چكيده به لاتين
Secondary aluminum dross (SAD) is an inorganic waste material that is generated during melting of primary dross in aluminum production industry. Using dross as adsorbent for removing pollutants from wastewater has two advantages: first, the amount of disposal and storage of this toxic and harmful material is reduced; second, this material can be used in various applications including water remediation. In this study, the SAD from Iran Aluminum Company was used as adsorbent for removing Pb(II) from synthetic wastewater solution. Water rinsing and further HCl modification were used to improve the adsorption characteristics of the SAD. X-ray fluorescence (XRF), X-ray diffractometry (XRD), scanning electron microscopy (SEM), and nitrogen adsorption- desorption techniques were used to characterize the samples. Results showed that raw SAD contains 64.8% alumina, 16.5% SiO 2 and small amounts of carbon and other metal oxides. Most of the soluble salts present in the raw SAD was removed after water washing at 95 °C. Nitrogen sorptometry indicated that the specific surface area increased from 13.98 to 32.40 and 58.28 m 2 /g for acid treated and washed dross, respectively. Primary adsorption experiments showed that washed dross has higher lead removal efficiency compared to acid-treated dross. Therefore, further adsorption experiments were conducted using the washed dross. The optimum adsorption pH was found to be around 5.8. Kinetics studies revealed that pseudo-second order model explains the adsorption mechanism well. In addition, equilibrium studies showed that Langmuir linear model could better fit the experimental data and maximum adsorption capacity was 26.59 mg/g.
