Research progress of nanoscale zero-valent iron in synergistic combinations of denitrifying bacteria for nitrate removal

Abstract:

Nitrate (NO₃^–-N) is a common inorganic nitrogen pollutant in water. Excessive NO₃^–-N can lead to water eutrophication and threaten human health. Nanoscale zero-valent iron (nZVI) has attracted much attention in NO₃^–-N removal due to its high specific surface and excellent electron donor properties. The combination of nZVI and denitrifying bacteria (DNB) demonstrates high efficiency in converting NO₃^–-N into N₂. This approach not only substantially enhances the removal rate of NO₃^–-N but also exhibits superior environmental sustainability compared with conventional chemical denitrification methods. Accordingly, it holds substantial promise for mitigating NO₃^–-N pollution and warrants further exploration in the pollution control. Therefore, it is necessary to understand the interaction mechanism between nZVI and DNB for NO₃^–-N removal. This paper details the factors affecting the removal of NO₃^–-N by nZVI combined with DNB, reviews the latest research progress in this field, elaborates on the interaction mechanism between nZVI and DNB for NO₃^–-N removal, and discusses the challenges and future research directions of NO₃^–-N removal by nZVI combined with DNB. This review aims to provide a theoretical basis for the development of efficient approaches for the remediation of NO₃^–-N pollution.