ABSTRAKPenelitian ini bertujuan untuk memanfaatkan sekam padi dan bagasse fly ash sebagai adsorben logam Cr. Pada penelitian ini, adsorpsi menggunakan sistem batch. Tahap-tahap penelitian ini meliputi preparasi bahan, aktivasi bahan dengan larutan HCl dan larutan NaOH, uji karakterisasi menggunakan SEM, FTIR dan AAS. Penentuan kondisi optimum adsorpsi logam Cr pada variasi komposisi adsorben, massa adsorben, konsentrasi adsorbat,dan kajian isoterm adsorpsi. Hasil penelitian menunjukkan adsorben sekam padi dan bagasse fly ash dapat digunakan sebagai adsorben karena terdapat pori-pori yang didasarkan pada analisis SEM, berdasarkan hasil FTIR terdapat gugus fungsi -OH (hidroksil) pada bilangan gelombang 3423,76 cm -1 dan gugus fungsi Si-O dari Si-O-Si (siloksan) pada bilangan gelombang 1048.36 cm -1 dalam kombinasi adsorben sekam padi dan bagasse fly ash, berdasarkan hasil AAS ditemukan bahwa perbandingan optimum adsorben sekam padi dan bagasse fly ash adalah 1:2 dengan presentase logam Cr teradsorpsi 98,90%, massa adsorben optimum 0,2 g dengan presentase logam Cr teradsorpsi 99.77%, dan konsentrasi adsorbat optimum pada 20,645 mg/L dengan presentase Cr teradsorpsi 99,63%. Pola isoterm adsorpsi cenderung mengikuti isoterm langmuir yang berarti proses adsorpsi secara kimia.
Kata Kunci: sekam padi, bagasse fly ash, adsorpsi, Cr
ABSTRACTThis study aimed to utilize rice husk and bagasse fly ash as Cr metal adsorbent. In this study, the adsorption used batch system. The steps of research were preparation of materials, activation of materials with HCl and NaOH solutions, characterization test using SEM, FTIR and AAS. Determination of optimum condition of Cr metal adsorption on variation of adsorbent composition, adsorbent mass, adsorbate concentration and isotherm adsorption study. The result showed that the adsorbent of rice husk and bagasse fly ash can be used as adsorbent because there were pores that is based on SEM analysis, based on FTIR results that there were a -OH (hydroxyl) functional group at wavenumber 3424.76 cm -1 and Si-O from Si-O-Si (siloxane) functional group at wavenumber 1048.36 cm -1 in the combination of rice husk and bagasse fly ash adsorbent, based on AAS results it was found that the optimum composition ratio of rice husk and bagasse fly ash adsorbent was 1:2 with the percentage of Cr adsorbed 98.90%, the optimum adsorbent mass at 0.2 g with the percentage of Cr adsorbed 99.77% and the optimum adsorbate concentration at 20.645 mg/L with the percentage of Cr adsorbed 99.63%. The pattern of adsorption isotherm tends followed the Langmuir isotherm which means the adsorption process chemically.