Anis Atikah Ahmad
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Anis Atikah Ahmad
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Anis Atikah, Ahmad
Alternative Name
Ahmad, Anis Atikah
Ahmad, Anis A.
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Scopus Author ID
56900415200
Researcher ID
P-6794-2018

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  • Publication
    Adsorption of basic green 4 onto gasified Glyricidia sepium woodchip based activated carbon: optimization, characterization, batch and column study
    (Scientific Scholar, 2020)
    Anis Atikah Ahmad
    ;
    Azam Taufik Mohd Din
    ;
    Nasehir Khan EM Yahaya
    ;
    Azduwin Khasri
    ;
    Mohd Azmier Ahmad
    The abundance of gasification char residues which contributed to solid waste management problem is one of the major concerns in biomass gasification industry. This study focuses on synthesizing gasified Glyricidia sepium woodchip based activated carbon (GGSWAC) for the removal of basic green 4 (BG4) dye, evaluating the GGSWAC physicochemical properties and assessing the BG4 adsorption performance in batch and fixed-bed column systems. The optimal conditions of GGSWAC synthesis were at radiation power, time, and impregnation ratio (IR) of 616 W, 1 min and 1.93 g/g, respectively. The surface area (SBET) and total pore volume (TPV) of GGSWAC were 633.30 m2/g and 0.34 cm3/g, respectively. The Fritz–Schlünder best fitted to the experimental data at all temperatures in the isothermal studies, indicating a monolayer adsorption. The kinetic study showed that BG4 adsorption followed Avrami kinetic model. Based on thermodynamic parameters, the adsorption of BG4 dye onto GGSWAC was an endothermic and spontaneous process. In continuous operation, the Thomas and Yoon–Nelson models successfully predicted BG4 adsorption onto GGSWAC. The low production cost of 0.54 USD/kg showed that GGSWAC is economically feasible for commercialization.
  • Publication
    Valorization of face mask waste as an adsorbent for cationic dye adsorption
    (Desalination Publications, 2023)
    Goy Khai Sze
    ;
    Anis Atikah Ahmad
    ;
    Azduwin Khasri
    The increasing environmental pollution caused by the disposal of untreated dye-containing effluent and face mask wastes in landfills has become a significant concern. To address this issue, this work focuses on the utilization of face mask wastes as alternative adsorbents for the adsorption of malachite green (MG) dye. These adsorbents offer advantages such as ease of operation, cost-effectiveness, high efficiency, and ready availability. In this study, the raw face mask wastes (RFM) undergo a thermal treatment process in a furnace at 800°C for 21 h before conducting the adsorption tests. The Fourier-transform infrared spectroscopy analysis revealed the presence of various functional groups, including alkane, alkene, alcohol, and carbonyl, in both the treated face mask adsorbent (TFMA) and RFM. The scanning electron microscopy with energy-dispersive X-ray spectroscopy analysis displayed the surface morphologies of RFM as a porous and homogeneous carbon sorbent structure, while TFMA exhibited a heterogeneous and flaky structure. Energy-dispersive X-ray spectroscopy analysis indicated that RFM primarily consisted of carbon elements, followed by oxygen and calcium elements, whereas TFMA predominantly comprised calcium and oxygen elements with a limited amount of carbon. The adsorption experiments, considering various parameters such as initial dye concentration (1,000–1,200 mg/L) and contact time (5–1,500 min), demonstrated that increasing the contact time and initial concentration led to an enhanced adsorption capacity. The maximum adsorption capacity of 2,127 mg/g confirmed the effectiveness of TFMA as an adsorbent for MG. Thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic. The isotherm and kinetic studies showed a good fit between the adsorption data and the Brunauer–Emmett–Teller and pseudo-second-order models as evidenced by high R2 values and low error function values, suggesting a heterogenous adsorption of MG on TFMA.
