Defluoridation of Groundwater Using Raw Material of Autoclaved Aerated Concrete

摘要

A batch process of defluoridation using raw material of autoclaved aerated concrete (AAC) was studied under optimum conditions. The parameters of adsorption method, such as pH, adsorbent dose and contact time were optimized under batch experiments. SPADNS method was used to quantitatively evaluate the residual fluoride concentration. Under optimum conditions, pH of solution, adsorbent dose and contact time was to be 7, 0.1 g/10 mL and 60 min, respectively. The amount of defluoridation was found to be 3.23 mgF~-/gACC. Deflouridation capacity of AAC can be explained on the basis of the chemical interaction of fluoride with the metal oxides under suitable pH conditions. The adsorption process was found to follow first order rate mechanism as well as Freundlich isotherm.