Journal Articles

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https://hdl.handle.net/20.500.14170/294

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Browsing Journal Articles by Subject "Adsorption"
  • 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
    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.
      10  4
  • Publication
    Comparison between commercial and synthesised nano flower-like rutile TiO₂ immobilised on green super adsorbent towards dye wastewater treatment
    (Elsevier, 2020)
    Siti Salwa Alias
    ;
    Zawati Harun
    ;
    Faiz Hafeez Azhar
    ;
    Siti Aida Ibrahim
    ;
    Banjuraizah Johar
    The combination of a semiconductor metal oxide with green low-cost adsorbent materials has prompted the emergence of new natural resources having higher efficiency for treating dye wastewater. This study investigated the characterisation and performance of synthesised nano flower-like rutile TiO₂ (F–TiO₂) via the facile hydrothermal method and sintered commercial TiO₂ (C–TiO₂). Both C–TiO₂ and F–TiO₂ were immobilised on green super adsorbent basil seed. The details of the structural properties were analysed by Rietveld refinement and the deconvolution method to verify the purity. The synthesised F–TiO₂ immobilised on basil seed (B–F–TiO₂) was found to have optimum physical and morphology properties. Kinetic and equilibrium studies illustrated that the adsorption behaviour of B–F–TiO₂ could be better described by pseudo-second-order kinetic (chemisorption). The maximum uptake capacity (49.47 mg g−1) with the highest removal of methylene blue (98.95%) was obtained at an equilibrium time of 180 min following photocatalysis and self-cleaning. A large antibacterial ring area (1.83 mm2) was also obtained from B–F–TiO₂. The removal of methylene blue dye for B–F–TiO₂ increased as the recycle times increased (3 times) due to the increase of the surface area exposed to methylene blue as the weight of B–F–TiO₂ immobilised on basil seed decreased. This demonstrates that B–F–TiO₂ provides better potential to apply as a multifunction green super adsorbent for dye wastewater treatment compared to B–C–TiO₂.
      17  1
  • Publication
    Diverse material based geopolymer towards heavy metals removal: a review
    ( 2023)
    Pilomeena Arokiasamy
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Monower Sadique
    ;
    Liew Yun Ming
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Mohd Remy Rozainy Mohd Arif Zainol
    ;
    Che Mohd Ruzaidi Ghazali
    Metakaolin is a commonly used aluminosilicate material for the synthesis of geopolymer based adsorbent. However, it presents characteristics that restrict its uses such as weak rheological properties brought on by the plate-like structure, processing challenges, high water demand and quick hydration reaction. Industrial waste, on the other hand, contains a variety of components and is a potential source of aluminosilicate material. Geopolymer adsorbent synthesized by utilizing industrial waste contains a wide range of elements that offer better ion-exchangeability and increase active sites on the surface of geopolymer. However, limited studies focused on the synthesized of geopolymer based adsorbent by utilizing industrial waste for heavy metal adsorption in wastewater treatment. Therefore, this paper reviews on the raw materials used in the synthesis of geopolymer for wastewater treatment. This would help in the development of low cost geopolymer based adsorbent that has a great potential for heavy metal adsorption, which could deliver double benefit in both waste management and wastewater treatment.
      19  2
  • 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
    Facial synthesis of colloidal stable magnetic nanoparticles coated with high hydrophilic negative charged poly(4‐styrenesulfonic acid co‐maleic acid) sodium for water remediation
    (Wiley, 2023)
    Lim Chuan Chuan
    ;
    Ng Qi Hwa
    ;
    Hoo Peng Yong
    ;
    Siti Kartini Enche Ab Rahim
    ;
    Mohd Riduan Jamalludin
    ;
    Amira Mohd Nasib
    ;
    Sigit Tri Wicaksono
    ;
    Azzah Dyah Pramata
    ;
    Siti Zullaikah
    The enhancement of the colloidal stability of magnetite nanoparticles (MNPs) for environmental‐related fields has greatly attracted researchers' attention. This study used a high hydrophilic negatively charged polyelectrolyte, poly(4‐styrenesulfonic acid co‐maleic acid) sodium (PSAAS), to enhance the colloidal stability of MNPs. Coating of the naked MNPs with PSAAS polyelectrolyte is a simple and rapid method to obtain colloidally stable MNPs while sustaining the chemical reactivity of MNPs in water purification. The prepared PSAAS‐coated MNPs were characterized by scanning electron microscope, energy dispersive X‐ray, Fourier transform infrared, zeta potential analysis, transmission electron microscope and X‐ray diffraction. Moreover, the colloidal stability and adsorption performance tests of these naked MNPs and PSAAS‐coated MNPs (with different concentrations of PSAAS coated) were investigated and compared. PSAAS‐coated MNPs with 0.001 g/ml PSAAS coating possessed the best colloidal stability and the highest methylene blue (MB) dye removal efficiency (94.53 ± 0.69%). The adsorption isotherm and kinetic studies for the adsorption of MB onto PSAAS‐coated MNPs were well‐described by the Langmuir model and pseudo‐second‐order kinetic model. These magnetic adsorbents, with high separation efficiency, simple and low production cost and recyclable property, are promising as practicable adsorbents in water treatment.
