Biotechnology for Zero Waste – Emerging Waste Management Techniques (Chaudhery Mustansar Hussain (editor) etc.)

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Recovery of Precious Metals from Electronic and Other

Secondary Solid Waste by Bioleaching Approach

Dayanand Peter, Leonard Shruti Arputha Sakayaraj, and Thottiam Vasudevan

Ranganathan

School of Agriculture and Biosciences, Karunya Institute of Technology and Sciences, Department of Food

Processing Technology, Coimbatore, 641114, Tamil Nadu, India

14.1

Introduction

Over the last decade, there is an increased demand for electronic and electrical gad-

gets due to rapid urbanization and population growth. Technological advancements

and development have enabled industries to come up with novel and smart elec-

tronic and electrical equipment (EEEs) to meet the growing demand of people. The

ever-growing production of EEE products has resulted in the production of a vast

quantity of waste electronic and electrical equipment (WEEEs) [1]. WEEE is the

amalgam of various metals such as copper, nickel, iron, and aluminum trapped in

materials like plastic and ceramic through mechanisms such as mixing or binding.

Metal groups (Au, Ag, and Pt) are considered as superior value waste due to their

high conductivity and high chemical stability [2]. There is a growing need for recov-

ery of these metals from e-wastes as they have toxic effect to human health and

environment apart from their superior value as waste [3]. Equipment such as cell

phones, smart phones, light-emitting diode lamps, printers, superior televisions, dri-

ers, refrigerators, temperature exchangers, and other devices are the major source

of e-waste [4]. Both hazardous and non-hazardous components are present in the

e-waste. The annual production of e-waste is estimated at around 20–50 Mt. glob-

ally. E-waste is separated from normal municipal waste as it contains toxic or unsafe

materials. When left untreated or not treated properly, these materials can pose

threat to humans when passed through air, soil, or water. These materials include

plastic, lead, mercury, cadmium, arsenic, etc., and they can create various kinds of

diseases when present in atmosphere. People working in recycling plants for e-waste

can be easily affected with chronic and acute diseases including cancer.

Bioleaching is one of the advanced methods which involves metal leaching from

waste materials, and it is of low cost and considered to be a green technology

approach [5]. There are several advantages to bioleaching approach in comparison

to conventional hydrometallurgy or pyrometallurgy methods which is considered

as threat to nature due to usage of chemicals. This chapter explains the mechanism

Biotechnology for Zero Waste: Emerging Waste Management Techniques, First Edition.

Edited by Chaudhery Mustansar Hussain and Ravi Kumar Kadeppagari.