How do inundation provoke the release of phosphorus in soil-originated sediment due to nitrogen reduction after reclaiming lake from polder

May 31, 2022

CRAES, Nanjing University of Information Science and Technology uses EasySensor DGT to publish the article as below:

Abstract

Different N and P fractions in microcosm incubation experiment was measured using high-resolution in-situ Peeper and DGT techniques combining with sequential extraction procedure. The results showed the synchronous desorption and release of PO43-, S2- and Fe2+ from the solid soil-originated sediment. This trend indicated that the significant reduction of Fe-P and SO42- occurred in the pore water during the inundation. The concentrations of PO43- in the overlying water and pore water increased to more than 0.1 and 0.2 mg/L at the beginning of the incubation experiment. Decreased NO3concentrations from more than 1.5 mg/L to less than 0.5 mg/L combining with increasing NH4+ concentrations from less than 1 mg/L to more than 5 mg/L suggested the remarkable NO3 reduction via dissimilatory nitrate reduction to ammonia (DNRA) pathway over time. High NH4+ concentrations in the pore water aggravated the release of Fe2+ through reduction of Fe(III)-P as electric acceptors under anaerobic conditions. This process further stimulated the remarkable releasing of labile PO43- from the solid phase to the solution and potential diffusion into overlying water. Additionally, high S2- concentration at deeper layer indicated the reduction and releasing of S2- from oxidation states, which can stimulated the NO3 reduction and the accumulation of NH4+ in the pore water. This process can also provoke the reduction of Fe-P as electric acceptors following the release of labile PO43- into pore water. Generally, inundation potentially facilitate the desorption of labile P and attention should be paid during the reclaiming lake from polder.

Writers:Yuan HZ, Jia BC, Wu J., 2022. How do inundation provoke the release of phosphorus in soil-originated sediment due to nitrogen reduction after reclaiming lake from polder, Journal of Environmental Sciences, Volume 118, Pages 147-157, ISSN 1001-0742, https://doi.org/10.1016/j.jes.2022.01.002.

Link:https://www.sciencedirect.com/science/article/abs/pii/S1001074222000031?via%3Dihub