电化学MAP工艺对鸡粪沼液中氮磷回收的试验

Experiment of Electrochemical MAP Process for Nitrogen and Phosphorus Recovery in Chicken Manure Biogas Fluid

针对鸡粪沼液中氮、磷残余量大且处理回收困难的特点,文中采用电化学结合鸟粪石结晶法(MAP)的工艺,回收沼液中的氮、磷。根据该工艺配置了小试和中试试验,测试了实际应用的可行性。通过单因素试验、正交设计得到最优反应条件:沼液pH值为9.0、反应时间为105 min、电流密度为20 mA/cm^(2),小试结果表明:该条件下氮、磷的去除效率分别可以达到74.51%、93.55%;中试结果表明:该工艺对氮、磷的回收率分别可达72.90%、93.48%。通过对回收产物进行X射线衍射(XRD)表征发现,其主要成分是鸟粪石,且纯度较高。电化学MAP工艺回收鸡粪沼液中氮、磷元素具有良好的实际应用前景。

Aiming at the characteristics of large amount of nitrogen and phosphorus residues in chicken manure biogas slurry and difficulty in treatment and recovery,this study adopted electrochemistry combined with magnesium ammonium phosphate(MAP)to recover nitrogen and phosphorus in biogas slurry.According to the process,small and pilot tests were configured to test the feasibility of practical applications.The optimal reaction conditions were obtained by one-factor test and orthogonal design:the pH value of the biogas slurry was 9.0,the reaction time was 105 min,and the current density was 20 mA/cm^(2),and the small test results showed that the removal efficiency of nitrogen and phosphorus under these conditions could reach 74.51%and 93.55%,respectively.The pilot results showed that the recovery rate of nitrogen and phosphorus in this process could reach 72.90%and 93.48%,respectively.Through X-ray diffraction(XRD)characterization of the recovered products,it was found that the main component was guano stone,and the purity was high.The application of electrochemistry MAP process to recover nitrogen and phosphorus in chicken manure biogas slurry has good prospects.