Advances and challenges in metal ion separation from water

Major technologies for metal ion recovery from water and wastewater include chemical precipitation, membrane filtration, adsorption, electrochemical separation. Recent studies have focused on membrane, methods, sophisticating them to obtain high selectivity recovery. Membrane filtration plays an important role in separating monovalent divalent ions. Metal–organic frameworks (MOFs), covalent organic (COFs), porous-organic polymers (POPs) recently been studied separate a specific selectively. Electrochemical methods are critical useful options make best use of adsorption because power can strengthen the recyclability stability adsorbents. Technologies selective separation currently attracting strong research interest as pathway greater sustainability. The chemistry processes is understanding mechanisms making viable. This paper discusses current advances challenges points view proposes how they should be approached future. porous materials adsorb contaminants. Kinetics uptake determined by its internal structure composition. chemicals (e.g., sulfide hydroxide reagents) react with ions form insoluble precipitates, which then separated sedimentation or filtration. target contaminants resources water, gases, salts, metals, compounds, aqueous phase reduce environmental impacts recycled used valuable resources. class that only involve light elements (C, N, O, B, Si) through bonds (B?O, C?N, B?N, B?O?Si). COFs emerged materials, advantages designed structures, tunable pore size, functionality. charge controlled electrodes capture release Design specificity between key performance. thermally driven process hydrophobic separates vapor warm liquid solution stream. hydrophobicity prevents passage pores while allowing solvent vapor. pressure drives particles larger than pores. approach most effective when sufficiently large. compounds made assembling inorganic units linkers one-, two-, three-dimensional structures. MOFs often polymers. noncrystalline, but still highly stable materials. More diverse synthetic coupling reactions, including Sonogashira?Hagihara, Suzuki?Miyaura, Yamamoto, Eglinton couplings high-performance POPs additional thiol chelating groups. transfer electrons subsequent oxidation reduction compound.