Various methods, such as air stripp

Various methods, such as air stripping, biological degradation, adsorption techniques have been used for ammonium removal (Mittal et al., 2010; Gupta et al., 2011b; Moradi et al., 2012). For practical applications, adsorption method seems to be one of the most favored wastewater treatment techniques because of its environmental and economic sustainability (Gupta et al., 1998; Europea, 2003; Gefenienė et al., 2006; Marañón et al., 2006; Mittal et al., 2010; Moussavi et al., 2011). Abundant natural clay minerals (NCM) are inexpensive and can be used as low-cost adsorbents due to their unique properties as well as no toxic effects to the ecosystems (Borisover and Davis, 2015; Ismadji et al., 2015; Sun et al., 2015; Zhu et al., 2016).