Pengambilan Kembali Logam Perak dari Limbah Cair Bekas Pencucian Foto Rontgen dengan Metode Elektrokimia

Abstract

X-rays photography activities generate hazardous wastewater containing silver nitrate and silver bromide which are mainly from the washing stage. X-rays washing liqour after being used will eventually be discharged into the environment. This leads to pollution and contamination of surface water. The hazardous contaminants may cause environmental problems and health risk for human and wildlife. Exposure to such pollutants can cause an irritation and burning sensation in the skin and mucous membranes, pain in the mouth, diarrhea, vomiting, coma, and convulsion. It also causes a serious gastroenteritis which will be fatalistic case. So it is crucial to reduce the amount of silver contained in the wastewater and in the same time the silver can be recovered. This study aimed to reduce the pollutants and to recover the metal silver from the wastewater using an electrochemical method. Operating conditions of electrical potential and current would be optimised. The effects of various anode-cathode pairs, electrical potentials and currents were observed. The results show that electrochemical reduction of silver possibly occurs at 1.8 to 2.2 V indicated by a significant increase of cathodic electrical current in the polarisation curves. The optimal condition was achived at a potential of 2.2 Volt within 10 minutes using an anode of copper plate and cathode of graphite rod that could reduce the amount of silver in the waste from  9.35 g/L to 1.56 g/L.