One of the biggest challenges to implementing ion exchange processes in
full scale at wastewater treatment works is regeneration of the media.
In this paper, regeneration efficiency as a function of brine type,
brine reuse, molarity and pH was investigated for the zeolite MesoLite
treating synthetic solutions of ammonium. When pretreating the zeolite
with KCl rather than NaCl, a 30% improvement in regeneration efficiency
was found in the first cycle, which dropped to a 10% improvement in the
fifth cycle. For both systems, the observed uptake capacity during the
load cycle remained constant, indicating that both were effective and
that the brine could be reused five times without deterioration in the
performance of the zeolite. The use of KCl was more effective at lower
molarities than NaCl such that equivalent regeneration efficiencies were
observed at 1.0M and 0.1M for NaCl and KCl respectively. Alteration of
the pH between 9 and 12 had no impact on the regeneration efficiency.
However, operation at pH 12 was possible without brine. Taken together,
these findings indicate that the choice of regenerant can have
significant implications on regeneration efficiency and that potassium
chloride might be a potentially viable alternative choice.
Impact of Presence and Concentration of Ionic Species on Regeneration Efficacy of Zeolites for Ammonium Removal