Naimah Ibrahim
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Preferred name
Naimah Ibrahim
Official Name
Ibrahim, Naimah
Alternative Name
Ibrahim, Naimah
Ibrahim, N.
Naimah, I.
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Scopus Author ID
23767004300
Researcher ID
AAA-9532-2021

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Sulfur dioxide removal by calcium-modified fibrous KCC-1 mesoporous silica: kinetics, thermodynamics, isotherm and mass transfer mechanism

2022-04-01 , Hanif M.A. , Naimah Ibrahim , Khairuddin Md Isa , Umi Fazara Md Ali , Tuan Abdullah T.A. , Jalil A.A.

The removal of sulfur dioxide from industrial flue gas through dry flue gas desulfurization method commonly involves the use of adsorption process with porous sorbent. The efficiency of this process is highly dependent on the adsorption capacity and the adsorption rate of SO2 onto the sorbent materials. The use of KCC-1 mesoporous silica modified with calcium metal additives (Ca/KCC-1) in SO2 adsorption is examined in a fixed bed reactor system. The adsorption capacity of Ca/KCC-1 is found to be critically governed by the reaction temperature and inlet SO2 concentration where low values of both parameters are favorable to achieve the highest adsorption capacity of 3241.94 mg SO2/g sorbent. SO2 molecules are adsorbed on the surface of Ca/KCC-1 by both physisorption and chemisorption processes as assumed by the Avrami kinetic model. Thermodynamic study shows that the process is exothermic and spontaneous in nature, and changes from an ordered stage on the surface of KCC-1 towards an increasingly random stage. The process is well explained by Freundlich isotherm model indicating a slightly heterogeneous process and moderate adsorption capacity. The adsorption stage is limited by film diffusion at the initial stage and by intraparticle diffusion during the transfer of SO2 into the network of pores before adsorption takes place on the active sites.

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Enhancement of microplastics and nanoplastics removal via filtration method using surface-engineered palm kernel shell biochar

2025-07 , Muhammad Adli Hanif , Naimah Ibrahim , Nur Adlyna Hayazi , Farrah Aini Dahalan , Aishah Abdul Jalil , Achmad Syafiuddin , Umi Fazara Md Ali

Microplastics (MP) and nanoplastics (NP) are major aquatic contaminants, raising concerns due to their strong affinity for other toxic substances. Filtration is widely employed for MP and NP removal due to its simplicity, efficiency and variety of available filtration media. In this study, the removal efficiency of MP and NP was investigated using surface-engineered biochar of palm kernel shell (PKS) origin, modified with cetyltrimethylammonium bromide (CTAB). The modified biochar demonstrated performance superior to the unmodified biochar, achieving 95.71 % and 96.12 % polyethylene MP (2–4 μm) removal efficiency as measured by turbidity and gravimetric methods, respectively, at an optimal CTAB concentration of 1.5CMC. The optimized biochar (PKS-1.5CMC) also improved the removal efficiencies for a range of other MP and NP particles varying in size (159 nm–48 μm), shape (irregular, spherical, fibrous) and polymer type (polyethylene, polyamide). The modification with CTAB increased the biochar's surface positive charge and hydrophobicity, resulting in stronger electrostatic attraction and hydrophobic interactions with MP and NP particles, which are negatively charged and hydrophobic by nature. In terms of MP and NP properties, higher removal efficiencies were obtained for (i) larger MPs due to easier retention, (ii) NPs due to their tendency to agglomerate, resulting in larger particle size, (iii) irregularly shaped particles, because of their surface roughness, providing more attachment sites and (iv) polyethylene MPs and NPs, owing to their higher hydrophobicity and lower negative zeta potential. Significant formation of a cake layer observed on the upper surface of the filter media suggested that filtration, rather than adsorption, was the dominant mechanism for the removal of MP and NP by biochar.

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Nitric oxide removal by zinc chloride activated oil palm empty fruit bunch fibre

2021-01-01 , Lin Cha Soon , Naimah Ibrahim , Norhidayah Ahmad , Muhammad Adli Hanif , Abdullah S.

