Thermal decomposition of magnesium ammonium phosphate and adsorption properties of its pyrolysis products toward ammonia nitrogen  

磷酸铵镁的热分解行为及热分解产物的氨氮吸附性能（英文）

作　　者：陈益清[1] 唐建军[1] 李文龙[1] 钟振辉[2] 尹娟[1] 

机构地区：[1]深圳职业技术学院深圳市工业节水与城市污水资源化技术重点实验室,深圳518055 [2]广州大学土木工程学院,广州510006

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第2期497-503,共7页中国有色金属学报（英文版）

基　　金：Project(ZDSY20120619093952884)supported by Shenzhen Strategic New Industry Development,China

摘　　要：High-purity magnesium ammonium phosphate （MAP） was precipitated by controlling pH value of the reaction system of 9.0-9.5. The thermal decomposition behavior of MAP and the adsorption properties of its pyrolysis products toward ammonia-nitrogen were also studied by XRD, SEM, TGA-DTA and FT-IR methods. The results indicated that high-purity MAP was obtained at pH value of 9.0-9.5. Upon heating to 100-120℃ for 120 min, MAP was thermally decomposed, losing water and ammonia concomitantly with a reduction in grain size and crystallinity. The capacity of pyrolysis products for ammonia nitrogen adsorption reached 72.5 mg/g, with a removal rate of up to 95% from an 800 mg/L solution. The characteristic diffraction peaks corresponding to MAP mainly appeared in their XRD patterns after adsorption of ammonia nitrogen. The pyrolysis products of MAP at 100-120 ℃ could be recycling-used as the chemical treatment regents of ammonia nitrogen in the practical application.通过控制反应体系的pH值为9．0～9．5，制得高纯度的磷酸铵镁（MAP）；利用XRD、SEM、TGA-DTA及FT-IR等技术，研究MAP的热分解行为及热解产物对氨氮的吸附性能。结果表明，在pH值为9．0～9．5的条件下可制得高纯度的MAP。将MAP在100～120℃下热解120min，可将氨及水脱除，热解固体产物粒径变小，结晶度降低，对氨氮的吸附量达72．5mg／g，对起始浓度为800mg／L溶液的氨氮去除率达95％以上。吸附氨氮后，其XRD谱中主要出现MAP的特征衍射峰。循环使用结果表明，将MAP在100～120℃条件下发生热解，热解固体产物可循环用于氨氮的处理药剂。

关 键 词：magnesium ammonium phosphate magnesium hydrogen phosphate thermal decomposition ammonia nitrogen adsorption properties 

分 类 号：TQ132.2[化学工程—无机化工] O647.3[理学—物理化学]