Ammonium Removal From Water by Eight Natural Zeolites: A Comparative Study

The effect of conditioning with NaCl, KCl and HCl on the performance of natural clinoptilolite’s removal efficiency of Cu²⁺ and Co²⁺ from Co/Cu synthetic solutions

“…The effect of treatment of clinoptilolite samples was investigated for the removal of NH 4 + ions from aqueous solution. Cuban clinoptilolite has been previously transformed into its Na + , K + , Ca 2+ and Mg 2+ forms after treatment (Rozic et al, 2002;Zamzow et al, 1990;Milan et al, 1997;Rahmani et al, 2009;Langwaldt, 2008). These studies revealed an improved performance when Na + -clinoptilolite was used.…”

Physical–Chemical Processes for Nitrogen Removal

“…The time required to achieve equilibrium varies widely in the literature because of variations in experimental conditions such as initial ammonium concentration, mixing speed, clinoptilolite dose (solid/liquid ratio), and other solution conditions. Equilibrium times reported are 20 min (Sarioglu, 2005), 30 min (Du et al, 2005), 60 min (Rožić et al, 2000), 120 min (Langwaldt, 2008), 200 min (Booker et al, 1996), 240 min (Du et al, 2005;Langwaldt, 2008), and 1440 min (Liu and Lo, 2001). In summary, experimental kinetic data are useful for providing removal efficiency and ammonium loading as a function of time and the time needed to reach equilibrium.…”

“…For example, Sarioglu (2005) showed B70% ammonium removal by Turkey clinoptilolite in 5 min. Smaller sized clinoptilolite particles show higher initial removal rates than larger particles because smaller particles have greater external surface area to mass ratio than larger particles (Booker et al, 1996;Liu and Lo, 2001;Langwaldt, 2008). Different particle size fractions eventually reach a similar level of ammonium loading at equilibrium (Bernal and Lopez-Real, 1993).…”

“…Clinoptilolite shows rapid uptake of ammonium in the first 10-15 min of mixing (Booker et al, 1996;Du et al, 2005;Langwaldt, 2008;Widiastuti et al, 2011). For example, Sarioglu (2005) showed B70% ammonium removal by Turkey clinoptilolite in 5 min.…”

“…In addition to natural variations in clinoptilolite composition, natural clinoptilolite used in environmental applications is often not pure but includes other zeolites and impurities. For example, Turkey clinoptilolite was 45% clinoptilolite, 35% mordenite, 15% feldspar, and 5% quartz (Sarioglu, 2005); the USA clinoptilolite was 81.2% clinoptilolite, 13.3% mordenite, 2.5% feldspar, and 1.6% quartz (Langwaldt, 2008).…”