Publications by authors named "Aishah A Jalil"

3 Publications

  • Page 1 of 1

Adsorption of methyl orange from aqueous solution onto calcined Lapindo volcanic mud.

J Hazard Mater 2010 Sep 24;181(1-3):755-62. Epub 2010 May 24.

Department of Chemical Engineering, Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, UTM Skudai, Johor, Malaysia.

In this study, calcined Lapindo volcanic mud (LVM) was used as an adsorbent to remove an anionic dye, methyl orange (MO), from an aqueous solution by the batch adsorption technique. Various conditions were evaluated, including initial dye concentration, adsorbent dosage, contact time, solution pH, and temperature. The adsorption kinetics and equilibrium isotherms of the LVM were studied using pseudo-first-order and -second-order kinetic equations, as well as the Freundlich and Langmuir models. The experimental data obtained with LVM fits best to the Langmuir isotherm model and exhibited a maximum adsorption capacity (q(max)) of 333.3 mg g(-1); the data followed the second-order equation. The intraparticle diffusion studies revealed that the adsorption rates were not controlled only by the diffusion step. The thermodynamic parameters, such as the changes in enthalpy, entropy, and Gibbs free energy, showed that the adsorption is endothermic, random and spontaneous at high temperature. The results indicate that LVM adsorbs MO efficiently and could be utilized as a low-cost alternative adsorbent for the removal of anionic dyes in wastewater treatment.
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http://dx.doi.org/10.1016/j.jhazmat.2010.05.078DOI Listing
September 2010

Complete electrochemical dechlorination of chlorobenzenes in the presence of various arene mediators.

J Hazard Mater 2010 Feb 30;174(1-3):581-5. Epub 2009 Sep 30.

Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia.

Electrochemical dechlorination of chlorobenzenes in the presence of various arene mediators such as naphthalene, biphenyl, phenanthrene, anthracene, and pyrene, was studied. The amount of mediator required was able to be reduced to 0.01 equiv. for all mediators except for anthracene, with the complete dechlorination of mono-, 1,3-di- and 1,2,4-trichlorobenzene still achieved. This catalytic amount of mediator plays an important role in accelerating the dechlorination through the rapid formation of radical anions prior to reduction of the chlorobenzenes.
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http://dx.doi.org/10.1016/j.jhazmat.2009.09.091DOI Listing
February 2010

Complete electrochemical dechlorination of chlorobenzenes in the presence of naphthalene mediator.

J Hazard Mater 2007 Sep 12;148(1-2):1-5. Epub 2007 Jun 12.

Faculty of Chemical and Natural Resources Engineering, Malaysia.

Electrochemical dechlorination of chlorobenzene in organic solutions was studied. Electrolysis of chlorobenzene in acetonitrile solution in a one-compartment cell fitted with a platinum cathode and a zinc anode at 60mA/cm(2) and 0 degrees C was found to be the optimum conditions, which gave complete dechlorination of chlorobenzene. However, similar result could not be achieved when applying these conditions to 1,3-dichlorobenzene and 1,2,4-trichlorobenzene. We found that the use of naphthalene which reacted as a mediator in the appropriate system could accelerate the reduction and gave complete dechlorination of those chlorobenzenes. Moreover, in the presence of naphthalene the reaction time could be shortened by half compared to dechlorination in the absence of naphthalene.
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http://dx.doi.org/10.1016/j.jhazmat.2007.06.024DOI Listing
September 2007