Chapter 13 - Metals recovery from wastewater by microbial electrochemical technologies

Abstract

Microbial electrochemical technologies (METs) are novel technologies that enable metal recovery from many different wastewater streams. This chapter describes how microbes can interact with metal ions for both metabolic and recovery purposes. Electroactive bacteria can donate electrons extracellularly to metal ions and electrodes. This ability allows the construction of microbial electrochemical devices to recover metal from polluted wastewaters. These devices can remove organic matter in the anodic compartment while simultaneously reducing metals in the cathodic compartment. This chapter explains the fundamentals of this technology and several factors to take into consideration before designing an experiment. A list of different metal recovery systems targeting metals of industrial and economic relevance are described herein. METs are a real and viable alternative to current technologies, and the field of microbial electrochemical metallurgy (MEM) is continually growing. In comparison to conventional technologies, MEM can offer energy-free and carbon-neutral ways to recover metals. Furthermore, valuable commodities can be produced by microbes using complexation, precipitation, and nanoparticle formation. In all, this chapter shows that the future of metal recovery and conversion is bright with MET and MEM.