Study on anaerobic phosphorus release from pig manure and phosphorus recovery by vivianite method

Abstract

In this study, pig manure rich in phosphorus was used as the recovery object, In order to realize the maximum recovery of phosphorus resources in pig manure, this study established a phosphorus recovery route combining the electrochemical method with the Vivianite method using sacrificial iron anode. And in order to obtain phosphorus rich supernatant, pig manure was treated with different pH values, and the changes in phosphorus components and metal content in the liquid phase were mainly investigated; Graded phosphorus components and microbial communities in the solid phase; Finally, the effect of electrolytic recovery of phosphorus from fermentation supernatant was studied. The results showed that the highest total phosphorus (TP) content in the liquid phase follows a trend of acidity > control > alkalinity; The analysis of the results of solid-phase phosphorus fractionation extraction shows that acidic conditions are more conducive to the release of Non-apatite inorganic phosphorus (NAIP) and Apatite inorganic phosphorus (AP); The microbial community promotes the release of phosphorus by participating in the decomposition of fermentation substrates; The analysis of the change of metal content in the liquid phase before and after electrolysis showed that the two chamber electrolytic cell can not remove other metal components while recovering the vivianite; More than 90% of the phosphorus in the supernatant after fermentation was recovered by electrolysis. The characterization results showed that 84.66% of the precipitate was Vivianite.