Publications by authors named "Rohana Adnan"

Herein, cellulose nanocrystals were synthesized from oil palm fronds (CNC-OPF) involving two pretreatment approaches, viz. autohydrolysis and soda pulping. The pretreatments were applied individually to OPF fibers to assess their influence on CNCs' physicochemical and thermal properties.

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In photocatalytic removal of organic pollutants, adsorption and degradation are two important processes that take place. Various instrumental techniques and trapping experiments have been used to identify the reactive species and the mechanism of photodegradation. The present work focuses on investigating the mechanism of photo-induced degradation from the comparative characterization of fresh and used samples, isotherm models, competitive adsorption, and desorption studies of pure and Ag-modified TiO NPs.

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The increase in new cases of drug resistance to first-line drugs such as ethambutol (ETB) makes it necessary to develop improvements for antituberculosis drugs. A new method for improving the bioavailability of active pharmaceutical ingredient (API) was investigated for preventing drug resistance and side-effects of antituberculosis drugs. In this study, an antituberculosis drug delivery system using β-cyclodextrin (β-CD) as the supramolecular carrier of ETB was prepared using the kneading method.

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Viruses have spread throughout the world and cause acute illness or death among millions of people. There is a growing concern about methods to control and combat early-stage viral infections to prevent the significant public health problem. However, conventional detection methods like polymerase chain reaction (PCR) requires sample purification and are time-consuming for further clinical diagnosis.

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The primary aim of this study is to develop an economical, stable, and effective heterogeneous catalyst for wastewater remediation via the Fenton oxidation process. For this purpose, FeO-montmorillonite alginate (FeMA) composite beads were synthesized by entrapping FeO-montmorillonite in calcium alginate beads. The performance of the catalysts was evaluated via the Fenton degradation of ofloxacin (OFL), an antibiotic that is frequently detected in water bodies.

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The purpose of this research is to synthesize environmentally friendly nanosorbents for the novel adsorption of diesel range organics (DRO) from contaminated water. Central composite design (CCD) analysis of response surface methodology (RSM) was employed in a model fitting of the variables predicting the adsorption efficiency of Moringa oleifera-functionalized zerovalent iron particles (ZINPs) for the removal of DRO. The effects of the reaction parameters on the response were screened using 2 factorial designs to determine the statistically significant independent variables.

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Ceramics-based filter for water treatment is an ancient technology to procure potable water at the household level. The traditional clay pots (vessels or hollow cylindrical container) have been used since long in the developing countries. The ceramic material (CaCuTiO or CCTO) is a hetero-junction of titanium oxide, a well-known UV-active photocatalyst, and visible light absorbing CuO materials.

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The influence of variable reaction time (t) on surface/textural properties (surface area, total pore volume, and pore diameter) of carbon-encapsulated magnetite (FeO@C) nanocomposites fabricated by a hydrothermal process at 190 °C for 3, 4, and 5 h was studied. The properties were calculated using the Brunauer-Emmett-Teller (BET) isotherms data. The nanocomposites were characterised using Fourier transform infrared spectroscopy, X-ray diffraction analysis, thermogravimetry, and scanning and transmission electron microscopies.

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Sustainable water processing techniques have been extensively investigated and are capable of improving water quality. Among the techniques, photocatalytic technology has shown great potential in recent years as a low cost, environmentally friendly and sustainable technology. However, the major challenge in the industrial development of photocatalyst technology is to develop an ideal photocatalyst which must have high photocatalytic activity, a large specific surface area, harvest sunlight and shows recyclability.

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Herein, the role of metal-based nanoparticles (NPs) in biomedical analysis and the treatment of critical deceases been highlighted. In the world of nanotechnology, noble elements such as the gold/silver/palladium (Au/Ag/Pd) NPs are the most promising emerging trend to design bioengineering materials that could to be employed as modern diagnostic tools and devices to combat serious diseases. NPs are considered a powerful and advanced chemical tool to diagnose and to cure critical ailments such as HIV, cancer, and other types of infectious illnesses.

