Authors: Yanpengy Mao Shanxiu Yang Qinyan Yue Wenlong Wang
Publish Date: 2016/09/20
Volume: 23, Issue: 23, Pages: 24265-24276
Abstract
A processoriented investigation of phosphate removal by ferric salt was carried out in this study The kinetics of amorphous ferric phosphate FePO4s formation has been investigated over the pH range of 60–80 using sulfosalicylic acid as a competitive ligand The FePO4s formation rate constants varied in a narrow range over the pH range examined in this study And the maximum of 090 ± 011 × 104 L mol−1 s−1 was obtained at pH 75 and the minimum value of 005 ± 001 × 104 L mol−1 s−1 was obtained at pH 60 These values are two orders of magnitude lower than the rate constants for FeIII hydrolysisprecipitation and hence the extent of FePO4s formation when ferric ions are added to aqueous solution is extremely low Subsequently the characteristics of the amorphous ferric oxide AFO with different ages were investigated and it was found that the BET surface area the average pore width and the charge capacitance were various for different AFO with various ages Phosphate adsorption by AFO was significantly affected by AFO aging and the manner of adding FeIII which was successfully described by a diffuse layer model By using surface sites concentration obtained the kinetics constant of AFO aging could be calculated by a functional equation at a certain pH and time
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