PEROLEHAN KEMBALI LOGAM PERAK DARI LIMBAH CAIR PENCUCIAN FILM STUDIO DIBANDING FILM X-RAY DENGAN MENGGUNAKAN METODE SN FLAKE

As the development in the photographic field is going very fast, so is the problem in the liquid waste of the process. Usually the liquid waste is just thrown away in the environment without undergoing a waste teratment, while the maximum amount of silver allowed in clean water is 0.05 mg/L. In this study, the content of silver in the hotografic waste is between 2944.53 mg/L to 6120.29 mg/L. To eliminate this high content of silver an experiment using a traditional methode of silver recovery is conducted. The methode is known as SN flake methode using sodium sulphide to precipitate the silver in the waste as silver sulphide, then taking the Ag off the presipitate using zinc metal, borax and potassium aluminium sulphate, and heat it in a ‘koi’ using a blower furnace at 900oC. Around 60 gram of silver can be collected from every 20 L of waste, with the yield of 71.26% - 84.37% and the purity is 64.90%. The silver left in the filtrate after treatment is still high, ie. 1.59 mg/l – 22.90 mg/L. Using this methode can cause a secondary waste problem because of waste material in the koi, and also a high risk for the workers due to the high heat and the gas produced in the process of heating. It is advisable to try another methode such as electrochemistry to recover more silver with lesser risk of side contamination, and safer for the workers. To analyse the silver concentration an Inductively Coupled Plasma Spectrophotometer is used