Microbial technology for metal recovery from e-waste printed circuit boards

Shailesh R Dave
2018 Journal of Bacteriology & Mycology Open Access  
End-of-Life Electrical and Electronic Equipments commonly know as e-waste is an emerging problem with developed as well as developing nations. Our obsession on electrical and electronic equipments, the unquenchable desire for latest devices and rapid advances in technology has resulted in the world wide generation of huge amount of e-waste. Printed circuit boards (PCBs), the core processing unit of electronic devices contain complex mixture of ceramics, metals and polymers. PCBs are considered
more » ... s secondary source of several metals. Only a small fraction of this being treated or recycled properly; lion share of e-waste is dumped as landfills or incinerated. Till date no standard eco-friendly technique is available for their safe disposal. In recent decades significant attempts have been done for developing pyrometallurgical and hydrometallurgical technology for recovery of metals from PCBs, but these processes are also non sustainable due to secondary pollution they create and they are cost intensive. Microbial biotechnology, based mainly on the potential of microorganisms to generate lixiviants which mobilize metals from PCBs. Iron and sulphur oxidizing bacteria generate ferric iron and protons which extract several metals in aqueous phase. Cynogenic microorganisms are effectively used extraction of gold and silver from PCBs. Some fungi are also reported for metal solubilisation from PCBs by generating organic acids. This technology is considered a novel approach to mobilize metals from various types of PCBs. The main advantage of microbial technology would it can work with dilute waste streams, work at ambient temperatures and pressures, it is cost effective, reduce environmental impacts and generate minimum secondary waste. Thus, this chapter explores furnish and the details on microorganism based technology for extractions of base and precious metals from e-waste PCBs.
doi:10.15406/jbmoa.2018.06.00212 fatcat:xvbppbu425dkjhu2lwtyfil4ja