Farrah Aini Dahalan
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Farrah Aini Dahalan
Official Name
Farrah Aini, Dahalan
Alternative Name
Dahalan, Farrah Aini
Dahalan, F. A.
Dahlan, Farrah Aini
Main Affiliation
Scopus Author ID
55845177800
Researcher ID
ABD-4811-2020

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The study of sensing elements parameters optimization for developed biosensor of SARS-CoV-2 detection

2023-04 , Fatin Syakirah Halim , Nor Azizah Parmin , Uda Hashim , Subash Chandra Bose Gopinath , Farrah Aini Dahalan , Iffah Izzati Zakaria , Wei Chern Ang , Nurfareezah Nadhirah Jaapar

New advancements in developing sensitive and selective biosensors have demonstrated outstanding potential for Deoxyribonucleic Acid (DNA biosensors). The detection mode of DNA biosensors primary depends on a particular DNA hybridization that precisely occurs on the surface of the physical transducer that can only be detected using high-performance assays due to slight current changes. The analytical performance (sensitivity) of the DNA biosensor is conclusively rely on the confluence constructing of the sensing surface, which must be optimized. Thus, in this study, the sensing elements of the developed biosensors were optimized for detecting RNA of SARS-CoV-2. This optimization included concentration of nanomaterials (carbon quantum dots), probe density (concentration of DNA probe) and concentration of linker (APTES). It was observed that 0.15 % V/V of concentration CQD, 0.1μM of DNA probe and 36% V/V of APTES were the optimum parameters which provided their maximum response during electrical measurements and increased the sensitivity of the developed biosensor for SARS-CoV-2 detection

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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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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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Removal of molluscicide compound: A comparison of metaldehyde removal performance between rubber-based aerobic granules and molasses-based aerobic granules

2023-12-01 , Saad A.M. , Farrah Aini Dahalan , Naimah Ibrahim , Sara Yasina Yusuf

Rubber-based aerobic granules (RAGS) were developed in a bioreactor. Outside of the bioreactor, RAGS were supplemented with molasses wastewater to produce molasses-based aerobic granules (MAGS). Rates of RAGS and MAGS elimination and growth were calculated across a range of 180–330 mg/L of metaldehyde. Metaldehyde removal rates for RAGS and MAGS were 84 % and 85 %, correspondingly. Rates of biodegradation (K1) ranged from 0.402 to 0.063 h−1 for RAGS and from 0.404 to 0.065 h−1 for MAGS. There was a negative correlation between metaldehyde concentration and the first-order rate constant. MAGS had somewhat higher metaldehyde removal capacities than RAGS, with a lower Ks value (234 mg/L) than RAGS (282 mg/L). The MAGS had a higher μmax (0.188 day−1) value than the RAGS (0.129 day−1). RAGS and MAGS show promise for use in aerobic granular sludge remedy of wastewater due to their ability to degrade metaldehyde.

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A proposed aerobic granules size development scheme for aerobic granulation process

2015-04 , Farrah Aini Dahalan , Norhayati Abdullah , Ali Yuzir , Gustaf Olsson , Myzairah Salmiati , Mohd Fadhil Mohd Hamdzah , Siti Aqlima Din , Khalilah Abdul Ahmad , Aznah Nor Khalil , Zainura Zainon Anuar , Zaini Noor

Aerobic granulation is increasingly used in wastewater treatment due to its unique physical properties and microbial functionalities. Granule size defines the physical properties of granules based on biomass accumulation. This study aims to determine the profile of size development under two physicochemical conditions. Two identical bioreactors namely Rnp and Rp were operated under non-phototrophic and phototrophic conditions, respectively. An illustrative scheme was developed to comprehend the mechanism of size development that delineates the granular size throughout the granulation. Observations on granules’ size variation have shown that activated sludge revolutionised into the form of aerobic granules through the increase of biomass concentration in bioreactors which also determined the changes of granule size. Both reactors demonstrated that size transformed in a similar trend when tested with and without illumination. Thus, different types of aerobic granules may increase in size in the same way as recommended in the aerobic granule size development scheme.