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4-Hydroxytamoxifen (4-OHT), the most common hormone used for the treatment of breast cancer, is a selective estrogen receptor modulator (SERM) inhibitor that acts as an antagonist in breast tissue and a partial agonist in the endometrium. However, the detailed molecular mechanism of 4-OHT structure modification has not been well investigated to date. Herein, molecular docking, molecular dynamics simulations and free energy calculations were performed to explore the mechanisms of the molecular interactions between newly designed benzophenone imines (BIs) and the three forms apo, antagonist and agonist of the human estrogen receptor hERα.

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Magnetic nanocellulose alginate hydrogel beads are produced from the assembly of alginate and magnetic nanocellulose (m-CNCs) as a potential drug delivery system. The m-CNCs were synthesized from cellulose nanocrystals (CNCs) that were isolated from rice husks (RH) by co-precipitation method and were incorporated into alginate-based hydrogel beads with the aim of enhancing mechanical strength and regulating drug release behavior. Ibuprofen was chosen as a model drug.

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The effects of dry biomass density in cryogel beads, shaking speed and initial concentration ratio of phenol to 4-chlorophenol (4-CP) on the bioregeneration efficiencies of binary phenol and 4-CP-loaded granular activated carbon (GAC) for phenol and 4-CP, respectively, were investigated under the simultaneous adsorption and biodegradation approach. The results revealed higher bioregeneration efficiencies of binary-loaded GAC for phenol and 4-CP at higher dry biomass density but moderate shaking speed. The optimum dry biomass density in cryogel beads and shaking speed for use in bioregeneration were found to be 0.

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Titanium dioxide (TiO2) has been considered a useful material for the treatment of wastewater due to its non-toxic character, chemical stability and excellent electrical and optical properties which contribute in its wide range of applications, particularly in environmental remediation technology. However, the wide band gap of TiO2 photocatalyst (anatase phase, 3.20 eV) limits its photocatalytic activity to the ultraviolet region of light.

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In this study, iron impregnated activated carbon (FeAC) was synthesized following an oxidation and iron impregnation of activated carbon (AC). Both the AC and FeAC were characterized by pHZPC and FTIR spectroscopy. The removal of Methylene Blue (MB) by AC and FeAC was examined under various experimental conditions.

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This study aimed to work out a simple and high-yield procedure for the immobilization of horseradish peroxidase on silver nanoparticle. Ultraviolet-visible (UV-vis) and Fourier-transform infrared spectroscopy and transmission electron microscopy were used to characterize silver nanoparticles. Horseradish peroxidase was immobilized on β-cyclodextrin-capped silver nanoparticles via glutaraldehyde cross-linking.

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Horizontal subsurface-flow (HSF) constructed wetland incorporating baffles was developed to facilitate upflow and downflow conditions so that the treatment of pollutants could be achieved under multiple aerobic, anoxic and anaerobic conditions sequentially in the same wetland bed. The performances of the baffled and conventional HSF constructed wetlands, planted and unplanted, in the removal of azo dye Acid Orange 7 (AO7) were compared at the hydraulic retention times (HRT) of 5, 3 and 2 days when treating domestic wastewater spiked with AO7 concentration of 300 mg/L. The planted baffled unit was found to achieve 100%, 83% and 69% AO7 removal against 73%, 46% and 30% for the conventional unit at HRT of 5, 3 and 2 days, respectively.

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To enhance the potential of activated carbon (AC), iron incorporation into the AC surface was examined in the present investigations. Iron doped activated carbon (FeAC) material was synthesized and characterized by using surface area analysis, energy dispersive X-ray (EDX), temperature programmed reduction (TPR) and temperature programmed desorption (TPD). The surface area of FeAC (543 m(2)/g) was found to be lower than AC (1043 m(2)/g) as a result of the pores widening due to diffusion of iron particles into the porous AC.

