Efficient and Low-Cost Surfactant-Assisted Solid Phase Extraction Procedure For Removal Of Methylene Blue Using Natural Dolomite

Abstract

Abstract    Water pollution results from rapid urbanization and industrialization which has harmful effects on human health. Adsorption is one of the most efficient processes to remove pollutants from contaminated water. Natural minerals, such as dolomite, are widely spread around the world and may be easily collected in huge quantities. In this work, dolomite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and Fourier-transform infrared spectroscopy (FTIR), and was investigated for its applicability for removal of methylene blue (MB) from aqueous medium in a surfactant-assisted procedure. Using the one-factor one-time approach, batch adsorption studies were performed to establish the best experimental conditions (pH, sorbent amount, shaking time, type and concentration of surfactant and ionic strength) for removal of MB by dolomite. At optimum conditions (pH 8.0, shaking time 90 min, 1.0 g L−1 dolomite, 0.1% w/v sodium dodecyl sulfate, 25 °C), the maximum adsorption capacity was 22.2 mg g−1 and the adsorption process obeyed Langmuir and Freundlich adsorption isotherms. The findings show that dolomite effectively adsorbs MB and may be used as a less expensive sorbent in wastewater treatment to remove MB. Graphical Abstract