利用轻烧镁回收水中氮磷元素的研究

The Research on Dealing with Simulated Wastewater that Include Nitrogen and Phosphorus by Light Calcined Magnesium Powder

采用磷酸铵镁(MAP)沉淀法,先向模拟磷废水中投加65%低品位轻烧镁粉,再利用除磷后的沉淀物处理氨氮废水,研究pH值、氨氮质量浓度、投加量和反应时间等对氮元素去除效果的影响。结果表明,65%轻烧镁粉处理含磷废水沉淀物在质量浓度50 mg/L、投加量9 g/L、pH值为2、反应时间15 min的试验条件下,沉降2 h,氨氮的去除率达到65.03%。利用低品位轻烧镁粉进行MAP结晶沉淀法可有效回收废水中的氮磷元素,制备氮磷缓释肥,在资源回收利用和环境保护方面具有广阔的应用前景。

Magnesium ammonium phosphate process was used to treat simulated wastewater that include nitrogen and phosphorus by low-grade light calcined powder. First, magnesium oxide content of 65% in light calcined powder was used to treat simulated wastewater included phosphorus. Second, the phosphorus-containing precipitate was used to treat included nitrogen. Some factors affecting the removal efficiency of nitrogen were discussed, including pH, nitrogen concentration, low-grade light calcined powder dosage, reaction time. The results indicated that, when phosphoruscontaining precipitate was used, the nitrogen concentration was 50 mg/L, the optimal dosage was 9 g/L, the pH value was 2, the reaction time was 15 min, settled 2 h, in this case, the removal efficiency of nitrogen was 65.03%. MAP precipitation method by low-grade light calcined powder can effectively recover nitrogen and phosphorus elements in wastewater and use low-grade light calcined powder, preparation of nitrogen and phosphorus slow release fertilizer, which has wide application prospect in resource recycling and environmental protection.