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Calcium oxide (CaO) nanoparticles are known to exhibit unique property due to their high adsorption capacity and good catalytic activity. In this work the CaO nanocatalysts were prepared by hydrothermal method using anionic surfactant, sodium dodecyl sulphate (SDS), as a templating agent. The as-synthesized nanocatalysts were further used as substrate for the synthesis of alumina doped calcium oxide (Al2O3·CaO) nanocatalysts via deposition-precipitation method at the isoelectric point of CaO.

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Background: Layered hydroxides salts (LHS), a layered inorganic compound is gaining attention in a wide range of applications, particularly due to its unique anion exchange properties. In this work, layered zinc hydroxide nitrate (LZH), a family member of LHS was intercalated with anionic ciprofloxacin (CFX), a broad spectrum antibiotic via ion exchange in a mixture solution of water:ethanol.

Results: Powder x-ray diffraction (XRD), Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA) confirmed the drug anions were successfully intercalated in the interlayer space of LZH.

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The feasibility of using dried attached-growth biomass from the polyurethane (PU) foam cubes as a solid carbon source to enhance the denitrification process in the intermittently aerated moving bed sequencing batch reactor (IA-MBSBR) during the treatment of low COD/N containing wastewater was investigated. By packing the IA-MBSBR with 8% (v/v) of 8-mL PU foam cubes saturated with dried attached-growth biomass, total nitrogen removal efficiency of 80% could be achieved for 10 consecutive cycles of operation when the intermittent aeration strategy of consecutive 1 h of aeration followed by 2 h of non-aeration period during the REACT period of the IA-MBSBR was adopted. Negligible release of ammonium nitrogen (NH4(+)-N) and slow-release of COD from the dried biomass would ensure that the use of this solid carbon source would not further burden the treatment system.

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The objectives of the study are to use immobilized acclimated biomass and immobilized biomass-powdered activated carbon (PAC) as a novel approach in the bioregeneration of granular activated carbon (GAC) loaded with phenol and o-cresol, respectively, and to compare the efficiency and rate of the bioregeneration of the phenolic compound-loaded GAC using immobilized and suspended biomasses under varying GAC dosages. Bioregeneration of GAC loaded with phenol and o-cresol, respectively, was conducted in batch system using the sequential adsorption and biodegradation approach. The results showed that the bioregeneration efficiency of GAC loaded with phenol or o-cresol was basically the same irrespective of whether the immobilized or suspended biomass was used.

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The aeration strategy ranging from intermittent to continuous aeration in the REACT period of moving bed sequencing batch reactor (MBSBR) was evaluated for simultaneous removal of 4-chlorophenol (4-CP) and nitrogen. The results show that the removal rates of 4-CP and ammonium nitrogen (NH(4)(+)-N) increased with the increase of continuous aeration period. In the presence of 4-CP, NH(4)(+)-N removal was mainly by the assimilation process.

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We present an investigation on a coupled system consists of gold nanoparticles and silicon nanocrystals. Gold nanoparticles (AuNPs) embedded into porous silicon (PSi) were prepared using the electrochemical deposition method. Scanning electron microscope images and energy-dispersive X-ray results indicated that the growth of AuNPs on PSi varies with current density.

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Moving bed sequencing batch reactors (MBSBRs) packed with 8% (v/v) of 8-, 27- and 64-mL polyurethane (PU) foam cubes, respectively, were investigated for simultaneous 4-chlorophenol (4-CP) and nitrogen removal at increasing 4-CP concentration. When the 4-CP concentration exceeded 300 mg L(-1), the MBSBR with 27-mL foam cubes was observed to outperform the other MBSBRs in removing 4-CP and nitrogen. The reasons were: (1) there were more biomass in inner layer of the 27-mL cubes, compared to that of the 8-mL cubes, which was more shielded from the inhibitory effect of 4-CP and (2) the 27-mL cubes were more mobile than the 64-mL cubes.

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