Hydrothermal deposition of CdS on vertically aligned ZnO nanorods for photoelectrochemical solar cell application

CdS/ZnO nanorods composite nanofilms were successfully synthesized via hydrothermal method on indium doped tin oxide glass substrates. Sequentially deposited CdS formed cauliflower like nanostructures on vertically aligned ZnO nanorods. The morphological, compositional, structural and optical properties of the films were characterized by field emission scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction and ultraviolet–visible spectroscopy. Photoelectrochemical conversion efficiencies were evaluated by photocurrent measurements in a mixture of Na2S and Na2SO3 akaline aqueous solution. The amount of deposit, as well as the diameter and crystallinity of the CdS cauliflower were found to increase with growth time. CdS/ZnO nanorods composite exhibited greater photocurrent response than ZnO nanorod arrays. Besides, the composite film with 90 min of growth duration displayed the highest photocurrent density which is nearly four times greater than plain ZnO nanorods under the illumination of halogen light. The result exhibited remarkable photoconversion efficiency (η) of 1.92 %

Removal of residual oils from palm oil mill effluent by adsorption on natural zeolite

The adsorption of residue oil from palm oil mill effluent using natural zeolite was investigated in this study. The adsorption was performed in batch mode, and the effect of different operational parameters such as pH, dose of adsorbent, stirring rate, contact time and initial oil concentration were explored. It was found that the pH plays a major role in the adsorption process. Isotherm data best fitted with the Freundlich model, and kinetic data followed the pseudo-second-order kinetic model. The results obtained demonstrated that the oil removal efficiencies by natural zeolite were up to 70 % at a pH of 3.0 and 50 min of contact time. The adsorbent material also has been characterised by X-ray diffraction, X-ray fluorescence and scanning electron microscopy. © 2012 Springer Science+Business Media B.V.info:eu-repo/semantics/publishe

Removal of Fe (III), Mn (II) and Zn (II) from palm oil mill effluent (POME) by natural zeolite

The adsorption capacity of natural zeolite for the removal of heavy metal ions, zinc Zn(II), manganese Mn(II) and iron Fe(III), found in palm oil mill effluent was investigated in this study. The effects of contact time, agitation speed, pH, and sorbent dosage on the sorption of heavy metals were evaluated. The desorption potential of zeolite was also investigated. The sorption was fast with equilibrium reached within 180. min. The metal sorption increased with pH, and adsorption capacities ranged between 0.015 and 1.157. mg/g of zeolite. Equilibrium data followed the Langmuir isotherm model while the kinetic data were well described by the pseudo-second-order model. Maximum desorption was attained by HCl with 69.638, 58.575 and 61.516% of the initial adsorbed amount for Fe, Zn and Mn, respectively. More than 50% of Zn(II) and Mn(II) and about 60% of Fe(III) could be removed in the experiments. © 2012 Taiwan Institute of Chemical Engineers.info:eu-repo/semantics/publishe

Methylene blue removal from aqueous solution by Hylocereus undatus (dragon fruit) foliage

Dragon fruit foliage in its natural form was applied for decolorization of methyleneblue,a cationic dye from aqueous solution. The effects of major parameters like initial dye concentration, pH, adsorbent dose, temperature and contact time were investigated in batch experimental set-up. The optimum values for removal of methylene blue were identified to be pH 9.0 with 30 hours contact time using 1.2 g L−1biosorbent dosage at 250mg L−1 initial dye concentration. The present results suggested that foliage of dragon fruit can be a potential agricultural byproduct to be used as an environmental friendly and low cost biosorbent. © 2014 Trans Tech Publications, Switzerland.info:eu-repo/semantics/published3rd International Conference on Process Engineering and Advanced Materials, ICPEAM 2014; Kuala Lumpur; Malaysia; 3 June 2014 through 5 June 201