mahmud S
    J Sci Food Agric, 2019 Apr;99(6):2716-2725.
    PMID: 30350410 DOI: 10.1002/jsfa.9439
    BACKGROUND: Active food packaging films with improved properties and strong antimicrobial activity were prepared by blending mixed nanomaterials with different ratio [1:4 (40 mg:160 mg), 3:2 (120 mg: 80 mg), 0:5 (0 mg: 200 mg) and 5:0 (200 mg:0 mg)] of ZnO and kaolin with semolina using a solvent casting method and used for the packaging of low moisture mozzarella cheese to test the effect of packaging on the quality change of the cheese for long-term (up to 72 days) refrigerated storage.

    RESULTS: Compared with the neat semolina film, mechanical strength (TS) of the nanocomposite films increased significantly (increase in 21-65%) and water vapor barrier (WVP) and O2 gas barrier (OP) properties decreased significantly (decrease in 43-50% and 60-65%, respectively) depending on the blending ratio of ZnO and kaolin nanoclay. The nanocomposite films also exhibited strong antimicrobial activity against bacteria (E. coli and S. aureus), yeast (C. albicans), and mold (A. niger). The nanocomposite packaging films were effectively prevented the growth of microorganisms (coliforms, total microbial, and fungi) of the cheese during storage at low-temperature and showed microbial growth of less than 2.5 log CFU/g after 72 days of storage compared to the control group, and the quality of the packaged cheese was still acceptable.

    CONCLUSION: The semolina-based nanocomposite films, especially Sem/Z3 K2 film, were effective for packaging of low moisture mozzarella cheese to maintain the physicochemical properties (pH, moisture, and fat content) and quality (color, taste, texture, and overall acceptability) of the cheese as well as preventing microbial growth (coliforms, total microbial, and fungi). © 2018 Society of Chemical Industry.

    Matched MeSH terms: Kaolin/pharmacology*; Kaolin/chemistry
  11. Solid-state fermentation of soybean residues for bioflocculant production in a pilot-scale bioreactor system
    Zulkeflee Z, Sánchez A
    Water Sci Technol, 2014;70(6):1032-9.
    PMID: 25259492 DOI: 10.2166/wst.2014.329
    An innovative approach using soybean residues for the production of bioflocculants through solid-state fermentation was carried out in 4.5 L near-to-adiabatic bioreactors at pilot-scale level. An added inoculum of the strain Bacillus subtilis UPMB13 was tested in comparison with control reactors without any inoculation after the thermophilic phase of the fermentation. The flocculating performances of the extracted bioflocculants were tested on kaolin suspensions, and crude bioflocculants were obtained from 20 g of fermented substrate through ethanol precipitation. The production of bioflocculants was observed to be higher during the death phase of microbial growth. The bioflocculants were observed to be granular in nature and consisted of hydroxyl, carboxyl and methoxyl groups that aid in their flocculating performance. The results show the vast potential of the idea of using wastes to produce bioactive materials that can replace the current dependence on chemicals, for future prospect in water treatment applications.
    Matched MeSH terms: Kaolin
  12. Fulltext Self-Fluxing Mechanism in Geopolymerization for Low-Sintering Temperature of Ceramic
    Jamil NH, Abdullah MMAB, Pa FC, Mohamad H, Ibrahim WMAW, Amonpattaratkit P, et al.
    Materials (Basel), 2021 Mar 10;14(6).
    PMID: 33801862 DOI: 10.3390/ma14061325
    Kaolin, theoretically known as having low reactivity during geopolymerization, was used as a source of aluminosilicate materials in this study. Due to this concern, it is challenging to directly produce kaolin geopolymers without pre-treatment. The addition of ground granulated blast furnace slag (GGBS) accelerated the geopolymerization process. Kaolin-GGBS geopolymer ceramic was prepared at a low sintering temperature due to the reaction of the chemical composition during the initial stage of geopolymerization. The objective of this work was to study the influence of the chemical composition towards sintering temperature of sintered kaolin-GGBS geopolymer. Kaolin-GGBS geopolymer was prepared with a ratio of solid to liquid 2:1 and cured at 60 °C for 14 days. The cured geopolymer was sintered at different temperatures: 800, 900, 1000, and 1100 °C. Sintering at 900 °C resulted in the highest compressive strength due to the formation of densified microstructure, while higher sintering temperature led to the formation of interconnected pores. The difference in the X-ray absorption near edge structure (XANES) spectra was related to the phases obtained from the X-ray diffraction analysis, such as akermanite and anothite. Thermal analysis indicated the stability of sintered kaolin-GGBS geopolymer when exposed to 1100 °C, proving that kaolin can be directly used without heat treatment in geopolymers. The geopolymerization process facilitates the stability of cured samples when directly sintered, as well as plays a significant role as a self-fluxing agent to reduce the sintering temperature when producing sintered kaolin-GGBS geopolymers.
