Continuous Flow Synthesis of Zeolite-A from Coal Fly Ash Utilizing Microwave Irradiation with Recycled Liquid Stream

Abstract

Coal Fly Ash (CFA) was converted to zeolite using continuous microwave reactors while minimizing the wastewater produced during the zeolitization process. At bench scale, a continuous flow tubular microwave reactor was used to explore the effect of microwave irradiation on the crystallinity of the product. The waste water was reused in consecutive runs and Inductively Coupled Plasma (ICP) analysis was conducted during and after each run to observe the concentration of the cations. An increase in the production of hydroxysodalite compared to zeolite-A was noted at higher levels of microwave energy. The XRD and SEM analyses were also conducted to corroborate the results. The Cation Exchange Capacity (CEC) measurement showed the highest value of 0.405 meq/g when Deionized (DI) water was used, the CEC dropped to 0.177 meq/g for thrice recycled waste stream. It was also found that higher microwave irradiation resulted in faster crystal growth and the product crystallinity reached its maximum at 810 W of microwave irradiation in 60 min while 335 W of microwave irradiation resulted in the same crystallinity after 120 min of reaction.

Production of nanostructured crystalline composite using residual ashes from flocculated sludge burning process in a poultry slaughterhouse wastewater treatment system

“…These residual ashes from the burning process are usually used on an industrial scale to make construction materials like Portland cement and/or refractory bricks, but the unused parts of this waste end up being stored in an area of the industry or disposed of as garbage, which can lead to soil degradation and pose a risk to groundwater bodies [4][5][6]. To avoid this risk, the use of these residual ashes for the synthesis of zeolitic material has been studied in the literature [7,8]. However, due to the high expense of the process and the difficulties of creating a material with a well-defined structure, this application has received little attention [9,10].…”