Dissimilatory nitrate reduction to ammonium (DNRA) potentially facilitates the accumulation of phosphorus in lake water from sediment. (September 2022)

• Record Type: Journal Article
• Authors: Yuan, Hezhong; Jia, Bingchan; Zeng, Qingfei; Zhou, Yanwen; Wu, Juan; Wang, Haixiang; Fang, Hao; Cai, Yiwei; Li, Qiang
• Is Part Of: Chemosphere. Volume 303:Part 1(2022)
• Publication Date: 2022-09
• Subjects: Dissimilatory nitrate reduction to ammonium (DNRA) -- nrfA -- Peeper -- DGT -- Phosphorus (P) diffusion -- Sediment; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.134664
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Nitrogen (N) and phosphorus (P) are crucial nutrients for eutrophication in the lacustrine ecosystem and attract the attention worldwide. However, the interaction between them need further clarification. This study aimed to assess the influence of dissimilatory nitrate reduction to ammonia (DNRA) on the cycle of P in lacustrine sediment. Different fractions of N and P in the pore water were measured using high-resolution in-situ measurement techniques, HR-Peeper and DGT, coupling with sequential extraction for solid sediment from a shallow freshwater lake. The results showed that elevated nitrate (NO3 − ) reduction via DNRA rather than denitrification was verified at deeper sediment layer, suggesting the generation of inorganic ammonia (NH4 + ) as electron donor under anaerobic episodes. High abundance of DNRA bacteria (nrfA gene) obtained using high-throughput sequencing analysis were detected at upper layer and responsible for the accumulation of NH4 + in the sediment coupling with chemolithoautotrophic metabolism. Additionally, significant desorption of ionic ferrous iron (Fe 2+ ) and dissolved reactive phosphate (DRP) from solid phase and the enrichment in the solution was simultaneously detected. Higher concentration of solid Fe bound P (Fe–P) at deeper layer indicated the potential re-oxidation of Fe 2+ as electron donor during DNRA process and sorption of DRP toward the Fe-containing minerals. However, obvious evidence of desorption proved by DGT indicated that higher NH4 + concentrations favored the reduction of Fe(III) oxy(hydr)oxides and the desorption of DRP into the pore water and diffusion toward the overlying water. Finally, noteworthy S 2− release from solid sediment was speculated to stimulate the DNRA and facilitated the accumulation of NH4 + in the solution, which further induced the enrichment of DRP in water from the solid phase. Overall, DNRA potentially facilitates the accumulation of P in lake water, and the synchronous control of N and P is important for the eutrophication management and restoration of lake eutrophication. Graphical abstract: Image 1 Highlights: NH4 + concentrations elevated due to DNRA pathways of NO3 − reduction under anaerobic conditions. Chemolithoautotrophic metabolism of DNRA bacteria dominated the release of P in the sediment. Accumulation of Fe 2+ linked to P desorption stimulated the DNRA process as electron donor. Control of DNRA process in the lake was important for the management of P-limited lakes.