Recently, Dr. Nan Li from the School of Environmental Science and Engineering published a paper titled “Phosphorus Competition in Bio-induced Vivianite Recovery from Wastewater” in the journal Environmental Science & Technology as the Home Page Recommendation article.
In this research, phosphorus competition between biomass growth and bioinduced vivianite mineralization were investigated at the batch scale. Biomass growth leads to phosphorus utilization over vivianite mineralization.Geobacter was selected as the main functional microorganism and presented higher vivianite recovery rates (20-48%) than sewage biomass (7-33%). An optimal Fe/P stoichiometric ratio of 1:1 was observed for both sewage biomass and Geobacter-inoculated batches. The highest vivianite yield of 4.3 mM was obtained in Geobacter-inoculated batches at a Fe:P of 1:1, with values 59% higher than those at a Fe:P of 1:0.67 (equal to the Fe/P molar ratio in vivianite). Sufficient PO43- stimulated cell growth and yielded a higher Fe3+ reduction rate and vivianite yield.
Nevertheless, excessive PO43- facilitated the precipitation of KFe3(PO4)2(OH) ·8H2O and Fe7(PO4)6, which inhibited vivianite synthesis. In the optimal Geobacterbatch, theμ-S curve indicated a mixed order reaction (0 <x< 1) for both vivianite formation and biomass growth. The vivianite growth series proceeded as follows: tiny blue particles, plain pieces, dark blue nodules, and large spherical crystals.
By Nan Li from the School of Environmental Science and Engineering
Editor: Eva Yin
