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
    Novel palm fatty acid functionalized magnetite nanoparticles for magnetic solid-phase extraction of trace polycyclic aromatic hydrocarbons from environmental samples
    ( 2017-01-01)
    Siti Khalijah Mahmad Rozi
    ;
    Hamid Rashidi Nodeh
    ;
    Muhammad Afzal Kamboh
    ;
    Ninie Suhana Abdul Manan
    ;
    Sharifah Mohamad
    A novel adsorbent, palm fatty acid coated magnetic Fe3O4 nanoparticles (MNP-FA) was successfully synthesized with immobilization of the palm fatty acid onto the surface of MNPs. The successful synthesis of MNP-FA was further confirmed by X-Ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and Energy dispersive X-Ray spectroscopy (EDX) analyses and water contact angle (WCA) measurement. This newly synthesized MNP-FA was applied as magnetic solid phase extraction (MSPE) adsorbent for the enrichment of polycyclic aromatic hydrocarbons (PAHs), namely fluoranthene (FLT), pyrene (Pyr), chrysene (Cry) and benzo(a)pyrene (BaP) from environmental samples prior to High Performance Liquid Chromatography- Diode Array Detector (HPLC-DAD) analysis. The MSPE method was optimized by several parameters such as amount of sorbent, desorption solvent, volume of desorption solvent, extraction time, desorption time, pH and sample volume. Under the optimized conditions, MSPE method provided a low detection limit (LOD) for FLT, Pyr, Cry and BaP in the range of 0.01-0.05 ng mL–1. The PAHs recoveries of the spiked leachate samples ranged from 98.5% to 113.8% with the RSDs (n = 5) ranging from 3.5% to 12.2%, while for the spiked sludge samples, the recoveries ranged from 81.1% to 119.3% with the RSDs (n = 5) ranging from 3.1% to 13.6%. The recyclability study revealed that MNP-FA has excellent reusability up to five times. Chromatrographic analysis demonstrated the suitability of MNP-FA as MSPE adsorbent for the efficient extraction of PAHs from environmental samples.
  • Publication
    New porous amine-functionalized biochar-based desiccated coconut waste as efficient CO2 adsorbents
    ( 2024-03-01)
    Zakaria D.S.
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Hairul Nazirah Abdul Halim
    ;
    Mohamad S.
    ;
    Zheng G.K.
    Climate change caused by the greenhouse gases CO2 remains a topic of global concern. To mitigate the excessive levels of anthrophonic CO2 in the atmosphere, CO2 capture methods have been developed and among these, adsorption is an especially promising method. This paper presents a series of amine functionalized biochar obtained from desiccated coconut waste (amine-biochar@DCW) for use as CO2 adsorbent. They are ethylenediamine-functionalized biochar@DCW (EDA-biochar@DCW), diethylenetriamine-functionalized biochar@DCW (DETA-biochar@DCW), triethylenetetramine-functionalized biochar@DCW (TETA-biochar@DCW), tetraethylenepentamine-functionalized biochar@DCW (TEPA-biochar@DCW), and pentaethylenehexamine-functionalized biochar@DCW (PEHA-biochar@DCW). The adsorbents were obtained through amine functionalization of biochar and they are characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, Brunauer–Emmett–Teller (BET), and thermogravimetric analysis (TGA). The CO2 adsorption study was conducted isothermally and using a thermogravimetric analyzer. From the results of the characterization analyses, a series of amine-biochar@DCW adsorbents had larger specific surface area in the range of 16.2 m2/g–37.1 m2/g as compare to surface area of pristine DCW (1.34 m2/g). Furthermore, the results showed an increase in C and N contents as well as the appearance of NH stretching, NH bending, CN stretching, and CN bending, suggesting the presence of amine on the surface of biochar@DCW. The CO2 adsorption experiment shows that among the amine modified biochar adsorbents, TETA-biochar@DCW has the highest CO2 adsorption capacity (61.78 mg/g) when using a mass ratio (m:m) of biochar@DCW:TETA (1:2). The adsorption kinetics on the TETA-biochar@DCW was best fitted by the pseudo-second model (R2 = 0.9998), suggesting the adsorption process occurs through chemisorption. Additionally, TETA-biochar@DCW was found to have high selectivity toward CO2 gas and good reusability even after five CO2 adsorption–desorption cycles. The results demonstrate the potential of novel CO2 adsorbents based on amine functionalized on desiccated coconut waste biochar. Graphical Abstract: (Figure presented.)