Nitric oxide (NO) emission is known to pose detrimental effects towards the environment and human beings. Low-temperature NO removal by activated carbon from agricultural waste materials is affordable due to the use of low-cost materials as precursor and elimination of the need for flue gas reheating. The use of chemical agents in activated carbon production improves the performance of waste materials in NO removal. The performance of NO removal was investigated via breakthrough experiment using oil palm empty fruit bunch (EFB) activated with zinc chloride (ZnCl2) at different concentrations (0.1, 0.5, and 1.5 M). Activation of EFB with 0.5 M ZnCl2 resulted in the formation of well-defined micropores, but the use of higher concentration of ZnCl2 resulted in widening of developed pores and intense pore blockage which reduce the accessibility of NO molecules to the adsorption sites. An adsorption isotherm study conducted using 0.5 M ZnCl2/EFB sample with varying NO concentration between 300-1000 ppm indicated that the adsorption process was best defined by Langmuir isotherm model. In addition, adsorption kinetic was investigated at different temperatures; i.e. 100, 150, 200, 250 and 300 °C. NO removal was found to follow Avrami kinetic model at T=100 °C, while upon further increase in temperature, the process was better fitted to the pseudo-second order kinetic model. NO adsorption capacity increases significantly beyond 250 °C up to 1000 mg/g. The activation energy of NO adsorption fell into two distinct regions: -4.73 kJ/mol at 100-200 °C and 84.04 kJ/mol at 200-300 °C. At lower temperature, the adsorption process was exothermic and followed physisorption path, while the increase in reaction temperature led to slower rate of reaction. It was concluded that the removal of NO using EFB modified with ZnCl2 at optimized condition could be a promising alternatives for treating NO-containing flue gas.

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Performance of Waste Cooking Oil Esterification for Biodiesel Production Using Various Catalysts

2024-03-01 , Herman I.T. , Khairuddin Md Isa , Naimah Ibrahim , Saiful Azhar Saad , Abdullah T.A.T. , Aziz M.A.A. , Hairunnaja M.A.

In this study, waste cooking oil (WCO) with high free fatty acid (FFA) content was esterified to produce biodiesel, and the catalysts’ performance was investigated. Two deep eutectic solvents (DESs) were employed as the liquid catalysts (K2CO3-Gly and KOH-Gly), while the solid heterogeneous catalysts used were spent bleaching earth (SBE), KCC-1, and Na/KCC-1. DESs were prepared by mixing at reaction temperature and time of 80°C and 120 min, respectively. The American Standard Testing Method (ASTM) D974 determined the acid value. The catalysts were first screened for their catalytic activity in WCO esterification. The parameters investigated in this study were oil-to-methanol molar ratio, catalyst loading, reaction time, and temperature. The highest conversion (94.7%) was obtained using Na/KCC-1. The performance of solid and liquid catalysts was evaluated using KOH-Gly and SBE for the reduction of FFA in WCO under different conditions of oil-to-methanol molar ratio (1:6–1:10), catalysts loading (0.2–2.0 g), reaction time (30–60 min), and temperature (40–100°C). The highest reduction of FFA in the esterification process for KOH-Gly and SBE as catalysts was 97.74% and 84.2%, respectively. Transesterification of the esterified oil shows a promising result (97%), and the process can potentially be scaled up. The GC-MS result shows that the produced oil has the highest percentage of hexadecanoic acid and methyl ester.

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Exsolution enhancement of metal-support CO oxidation perovskite catalyst with parameter modification

2021-05-24 , Lew G.L. , Naimah Ibrahim , Abdullah S. , Wan Daud W.R. , Wan Khairunnisa Wan Ramli

This study aimed to further tune the capability of active metal exsolution onto the surface of the CO oxidative perovskite catalyst La0.7Ce0.1Co0.3Ni0.1Ti0.6O3 by tuning the reducing parameter. Under same calcination temperature of 800℃, XRD analysis shown that the precursors with calcination duration of 6 hours (S2T8H6) was able to achieve similar crystalline structure to those with calcination duration of 12 hours (S2T8H12). In order for the active metal (CoNi) to be exsolved onto the perovskite surface, reducing parameter such as temperature and duration are deemed crucial to the reduction process. The exsolution of the active metals was observed when the samples were treated under reducing condition with varying temperatures of 550℃ and 700℃ and duration from 200 to 300 minutes. Through comparison with their EDX readings, S2T8H6 treated under 700℃ and 300 minutes (S2T8H6-R7H5) achieved the highest weight percentage of surface Cobalt and Nickel of 3.83 and 2.81. It was clear that by tuning the temperature and duration of reduction, the exsolution of the active metals onto the surface of the perovskite could be improved resulting in better exposure and dispersion of active metals onto the surface of catalyst.