  • 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.
      20  4
  • Publication
    Optimization of microwave sol–gel synthesis of N-Ce-AC/TiO₂ for adsorption/photodegradation of tetracycline
    (Elsevier, 2023)
    Nur Athirah Awatif Abdul Rahman
    ;
    Azduwin Khasri
    ;
    Sabah Ansar
    ;
    Noor Hasyierah Mohd Salleh
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Raj Boopathy
    ;
    Achmad Syafiuddin
    Nitrogen (N) and cerium (Ce) co-doped titanium dioxide (TiO₂) supported activated carbon (AC) (N-Ce-AC/TiO₂) were synthesized to remove antibiotic tetracycline from aqueous solution via adsorption and photodegradation. The sol–gel technique, aided by microwave radiation, was used to synthesize N-Ce-AC/TiO₂. Central composite design under response surface methodology was used to optimize the variables comprising urea (N source) (A: 0.02–0.20 g), cerium(III) nitrate hexahydrate (Ce source) (B: 0.02–0.20 g), activated carbon (C: 0.10–0.50 g), and microwave power (D: 600–800 W), where the degradation of tetracycline was the response. Characterization of the produced catalyst was carried out by means of X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and the Brunauer–Emmett–Teller method for determining surface-texture parameters. N-Ce-AC/TiO₂ prepared with 0.50 g activated carbon, doped with 0.02 g urea and 0.20 g cerium, and activated at microwave power 600 W for 15 min exhibited 91.08% tetracycline removal when subjected to 7 W of UV irradiation, according to the results of optimal variable preparation.
  • Publication
    Study on the enhancement of colloidal stable poly(sodium 4‐styrene sulfonate) coated magnetite nanoparticles and regeneration capability for rapid magnetophoretic removal of organic dye
    (Society of Chemical Industry (SCI), 2020)
    Wai Hong Chong
    ;
    Ng Qi Hwa
    ;
    Jit Kang Lim
    ;
    Swee Pin Yeap
    ;
    Siew Chun Low
    BACKGROUND: A good colloidal stability of magnetite nanoparticles (MNPs) dispersion is of utmost importance for its environmentally related applications. In the present work, a water-soluble anionic polyelectrolyte, poly(sodium 4-styrene sulfonate) (PSS), was used to stabilize dispersions of MNPs in a pH-dependent aqueous medium. RESULTS: An excellent methylene blue (MB) dye removal efficiency at equilibrium of up to 94% has been observed by the colloidally stabilized nano-magnetites. Dynamic light scattering and electrophoretic analysis showed that the PSS-coated MNPs exhibited better colloidal stability, with an almost constant hydrodynamic diameter of ~150 nm and insignificant clustering behavior throughout the measuring time scale of 5 h. Transmission electron microscopy evidenced the success coating of PSS onto MNPs. In terms of its chemical resistance, the PSS-coated MNPs were able to tolerate a wide pH range from 2 to 10. This work depicts a simple physiochemical coating method to stabilize dispersions of nano-magnetites, which promoted a better MB adsorption capacity of PSS-coated MNPs at 14.9 mg g–1 than the naked MNPs at 10.38 mg g–1. The adsorption process follows Langmuir isotherm and pseudo-second-order reaction kinetics with both correlations R2 > 0.99. PSS-coated MNPs demonstrated outstanding regeneration capacity for four batch adsorption cycles with an almost consistent MB removal efficiency higher than 85%. CONCLUSION: This in-house developed nano-sorbent has potential in economical applications with a less budgeted adsorbent replacement (at least 4 cycles of regeneration) for low-cost separation of pollutants, such as MB from polluted water.
