Zeolites as versatile material for sustainable water purification: a review

Water contaminants are prevalent in various sources and this poses high risks to the environment as well as human health thereby increasing the need for an efficient sustainable water management. Zeolites are a special type of crystalline aluminosilicate minerals that possess rich frameworks of interconnecting channels and cages. They have exceptionally high cation exchange capacities and has drawn much attention as suitable adsorbent material for the elimination of different types of pollutants in water systems. Besides the use in water purification, zeolites are also used environmentally as filters of toxicants and as sources of nutrition to crops. Zeolites have multiple functions in commercial and environmental processes because of their structural and chemical characteristics. They can act as requisite catalysts, adsorbents, and ion exchangers due to the broad applicability in commercial and environmental processes across industries. This review aims at examining the use of zeolites in different water purification processes with the view of explaining the nature/extent of adsorption properties and ion exchange of the material. The effectiveness of various kinds of zeolites, such as clinoptilolite, chabazite, etc is presented with special reference to the removal of heavy metals, ammonia, organic contaminants, and operation of desalination. Furthermore, the review provides an account of the limitations and comparison with other technologies.