【作者】 武奇；

【导师】 马三剑；

【作者基本信息】 苏州科技学院 ， 环境工程， 2009， 硕士

【摘要】 传统的MAP沉淀法需要镁源(如MgC12)和磷源(如Na2HPO4)作投加剂,而且由于磷酸根离子容易与钙离子生成磷酸钙沉淀,需要使用NaOH作为pH调节剂,导致MAP沉淀法处理成本高,阻碍了实际应用。因此寻求廉价的沉淀剂一直都是化学沉淀法处理氨氮废水需要解决的关键问题。本研究根据磷酸氨镁热解产物(MAP)加热分解后能产生氨气和磷酸氢镁、磷酸镁等物质,而磷酸氢镁和硫酸镁皆可与废水中的氨氮产生结晶,从而达到再利用的目的。磷酸氨镁热解产物吸收氨氮后生成的MAP经热分解后可再生磷酸氨镁热解产物,构成MHP的循环,从而大大减少了成本。(1)磷酸氨镁热解产物对废水中的氨氮有着良好的去除效果,特别是在高浓度废水的处理当中,在处理2000mg/l的中高浓度氨氮废水时,对水中氨氮的去除率达到90%以上。(2)磷酸氨镁热解产物用来循环处理氨氮废水行之有效,前三次循环的氨氮去除率均保持在90%左右,具有良好的去氨氮效果。磷酸氨镁热解产物循环处理氨氮废水操作过程当中不需要额外添加镁盐或磷盐,同时也解决了磷酸氨镁的处置问题,可谓是一举两得,具有良好的经济效益和可行性。更多还原

【Abstract】 The traditional struvite precipitation need MgC12 and Na2HPO4 and PH regulator such as NaOH that is forbidden the calcium phosphate deposition,It result in the expensive cost of struvite precipitation.So It is important to find a cheap way to deal with the treatment of high concentration of ammonia nitrogen wastewater.In this paper, based on ammonium can elimination from MAP to magnesium phosphates and ammonium incorporation into the magnesium phosphates. It is confirmed that magnesium hydrogen phosphate (MgHPO4) is favorably obtained from the ammonium elimination from MAP at temperatures greater than 353 K, although magnesium phosphate (Mg3(PO4)?2) and magnesium pyrophosphate (Mg2P2O7) have been suggested as possible candidates. Based on the dissolution–precipitation mechanism for the removal of aqueous ammonium with magnesium phosphates, three magnesium phosphates were employed for the removal of aqueous ammonium.(1)MHP precipitation is effective in treatment of high concentration of ammonia nitrogen wastewater. Under the most favorible condition, the removal rate of ammonia nitrogen can comes to 90% above.(2)The present results show that MAP can be employed as an advanced material for the removal/recovery of ammonium,although it is generally accepted that an excess of MAP obtained from the wastewater treatment can be only used as a slow-acting fertilizer.The result show that the removal rate of ammonia nitrogen is still about 90% after 3 cycles.It is unnecessary to add magnesium salt and phosphate salt in this method,and also resolve the treatment of MAP,so it is feasibility and have a good economic benefit.更多还原