Modified mesoporous clinoptilolite characterization for non-biodegradable organic material removal

This paper reports the study of a novel mesoporous material modified from natural clinoptilolite (NC) through pore broadening and organic modification. In order to reveal purification capacity enhancement, micrographs obtained by performing high-resolution transmission electron microscopy on the materials were used to compare the inner structures of NC and mesoporous clinoptilolite (MC) at various magnifications. In MC, broader pores (from microporous to mesoporous) at the surface of MC and sublimation clouds of particles inside the pores and channels were found, while NC exhibited none of these features. The results obtained from energy-dispersive X-ray spectroscopy analysis indicate that the contents of impurities in MC were lesser than that of NC; the crystallinity of MC was also found to be more than that of NC. The decolorization rate of the MC material can reach up to 98·6%, while that of NC is 87%, and the removal rates of MC’s chemical oxygen demand as analyzed by the dichromate method (COD_Cr) can reach 91·3%, while the rate for NC is 56%. The results indicate that the MC material has better adsorption with some mesoporous level (2–50 nm) on soluble organics, which is related to the pore diameter and the framework of the MC material from wastewater.