Siti Khalijah Mahmad Rozi
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Siti Khalijah Mahmad Rozi
Official Name
Siti Khalijah, Mahmad Rozi
Alternative Name
Rozi, Siti Khalijah Mahmad
Rozi, S.K.M
Mahmad Rozi, S.K
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Scopus Author ID
57190815094

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  • Publication
    Kinetics and Effects of Process Parameters on Oil Adsorption using Activated Carbon from Rubber Seed Kernels (Hevea brasiliensis)
    ( 2023-01-01)
    Aswadi M.A.H.
    ;
    Hairul Nazirah Abdul Halim
    ;
    Nasaruddin N.F.N.
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Zulfakar Mokhtar
    ;
    Tan L.S.
    ;
    Jusoh N.W.C.
    Wastewater contaminated with oil discharged from food processing industries need to be treated properly in order to avoid clogging the drainage and sewerage systems. The removal of oil via the adsorption technique using biomass as a low-cost adsorbent was proposed in this study. Rubber seed kernels (RSKs) were used as the raw material to synthesise activated carbon. The RSKs were impregnated with 10 wt% of phosphoric acid (H3PO4) and carbonised at 500 °C to produce rubber seed kernel activated carbon (RSKAC). Different parameters were included in batch adsorption studies, namely, contact time (30 to 240 min), activated carbon dosage (0.5 to 2.5 g), and temperature (25 to 65 °C). The performance of each process parameter was evaluated based on the adsorption capacity of oil onto the synthesised RSKAC. Pseudo-first order and pseudo-second order models were applied to analyse oil adsorption kinetics using RSKAC. Based on the experimental results, the highest oil adsorption was achieved at 150 min of contact time, 2.5 g of RSKAC, and at a temperature of 35 °C. Oil adsorption using RSKAC in this study followed the pseudo-second order kinetics model. These findings revealed that RSKAC could be synthesised as a low-cost adsorbent for oil adsorption.
  • Publication
    Potential of Pretreated Spent Coffee Ground as Adsorbent for Oil Adsorption
    ( 2022-01-01)
    Nasaruddin N.F.N.
    ;
    Hairul Nazirah Abdul Halim
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Zulfakar Mokhtar
    ;
    Tan L.S.
    ;
    Jusoh N.W.C.
    Spent Coffee Ground (SCG) has the potential of becoming a low-cost adsorbent for oil removal. However, the effectiveness of SCG as an oil adsorbent is limited by its hydrophilicity. In this work, chemical pretreatment of SCG with acid and alkali was evaluated as a means of enhancing its performance for adsorbing palm cooking oil. The surface morphology of raw and pretreated SCG samples was characterised using a Scanning Electron Microscope (SEM). The functional groups were analysed using Fourier Transform Infrared (FTIR) spectroscopy. A comparison between adsorption performances was performed in terms of contact time in batch adsorption experiments to determine the adsorption capacity of SCG-based adsorbents with oil. The SEM results showed that more developed pores were present on the acid- and alkali-treated SCG samples compared to on the raw SCG sample, while the FTIR results indicated the elimination of hydrophilic cellulose and hemicellulose on these samples. According to these results, both acid- and alkali-treated SCG have better tendencies of adsorbing oil compared to raw SCG. The maximum oil adsorption capacity (2.549 g/g) occurred after 150 min of contact time between alkali-treated SCG adsorbents and oil.
  • Publication
    Performance of fatty acid-modified spent coffee grounds as a potential adsorbent for oil adsorption
    ( 2022-11-18)
    Nasaruddin N.F.N.
    ;
    Hairul Nazirah Abdul Halim
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Zulfakar Mokhtar
    ;
    Tan L.S.
    ;
    Jusoh N.W.C.
    Problems caused by fats, oils, and grease (FOG) in sewer systems have escalated over the years. FOG produced from households, restaurants, stalls, and food processing facilities have contaminated water resources through the sewer system. Thus, trace removal of oil from wastewater is a necessary measure to ensure minimal discharge of FOG into the environment. In the present study, due to the high volumes of coffee waste with no commercial value being generated daily, spent coffee grounds (SCG) were exploited as an oil adsorbent. However, due to their low hydrophobicity, SCG tend to have limited oil adsorption capacity. In this work, SCG underwent pre-treatment using alkali and were further modified with waste cooking oil (WCO) that contained free fatty acids (FFAs) at different ratios (1:10, 1:20, and 1:30) in order to enhance their oil adsorption performance. The performance of the synthesised adsorbents was tested in a batch adsorption process at different contact times. From the batch adsorption test, the highest oil adsorption capacity (2.807 ± 0.086?g/g) was observed using the 1:10 ratio of SCG to FFAs-WCO within 180?min of contact time.
  • Publication
    Performance of Alkali-Treated Spent Coffee Ground as Potential Adsorbent for Oil Adsorption
    ( 2023-06-09)
    Nasaruddin N.F.N.
    ;
    Hairul Nazirah Abdul Halim
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Zulfakar Mokhtar
    ;
    Tan L.S.
    ;
    Jusoh N.W.C.
    The increase in food industrial and domestic activities have led to massive generations of oily wastewater with high proportions of fat, oil, and grease (FOG). The growing awareness of the detrimental effects of oil pollutants on the aquatic population and the economy, has made the minimal discharge of FOG into the environment a compulsory mitigative measure. In this work, spent coffee grounds (SCGs) were exploited as an oil adsorbent to minimize the amount of SCGs that are primarily discarded as waste. SCGs were pre-treated with alkali to enhance their performance for adsorbing oil. Batch adsorption tests that consisted of contact time, adsorbent dosage, and temperature for oil adsorption, were carried out to analyse the performance of the alkali-treated SCGs. Based on the results, the maximum oil adsorption capacity was obtained after 150 min of contact time between 0.5g of alkali-treated SCG adsorbents and oil, at 25 °C. These alkali-treated SCGs have also shown the potential for converting wastes into efficient green oil adsorbents.