E-Waste to Z-Waste | AIChE

E-Waste to Z-Waste

In 2014, 41.8 million tons of E-Waste was globally generated indicating a rise of 5 percent from 2013. The current growth rate of E-Waste production is 4-5 per cent which is expected to rise to 8 percent in 2018. Presently, only 15-20 per cent of the waste is recycled and the rest is incinerated, landfilled or exported to poor and developing countries. The figures are touching alarmingly high levels, which if not industrially treated, will be environmentally hazardous and uneconomical. From, 2001-2011, E-industry used 197-320 tons of gold, making E-Waste a 40-50 times more potential source for extraction of gold than from its ore. The conventional methods of recycling are Pyrometallurgy and Hydrometallurgy which although, economically feasible are non eco-friendly. Biometallurgy, an eco-friendly alternative, consists of leaching the E-Waste sludge using bacteria of genus Acidthiobacillus, Sulfolobus, Acidianus and Leptospirillum. Acidthiobacillus and Cyanogenic bacteria recover 60-90 per cent of metals depending on the methodology used. In the present study, different types of bacteria are analyzed based on their leaching efficiencies, chemical and biological properties with kinetics. Z-Waste (Zero Waste) approach has been put forward for industrial treatment of waste using Biometallurgy as base method. This review proposes a technology that converts E-Waste to Z-Waste.