Comparative Study on the Adsorption Efficiency of Two Different Local Clays for the Cationic Dye; Application for Adsorption of Methylene Blue From Medical Laboratories Wastewater

Abstract

The fine fraction of clay from Tagaran (TC) was characterized with X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), and Fourier-Transform Infrared Spectroscopy (FT-IR) and compared with the fine fraction of Topkhana clay (TPC). Both, TC and TPC were dominated by a trioctahedral swelling clay mineral (saponite). The use of TC was investigated for the adsorptive removal of methylene blue (MB) from blood film preparation washing waste of medical laboratory and undergraduate microbiology laboratory wastewater of the University of Sulaimani. The effect of initial pH of the dye solution was negligible at the studied range of dye concentration. The optimum adsorbent (TC) dose was 5\xa0g/L for 50\xa0mg/L of MB with an optimum equilibration time of 120 minutes. Adsorption isotherms were fitted to Langmuir and Redlich-Peterson isotherms by non-linear regression method. Pseudo-second-order kinetics best describe the analytical results. The thermodynamic parameters confirmed spontaneous endothermic adsorption. The study showed that local clays can be used to clean MB contaminated wastewaters.