Abstract
High-silica zeolites have been found to be effective adsorbents for the removal of organic micro-pollutants (OMPs) from impaired water, including various pharmaceuticals, personal care products, industrial chemicals, etc. In this review, the properties and fundamentals of high-silica zeolites are summarised. Recent research on mechanisms and efficiencies of OMP adsorption by high-silica zeolites are reviewed to assess the potential opportunities and challenges for the application of high-silica zeolites for OMP adsorption in water treatment. It is concluded that the adsorption capacities are well-related to surface hydrophobicity/hydrophilicity and structural features, e.g. micropore volume and pore size of high-silica zeolites, as well as the properties of OMPs. By using high-silica zeolites, the undesired competitive adsorption of background organic matter (BOM) in natural water could potentially be prevented. In addition, oxidative regeneration could be applied on-site to restore the adsorption capacity of zeolites for OMPs and prevent the toxic residues from re-entering the environment.
Highlights
Organic micro-pollutants (OMPs) have become a worldwide issue of increasing environmental concern (Petrie et al, 2015; Schwarzenbach et al, 2006)
The OMP adsorption efficiency of activated carbon might be lowered by the co-existence of background organic matter (BOM) with OMPs, which will reduce the operational period between activated carbon regeneration events (Narbaitz and Cen, 1997; Pelekani and Snoeyink, 1999; Schork and Fair, 1988; Zietzschmann et al, 2014)
The OMP adsorption efficiency by high-silica zeolites will depend on the OMP-zeolite interaction (WOZ), zeolite-water interactions, (WZW) and OMPwater interactions (WOW), which will include the effect of structural features, surface hydrophobicity and existing adsorption sites of high-silica zeolites as well as characteristics of OMPs
Summary
Organic micro-pollutants (OMPs) have become a worldwide issue of increasing environmental concern (Petrie et al, 2015; Schwarzenbach et al, 2006). The regeneration processes considerably influence the pore structure and chemical functional groups in the activated carbon, which deteriorates their OMP adsorption performance (Cooney et al, 1983; Martin and Ng, 1984). High-silica zeolites (Fig. 1) with Si/Al ratios up to several thousands are industrially manufactured by replacing the aluminium contents with silica (Burton, 2018; Burton et al, 2005) The hydrophobicity of these zeolites provides favourable characteristics for OMP adsorption in aqueous solutions (Maesen, 2007; Tsitsishvili, 1973). High-silica zeolite powders have been proven to be effective adsorbents for the removal of OMPs from water, including pharmaceuticals, personal care products and industrial chemicals, based on information provided only by batch tests (Damjanovic et al, 2010; Rakic et al, 2010; Rossner et al, 2009). The potential opportunities and challenges of applying high-silica zeolites to water treatment are discussed
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
