PENGARUH TEGANGAN, WAKTU DAN KEASAMAN PADA PROSES ELEKTRODIALISIS LARUTAN URANIL NITRAT

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ABSTRAK

PENGARUH TEGANGAN, WAKTU DAN KEASAMAN PADA PROSES ELEKTRODIALISIS LARUTAN URANIL NITRAT. Telah dipelajari proses elektrodialisis dari larutan uranil nitrat sebagai umpan dengan variabel tegangan, waktu dan keasaman dengan tujuan untuk mempelajari pemisahan uranium dari larutan umpan. Sel elektrodialisis yang digunakan berbentuk kotak empat persegi yang dibagi menjadi tiga bagian yaitu bilik anode, bilik umpan dan bilik katode. Pada bilik anode dipasang anode, pada bilik katode dipasang katode, sedangkan umpan uranil nitrat ditempatkan pada bilik umpan yang berada di antara bilik anode dan katode. Antara bilik anode dan bilik umpan dibatasi dengan membran tukar anion (MTA) dan antara bilik umpan dan bilik katode dibatasi dengan membran tukar kation (MTK). Pada saat proses elektrodialisis berlangsung, ion uranil ditarik oleh katode menuju bilik katode melewati MTK, sedangkan ion nitrat ditarik oleh anode ke bilik anode. Untuk mengetahui konsentrasi uranium pada bilik umpan, dilakukan analisis menggunakan titroprosesor. Hasil percobaan menunjukkan bahwa semakin tinggi tegangan dan semakin lama waktu proses elektrodialisis, semakin kecil kadar uranium dalam bilik umpan. Sebaliknya, semakin besar konsentrasi uranium dalam bilik katode berarti telah terjadi pemisahan uranium dari umpan menuju bilik katode. Penurunan kadar uranium dalam umpan terbesar terjadi pada tegangan 8 Volt yaitu 38,09% atau kadar U akhir dalam umpan sebesar 0,832 g/L untuk waktu elektrodialisis selama 180 menit dan keasaman (normalitas asam nitrat) pada umpan 4,58 N. Keasaman umpan juga berpengaruh terhadap penurunan kadar uranium. Untuk tegangan 4 dan 5 Volt, keasaman pada umpan yang rendah yaitu 2 N memberikan kenaikan kadar uranium yang rendah pada bilik katode. Kadar uranium selanjutnya naik sewaktu keasaman umpan bertambah menjadi 3,56 N, tetapi menurun lagi pada keasaman umpan 4,58 N.

KATA KUNCI: elektrodialisis, uranil nitrat, tegangan, keasaman (normalitas asam nitrat)

ABSTRACT

THE INFLUENCE OF VOLTAGE, TIME AND ACIDITY ON ELECTRODIALYSIS PROCESS OF URANYL NITRATE SOLUTION. Electrodialysis of uranyl nitrate solution with voltage, time and acidity as the process variables has been investigated in order to study uranium separation from feed solution. The electrodialysis cell is of a box shape that is divided into three sections, which are the anode, feed and cathode compartments. In the anode and cathode compartments, the anode and cathode were fitted correspondingly, while the feed was placed in the feed compartment. The anode and feed compartments are separated by an anion exchange membrane (AEM), and the cathode and feed compartments are separated by a cation exchange membrane (CEM). When the electrodialysis was performed, the uranyl ions were drawn by the cathode toward the CEM, while the nitrate ions were drawn by the anode toward the MTA. The uranium concentration in the feed was analysed by using a titroprocessor. The experiment results showed that the higher the electrodialysis voltage and the longer the time, the less the uranium concentration in the feed compartment. On the other hand, increasing the concentration of the uranium in the cathode compartment resulted in a separation of uranium from the feed toward the cathode compartment. A decrease of the uranium concentration in the feed occurred at a voltage of 8 Volts, which was 38.09%, or the final U concentration in the feed was 0.832 g/L for electrodialysis time of 180 minutes and the feed acidity (nitric acid normality) of 4.58 N. The acidity of the feed also posed an influence toward the decrease of uranium concentration. At voltages of 4 and 5 Volts, the low acidity of 2 N in the feed resulted in a small increase of uranium concentration in the cathode compartment. The uranium concentration then increased as the feed acidity was increased to 3.56 N, but decreased again at the feed acidity of 4.58 N.

FREE TERMS: electrodialysis, uranyl nitrate, voltage, acidity (nitric acid normality)