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Sulfur dioxide removal using deep eutectic solvent–functionalized palm kernel shell–activated carbon

2025-02 , Wan Nur Amanna Wan Nuzi , Muhammad Adli Hanif , Naimah Ibrahim , Farrah Aini Dahalan , Nabilah Aminah Lutpi , Masitah Hasan , Raja Nazrul Hakim Raja Nazri , Umi Fazara Md Ali

The release of SO₂ into the atmosphere is concerning due to its role in acidification, which threatens living organisms and the environment. Adsorption processes using materials like chemically modified activated carbon (AC) have demonstrated strong potential for removing SO₂ before its release. This study evaluates the performance of AC derived from palm kernel shells, and AC functionalized with choline chloride-glycerol, a deep eutectic solvent (DES) (AC-DES), in removing SO₂ through breakthrough experiments conducted in a fixed bed reactor. AC and AC-DES achieved SO₂ adsorption capacities of 0.522 and 2.763 mg SO₂/g adsorbent, respectively. Characterization of the adsorbents indicated that DES functionalization significantly increased the number of active sites for SO₂ adsorption, leading to superior adsorption performance of AC-DES. The optimization of process parameters identified 40 °C and 1500 ppm inlet SO₂ concentration as the ideal conditions for optimal SO₂ adsorption. Experimental data fitted with three adsorption kinetic and isotherm models indicated that SO₂ adsorption onto AC-DES is best described by the Avrami kinetic model and the Sips isotherm model. Thermodynamics studies revealed that the process is exothermic, thermodynamically non-spontaneous, and goes from a random state to an ordered one. The findings suggest that SO₂ adsorption onto AC-DES follows a complex mixed mechanism involving both physisorption and chemisorption, with surface heterogeneity and adsorbate-adsorbent interactions playing a critical role in controlling the adsorption process.

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Microplastics in facial cleanser: extraction, identification, potential toxicity, and continuous-flow removal using agricultural waste–based biochar

2023-05-01 , Hanif M.A. , Naimah Ibrahim , Farrah Aini Dahalan , Umi Fazara Md Ali , Masitah Hasan , Ayu Wazira Azhari , Jalil A.A.

Microplastic (MP) is an emerging contaminant of concern due to its ubiquitous quantity in the environment, small size, and potential toxicity due to strong affinity towards other contaminants. In this work, MP particles (5–300 μm) were extracted from a commercial facial cleanser and determined to be irregular polyethylene (PE) microbeads based on characterization with field emission scanning electron microscopy (FESEM) and Raman spectroscopy. The potential of extracted MP acting as toxic pollutants’ vector was analyzed via adsorption of methylene blue and methyl orange dye where significant dye uptake was observed. Synthetic wastewater containing the extracted MP was subjected to a continuous-flow column study using palm kernel shell and coconut shell biochar as the filter/adsorbent media. The prepared biochar was characterized via proximate and ultimate analysis, FESEM, contact angle measurement, atomic force microscopy (AFM), and Fourier transform infrared (FTIR) spectroscopy to investigate the role of the biochar properties in MP removal. MP removal performance was determined by measuring the turbidity and weighing the dry mass of particles remaining in the effluent following treatment. Promising results were obtained from the study with highest removal of MP (96.65%) attained through palm kernel shell biochar with particle size of 0.6–1.18 mm and continuous-flow column size of 20 mm. Graphical abstract: [Figure not available: see fulltext.].

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Oil palm waste-derived reduced graphene oxide (rGO) for dynamic adsorption of dye in a fixed-bed system

2024-01-01 , Mohd Ali Jinnah S.N.H. , Umi Fazara Md Ali , Subash Chandra Bose Gopinath , Naimah Ibrahim , Razi Ahmad , Mohamed Zuki F.

