Removal and recovery of metals and nutrients from wastewater using bioelectrochemical systems

Processes which not only treat wastewaters, but also recover resources such as metals and nutrients are attractive for developing sustainable technologies. In this context, bioelectrochemical systems are emerging as a new technology platform for recovering metal, ammonium, phosphorus, and water. Bioelectrochemical systems have attracted potential interest for the removal and recovery of metal ions from metallurgical wastes, process streams, and wastewaters. In these systems, biodegradation of organic matter at the anode is coupled to the reduction of metal ions at the cathode. Both mobilization and immobilization of metals from synthetic matrices have been demonstrated in bioelectrochemical systems. For example, leaching of Co(II) from LiCoO₂ particles via reduction of Co(0) to Co(II) was shown at the cathode. Removal of Co(III/II), Cr(VI), Cu(II), Hg(II), Ag(I), Se(VI), and Cd(II) ions from aqueous streams was demonstrated at the cathode. In addition, bioelectrochemical systems have shown potential for recovering ammonium and phosphorus from high strength waste streams such as source separated urine. This chapter covers the basic principles and potential applications of bioelectrochemical systems in removing and recovering metals, ammonium, and phosphorus from synthetic solutions and real waste streams.