Critical review on the synthesis and advancement of industrial and biomass waste-based zeolites and their applications in gas adsorption and biomedical studies

Abstract

Nowadays, wastes such as coal fly ash (CFA), biomass ash (rice husk, bagasse ash), steel and glass waste significantly originated from industrial and other sources. Solid waste is of substantial environmental concern due to its increasing volume of waste in landfills. Typical uses of such waste include agricultural applications, cement, and concrete industries, and soil stabilization. The transformation of solid waste to zeolite has been performed via several techniques; hydrothermal and fusion-facilitated hydrothermal treatment. These methods convert ash waste from landfills into secondary products like zeolite, useful for environmental protection and biomedical research. The current review provides an in-depth discussion of different synthesis techniques and various solid waste resources employed to prepare zeolites. Different perspectives of the synthesis process, including recent technologies for modification and various utilities, ranging from harmful gas adsorption to bio-medical applications, are summarized elaborately. A detailed description of parameters affecting the zeolite synthesis, the limitations of each technique, along with the toxicological effects of zeolites on the human body have been discussed in this review. The readers will greatly benefit from this review work as it will provide them with a comprehensive understanding of waste material-based zeolite preparation, its different synthesis parameters, novel synthesis strategies, and significant success in the removal of hazardous gaseous elements for environmental remediation. Furthermore, the use of waste-based zeolites in biological applications is discussed, which may be of interest to researchers working in the same field.