Integrated synthesis of zeolites 4A and Na–P1 using coal fly ash for application in the formulation of detergents and swine wastewater treatment

• Published in: Journal of hazardous materials 2015-04, Vol.287, p.69-77
• Main Authors: Cardoso, Ariela M., Horn, Martha B., Ferret, Lizete S., Azevedo, Carla M.N., Pires, Marçal
• Format: Article
• Language: English
• Subjects: Ammonium Compounds - isolation & purification; Animals; Coal; Coal Ash - chemistry; Coal fly ash; Construction; Detergents; Detergents - chemical synthesis; Fly ash; Green Chemistry Technology; Integrated synthesis; Swine; Swine wastewater; Synthesis; Wastewater treatment; Water Purification; Zeolites; Zeolites - chemical synthesis
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2015.01.042

•The two integrated synthesis processes, resulted in zeolites of similar purity.•Process 1 was more favorable than process 2 in terms of greater incorporation of Si.•Zeolite 4A was synthesized according to the conformity parameters for use in detergents.•Zeolite Na–P1 in the treatment of swine wastewater confirmed its high ion exchange capacity. Several researchers have reported zeolite synthesis using coal ash for a wide range of applications. However, little attention has been given to green processes, including moderate synthesis conditions, using waste as raw material and effluent reuse or reduction. In this study, Brazilian coal fly ashes were used for integrated synthesis of zeolites 4A and Na–P1 by two different routes and under moderate operating conditions (temperature and pressure). Both procedures produced zeolites with similar conversions (zeolite 4A at 82% purity and zeolite Na–P1 at 57–61%) and high CEC values (zeolites 4A: 4.5meqCa2+g−1 and zeolites Na–P1: 2.6–2.8meqNH4+g−1). However, process 1 generated less effluent for the zeolite mass produced (7mLg−1), with low residual Si and Al levels and 74% of the Si available in the coal fly ash incorporated into the zeolite, while only 55% is used in process 2. For use as a builder in detergents, synthetic zeolite 4A exhibited conformity parameters equal to or greater than those of the commercial zeolite adopted as reference. Treatment of swine wastewater with zeolite Na–P1 resulted in a high removal capacity for total ammoniacal nitrogen (31mgg−1).