化学
废水
铵
氮气
氢氧化铵
降水
核化学
磷酸铵
傅里叶变换红外光谱
磷酸盐
无机化学
废物管理
化学工程
有机化学
气象学
工程类
物理
肥料
作者
Tao Zhang,Lili Ding,Hongqiang Ren,Xiang Xiong
出处
期刊:Water Research
[Elsevier]
日期:2009-12-01
卷期号:43 (20): 5209-5215
被引量:162
标识
DOI:10.1016/j.watres.2009.08.054
摘要
Ammonium nitrogen removal from wastewater has been of considerable concern for several decades. In the present research, we examined chemical precipitation recycle technology (CPRT) for ammonium nitrogen removal from coking wastewater. The pyrolysate resulting from magnesium ammonium phosphate (MAP) pyrogenation in sodium hydroxide (NaOH) solution was recycled for ammonium nitrogen removal from coking wastewater. The objective of this study was to investigate the conditions for MAP pyrogenation and to characterize of MAP pyrolysate for its feasibility in recycling. Furthermore, MAP pyrolysate was characterized by scanning electron microscope (FESEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) as well as X-ray diffraction (XRD). The MAP pyrolysate could be produced at the optimal condition of a hydroxyl (OH−) to ammonium molar ratio of 2:1, a heating temperature of 110 °C, and a heating time of 3 h. Surface characterization analysis indicated that the main component of the pyrolysate was amorphous magnesium sodium phosphate (MgNaPO4). The pyrolysate could be recycled as a magnesium and phosphate source at an optimum pH of 9.5. When the recycle times were increased, the ammonium nitrogen removal ratio gradually decreased if the pyrolysate was used without supplementation. When the recycle times were increased, the ammonium nitrogen removal efficiency was not decreased if the added pyrolysate was supplemented with MgCl2·6H2O plus Na2HPO4·12H2O during treatment. A high ammonium nitrogen removal ratio was obtained by using pre-formed MAP as seeding material.
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