    Matched MeSH terms: Kaolin
  13. Fulltext Bioflocculants Produced by Bacterial Strains Isolated from Palm Oil Mill Effluent for Application in the Removal of Eriochrome Black T Dye from Water
    Abbas SZ, Yong YC, Ali Khan M, Siddiqui MR, Hakami AAH, Alshareef SA, et al.
    Polymers (Basel), 2020 Jul 13;12(7).
    PMID: 32668712 DOI: 10.3390/polym12071545
    Four strains of bioflocculant-producing bacteria were isolated from a palm oil mill effluent (POME). The four bacterial strains were identified as Pseudomonas alcaliphila (B1), Pseudomonas oleovorans (B2), Pseudomonas chengduensis (B3), and Bacillus nitratireducens (B4) by molecular identification. Among the four bacterial strains, Bacillus nitratireducens (B4) achieved the highest flocculating activity (49.15%) towards kaolin clay suspension after eight hours of cultivation time and was selected for further studies. The optimum conditions for Eriochrome Black T (EBT) flocculation regarding initial pH, type of cation, and B4 dosage were determined to be pH 2, Ca2⁺ cations, and a dosage of 250 mL/L of nutrient broth containing B4. Under these conditions, above 90% of EBT dye removal was attained. Fourier transform infrared spectroscopic (FT-IR) analysis of the bioflocculant revealed the presence of hydroxyl, alkyl, carboxyl, and amino groups. This bioflocculant was demonstrated to possess a good flocculating activity, being a promissory, low-cost, harmless, and environmentally friendly alternative for the treatment of effluents contaminated with dyes.
    Matched MeSH terms: Kaolin
  14. Fulltext A Study on the Utilization of Coal Fly Ash Derived Grog in Clay Ceramics
    Choo TF, Mohd Salleh MA, Kok KY, Matori KA, Abdul Rashid S
    Materials (Basel), 2020 Nov 18;13(22).
    PMID: 33218206 DOI: 10.3390/ma13225218
    Grog is an additive material that plays important roles in ceramic making. It improves the fabrication process of green bodies as well as the physical properties of fired bodies. Few low-cost materials and wastes have found their application as grog in recent years, thus encouraging the replacement of commercial grogs with cost-saving materials. Coal fly ash, a combustion waste produced by coal-fired power plant, has the potential to be converted into grog owing to its small particle sizes and high content of silica and alumina. In this study, grog was derived from coal fly ash and mixed with kaolin clay to produce ceramics. Effects of the grog addition on the resultant ceramics were investigated. It was found that, to a certain extent, the grog addition reduced the firing shrinkage and increased the total porosity of the ceramics. The dimensional stability of the ceramics at a firing temperature of 1200 °C was also not noticeably affected by the grog. However, the grog addition in general had negative effects on the biaxial flexural strength and refractoriness of the ceramics.
    Matched MeSH terms: Kaolin
  15. Fulltext Influence of Sintering Temperature of Kaolin, Slag, and Fly Ash Geopolymers on the Microstructure, Phase Analysis, and Electrical Conductivity
    Zulkifli NNI, Abdullah MMAB, Przybył A, Pietrusiewicz P, Salleh MAAM, Aziz IH, et al.
    Materials (Basel), 2021 Apr 26;14(9).
