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

Abstract

Rapid urbanization, industrialization, and population growth have resulted in increased demand of electronic and electrical gadgets. With fast technological advancement and development, due to the demand of people, industries are now manufacturing novel, superior and smart electronic and electrical equipments (EEEs) at an alarming rate. More and more EEEs products are produced purchased, used and discarded resulting in the generation of huge amount of waste electronic and electrical equipments (WEEEs).1 The electronic waste (e-Waste) normally consist of small and large equipment such as LED lamps, cell phones, smart mobile phones, superior televisions, refrigerators, printers, driers, temperature exchangers as well as advance computing devices.2 Due to the fast advancement in technology and tremendous market growth most of these electronic and electric material have very short life span, which resulted in the fastest accumulation in e-Waste.3 Broadly, the end of life electrical and electronic equipments without intent of reuse is considered as e-Waste. As per the information available in literature in 2014, about 41.8 million tons of e-Waste generated globally and as per the estimation e-Waste is growing at the rate of 4-5% annually, which leads to about 49.8 million tons of e-Waste generation in 2018.4 The large amounts of complex and diverse e-Waste generated have adverse impact on environment as well as human being, if they are not properly managed. Unfortunately there is no proper system to collect, store, transport, treat, and disposal of e-Waste. Thus, it has become major issue of concern for the industries, government and non-government organization and even for the public to protect the environment from the hazardous effect of improperly managed e-Waste.5 Most of us know that e-Waste has been accumulated since many years, but their devastating environmental effects is realized recently, which has created keen awareness in the scientific community as well as in common people throughout the world and it has forced concerned peoples for their proper treatment. E-Waste has been accumulated since many years; contain several hazardous organic pollutant as well as considerable amount of base, precious and rare earth metals.6 The core component of all electronic and many electrical equipment is printed circuit boards (PCBs), which is used for smooth, fast and convenient functioning of small to large electronic devices. PCBs contain several metals as well as various organic pollutants. Thus, it cannot be dumped as landfill or incinerated. However, incineration and land filling are the common method adapted for e-Waste management, which leads to the release of toxic gases in atmosphere and highly harmful metals in soil and ground waters. These pollutants will accumulate and transport in plant systems, which ultimately reach to animals and human.7,8 Due to this awareness e-Waste management has become a vital and significant field of research throughout the world. The current chapter mainly focus on bio-treatment of PCBs with special reference to extraction of metals from waste PCBs by using microbial technology. Types of microorganisms involved in the metal solubilisation process and major mechanisms of metal extractions are illustrated.

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Identifiers

DOI

10.15406/JBMOA.2018.06.00212

Journal

Journal of Bacteriology & Mycology: Open Access

Year

2018