  • Publication
    Effective removal of methylene blue from aqueous solution by adsorption onto gasification char: isotherm, kinetic and thermodynamics studies
    (Elsevier, 2023)
    Nurul Najihah Ahmad
    ;
    Anis Atikah Ahmad
    ;
    Azduwin Khasri
    This study presents the preparation of oil palm empty fruit bunch (OPEFB) activated char from gas-ification plant residues via phosphoric acid chemical treatment for adsorption of methylene blue (MB) in aqueous solution. The Fourier-transform infrared (FTIR), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) analysis were conducted to identify the characteristic of OPEFB. Adsorption experiments were carried out to determine the effects of initial dye concentration 100–300 mg/L, contact time, pH 2–10 and temperature 30°C–60°C. The optimum conditions were achieved at adsorbent dosage, pH, initial dye concentration and temperature of 0.2 g/200 mL, 6, 100 mg/L and 60°C, respectively with 91.44% of MB removal. From isotherm study, the Freundlich isotherm model fitted the adsorption data very well owing to its higher value of correlation factor (R2 = 0.9352), compared to Langmuir model (R2 = 0.8682). The Langmuir maximum monolayer capac-ity, qm was estimated at 167.2 mg/g. The results from the kinetic study showed that the MB adsorp-tion followed a pseudo-second-order kinetic model (R2 = 0.9216–0.9581). The adsorption of the MB dye onto OPEFB activated char was an endothermic and spontaneous process with ΔH°, ΔG° and ΔS° values of 58.379 kJ/mol, –0.70505 kJ/mol and 194.955 J/mol‧K, respectively. The obtained results suggest that the OPEFB char could be a promising candidate as an adsorbent for MB removal.
  • Publication
    Non-functionalized oil palm waste-derived reduced graphene oxide for methylene blue removal: Isotherm, kinetics, thermodynamics, and mass transfer mechanism
    ( 2023-01-01)
    Ab Aziz N.A.H.
    ;
    Umi Fazara Md Ali
    ;
    Anis Atikah Ahmad
    ;
    Mohd Irfan Hatim Mohamed Dzahir
    ;
    Khamidun M.H.
    ;
    Muhammad Faiq Abdullah
    The discharge of colored effluents from industries is one of the significant sources of water pollution. Therefore, there is a growing demand for efficient and low-cost treatment methods. An adsorption process with reduced graphene oxide (rGO) synthesized using a novel double carbonization and oxidation method from the natural precursor of oil palm empty fruit bunch (OPEFB) as adsorbent is a promising approach for addressing the problem. In this study, OPEFB biochar was mixed with ferrocene with a ratio of 5:1 (m/m) and oxidized under nitrogen flow at a temperature of 300 °C for 20 min, which resulted in 75.8 wt% of yield. The potential of the synthesized rGO as an effective adsorbent for dye removal from water and wastewater was explored using methylene blue (MB) as a model. Several factors were investigated, including adsorbent dosage, initial concentration, contact time, and pH, to obtain the optimum adsorption condition through batch studies. The physical and chemical characteristics of the rGO in terms of functional groups, surface morphology, elemental composition, and crystallinity phase were determined through characterization. The nonlinear isotherms were appropriated using several error functions to describe the adsorption isotherm with a maximum adsorption capacity of 50.07 mg/g. The kinetic study demonstrates that MB's adsorption fits the PFO kinetic model and agrees with Bangham's interpretation of pore diffusion. The adsorption mechanism was found to be physisorption on the multilayer heterogeneous surface of the rGO involving π-π interaction, hydrophobic association, and electrostatic interaction. The thermodynamics study showed that the process was spontaneous and exothermic. The mass transfer mechanism study shows that the adsorption is controlled by intraparticle diffusion and involves complex pathways. The study found that the novel non- functionalized rGO could remove cationic dyes from water and wastewater.
