CHAPTER 5: Zeolites in Wastewater Treatment

The world consumption of natural zeolites is approximately 6.0 Mt annually and is increasing at a fast rate. Natural zeolites are crystalline hydrated aluminosilicates with a framework structure containing pores. The porous zeolite is host to water molecules as well as a variety of positively charged ions. One important property of zeolites is the ability to exchange cations. Owing to their high cation-exchange ability as well as to their molecular sieve properties, natural zeolites have been widely used as adsorbents in separation and purification processes in recent decades. In this chapter we review the recent developments of natural zeolites as adsorbents in wastewater treatment, specifically for the removal of ammonia from wastewater.