Over the last two decades, the world has seen a rapid advancement and growth of electronic industries, as result of which the lifetime of electronic and electrical equipment is decreasing very fast. Due to high demand of newer products and continuous development of hardware as well as software section, the electrical and electronic equipment are replaced and discarded every day. As a consequence of that, a large volume of waste electrical and electronic equipment (WEEE or E-waste) is generated such as computers, monitors, household electronics, mobile phones, televisions etc. According to United Nations Environmental program, around 20-50 million tons of E-waste are generated worldwide per year. Due to presence of environmentally hazardous components, these WEEE has been termed as “largest toxic waste problem of the 21st century”.
Printed Circuit Boards (PCB) are the indispensable part of the electronic equipment and account for ~3% by weight of WEEE. Nevertheless, waste PCBs contains one of the most hazardous components of E-waste directory as well as most of the precious metals. The precious metal concentration such as gold, platinum, palladium concentration in waste PCBs is much higher than their respective primary ores. The presence of precious metals and lack of regulation and control on recycling industries in developing countries, the poorest stratum of population finds economic benefits in recovering of precious metals with non-scientific methods while simply dumping the non-profitable and hazardous elements. The conventional waste treatment of landfilling and incineration leads to release of the hazardous components to the environment endangering the eco-system. The backyard operations in Asia, Africa especially in China, India and Ghana, are worrisome because of the primitive way of recycling techniques that lead to most of the hazardous elements either leach into waste water stream or soil and can have adverse effect on the environment. Additionally, in some processes, new hazardous compounds such as dioxins and furans may be formed as the original e-waste components are degraded. As per the reported literature, more than 80% of children in Guiyu, China, one of the desired destinations of E-waste, have a blood lead level above 10µg/dl. The contamination of polybrominated diphenyl ethers (PBDEs), heavy metals, polycyclic aromatic hydrocarbons (PAHs) in soil, water and air is found to be 100 times higher than the other places[4-6]. Therefore, with a proper recycling, these solid wastes can generate very good revenue with the prime objective of recycling vis-à-vis lowering of their impact on the environment in a sustainable manner. The advantages of such clean and environment friendly technology will be manifold, from reutilizations of resource to reduce the carbon footprint, from reduction of pollution to protect environment along with economic benefits to the organizations.
Manufacturers, environmental agencies...