Removal of Oil from Steel Wastewater by Adsorption onto Organic Modified Sepiolite
The effect of operating conditions, such as adsorption time, adsorbent dosage, influent pH and influent oil concentration, on the performance of organic modified sepiolite used for the treatment of steel rolling oily wastewater was investigated via single factor method, and the adsorption kinetics and thermodynamics were also studied with batch test. Results indicated that oil removal rate reached 96.78% in 45 min which increased by 55.44% compared with crude sepiolite. Reasons for oil removal efficiency rise with organic modified sepiolite included augmentation of interlayer distance (0.007 nm larger than crude sepiolite), increase of specific surface area (from 41.63 to 104.40 m2/g) and stronger hydrophobic. The pseudo second order kinetic model well described experiment data with a perfect correlation coefficient value of 0.9999. Thermodynamic parameters including the Gibbs free energy (△G0), enthalpy (△H0), and entropy (△S0) revealed that adsorption process was a spontaneous, exothermic and physical adsorption process.
F. W. Li et al., "Removal of Oil from Steel Wastewater by Adsorption onto Organic Modified Sepiolite", Key Engineering Materials, Vols. 474-476, pp. 786-791, 2011