A review of membrane crystallization, forward osmosis and membrane capacitive deionization for liquid mining

Socio-economic development and new technological advancements have greatly increased the demand for metals, minerals and nutrients. Thus, substantial interest in developing technologies to recover these commodities from seawater, various brines and wastewater streams (industrial and domestic) has emerged. Less explored and innovative membrane processes including membrane crystallization (MCr), forward osmosis (FO) and membrane capacitive deionization (MCDI) are gaining interest in this regard. The current study provides a critical review of the current trends in applying MCr, FO and MCDI for recovery of metals, minerals and nutrients from various streams. The processes are compared in terms of types of fouling, energy consumption, overall composition of suitable feed solutions, feasible concentration ranges and potential to recover the targeted metal from a multi-component solution. The ultimate objective is to establish future research directions for further improvement of each process and to identify which of the processes is more suitable under a given scenario.