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).