Valuable components recovery from wastewater and brine using electrocoagulation-based coupled process: A systematic review

Wastewater and brine can be regarded as significant resources since they contain various valuable components, including precious metals, energy metals, heavy metals, anion salts, oil, fats, ammonium, and uranium. Conventional electrocoagulation appears to possess massive evolutionary potential and superior application prospects but is generally concentrated on removing impurities. Recently, electrocoagulation has attracted significant attention for valuable component recovery in terms of comprehensive utilization of resources. This work reviews the recovery of the valuable components from wastewater and brine using various electrocoagulation systems with novel anode materials and coupling apparatus. Appropriate parameters like current density and solution pH are imperative to enhance recovery efficiency and reduce energy consumption via adjusting the properties of flocculates. These valuable components can be recovered as metal elements, high-concentration leachates, and solid-phase products. Various enhanced electrocoagulation-based coupled systems have been developed from perspectives of recovery efficiency and energy saving. Besides, perspectives for further investigation are proposed for recovery process enhancement and industrial applications. [Display omitted] •Electrocoagulation is used to recover valuable components from wastewater and brines.•Valuable components were recovered efficiently as various forms of products.•Novel anode materials and coupling systems are investigated.•Metal-air fuel cells, H2 recovery, and large-scale operation need future research.