  • Publication
    EFFECTIVE AND FAST ADSORPTIVE REMOVAL OF COOMASSIE BRILLIANT BLUE G 250 DYE FROM WATER USING Fe₃O₄ MAGNETIC NANOPARTICLES
    ( 2023-01-01)
    Siti Khalijah Mahmad Rozi
    ;
    Saufi N.A.
    ;
    Rashidi N.A.N.M.
    Coomassie Brilliant Blue G 250 (CBB G 250) is mainly generated from industrial textile effluent. Due to its non-degradable nature, it is not only environmentally hazardous, but also affect human health, causing irritations of the eye, respiratory or gastrointestinal tract. Therefore, a strategy for treating this colorant is necessary. This research highlights the synthesis of Fe3O4 Magnetic nanoparticles (Fe3O4 MNPs) as a low-cost adsorbent for removal of CBB G 250 dye from aqueous solutions. Fe3O4 MNPs were synthesized using chemical coprecipitation method. Characterization results revealed that the peaks at 537, 3400 and 1604 cm-1 in the Fourier Transform Infrared Spectroscopy spectrum represented the Fe-O band, O-H stretching and bending on the Fe3O4 MNPs surface, respectively. Crystal phase analysis indicated that Fe3O4 MNPs has a cubic spinel structure. Morphological analysis showed Fe3O4 MNPs are in nano-sized, spherical in shape, and have uniformly distributed particle size. The result from magnetic and surface area analyses demonstrated that Fe3O4 MNPs have 63.30 emu g-1 saturation magnetization and 123.5 m2 g-1 surface area. Thermal stability analysis showed that adsorbed water and hydroxyl group (6.25%) were lost at temperature below 100 ℃. At temperature between 260 ℃ and 540 ℃, approximately 2.09% weight loss were recorded due to change from magnetite (Fe3O4) to maghemite (Ɣ-Fe2O3) in crystal phase. Elemental analysis revealed that the Fe3O4 MNPs showed 24.50 % of Fe and 75.50 % of O. Following the confirmation of Fe3O4 MNPs structure, the impact of various parameters such as adsorbent dosage (0.02-0.14 g), contact time (5-20 minutes), initial concentration (25-100 ppm) and pH (3-10) on the adsorption of CBB G 250 dyes were investigated. Experimental results showed that Fe3O4 MNPs achieved 95% removal of CBB G 250 at optimum conditions of 0.12 g dosage, 15 minutes contact time, 50 ppm initial dye concentration and at pH value of 8. Adsorption isotherms and kinetics revealed that the adsorption process using Fe3O4 MNPs in this study obeys both Langmuir and Freundlich isotherm and pseudo-second-order kinetic. The results obtained from this study confirmed that Fe3O4 MNPs can be used as an adsorbent material for the removal of dye from effluent.
  • 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
    Asam gelugur-based carbon aerogels for highly recyclable oils adsorption
    ( 2023-07)
    Cheong Yi Xin
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Monisha Devi Elan Solan
    ;
    Syazwani Mahmad Puzi
    Rapid development of the oil industries and improper oil management caused a huge amount of oil pollutant released into the water environment. Oil pollutant is toxic and may harm aquatic biodiversity. The present work highlights the facile preparation of carbon aerogels based from Asam Gelugur (CA@Ga) for oil remediation from aqueous. Analysis on the structure of CA@Ga using Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive X-ray (EDX) and Scanning Electron Microscopy (SEM), confirmed the successful preparation of CA@Ga through hydrothermal carbonization. The main parameters affecting the adsorption of oil such as the sorption time, pH and mass of sorbent were screened and oil adsorption studies revealed that the optimum conditions were at contact time of 3 minutes, pH of solution at 7 and the adsorbent mass of 2 g with the highest adsorption capacity of 0.82 + 0.01 g/g. CA@Ga displayed a good stability towards thermal treatment and exhibited good adsorption ability towards several types of oil. Recyclability study depicts that CA@Ga could be regenerated by simple physical treatments and retained a high sorption after 10 cycles with adsorption capacity of 0.80 + 0.01 g/g. Therefore, the prepared CA@Ga has potential in application of oil recovery and environmental protection.
