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
    Novel hydroxyapatite-based bio-ceramic hollow fiber membrane derived from waste cow bone for textile wastewater treatment
    ( 2020-01-01)
    Hubadillah S.K.
    ;
    Othman M.H.D.
    ;
    Tai Z.S.
    ;
    ;
    Yusuf N.K.
    ;
    Ahmad AA.
    ;
    Rahman M.A.
    ;
    Jaafar J.
    ;
    Kadir S.H.S.A.
    ;
    Harun Z.
    Industrial textile wastewater is toxic due to the presence of recalcitrant color pigments and poisonous heavy metals. In this study, the hydroxyapatite (HAp)-based bio-ceramic hollow fiber membranes (h-bio-CHFM) were developed via the combined phase inversion and sintering technique. It was found that the properties of the developed h-bio-CHFMs were greatly affected by the HAp content of the ceramic suspension, and sintering temperature. The h-bio-CHFM with the sintering temperature of 1200 °C exhibited the long rod-shaped HAp particles and the smallest pore size (0.013 μm). High removals of color (99.9%), COD (80.1%), turbidity (99.4%) and conductivity (30.1%) were achieved using the h-bio-CHFM sintered at 1200 °C with stable high flux of 88.3 L/m2h. Remarkably, the h-bio-CHFM sintered in the temperature range of 1000–1200 °C also demonstrated excellent adsorption ability towards heavy metals with 100% removals. The results of this study show the potential of the h-bio-CHFM for the efficient industrial textile wastewater treatment applications.
  • Publication
    Facile fabrication of superhydrophobic and superoleophilic green ceramic hollow fiber membrane derived from waste sugarcane bagasse ash for oil/water separation
    ( 2020-01-01) ;
    Hubadillah S.K.
    ;
    Harun Z.
    ;
    Othman M.H.D.
    ;
    Yunos M.Z.
    ;
    Ismail A.F.
    ;
    Salleh W.N.W.
    Green ceramic hollow fiber membranes with superhydrophobic and superoleophilic surfaces (ss-CHFM/WSBA) were successfully fabricated via facile sol–gel process using tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) as precursors. In this work, silica solution was prepared using the modified Stöber method. This process was followed by dipping the pristine membranes into the sol–gel solution at various grafting times (0–90 min), grafting cycles (0–4 cycles), and calcination temperatures (400–600 °C). The wettability, surface morphology, and chemical composition of the pristine and ss-CHFM/WSBA membranes were investigated. The results showed that increasing the grafting time has increased the wettability of ss-CHFM/WSBA with high contact angle of up to 163.9°. Similarly, increasing grafting cycle has enhanced the hydrophobicity of ss-CHFM/WSBA due to the formation of hierarchical structure of grafting cycle which were more than one. The optimum calcination temperature for ss-CHFM/WSBA was identified. It was found that increasing the calcination temperature has degraded the sol template on the surface of ss-CHFM/WSBA, hence decreasing the wettability. The preliminary performance tests showed that ss-CHFM/WSBA grafted at 60 min, 3 cycles, and calcined at 400 °C showed excellent oil/water separation efficiency of 99.9% and oil flux of 137.2 L/m2h.