<![CDATA[Kegiatan yang melibatkan uranium sebagai bahan bakar nuklir berpotensi menimbulkan pencemaran lingkungan. Uranium merupakan salah satu logam berat berbahaya dan bersifat radioaktif sehingga perlu diketahui penyebarannya di alam. Penelitian ini bertujuan untuk menentukan model kesetimbangan adsorpsi uranium pada air dan sedimen. Model yang disusun diharapkan sesuai untuk berbagai pH air. Percobaan adsorpsi uranium dijalankan dalam sistem batch. Air limbah sebanyak 100 ml yang mengandung uranium dimasukkan ke dalam erlenmeyer dan pH larutan diatur menjadi 3, 5, 7, atau 9. Sebanyak 0,5 g tanah dimasukkan ke dalam erlenmeyer. Erlenmeyer ditempatkan dalam shaker dengan kecepatan 100 rpm selama 6 jam dan dibiarkan selama 24 jam sampai tercapai kesetimbangan. Filtrat yang terbentuk disaring dan dianalisis menggunakan spektrofotometer. Lima model kesetimbangan isotermal diajukan untuk mendekati data kesetimbangan. Sebagai hasil, kesetimbangan Chapman cocok dalam mendekati data percobaan pada berbagai pH air. Dari hasil perhitungan diketahui ion UO22+ memiliki nilai parameter α, β, γ masing-masing sebesar 25 mg/g, 2,3 l/mg, dan 18,1 sedangkan untuk ion (UO2)3(OH)7- masing-masing sebesar 19 mg/g, 0,095 l/mg, dan 3,4. Penelitian ini diharapkan bermanfaat sebagai data pendukung bagi analisis dampak lingkungan dalam pembangunan PLTN. Kata kunci: adsorpsi, kesetimbangan, uranium, prediksi, sedimen, pH Activities involving uranium as nuclear fuel has potentially polluted the environment. Since uranium is a toxic and radioactive heavy metal, it is necessary to identify its distribution in nature. This study aims to define uranium adsorption equilibrium model in water and sediment. The model is also supposed to be appropriate for various pH of water. Experiments were performed in a batch system. One hundred mL of waste water for National Atomic Energy Agency (BATAN) containing uranium was placed in an erlenmeyer flask and the pH was varied at 3, 5, 7, or 9. Soil was used as adsorbent. The process was shaken at 100 rpm for six hours and then was left for 24 hours to reach the equilibrium. The resulting filtrate was filtered and analyzed using a spectrophotometer. Five different isotherm equilibrium models were proposed in order to fit the equilibrium experimental data. It was found that Chapman equilibrium could fit the data more thoroughly than the other models. From the calculation, it was known that UO22+ parameter values of α, β, γ were 25 mg/g-soil, 2,3 l/mg, and 18,1 respectively, while for (UO2)3(OH)7- were 19 mg/g, 0,095 l/mg, and 3,4 respectively. It is expected that this research will be useful as supporting data for environment impact analysis in nuclear power plants development. Keywords: adsorption, equilibrium, uranium, sediment, pH]]>
