Abstract

In this work, the capability of two commercial high silica zeolites (HSZs), namely ZSM-5 and Y, for the removal of chlorobenzene (CB) from water was investigated by combining chromatographic and diffractometric techniques. The adsorption isotherms and kinetics of CB on ZSM-5 and Y zeolites were determined from batch tests. The adsorption kinetics were very fast; the time to reach equilibrium was less than 10 min. The equilibrium data of CB on the two HSZs showed dissimilarities that are particularly evident in the adsorption data concerning the low concentration range, where Y zeolite is characterized by low adsorption. On the contrary, at higher solution concentrations the adsorption capacity of Y is higher than that of ZSM-5. The crystalline structures of Y and ZSM-5 saturated with CB were investigated by X-ray diffraction (XRD) techniques. Rietveld refinement analyses of XRD data allowed for quantitative probing of the structural modifications of both zeolites after CB adsorption and provided insight into the preferred zeolite adsorption sites in both microporous materials. The refined framework–extraframework bond distances confirm that interactions between the selected organic contaminant and hydrophobic zeolites are mediated via co-adsorbed H2O. The occurrence of H2O–CB–framework oxygen oligomers explains variations in both the unit cell parameters and the shape of the channels, clearly confirming that water plays a very relevant role in controlling the diffusion and adsorption processes in hydrophobic zeolites.

Highlights

  • Industrial and agricultural discharges, chlorine disinfection by-products (DBPs) of drinking water and wastewater, and incineration of wastes are the main sources of chlorine and organochlorine compounds (OClCs), such as chlorobenzene (CB)

  • The objective of this study is to evaluate the capability of two commercial high silica zeolites (HSZs), ZSM-5 (MFI topology), and Y zeolite (FAU topology) [34], for removal of chlorobenzene (CB) from water

  • This work aims to highlight the adsorptive capacity of commercial high silica zeolites ZSM-5 (MFI topology), and Y zeolite (FAU topology), for removal of chlorobenzene (CB) from water

Read more

Summary

Introduction

Industrial and agricultural discharges, chlorine disinfection by-products (DBPs) of drinking water and wastewater, and incineration of wastes are the main sources of chlorine and organochlorine compounds (OClCs), such as chlorobenzene (CB). These compounds can cause toxic effects on both human health and environmental systems, even at low concentration [1]. Carbonaceous adsorbents are low cost materials, widely employed in remediation technology Their applicability can be limited by fouling that cause a pore blocking (i.e., to the presence of dissolved organic matter), to low adsorption capacity, sharp rise of bed temperature and difficulty of regeneration [14,15,16,17]. In the past few decades, surfactant modified clays have been proposed as a potential alternative to carbonaceous adsorbents for removing OClC pollutants

Objectives
Methods
Results
Conclusion
Full Text
Paper version not known

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 call

Disclaimer: 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.