Removal and recovery of phosphorus in sewage water by superconducting high gradient magnetic separation with ferromagnetic adsorbent

高梯度磁分离系统（HGMS）在200 mg/L铁酸锆吸附剂的作用下，吸附时间为15 min，可对废水中的磷进行绝对脱除（约90%）。通过Langmuir图分析，我们发现该铁酸锆吸附剂的吸附量为12.8mg-P/g-ZrFe。我们还证实，2000mg/L的铁酸锆吸附的磷，经过15分钟的碱处理，可以脱除70%以上的磷。解吸后，经酸处理恢复铁酸锆吸附剂，对磷进行反复吸附。磁选速度达到1m/s，在外加磁场为2T，磁滤填料系数为8%的条件下，磁选速度达到1m/s。上述结果表明，粉状铁酸锆吸附剂HGMS适用于污水厂的大规模污水处理，且有可能在不产生二次废物的情况下从处理后的污水中回收磷。

Phosphorus in the treated wastewater could be removed absolutely (>90%) by high gradient magnetic separation system (HGMS) with 200 mg/L zirconium ferrite adsorbent for 15 minutes in adsorption time. According to Langmuir plot analysis, we found that this zirconium ferrite adsorbent had the capacity of adsorption of 12.8mg-P/g-ZrFe. We also confirmed that over 70% phosphorus adsorbed by 2000mg/L zirconium ferrite could be desorbed from it by alkali treatment for 15 minutes. After desorbing, zirconium ferrite adsorbent was restored by acid treatment to adsorb phosphorus repeatedly. Magnetic separation speed achieved 1m/sec which was necessary for practical use with an applied magnetic field of 2T and magnetic filter of 8% packing factor. These results suggest that HGMS using powdered zirconium ferrite adsorbent is suitable for a large-scale wastewater treatment at sewage plants, and the possibility of the recovery of phosphorus from the treated sewage water without secondary waste.