      1  26
  • Publication
    Atenolol sequestration using activated carbon derived from gasified Glyricidia sepium
    (Elsevier, 2020)
    Anis Atikah Ahmad
    ;
    Azam Taufik Mohd Din
    ;
    Nasehir Khan E.M. Yahaya
    ;
    Jamilah Karim
    ;
    Mohd Azmier Ahmad
    Activated carbon (AC) derived from gasified Glyricidia sepium woodchip (GGSWAC) was prepared using KOH and CO2 activation via microwave radiation technique to remove atenolol (ATN) from aqueous solution. The surface area (SBET) and total pore volume (TPV) of GGSWAC were 483.07 m2/g and 0.255 cm3, respectively. The n-BET model fits well with the isothermal data indicating a multilayer adsorption with the saturation capacity of 121, 143 and 163 mg/g at 30, 45 and 60 °C, respectively. The kinetic study showed that ATN adsorption followed Avrami model equation (R2 ≅ 0.99). Based on the thermodynamic parameters, the adsorption of ATN onto GGSWAC was endothermic (ΔHS = 234.17 kJ/mol) in the first layer of adsorption and exothermic in the subsequent layer (ΔHL = −165.62 kJ/mol). The ATN adsorption was controlled by both diffusion and chemisorption. In continuous operation, the Thomas (R2 = 0.9822) and Yoon–Nelson (R2 = 0.9817) models successfully predicted the ATN adsorption.
      9  4
  • Publication
    Gasification char residues management: Assessing the characteristics for adsorption application
    ( 2023-09-01)
    Anis Atikah Ahmad
    ;
    Ahmad M.A.
    ;
    Umi Fazara Md Ali
    ;
    Ken K.
    Due to the world-wide energy crisis and economic issues, biomass has become a resource of global interest as an alternative to activated carbon (AC) produced using non-renewable feedstock (i.e. coal-based). The production of AC from biomass has been determined to be sustainable owing to the abundance of biomass resources on Earth. Biomass gasification has significantly gained market interest and was predicted to reach a value of USD 126 billion by 2023. A critical concern for the existing commercial gasification plants is the handling of char residues, which represent approximately 10% of the initial feedstock mass and are presently treated as waste. The conversion of these chars into AC that can be used for adsorption applications is a possible alternative. This review article focuses on evaluating the characteristic of the gasification char (GC) that is used for adsorption processes. The current AC production method was briefly reviewed. In addition, recent studies on adsorption using GC were explored and summarised.
      1  26
  • Publication
    Honeycomb-like porous-activated carbon derived from gasification waste for malachite green adsorption: equilibrium, kinetic, thermodynamic and fixed-bed column analysis
    (Elsevier, 2020)
    Anis Atikah Ahmad
    ;
    Mohd Azmier Ahmad
    ;
    Nasehir Khan E.M. Yahaya
    ;
    Azam Taufik Mohd Din
    ;
    Ahmad Radi Wan Yaakub
    In this study, the preparation conditions for the gasification waste-based activated carbon (GWAC) were optimized with malachite green (MG) dye removal and GWAC yield as responses. The adsorption equilibrium, kinetic behavior, and thermodynamics properties were also ana-lyzed. The optimum conditions for synthesizing GWAC were found at a radiation power, time, and impregnation ratios of 616 W, 1 min, and 1.06 g g–1, respectively, which resulted in an 89.98% yield of GWAC and 99.01% MG removal. This sample shows the surface area and total pore volume of 351.92 m2 g–1 and 0.22 cm3, respectively. For the isotherm study, the Fritz–Schlünder model fitted the adsorption data very well with an R2 value of 0.9919–0.9932. The results of the kinetic study showed that the MG adsorption followed a pseudo-first-order kinetic model (R2 = 0.9625–0.9871). The film diffusion was found to be the rate-limiting step of MG adsorption. The adsorption of the MG dye onto GWAC was an endothermic and spontaneous process with ΔH of 9.183 kJ mol–1. In continuous mode, Thomas and Yoon–Nelson models successfully predicted the MG adsorption on the GWAC. GWAC demonstrates its commercial feasibility based on a low production cost of 0.23 USD kg–1.
      18  4