Abstract

Low-carbon and high-efficiency processes for achieving simultaneous nitrogen removal and phosphorus recovery from wastewater are gaining increasing attention from researchers. This study investigated the performance and mechanism of a novel Fe(II)-mediated anaerobic ammonia oxidation (anammox) process characterized by stable nitrogen removal and production of high-value Fe–P crystals (FePs) as byproducts. Fe(II) promotes the synthesis of heme C and enhances the activity of nitrate reduction metabolic genes, which induce nitrate-dependent ferrous oxidation to form a complex Fe–N cycle. In addition, Fe(II) significantly enhanced the phosphorus removal efficiency up to 79.2 ± 6.9% by inducing Fe–P biomineralization. Biomolecular analysis has shown that most iron absorption and transport genes, as well as phosphate transport and regulation genes, are promoted by Fe(II). The composition and microstructure analyses of the anammox granules revealed the formation of FePs that consisted of phosphosiderite (FePO4·2H2O), ludlamite (Fe3(PO4)2·4H2O), and vivianite (Fe3(PO4)2∙8H2O). This study also provides an in-depth illustration of the structural characteristics and formation processes of anammox-FePs granules. Thus, an Fe(II)-induced Fe–N–P metabolic network in an anammox-dominated system was uncovered, offering a feasible approach for simultaneous nitrogen removal and phosphorus recovery.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.