Impact of Cations (Na⁺, K⁺, Mg⁺²) and Anions (F^-, Cl^-, SO₄^2-) Leaching from Filters Packed with Natural Zeolite and Ferric Nanoparticles for Wastewater Treatment

Natural zeolites have been employed to adsorb contaminants in water. This study is aimed to evaluate the cation and anion leaching from the zeolite after the wastewater was passed through filters packed with a natural zeolite (heulandite-CaAl₂Si₇O₁₈·6H₂O). Eight treatments were evaluated in a 2 × 2 × 2 factorial treatment design. Factor A was the zeolite with two levels: 127 g and 80.4 g. Factor B was the nanoparticles with two levels: one bag (3.19 g) and two bags (6.39 g); and Factor C was the use of a magnet: with and without. There were two replications; hence, a total of 16 filters were employed. The water was obtained from a municipal wastewater treatment plant (MWTP). The cations (Na⁺, K⁺; Mg⁺² and Ca⁺²) and anions (F^-, Cl^- and SO₄^2-) were measured before (influent = IW) and after filtering (effluent = EW) three times. All treatments leached the cations Na⁺ (EW in a range of 175 to 232 ppm), K⁺ (EW in a range of 15.4 to 33.2 ppm), and Mg⁺² (EW in a range of 7.40 to 10.8 ppm) but did not leach Ca⁺². Likewise, the treatments leached the anions F^- (EW in a range of 7.59 to 8.87 ppm), Cl^- (EW in a range of 85.9 to 120 ppm), and SO₄^2- (EW in a range of 139 to 146 ppm). We conclude that this natural zeolite leaches cations (except Ca⁺²) and anions in MWTP passed through filters. Therefore, its application in wastewater treatment should be considered for purposes such as agriculture and animal production and not for drinking water.