Bioleaching of Gold and Silver From Mobile Phone Printed Circuit Boards (Mppcbs) Using Pseudomonas Balearica SAE1

Abstract

Electronic waste (e-waste) is known to be one of the major growing environmental issues around the globe. The global production of e-waste is increasing rapidly and is expected to accelerate in the near future. World has produced 5.9 kg/inhabitant (41.8 million tons) of e-waste and is expected to increase up to 6.7 kg/inhabitant (49.8 million tons) of e-waste by 2018. E-waste comprises of a multitude of components such as toxics metals, precious metals and persistent organic pollutants (PCBs and PBDEs). These poisonous ingredients have adverse impact on human health and the surroundings if not controlled properly. On the other hand, e-waste is treated as secondary/artificial ore due to higher concentration of precious metals like Au, Ag and Pd. Among the e-waste, mobile phone printed circuit boards (MPPCBs) are the most important targets because of their rich metal content, high production volume and short life times. The total metallic content in a mobile phone is about 23%. Precious metals Au and Ag was in significant proportion i.e. 1800 ppm and 3589 ppm, respectively in MPPCBs. This makes MPPCBs recycling worth economic [1].The conventional hydrometallurgical and pyro metallurgical recycling of e waste consumes a large amount of energy and releases high volume of hazardous substance [24]. However, biohydrometallurgical technology which is based on microbial aided leaching of the precious metals (Au & Ag) from metals containing solid waste/ores/e-waste is an eco-friendly and cost effective technology. The MPPCBs waste in shredded dust and processed fine powder form of size <150um was procured from Exigo Recycling Pvt. Ltd. Haryana.