SOLVENT EXTRACTION OF METALS FROM LIQUID PHOTOGRAPHIC WASTE 25 Jurnal Teknologi, 42(F) Jun. 2005: 25–34 © Universiti Teknologi Malaysia 1&3 Advanced Process Engineering Research Group, Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310 UTM, Skudai, Johor, Malaysia. 2 Department of Applied Chemistry, Kyushu University, Fukuoka 812-8581, Japan. *Corresponding author: Email: Norasikin@fkkksa.utm.my SOLVENT EXTRACTION OF METALS FROM LIQUID PHOTOGRAPHIC WASTE USING ACIDIC EXTRACTANTS NORASIKIN OTHMAN 1 *, MASAHIRO GOTO 2 & HANAPI MAT 3 Abstract. Currently, the exhaustion of hazardous wastes from industrial becomes a more serious problem all over the world. If we focus to photographic waste, the valuable metals and its toxicity become a factor of consideration in economic and environmental aspects for recovery and separation. Solvent extraction technology is a technique which has a great potential for metal recovery. Therefore, different types of acidic extractants (Cyanex 272, Cyanex 302, and D2EHPA) were examined in terms of their capability and selectivity in extracting metals from photographic wastes. It was found that an extractant containing a P=S functional groups (Cyanex 302) strongly extracts almost 97% silver at pH equilibrium ranging from 6 to 9. It is also found that Cyanex 302 was very selective towards silver than other metals that existed in the real photographic waste. The Cyanex 272 and D2EHPA also provide a good metal extraction performance at pH 7 and 8.3 respectively but they are only selective to iron at pH 9. Furthermore, the extraction capacity increases with increasing in extractant concentration until it achieves plateau due to excess of free extractant. Keywords: Solvent extraction, acidic extractant, photographic waste, silver, Cyanex 302 Abstrak. Pada masa kini, pembuangan sisa berbahaya daripada industri menjadi satu masalah besar kepada dunia. Jika kita memfokus pada sisa fotografik, faktor yang dipertimbangkan ialah logam bernilai dari segi ekonomi dan ketoksikan dari aspek alam sekitar bagi tujuan perolehan semula atau pemisahan bahan tersebut. Teknologi pengekstrakan pelarut adalah salah satu teknik yang berpotensi bagi penghasilan semula logam. Dalam kajian ini, beberapa agen pengekstrak berasid (Cyanex 272, Cyanex 302, dan D2EHPA) telah diuji dari segi kemampuan dan kepemilihannya dalam mengekstrak logam daripada sisa fotografik. Hasil kajian mendapati pengekstrak yang mempunyai kumpulan fungsi P=S (Cyanex 302) telah dapat mengekstrak perak sebanyak 97% pada julat pH keseimbangan antara 6 hingga 9. Kajian juga menunjukkan Cyanex 302 memberikan kepemilihan yang baik terhadap perak berbanding logam-logam yang lain. Walau bagaimanapun Cyanex 272 dan D2EHPA juga menunjukkan pengekstrakan yang baik terhadap logam lain pada pH 7 dan pH 8.3 dan bersifat memilih hanya terhadap logam ferum pada pH 9. Selain itu kapasiti pengekstrakan bertambah dengan kepekatan pengekstrak sehinggalah lebihan pengekstrak berlaku. Kata kunci: Pengekstrakan pelarut, pengekstrak berasid, sisa fotografik, perak, Cyanex 302 Untitled-4 02/17/2007, 01:35 25