      6  4
  • Publication
    Sulfonated magnetic multi-walled carbon nanotubes with enhanced bonding stability, high adsorption performance, and reusability for water remediation
    (Springer, 2023)
    Lim Chuan Chuan
    ;
    Siew Hoong Shuit
    ;
    Ng Qi Hwa
    ;
    Siti Kartini Enche Ab Rahim
    ;
    Wei Ming Yeoh
    ;
    Hoo Peng Yong
    ;
    Soon Wah Goh
    In view of the simple and rapid conveniency of magnetic separation, magnetic nanocomposites had notably gained attention from researchers for environmental field applications. In this work, carboxylated magnetic multi-walled carbon nanotubes (c-MMWCNTs) and novel sulfonated MMWCNTs (s-MMWCNTs) were synthesized by a facile solvent-free direct doping method. Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, energy dispersive X-ray, vibrating sample magnetometer, and point of zero charge analyses confirmed the successful doping of the Fe3O4 nanoparticles into the functionalized MWCNTs to form MMWCNTs. Besides, the bonding stabilities of both c-MMWCNTs and s-MMWCNTs were compared, and results showed that s-MMWCNTs possessed more substantial bonding stability than that of c-MMWCNTs with significantly less leaching amount of Fe3O4. The adsorption capacity of s-MMWCNTs was higher than that of c-MMWCNTs owing to the stronger electronegativity sulfonic group in s-MMWCNTs. Moreover, the reusability experiments proved that the adsorbent remained consistently excellent MB removal efficiency (R > 94%) even reused for twelve cycles of batch adsorption. The finding of the present work highlights the simple fabrication of novel s-MMWCNTs and its potential to be served as a promising and sustainable adsorbent for water remediation owing to its enhanced bonding stability, high adsorption performance, magnetic separability, and supreme recyclability.
  • Publication
    Synthesis of metakaolin based alkali activated materials as an adsorbent at different Na2SiO3/NaOH ratios and exposing temperatures for Cu2+ Removal
    ( 2023)
    Masdiyana Ibrahim
    ;
    Wan Mastura Wan Ibrahim
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Marcin Nabialek
    ;
    Ramadhansyah Putra Jaya
    ;
    Monthian Setkit
    ;
    Romisuhani Ahmad
    ;
    Bartłomiej Jeż
    Water contamination is a major issue due to industrial releases of hazardous heavy metals. Copper ions are among the most dangerous heavy metals owing to their carcinogenicity and harmful effects on the environment and human health. Adsorption of copper ions using alkali activated materials synthesized through the polycondensation reaction of an alkali source and aluminosilicates is the most promising technique, and has a high adsorption capability owing to a large surface area and pore volume. This research focuses on the effect of the alkaline activator ratio, which is a sodium silicate to sodium hydroxide ratio. Various exposing temperatures on metakaolin based alkali activated materials on a surface structure with excellent functional properties can be used as adsorbent materials for the removal of copper ions. A variety of mix designs were created with varying sodium silicate to sodium hydroxide ratios, with a fixed sodium hydroxide molarity, metakaolin to alkali activator ratio, hydrogen peroxide, and surfactant content of 10 M, 0.8, 1.00 wt%, and 3.0 wt%, respectively. Most wastewater adsorbents need high sintering temperatures, requiring an energy-intensive and time-consuming manufacturing process. In this way, metakaolin-based alkali activated materials are adsorbent and may be produced easily by solidifying the sample at 60 °C without using much energy. The specific surface area, water absorption, microstructure, phase analysis, functional group analysis, and adsorption capability of copper ions by metakaolin based alkali activated materials as adsorbents were evaluated. The water absorption test on the samples revealed that the sodium silicate to sodium hydroxide 0.5 ratio had the highest water absorption percentage of 36.24%, superior pore size distribution, and homogeneous porosity at 60 °C, with a surface area of 24.6076 m2/g and the highest copper ion uptake of 63.726 mg/g with 95.59% copper ion removal efficiency at adsorption condition of pH = 5, a dosage of 0.15 g, 100 mg/L of the initial copper solution, the temperature of 25 °C, and contact time of 60 min. It is concluded that self-supported metakaolin based alkali activated material adsorbents synthesized at low temperatures effectively remove copper ions in aqueous solutions, making them an excellent alternative for wastewater treatment applications.
      1  15