  • Publication
    Amine functionalized carbon-based soybean curd residues (SCR) as potential adsorbent for carbon dioxide adsorption
    ( 2021-05-24)
    Zakaria D.S.
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Hairul Nazirah Abdul Halim
    ;
    Mohamad S.
    Currently, carbon dioxide (CO2) capture can preserve environmental quality by using carbon- based adsorbent. In this research, Polyethylenehexamine (PEHA) functionalized carbon-based soybean curd residues (carbonized SCR-PEHA) was prepared for CO2 adsorption. Analysis of functional groups of the prepared adsorbent using Fourier Transform Infrared Spectroscopy (FTIR), confirmed the functionalization of PEHA on the carbonized SCR. CO2 uptake of the carbonized SCR-PEHA was compared with the bare SCR using Thermogravimetric Analyzer (TGA) analysis. TGA results revealed that the adsorption capacity of CO2 for carbonized SCR-PEHA and bare SCR are 8.816 mg/g and 3.027 mg/g respectively. It was observed that functionalization of the PEHA on the surface of carbonized SCR had improved the adsorption capacity of CO2 by 2.92 times as compared to bare SCR. The phenomenon can be explained from the interaction of the CO2 with the available amine sites provided for the carbonized SCR-PEHA which significantly improved the CO2 adsorption. Hence, the carbonized SCR-PEHA demonstrate potential adsorbent for CO2.
  • Publication
    Fe₃O₄-Doped polysulfane membrane for enhanced adsorption of copper from aqueos solution
    ( 2024-01-01)
    Wan Khairunnisa Wan Ramli
    ;
    Nur Maisyatul Syalina Abdul Wahab
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Syumayyah Rasis
    ;
    Gavin Chew Tiong Chuen
    ;
    Lew Guo Liang
    Water pollution, especially from industrial wastewater has become one of the major global environmental problems. As the result of rapid industrialization, the expansion of industries such as the electroplating industry has resulted in an increase in heavy metals effluent, especially copper, in the wastewater, and this poses detrimental effects on the biodiversity and environment. The abatement of copper pollution has received widespread attention, and continuous research advancement has been observed in adsorption and membrane technology. Nanofiltration membranes with nanopores recorded higher suitability to remove ions but at the expense of membrane fouling as a result of the formation of contaminants on the surface layer that blocks the diffusion of contaminants into the membrane substructure. This research highlights the incorporation of Fe3O4 nanoparticles into the polysulfone (PSf) membrane matrix as an adsorptive membrane and their possible adsorption mechanism towards Cu, which can manifest the combined characteristics of both removal techniques. Fe3O4 nanoparticles were synthesized using the co-precipitation method. Fe3O4-doped PSf membranes were then synthesized with various concentrations of Fe via the Non-solvent Induced Phase Separation (NIPS) technique. The physicochemical properties of the Fe nanoparticles and the membranes were evaluated using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), water contact angle and porosity testing. Crystal phase analysis confirmed the formation of magnetite Fe3O4 in a cubic structure. Agglomerations of Fe NPs on the membrane surface were observed for membranes with lower Fe concentrations, suggesting the possibility of poor blending and this contributed to the lower adsorption capability of these membranes. Membranes with 2 wt.% Fe concentration (Fe-2.0) exhibited the highest Cu(II) ions adsorption capacity of 637 mg/g, which is trifold of those recorded for pristine PSF membrane (Fe-0.0). The adsorption data of Cu adsorption were best fitted into the Temkin isotherm and pseudo-second-order models, suggesting an adsorption mechanism involving an exothermic chemical interaction between Cu ions and the Fe3O4 NPs within the membrane. This research confirms the potential of incorporating Fe3O4 in the PSf membrane backbone to enhance Cu removal as an adsorptive membrane, even at lower NP concentrations.
  • 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.