Resourcization and valorization of waste incineration fly ash for the synthesis of zeolite and applications

The current and traditional treatment method of waste incineration fly ash is solidification and landfill, but this method encounters more and more challenges because the available landfill space is decreasing and the hazardous substances may leach out. The development of new method to treat and reuse the incineration fly ash is quite important and urgent. This study explores the feasibility of recycling and reusing incineration fly ash for the synthesis of zeolite by alkali fusion and hydrothermal methods. The influences of different synthesis parameters and the optimum operating conditions are established. Experimental results indicate that the major control factors and optimal operating conditions for the synthesis of zeolite from incineration fly ash were that silicon/aluminum ratio was 40, alkali/ash ratio was 1.5, liquid/solid ratio was 200, and hydrothermal time was 48 h. The synthetic zeolite was identified as ZSM-23 zeolite, and its specific surface area was greatly increased to 880.05 m(2)/g. The adsorption capacity of synthesized zeolite for iodine and heavy metals were excellent and better than the commercial activated carbon. Moreover, the heavy metals and dioxin in the fly ash can be removed during the synthesis process. The quality of synthetic zeolite was superior and it can be reused as adsorbent and green material with a wide range of applications. The resourcization and valorization of incineration fly ash can be achieved through the appropriate alkali-fusion and hydrothermal synthesis process.