    PMID: 33925777 DOI: 10.3390/ma14092213
    This paper clarified the microstructural element distribution and electrical conductivity changes of kaolin, fly ash, and slag geopolymer at 900 °C. The surface microstructure analysis showed the development in surface densification within the geopolymer when in contact with sintering temperature. It was found that the electrical conductivity was majorly influenced by the existence of the crystalline phase within the geopolymer sample. The highest electrical conductivity (8.3 × 10-4 Ωm-1) was delivered by slag geopolymer due to the crystalline mineral of gehlenite (3Ca2Al2SiO7). Using synchrotron radiation X-ray fluorescence, the high concentration Ca boundaries revealed the appearance of gehlenite crystallisation, which was believed to contribute to development of denser microstructure and electrical conductivity.
    Matched MeSH terms: Kaolin
  16. Fulltext XRF determination of major elemental contents of clay samples from north-west Peninsular Malaysia
    Ahmad Saat, Zaini Hamzah, Zaharidah Abu Bakar
    Journal of Nuclear and Related Technologies, 2009;2009(1):230-236.
    MyJurnal
    Being an imperative material for man either used as building materials, pottery or as components in material industry and technology, knowledge of clays elemental contents is important. In the present study ten clay samples obtained from various locations in North-West Peninsular Malaysia were used. Majority of the clays were economically manufactured to be used as building materials or pottery. The objective of study was to determine the main elemental contents of the samples, and relate the results to the types of minerals, as well as to compare them with clays from other studies. In the study X-ray Fluorescence (XRF) coupled to samples dilution method and standard calibration samples was used. The elements detected in the study were Si, Al, Fe, Ti, K and Ca. Depending on locations, the percentage concentration ranged between 24.8 – 32.4 for Si, 10.8 – 19.0 for Al, 0.09 – 2.12 for Fe, 0.08 – 1.13 for Ti, 0.45 – 3.39 for K and trace amount of Ca and P. However, Mg that normally found in typical clay was not found in the studied samples. Comparing the oxide of the major elements with other studies, it was found that the clay samples contained mixtures of kaolinite (two-layered structure) and illite (three-layered structure).
    Matched MeSH terms: Kaolin
  17. Fulltext X-ray diffraction study of clay from north-west Peninsular Malaysia
    Ahmad Saat, Zaini Hamzah
    Journal of Nuclear and Related Technologies, 2008;2008(1):1-9.
    MyJurnal
    Clay has been regarded as very important natural industrial materials. All these industries exploit the properties that clay can be molded into any shape and fired to dry without losing its form. A study was carried out on clay samples from eight sites in the north-eastern part of Peninsular Malaysia. The study was accomplished by using X-ray diffraction (XRD) technique. The x-ray diffraction spectra obtained enable the determination of the lattice spacing associated with the types of clay and nonclay minerals present in the samples. Results of the study shows that the major components of clay minerals present in all samples studied are kaolinite and illite. The presence of kaolinite is confirmed by firing test in which the kaolinite diffraction peaks disappeared upon heating the samples at 600 o C. The presence of non-clay minerals such as quartz, mica, feldspar and chlorite are also observed.
    Matched MeSH terms: Kaolin
  18. Perlakuan Beberapa Unsur Major dan Unsur Surih dalam Profil Luluhawa Batuan Basalt di Segamat Johor
    Baba Musta, Mohamad Md. Tan
    Sains Malaysiana, 1996;25.
    Highly weathered basaltic rock was exposed at PSK profile of Kuantan, Segamat Highway. The weathering profile from fresh rock soil can be observed at PKJ profile at Kg. Jabi Quarry. Twelve rock and soil samples from PSK profile and thirteen samples from PKJ profile have been collected for geochemical analysis. The objective of the analysis is to establish the behaviour of several major and trace elements in the weathering profile of the basaltic rock. The samples were analysed by XRF and XRD techniques. Petrographic study was done on fresh rock samples and concretions. The concentration of major elements (TiO2, Al2O3 and Fe2O3) appear to be increased with the increasing of the degree of weathering whereas the concentration of SiO2 and CaO are decreased. There is a clear correlation between Fe2O3 + Al2O3 with L.O.I as well as between Fe2O3 with Al2O3. Behaviour of the trace elements (Ni, Co, Cr and Zn) against the weathering process are totally different. The secondary minerals (kaolinite, nactire, geothite, hematite and gibbsite) appear to control the behaviour of the major and trace elements.
