Adsorption Removal of Safranin Dye Contaminants from Water Using Various Types of Natural Zeolite

The presented study involved detail investigation for the adsorption properties of three types of natural zeolite (heulandite, clinoptilolite, and phillipsite). The studied zeolite samples were described based on the structural features from the XRD patterns and the surficial morphologies from SEM images. The selected zeolite minerals were applied as adsorbents in the decolorization of safranin-T dye from water. The estimated uptake capacities for safranin revealed the higher capacity of heulandite than clinoptilolite and Phillipsite (heulandite>clinoptilolite>phillipsite). As per the kinetic studies, 240min was detected as the decolorization equilibrium of safranin by heulandite and clinoptilolite; and 480min for phillipsite zeolite. The decolorization mechanisms were classified as chemical processes and represented strongly by Lagergren assumption and Elovich model. Monolayer adsorption form was suggested for the uptake by heulandite and clinoptilolite (Langmuir); and multilayer form was predicted for phillipsite (Freundlich). Neutral to alkaline environment was detected to be the best medium for considerable removal of safranin. Natural zeolite minerals also were applied effectively in safarnin decontamination from raw water and showed effective values in the decolorization of other types of dyes.