水合氧化铁对废水中磷酸根的吸附-解吸性能研究

以FeCl₃为原料制备水合氧化铁吸附剂，研究其对废水中磷酸根的吸附-解吸性能.结果表明，随着溶液pH的降低，水合氧化铁对磷酸根的吸附能力不断提高，其吸附动力学曲线符合二级动力学模型，吸附等温线符合Langmuir吸附模型.被吸附的磷酸根在50 g/L的NaOH溶液中进行解吸，解吸率>98%.解吸率与单位水合氧化铁的吸附饱和程度没有相关性.利用水合氧化铁对城市某污水处理厂污泥浓缩池上清液进行磷的吸附和解吸实验，结果表明该工艺对磷的回收率>90%.根据实验结果设计了城市污水中磷去除和回收工艺流程，该流程包括：吸附过程、解吸再生过程、富磷解吸液中磷回收等过程.

Sorption-desorption of Phosphate in Wastewater by Hydrous Iron Oxide

FeCl₃was used to prepare hydrous iron oxide (HIO) as an absorbent for phosphate (P) sorption and desorption study. The results showed that as pH decreased, the sorption capacity of HIO increased, and the sorption kinetics followed the second-order model, and the sorption isotherm could be fitted by the Langmuir equation. A 50 g/L NaOH solution was used for desorption of P from HIO, and the desorption rate could be reached over 98%. No relation was found between desorption rate and adsorption capacity. Based on above results, HIO was applied to adsorption of P from supernatant of sludge thickener, and after desorption, more than 90% of P was recovered. According to the results obtained, an effective system for P removal and recovery from municipal wastewater was suggested, which includes the following processes: adsorption, desorption, regeneration of HIO, and of recovery of P from P-rich desorption solution.