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.