This study focuses on investigating the dynamic adsorption of Rhodamine B (RhB) from reduced graphene oxide (rGO) derived from oil palm waste. The synthesis of rGO from palm kernel shell (PKS) was achieved through double oxidation and carbonization method, resulting in a yield of 73.5 wt%. The reduction of oxygen-containing functionalities process using PKS was confirmed by FTIR spectroscopy, microscopic evaluation, and X-ray diffraction analyses. Laboratory-scale fixed-bed experiments were conducted with various process parameters. Both PKS and rGO were used as adsorbents, and a comparison was made based on breakthrough curve analysis, adsorption capacity and percentage removal of dye. The adsorption kinetics of RhB on PKS and rGO were best described by the non-linear Yoon-Nelson model, with a high adsorption capacity of 88.32 mg/g and 195.24 mg/g respectively. Using both PKS and rGO, the maximum adsorption capacity was observed when using 10 cm bed depth column, inlet dye concentration of 5 mg/L, flow rate of 12 mL/min and pH of 7. PKS exhibited good dye removal with an efficiency of 66.54%. Meanwhile, the exothermic behavior highlighted the potential of utilizing rGO for maximum dye removal, achieving an efficiency of 90.35%. This study justifies rGO as a cost-effective superior dye removal adsorbent, providing new prospect for large-scale dye removal.

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Enhancing carbon monoxide oxidation of Cobalt-Nickel containing a-deficient Perovskites through exsolution agents and reduction-oxidation pretreatment

2025-04 , Lew Guo Liang , Wan Khairunnisa Wan Ramli , Naimah Ibrahim , Sureena Abdullah

In this work, different types of exsolution agents and pretreatment processes, comprising reduction-oxidation (RO) components, were introduced to modulate the exsolution process of A-deficient perovskites, La₀.7Ce₀.₁Co₀.₃Ni₀.₁Ti₀.6O₃. The catalysts were assessed using field emission scanning electron microscopy with energy dispersive spectroscopy (FESEM/EDS), X-ray Diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Their carbon monoxide (CO) oxidation activity was also compared. The results showed that the catalytic activity degraded at 520°C when hydrogen (E-H) was used as the exsolution agent. When RO components were introduced as exsolution agents (E-CO/O₂) or in the pretreatment (RO2% and RO18%), the deactivation at high temperatures was mitigated. The results of this study showed that RO18% was favourably pretreated with RO components, recording the highest CO conversion of 60.57% at 520°C and across all temperatures with no degradation at high temperature. It also recorded the lowest activation energy of 14.449 kJ/mol. The EDS, XRD, and XPS analyses of the catalyst demonstrated that the active sites for this reaction are primarily Co₂+ with Ni serving as the anchor between the metals and perovskites support. A high amount of lattice oxygen (O₂) with higher binding energy and chemisorbed O2 species also influenced the improved catalytic activity, attracting CO for reaction, reacting with the available surface O₂ and the faster replenishment of O₂ vacancies by the absorbed and bulk O2 lattice. These findings highlight the prospects of CO and O₂ inclusion in pretreatment for perovskite catalyst as options to reduce metal agglomeration and further improve CO oxidation activity.

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Column-based removal of high concentration microplastics in synthetic wastewater using granular activated carbon

2023-01-01 , Amirah Mohd Napi N.n. , Naimah Ibrahim , Adli Hanif M. , Masitah Hasan , Farrah Aini Dahalan , Syafiuddin A. , Boopathy R.

Microplastic (MP) is an emerging contaminant of concern due to its abundance in the environment. Wastewater treatment plant (WWTP) can be considered as one of the main sources of microplastics in freshwater due to its inefficiency in the complete removal of small MPs. In this study, a column-based MP removal which could serve as a tertiary treatment in WWTPs is evaluated using granular activated carbon (GAC) as adsorbent/filter media, eliminating clogging problems commonly caused by powder form activated carbon (PAC). The GAC is characterized via N2 adsorption–desorption isotherm, field emission scanning electron microscopy, and contact angle measurement to determine the influence of its properties on MP removal efficiency. MPs (40–48 μm) removal up to 95.5% was observed with 0.2 g/L MP, which is the lowest concentration tested in this work, but still higher than commonly used MP concentration in other studies. The performance is reduced with further increase in MP concentration (up to 1.0 g/L), but increasing the GAC bed length from 7.5 to 17.5 cm could lead to better removal efficiencies. MP particles are immobilized by the GAC predominantly by filtration process by being entangled with small GAC particles/chips or stuck between the GAC particles. MPs are insignificantly removed by adsorption process through entrapment in GAC porous structure or attachment onto the GAC surface.

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