ADSORPSI Cr(III) PADA SILIKA GEL TERMODIFIKASI DIFENILKARBAZON SECARA SOL-GEL - Astiti Asih, Ida Ayu Raka; Sudiarta, I Wayan (CAKRA KIMIA (Indonesian E-Journal of Applied Chemistry); Vol 4 No 1 (2016), 2016)
ABSTRAK : Telah dilakukan penelitian mengenai pemanfaatan silika gel termodifikasi difenilkarbazon (Si-CPTMS-DPZon) secara sol-gel untuk mengadsorpsi ion logam kromium(III).  Studi adsorpsi  dilakukan  dengan metode Batch . Pengaruh waktu dan pH awal larutan kromium dipelajari untuk mendapatkan kondisi optimum adsorpsi dan variasi konsentrasi ion kromium digunakan untuk mendapatkan kapasitas adsorpsi. Model isotermal Langmuir dan Freundlich digunakan untuk menentukan isoterm adsorpsi. Hasil penelitian menunjukkan bahwa adsorpsi Cr(III) pada adsorben Si-CPTMS-DPZon optimum terjadi pada pH 4 dan waktu interaksi 90 menit, dengan kapasitas adsorpsi sebesar 36,28 mg/g dan energi adsorpsi sebesar 29,16 kJ/mol. Adsorpsi yang terjadi lebih cenderung mengikuti isoterm Langmuir dengan nilai R 2 sebesar 0,9971 dibanding dengan isoterm Freundlich dengan R 2 0,5612.  Adsorpsi Cr(III) pada adsorben dominan melalui adsorpsi kimia.     ABSTRACT : Research about utilizing of diphenylcarbazone-modified silica gel prepared by sol-gel method (Si-CPTMS-DPZon) to adsorp chromium (III) ions has been carried out. This study was conducted using batch adsorption. The influence of time and initial pH of chromium solution were studied to obtain the optimum adsorption conditions, and the variation of the concentration of chromium ion was used to obtain the adsorption capacity. Langmuir and Freundlich isotherm models were used to determine the model of isotherm adsorption. The results showed that the optimum adsorption of Cr (III) on the adsorbent Si-CPTMS-DPZ occurred at pH 4 with 90 minutes of contact time. The adsorption capacity of Cr(III) on Si-CPTMS-DPZ was 36.28 mg/g with the adsorption energy of 29.16 kJ/mol. The adsorption profile tends to follow the Langmuir isotherm with R 2 values of 0.9971 rather than the Freundlich isotherm with R 2 of 0.5612. Adsorption of Cr (III) on the adsorbent dominantly occurred through chemical adsorption.
Keywords: modified silica gel; diphenylcarbazone; adsorption; ion metal chromium (III)