镁盐对高速铁路列车粪便污水中磷回收的响应面法优化研究

The optimization of phosphorus recovery from high-speed rail fecal sewage using magnesium salt based on a response surface method

通过响应面Box-Behnken实验设计,对镁盐回收高速铁路列车(高铁)粪便污水中磷进行优化研究,并对回收的产物进行分析.考察了p H值(8~10)、镁磷元素物质的量比(2~6)、反应时间(5~25 min)和温度(5~25℃)等条件对磷回收率的影响.结果表明,镁盐回收高铁粪便污水中磷的最优参数为:p H为9.5,镁磷元素物质的量比为5.7、反应时间为6.4 min、温度为5.0℃,磷的回收率响应值可达到95.3%.傅里叶变换红外光谱(FT-IR)和扫描电子显微镜(SEM)分析回收产物,表明主要的物质为磷酸铵镁,可能存在一定磷酸镁.能量弥散X射线(EDAX)分析回收产物,得到物质中磷元素的质量分数为17.1%.研究结果表明,运用镁盐从高铁粪便污水回收磷是可行的,具有一定的参考和借鉴意义.

Through response surface method（ RSM）,phosphorus recovery from high-speed rail fecal sewage was improved along with the chemical analysis of the harvested product. Initially,the effects of p H（ 8 ~ 10）,molar ratio of magnesium to phosphorus（ 2 ~ 6）,reaction time（ 5 ~ 25 min）,and reaction temperature（ 5 ~ 25 ℃） among other factors on phosphors recovery efficiency were investigated. The RSM-derived findings indicate that the optimal set of operational parameters was p H 9.5,magnesium-to phosphorus-molar ratio 5.7,reaction time 6. 4 min and temperature 5. 0 ℃. Under the above combined condition,the phosphorus recovery rate could reach at 95. 3%. Based on the results of Fourier Transform infrared spectroscopy and scanning electron microscopy,it could be easily found that the majority of the recovered product consisted of magnesium ammonium phosphate and magnesium phosphate. With further analysis by energy dispersive X-ray approach,the phosphorus content was observed to account for nearly 17.1% of the recovered product. Overall,this work proves the feasibility of using magnesium salt to recover phosphorus from high-speed rail fecal sewage,providing a scientific reference for further exploration in the related field.