State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, People's Republic of China.
Jingdezhen Ceramic Institute, Jingdezhen, 333001, Jiangxi, People's Republic of China.
Environ Sci Pollut Res Int. 2017 Oct;24(28):22204-22213. doi: 10.1007/s11356-017-9708-8. Epub 2017 Aug 9.
By crystallization process, phosphorus can be recycled from wastewater. However, the reagent cost limits the application of struvite precipitation. Magnesite, as a low-cost magnesium source, can result in a cost savings, while the poor dissolution offset of low-cost reagent. In this study, most of the pyrolysate of magnesite was dissolved by changing the process of reagent addition; the solubility of the pyrolysate was increased at acid wastewater. The removal rate of phosphate by the pyrolysate was higher than that of magnesite, the phosphate removal rate was from 70.2 to 88.2% at 600 °C, 0.5 h to 1200 °C, 3 h. Phosphate removal rate was achieved optimal when calcination temperature was 700 °C at 2 h. By adding the pyrolysate to acid wastewater (pH ≤ 2) before NHCl, phosphate removal rate was closed to that of MgCl as magnesium source, while magnesite was priced at similar levels to lime.
通过结晶过程，可以从废水中回收磷。然而，试剂成本限制了鸟粪石沉淀的应用。菱镁矿作为一种低成本的镁源，可以节省成本，但其低成本试剂的溶解性能较差。在本研究中，通过改变试剂添加过程，大部分菱镁矿热解物得以溶解；在酸性废水中，热解物的溶解度增加。热解物对磷酸盐的去除率高于菱镁矿，在 600°C、0.5-1200°C、3h 的条件下，磷酸盐的去除率从 70.2%提高到 88.2%。当煅烧温度为 700°C、时间为 2h 时，磷酸盐的去除率达到最佳。在向 pH≤2 的酸性废水中添加热解物之前添加 NHCl，磷酸盐的去除率接近以 MgCl 为镁源的去除率，而菱镁矿的价格与石灰相似。
