Removal of Lead and Chromium (VI) metals from Water in the Batch System Using Activated Gamma Alumina

Abstract

Increased water pollution has become an important environmental problem due to the discharge of urban and industrial wastewater into water resources that contain heavy metals and other pollutants. Therefore, the aim of this study was to investigate the effectiveness of Activated Gamma Alumina (AGA) in the removal of lead and chromium (VI) from water, for the synthesis of which, aluminum hydrate has been used. Aluminum hydrate was exposed to 700 °C and converted to gamma alumina. The effect of variables such as pH, contact time, adsorbent dose and initial concentration of pollutants that are effective in removing lead (II) and chromium (VI) also investigated. The maximum removal efficiency of lead and chromium (VI) removal was obtained by Activated Gamma Alumina at a dose of 1 g/L, pH equivalent of 8 for lead and equivalent of 3 for chromium (VI), initial lead and chromium (VI) concentration 20 mg/L and contact time 60 min. Also, the study of absorption isotherm and kinetic model showed that the data of the elimination process are correlated with Langmuir model (Lead: R2 = 0.9805 and Chromium: R2 =0.9865) and kinetic of the pseudo-second-order models (Lead R2=0.9914 and Chromium R2=0.9536). The maximum adsorption capacity for lead and chromium (VI) obtained 27.78 and 30.77 mg/g, respectively. According to the results obtained in this study, the AGA adsorbent has a high ability to remove lead and chromium (VI) and can be recommended as a cheap adsorbent for the filtration of lead and chromium contaminated backwater.

Keywords

• water pollution
• activated gamma alumina (aga)
• lead (ii)
• chromium (vi)