AbstrakPertukaran ion antara Cr 3+ dan H + menggunakan zeolit sebagai penukar ion adalah salah satu metode untuk memurnikan air dari ion kromium. Zeolit adalah senyawa aluminosilikat tetrahedral dengan struktur ikatan 3-dimesi, memiliki pori bagian dalam, dan luas permukaan yang tinggi, karena itu dapat digunakan sebagai adsorben. Tujuan penelitian ini adalah untuk mengevaluasi pengaruh waktu kontak optimum, suhu, dan konsentrasi kromium terhadap kapasitas penyerapan. Tahap pertama adalah mencampur zeolit yang telah diaktifkan dengan larutan kromium (10 ppm kromium) dalam tangki berpengaduk pada 25 and H + by using zeolite as its ion exchanger is one of methods to purify water from cromium ion content. Zeolite is aluminosilicate tetrahedral compound that has 3-dimensional framework structures with pore inside and high surface area, therefore it can be used as adsorbent. The objective of this research is to evaluate the effect of optimum contact time temperature and cromium concentration toward adsorption capacity. The first step is mixing activated zeolite and cromium solution (10 ppm) in a stirred tank at 25 o C. Then solution was taken for every 60 minutes until concentration of cromium residue solution was constant. For temperature effect test, cromium solution used were 10 ppm with temperature variation of 25, 30, 35, 40, 45, and 50 o C. For isotermal adsorption test, the best temperature was used from step before with concentration variation of 10, 20, 40, 60, and 100 ppm. Dosage of adsorbent used is 3 gram adsorbent/200 mL cromium solution with stirring speed 240 rpm. Cromium ion is detected by using AAS (Atomic Adsorption Spectroscopy). The results showed that optimum contact time is 3 hours by using acid activated zeolite with optimum adsorption 99.275%. Isoterm model followed Freundlich isoterm with equation Qe = 0.044463C 1/2.5125 that adsorption capacity Kf = 0.044463 mmol/gram adsorbent and adsorption intensity n = 2.5125.

A B S T R A C TThe mixture of adsorbents of moringa seed (BK) and natural zeolite of Lampung (ZAL) is placed in a fixed bed adsorber column arranged at a certain height according to the designed height ratio. BK is processed by extraction to remove its oil content while ZAL is activated by chemical and physical treatments. Composition ratio of BK-ZAL (cm/cm) was varied i.e.1:1, 1:2 and 1:3 and concentrations of Pb entering adsorber were 1 ppm and 2 ppm. The adsorption conditions were 20-35 mesh of adsorbent size, 4 cm column diameter of adsorber, 5 cm bed height, and 8 liters/3 hours flowrate. Upflow adsorption was performed in the fixed bed adsorption column for 3 hours and Pb solution of the adsorber output was taken at every 30 minutes. Analysis of Pb content was performed by Atomic Absorption Spectroscopy (AAS). The BK Adsorbent before and after extracted, and after adsorption were characterized using Fourier Transmission Infra Red (FTIR). ZAL before and after activation were characterized using X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), and Fourier Transmission Infra Red (FTIR). The characterization results of XRD, XRF and FTIR showed that the crystalline phases of ZAL increased, the activation process of ZAL only caused a shift in the peak, no significant change in the structure of solids, and the content of impurities in ZAL reduced after activation, thereby enhancing its ability to adsorb Pb. AAS analysis results showed that the best combination adsorbent BK-ZAL (cm/cm) was 1: 2 with the highest effectiveness of the entrapment of Pb metal reached 99.90%. The adsorption capacity of adsorbent was 2.25 mg Pb/ gram adsorbent as calculated using Freundlich equilibrium model.

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AbstrakTelah dilakukan penelitian penggunaan material aluminasilikat MCM-41 sebagai adsorben limbah cair tapioka. Dalam penelitian ini dipelajari permodelan isotermal dan kinetika adsorpsi dari material MCM-41 pada proses adsorpsi limbah cair tapioka. Isotermal Langmuir dan Freundlich digunakan sebagai permodelan isotermal data penelitian. Dari data penelitian yang diperoleh pada konsentrasi COD sebesar 416 -784 mg/L, proses adsorpsi limbah cair tapioka oleh MCM-41 sesuai dengan pendekatan isothermal Langmuir. Kapasitas maksimum adsorpsi MCM-41 diperoleh dari pendekatan Langmuir adalah sebesar 15,92 mg/g. Model kinetika pseudo-orde pertama dan pseudo-orde kedua digunakan untuk analisis kinetika adsorpsi pada data penelitian. Model kinetik pseudo-orde pertama yang sesuai dengan proses adsorpsi limbah cair tapioka dengan laju penyerapan adalah 7,48 x 10 -2 dan 7,37 x 10 -2 g/(min-mg) untuk konsentrasi awal secara berturut-turut adalah 608 dan 784 mg/L. Kata kunci: adsorpsi, kinetika adsorpsi, limbah cair, MCM-41, tapioka AbstractAluminasilicate MCM -41 material was studied as an adsorbent for tapioca wastewater. The adsorption isotherm modeling and adsorption kinetics of MCM -41 to the liquid waste of tapioca was investigated. Langmuir and Freundlich isotherms were applied to describe the experimental data. Equilibrium data fitted well to the Langmuir model for COD concentration range of 416 -784 mg/L. The maximum adsorption capacity of the MCM-41 obtained from the Langmuir model was 15.92 mg/g. The pseudo-first-order and pseudo-second-order kinetic models were employed to describe the kinetic data. The experimental data fitted well to the pseudo-first-order kinetic model with constant rates 7.48 x 10 -2 and 7.37 x 10 -2 g/(min-mg) for initial concentrations 608 and 784 mg/L, repectively.