The Optimum Operating Conditions for the Synthesis of Zeolite from Waste Incineration Fly Ash by Alkali Fusion and Hydrothermal Methods
The fly ash of waste incineration processes is usually hazardous and the disposal or reuse of waste incineration fly ash is difficult. In this study, the waste incineration fly ash was converted to useful zeolites by the alkali fusion and hydrothermal synthesis method. The influence of different operating conditions (the ratio of Si/Al, the ratio of hydrolysis liquid to solid, and hydrothermal time) was investigated to seek the optimum operating conditions for the synthesis of zeolite from waste incineration fly ash. The results showed that concentrations of heavy metals in the leachate of Toxicity Characteristic Leaching Procedure (TCLP) were all lower than the regulatory limits except lead. The optimum operating conditions for the synthesis of zeolite from waste incineration fly ash by the alkali fusion and hydrothermal synthesis method were Si/Al=40, NaOH/ash=1.5, alkali fusion at 400 oC for 40 min, hydrolysis with Liquid to Solid ratio (L/S)= 200 at 105 oC for 24 h, and hydrothermal synthesis at 105 oC for 24 h. The specific surface area of fly ash could be significantly increased from 8.59 m2/g to 651.51 m2/g (synthesized zeolite). The influence of different operating conditions on the synthesis of zeolite from waste incineration fly ash followed the sequence of Si/Al ratio > hydrothermal time > hydrolysis L/S ratio. The synthesized zeolites can be reused as good adsorbents to control the air or wastewater pollutants. The purpose of fly ash detoxification, reduction and waste recycling/reuse is achieved successfully.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.2021657Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 391
 Taiwan Environmental Protection Agency, Environmental Statistics Annual Report, https://www.epa.gov.tw/ct.asp?xItem=61195&CtNode= 35638&mp=epaen, 2018.
 E.B.G. Johnson, S.E. Arshad., “Hydrothermally synthesized zeolites based on kaolinite: a review,” Applied Clay Science, vol. 97-98, pp. 215–221, 2014.
 R. Xu, W. Pang, J. Yu, Chemistry of Zeolites and Related Porous Materials, Hoboken, N.J., John Wiley & Sons (Asia), pp.128, 2007.
 R. Barrer, Hydrothermal Chemistry of Zeolites, Academic Press, England, Ch. 5, 1982.
 D. Breck, Hydrothermal Chemistry of Zeolites: Structure, Chemistry and Uses, Wiley, New York, Ch. 1–4, 1974.
 C.F. Wang, J.S. Li, L.J. Wang, X.Y. Sun, “Influence of NaOH concentration on synthesis of pure-form zeolite A from fly ash using two-stage method,” Journal of Hazardous Materials, vol. 155, no. 1-2, pp. 54-64, 2008.
 N. Shigemoto, H. Hayashi, K. Miyaura, “Selective formation of Na-X zeolite from coal fly ash by fusion with sodium hydroxide prior to hydrothermal reaction,” Mineral Science, vol. 28, no. 17, pp. 4781-4786, 1993.
 C. Tamura, M. Matsuda, M. Miyake, “Conversion of waste incineration fly ash into zeolite A and zeolite P by hydrothermal treatment,” Journal of Ceramic Society of Japan, vol. 114, issue 1326, pp. 205-209, 2006.
 J. Bhagwanjee, D.N. Singh, “A three step process for purification of fly ash zeolites by hydrothermal treatment,” Applied Clay Science, vol. 90, pp. 122-129, 2014.
 J. Etoh, T. Kawagoe, T. Shimaoka, K. Watanabe, “Hydrothermal treatment of MSWI bottom ash forming acid-resistant material,” Waste Management, vol. 29, issue 3, pp. 1048-1057, 2009.
 M. Inada, E. Yukari, E. Naoya, H. Junichi, “Synthesis of zeolite from coal fly ashes with different silica–alumina composition,” Fuel, vol. 84, pp. 299–304, 2005.
 C. Belviso, F. Cavalcante, S. Fiore, “Synthesis of zeolite from Italian coal fly ash: differences in crystallization temperature using seawater instead of distilled water,” Waste Management, vol. 30, issue 5, pp. 839-847, 2010.