    Batuan basalt yang terluluhawa sepenuhnya telah dicerap di lokaliti PSK Lebuhraya Segamat-Kuantan. Profil luluhawa yang boleh dilihat perubahan daripada batuan segar hingga tanih didapati di lokaliti PKJ Kuari Kg. Jabi. Dua contoh profil dengan masing-masing 12 sampel dan 13 sample tanih telah dikaji untuk menentukan perlakuan beberapa unsur major dan unsur surih batuan basalt yang terluluhawa. Kaedah analisis yang digunakan ialah pendarflour sinar-X (XRF) dan pembelauan sinar-X (XRF). Kajian petrografi pula dibuat pada sampel batuan segar dan sampel konkresi. Nilai unsur major TiO2, Al2O3 dan Fe2O3 bertambah dengan bertambahnya darjah luluhawa manakala SiO2 dan CaO menyusut. Hubungan korelasi Fe2O3 + Al2O3 dengan L.O.I dan Fe2O3 denagn Al2O3 adalah jelas. Unsur surih nikel (Ni) kobalt (Co), kromium (Cr) dan zink (Zn) mempunyai perlakuan yang berbeza-beza dengan luluhawa. Perlakuan yang ditunjukkan oleh unsur major dan surih tersebut dikawal oleh mineral sekunder (koalinit, nakrit, geotit, hematit dan gibsit).
    Matched MeSH terms: Kaolin
  19. Effect of compatibilizer on the dynamic mechanical and electrical properties of kaolin clay reinforced EPDM rubber
    Gautam Sarkhel, Sanjay Manjhi
    Sains Malaysiana, 2013;42:495-501.
    Industrial pollution issue and dark colour of carbon black, clay based non black filler are getting more importance for reinforcing elastomer. EPDM-Kaolin composites with various maleated EPDM concentration have been prepared by mixing on a two roll mill. The rheometry data showed the optimum cure time increases with increasing compatibilizer concentration without decreasing torque value indicating that acidic functional groups comes from compatibilizer could retard cure rate and increase the optimum cure time rather than change in the ultimate cure state. As the filler
    concentration increases, the edge to edge and face to edge interaction between filler and EPDM increases and the free volume between EPDM molecules is reduced, the storage modulus increases. Moreover, the dynamic mechanical analysis also showed the increase in glass transition temperature with increase in filler concentration due to the inter-tubular diffusion of EPDM inside the clay. It was also observed that with increasing filler concentration, the resistivity and dielectric strength decreases and moreover with increasing compatibilizer concentration the resistivity decreases due to better dispersion of filler helps to build conduction path. The morphological study also revealed that homogeneity of filler dispersion increases with increase in compatibilizer concentration.
    Matched MeSH terms: Kaolin
  20. A novel biocoagulant agent from mushroom chitosan as water and wastewater therapy
    Adnan O, Abidin ZZ, Idris A, Kamarudin S, Al-Qubaisi MS
    Environ Sci Pollut Res Int, 2017 Aug;24(24):20104-20112.
    PMID: 28702910 DOI: 10.1007/s11356-017-9560-x
    A new commercial cationic polyelectrolyte chitosan (CM), obtained from the waste of mushroom production, was examined using models of water and wastewater namely kaolin and palm oil mill effluent (pome). As it is biocompatible, widely available, and economically feasible, chitosan mushroom has high potential to be a suitable replacement for alum. Also, it can be a promising alternative to chitosan obtained traditionally from Crustaceans due to its higher zeta potential and homogeneity based on the raw material required for its production. A wide range of coagulant dose (5-60 mg l(-1)) and wastewater pH (2-12) were taken into account to find the optimal conditions of coagulation. The optimal doses are 10 and 20 mg l(-1) at best pH (11 and 3) when treated with kaolin and palm oil mill effluent, respectively, while 1200 mg l(-1) of alum was not enough to reach the efficiency of chitosan mushroom. On the other hand, the optimum dose of chitosan mushroom (20 mg l(-1)) at pH 3 of pome produced (75, 73, and 98%) removal of chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solids (TSS), respectively. The significant potential of chitosan mushroom was proved by zeta potential measurement. Indeed, it possesses the highest zeta potential (+70 mV) as compared to the traditional chitosan produced from crustaceans. In short, chitosan mushroom as a biocoagulant is eco-friendly and it enhances water quality that meets the requirements of environmental conservatives.
    Matched MeSH terms: Kaolin
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