Removal of Cd(II) from Wastewater by Autoclaved Aerated Concrete Waste

The removal efficiency and mechanism of Cd2+ in wastewater were studied by using the powder of autoclaved aerated concrete (AAC) waste. The structure and physical properties of AAC were characterized by XRF, SEM, XRD and its adsorption properties for removal of 3 mg/L Cd2+ under different conditions were investigated. The results showed that the removal rate of AAC for Cd2+ has attained 97% after 90 min when the initial dosage of AAC was 10 g/L. The adsorption process fitted to Langmuir model and pseudo-second-order kinetic model. Physical adsorption and chemisorption were both observed during the process. Besides, AAC possesses comprehensive removal effect for other heavy metal ions include Cu2+, Pb2+ and Zn2+ in industrial wastewater. AAC of the construction industry can effectively remove the toxic heavy metal ions in the aqueous solution and is a low cost and promising water purifying agent.