Contemporary applications of natural and synthetic zeolites from fly ash in agriculture and environmental protection

Abstract Environmental protection, including rational waste management, is one of the main goals of sustainable development. Scientists are continuously searching for new approaches and solutions to counteract an increasing environmental pollution. Zeolites, due to their unique properties are a subject of an ongoing scientific research for applications as adsorbents and ion exchangers in numerous areas of agriculture and environmental protection. In agriculture, studies mainly concentrate around the application of natural zeolite which can be a useful soil conditioner and an additive to fertilizer. However, the main focus of attention in the environmental remediation is currently on synthesized zeolites. Because the main product of coal combustion, namely fly ash, exhibits similar chemical composition to a zeolite, it is a promising low-cost material for their synthesis. Although numerous papers have been published regarding zeolites’ application in agriculture and environmental protection, their great potential has not been fully explored yet. This review presents state-of-art achievements in synthesis and modifications of zeolites and also an overview of their application in agricultural production and protection of water, air, and soil. Issues relating to cost of regeneration of zeolite adsorbents, estimated costs of their mining and production from fly ash are also discussed.