Now showing 1 - 3 of 3
  • Publication
    Effects of temperature on rice husk silica ash additive for fouling mitigation by polysulfone–RHS ash mixed-matrix composite membranes
    ( 2020-08-01)
    Alias S.S.
    ;
    Harun Z.
    ;
    Manoh N.
    ;
    Abstract: It has been found that the preparation of green silica based on agricultural crops preserves environmental sustainability. In this study, rice husk silica (RHS) ash was prepared by burning rice husk (RH) at different temperatures (400 and 1200 Â°C). Both types of green RHS ash additives were blended with polysulfone dope, after which membranes were fabricated via phase inversion. The RHS ash that was synthesised at 400 Â°C (RHS400) had an amorphous structure with strong hydrophilic properties, while the composite membrane containing 3 wt% of RHS400 (A3 membrane) achieved the optimum properties of a dense top, an extended sub-layer of continuous smaller finger-like pores and a bottom layer of macrovoids. A satisfactory mean surface roughness, average pore size (1.90 ± 9.50 × 10−2 µm), porosity (40.66 ± 2.03%) and tensile strength (3.27 ± 0.16 MPa) were also obtained. The contact angle (52.5° ± 3.6°) further proved that this membrane was hydrophilic. The elemental and thermal analyses confirmed the presence of Si and O, which correlated with the 12% residual that was contributed by the silica inside the membrane. The optimum properties of the A3 membrane were an increased PWF (154.04 ± 7.70 L m−2 h−1) with the highest rejection of HA (96.00 ± 4.80%) and a fouling mitigation with the lowest internal resistance (6.79 ± 0.34 × 1012 m−1). Graphic abstract: [Figure not available: see fulltext.]
  • Publication
    The Route of Hydrothermal Synthesis Zeolite-A from the Low-Grade Perak kaolin, Malaysia
    ( 2022-08-01)
    Sazali N.
    ;
    Harun Z.
    ;
    Abdullahi T.
    ;
    Kamarudin N.H.
    ;
    Sazali N.
    ;
    ;
    Hubadillah S.K.
    ;
    Alias S.S.
    Zeolite A was successfully synthesized using Perak kaolin which acts as the main source of silica and alumina. The process of beneficiation was conducted on raw kaolin to remove the impurities that existed in natural kaolin and also to increase the physical and chemical characteristic of kaolin. The kaolin was continued to be heated in the furnace with the temperature of 6000C for 4 h which described as a metakaolinization process that transformed it into the amorphous stage. The raw kaolin was characterized by XRD, FESEM, FTIR, PSA, TGA, while metakaolin by XRD, FESEM and FTIR. The mixture of zeolite A was achieved by adding the metakaolin into sodium hydroxide (NaOH) solution without adding other sources of silica and alumina. The solution mixture was stirred for 24 h before undergoing the process of hydrothermal synthesis. Two optimum conditions were studied for Zeolite A synthesizing, which were different molarity of sodium hydroxide and crystallizations time during the hydrothermal process. The successful synthesis of Zeolite A was then characterized by XRD, FESEM, FTIR, PSA, and BET surface area. The BET surface area of Zeolite-A is higher, 5.26 m2/g, compared to natural zeolite, 2.9 m2/g. As demonstrated in this work, Perak kaolin which was successfully synthesized into Zeolite-A with 2 M NaOH and 12-h crystallization time, gave a higher crystallinity percentage, 72.97%. The results obtained revealed that formation The of zeolite A has been highly affected by the NaOH molarity and crystallization time used in the combination of reactions.
  • Publication
    The effect of silica toward polymer membrane for water separation process
    The aim of this present work was to investigate the effect of different percentage rice husk silica (RHS) particles composition towards polymer mixed matrix membrane microstructure and performance in water separation process. The polymer membranes were prepared by a phase inversion method using polysulfone (PSf), N-methyl-2-pyrrolidone (NMP) as solvent, distilled water as non-solvent and fixed RHS at 400°C as an additive. The microstructures of PSf/PEG/RHS sample were characterized by performing scanning electron microscope (SEM). The performance was measured by using pure water flux and humic acid for the rejection test. The analyzed result of SEM analysis revealed that the addition of RHS obviously improved the microstructure of the membrane especially at the top and sub layer at the range of 1 until 3 wt. %. This was proven by the pure water flux (PWF) value measured from 114.47 LMH to 154.04 LMH and rejection from value 83% to 96% at this specified range substantially higher than the mixed matrix membrane with synthetic silica. In fact, the presence of RHS particles not only improved the properties and performance of membrane but also possess biodegradable properties which can minimize the pollution and provide a membrane green technology system.