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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 SOâ‚‚ 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 SOâ‚‚ 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 SOâ‚‚ through breakthrough experiments conducted in a fixed bed reactor. AC and AC-DES achieved SOâ‚‚ adsorption capacities of 0.522 and 2.763 mg SOâ‚‚/g adsorbent, respectively. Characterization of the adsorbents indicated that DES functionalization significantly increased the number of active sites for SOâ‚‚ adsorption, leading to superior adsorption performance of AC-DES. The optimization of process parameters identified 40 Â°C and 1500 ppm inlet SOâ‚‚ concentration as the ideal conditions for optimal SOâ‚‚ adsorption. Experimental data fitted with three adsorption kinetic and isotherm models indicated that SOâ‚‚ 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 SOâ‚‚ 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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Wastewater remediation and bioelectricity generation in dual chambered salt bridge microbial fuel cell: A mini-review

2024-09-01 , Nur Izzati Iberahim , Nabilah Aminah Lutpi , Ho Li Ngee , Wong Y.S. , Ong Soon An , Farrah Aini Dahalan

The purpose of this article is to assess the feasibility analysis of microbial fuel cells (MFCs), particularly in the configuration of dual chamber salt bridge microbial fuel cell (DCSB-MFC), as a promising approach for simultaneous bioelectricity generation and wastewater remediation. The application of a salt bridge presents an economically viable alternative to the use of a proton exchange membrane, which is known for its high cost, in the construction of MFCs. This arrangement has been demonstrated to offer significant benefits in terms of enhancing the performance of new elements and evaluating operational parameters. However, it also encounters issues related to the total internal resistance (Rint) of the MFCs as well as power density (P). In addition, it has been found that traditional packing materials such activated carbon and gravel demonstrate poor permeability, internal resistance, and slow biofilm growth. Furthermore, there is a necessity to search for electrodes that possess high resistance to corrosion and are cost-effective to achieve optimal bioelectricity generation. Therefore, this article aims to emphasize the research areas that require attention. By addressing these areas, the actual implementation of this configuration can be brought closer to practical implementation.

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Designing specific SARS-CoV-2 DNA probe as biosensing element for development of biosensor

2024-03-21 , Halim F.S. , Nor Azizah Parmin , Uda Hashim , Farrah Aini Dahalan , Zakaria I.I. , Subash Chandra Bose Gopinath , Ang W.C. , Jaapar N.F.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a part of the family of beta-coronaviruses inducing COVID-19 disease. COVID-19 became the most life-threatening and highly contagious viral disease compare to another disease family of coronavirus. Right now, the RT-PCR is the gold standard for the diagnostic of COVID-19. To produce successful prevention strategies, medical testing, vaccinations, and antiviral drugs against COVID-19, comprehensive biological information is critical. Conserved coding RNA sequence within the N gene region of the open reading frame in the SARS-CoV-2 genome was employed as the foundation for creating an oligonucleotide probe as it is a crucial component for the development of a biosensor to identify the virus. The study aimed to develop a DNA probe that complementary to the RNA target of the N region for SARS-CoV-2. Studies were conducted on various strains of coronavirus sequences to verify the percent of correlation as well as the region of consensus that triggers various strains of viruses. Basic local alignment search tools (BLAST) and CLUSTLW had devoted additional statistical parameters, for example, desire values (E-values) and score bits. The 30 mer DNA probe with 50.0% of GC content was developed, CTG AAG CGC TGG GGG CAA ATT GTG CAA TTT. The adequate length of the probe is between 22 and 31 mer. The complementary DNA probe was designed based on the RNA target from the N-region selection that has been identified that could be used as a biomarker probe to produce a biosensor that can be implemented to the clinical and environmental diagnosis of COVID-19.

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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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Microplastics and nanoplastics: Recent literature studies and patents on their removal from aqueous environment

2022-03-01 , Hanif M.A. , Naimah Ibrahim , Farrah Aini Dahalan , Umi Fazara Md Ali , Masitah Hasan , Jalil A.A.

The presence of microplastics (MP) and nanoplastics (NP) in the environment poses significant hazards towards microorganisms, humans, animals and plants. This paper is focused on recent literature studies and patents discussing the removal process of these plastic pollutants. Microplastics and nanoplastics can be quantified by counting, weighing, absorbance and turbidity and can be further analyzed using scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, surface-enhanced Raman spectroscopy and Raman tweezers. Mitigation methods reported are categorized depending on the removal characteristics: (i) Filtration and separation method: Filtration and separation, electrospun nanofiber membrane, constructed wetlands; (ii) Capture and surface attachment method: coagulation, flocculation and sedimentation (CFS), electrocoagulation, adsorption, magnetization, micromachines, superhydrophobic materials and microorganism aggregation; and (iii) Degradation method: photocatalytic degradation, microorganism degradation and thermal degradation; where removal efficiency between 58 and 100% were reported. As these methods are significantly distinctive, the parameters which affect the MP/NP removal performance e.g., pH, type of plastics, presence of interfering chemicals or ions, surface charges etc. are also discussed. 42 granted international patents related to microplastics and nanoplastics removal are also reviewed where the majority of these patents are focused on separation or filtration devices. These devices are efficient for microplastics up to 20 μm but may be ineffective for nanoplastics or fibrous plastics. Several patents were found to focus on methods similar to literature studies e.g., magnetization, CFS, biofilm and microorganism aggregation; with the addition of another method: thermal degradation.

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