Dalam kajian ini, karbon yang telah diaktifkan daripada tongkol jagung (KATJ)disediakan melalui pengaktifan fizikal menggunakan penyinaran gelombang mikro sebagai sumber pemanasan telah diperoleh daripada sisa pertanian dan prestasi penjerapannya dalam penyingkiran pewarna metilena biru (MB) daripada larutan akueus dianalisis dalam sistem kumpulan.Keadaan penyedian optimum diperolehi pada kuasa radiasi 400W dan masa pengaktifan selama 4minit telah menghasilkan KATJyang mempunyai luas permukaan BET, kawasan permukaan mesopore, jumlah isipadu liang dan peratusan karbon tetap masing-masing sebanyak 604.6m2/g, 458.32m2/g, 0.4557cm3/g dan 66.84%. Diameter purata liang KATJ (5.45nm) yang diperolehi berada dalam lingkungan julat mesoporous yang berada di antara 2nm hingga 50nm. Faktor-faktor yang mempengaruhi penjerapan MB keatas KATJ seperti masa (0-24jam), kepekatan awal pewarna (25mg/L-300mg/L) dan suhu larutan (30oC-60oC) telah dinilai. Keputusan menunjukkan bahawa penjerapan MB keatas KATJ didapati meningkat dengan peningkatan masa, kepekatan awal pewarna dan suhu larutan. Data keseimbangan dinilai menggunakan garis sesuhuLangmuir, Freundlich dan Temkinmanakala model kinetik pseudo tertib pertama dan pseudo tertib kedua digunakan untuk menguji data eksperimen. Garis sesuhu Freundlich dan model kinetik pseudo tertib kedua terbaik untuk menerangkan penjerapan MB keatas KATJ. Kajian termodinamik dijalankan untuk menentukan parameter termodinamik seperti tenaga bebas Gibbs (ΔG), entalpi (ΔH) dan entropi (ΔS). Daripada kajian ini, didapati bahawa penjerapan pewarna MB keatas KATJ adalah penjerapan fizikal,bersifat spontan dan endotermik.
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In this study, the corn cob based activated carbon (CCAC) prepared by physical activation using microwave radiation as a heating source was derived from agricultural waste and its adsorption performance in the removal of methylene blue (MB) from an aqueous solution was analyzed in a batch system. The optimum preparation conditions were obtained at radiation power of 400 W and activation time of 4 minutes which resulted with CCAC of BET surface area, mesopore surface area, total pore volume and percentage of fixed carbon of 604.6m2/g, 458.32m2/g, 0.4557cm3/g and 66.84%, respectively. The obtained average pore diameter of the CCAC (5.45nm) lies within the range of mesoporous region which is in between 2nm to 50nm. The factors that influence the adsorption of MB onto CCAC such as contact time (0-24hours), initial dye concentration (25mg/L-300mg/L) and solution temperature (30oC-60oC) were evaluated. The result showed that the adsorption uptake was found to increase with an increase in contact time, initial dye concentration and solution temperature. The equilibrium data were evaluated using Langmuir, Freundlich and Temkin isotherms while pseudo-first order and pseudo-second order kinetic models were applied to test the experimental data. The Freundlich isotherm and pseudo-second order kinetic model were best describes the MB adsorption onto the CCAC. Thermodynamic studies were carried out to determine the thermodynamic parameters such as Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS).From the studies, it was found that the MB adsorption on CCAC was physisorption process, spontaneous and endothermic in nature.
Adsorption of basic dye (methylene blue) on corn cob based activated carbon (ccac) equilibrium, kinetic and thermodynamic studies / Ahmad Arif Aiman Ahmad Rasidi