Effects of Sediment Chemical Properties on Phosphorus Release Rates in the Sediment-Water Interface of the Steppe Wetlands

Abstract

Rising temperature causes a process of phosphorus release, which can be characterized well using phosphorus release rates (VP). The objective of the present study was to investigate the major factors affecting sediment phosphorus release rates through a wetland habitat simulation experiment. The results showed that the VP of different wetland sediments were different and changed with the order of W–R (river wetland) > W–L (lake wetland) > W–M (grassy marsh wetland) > W–A (reservoir wetland). The main driving factors which influenced sediment phosphorus flux velocity in the sediment–water interface were sediment B-SO42−, B-MBN and A-MBP content. Path analysis and determination coefficient analysis indicated the standard multiple regression equation for sediment phosphorus release rates in the sediment–water interface, and each main factor was Y = −0.105 + 0.096X1 + 0.275X2 − 0.010X3 (r = 0.416, p < 0.01, n = 144), where Y is sediment phosphorus release rates; X1 is sediment B-SO42− content; X2 is sediment B-MBN; and X3 is sediment A-MBP content. Sediment B-SO42−, B-MBN and A-MBP content and the interaction between them were the main factors affecting sediment phosphorus release rates in the sediment–water interface. Therefore, these results suggest that soil chemical properties and microbial activities likely play an important role in phosphorus release rates in the sediment–water interface. We hope to provide effective scientific management and control methods for relevant environmental protection departments.

Internal phoshorus loading potential of a semiarid reservoir: an experimental study

“…The values of P release rates found in this study (0.22 -2.1 mg m -2 d -1 ) were lower than the P flux found in recent studies: in Jacarepaguá Lagoon, Brazil (2.5 -9.2 mg m -2 d -1 ) (Marinho et al, 2020); in two semiarid reservoirs, Brazil (4 and 10 mg m -2 d -1 ) (Moura et al, 2020); and lake Diefenbaker, Canada (15 -20 mg m -2 d -1 ) (Doig et al, 2017). However, the rates of this study were similar to the values found in hypereutrophic lakes in China, as Yangcheng (1.1 to 1.5 mg m -2 d -1 ) (Yang et al, 2020b) and Lake Chaohu (0.03 to 3.34 mg m -2 d -1 ) (Yang et al, 2020a); and higher than other environments also in China: wetlands sediments (0.002 to 0.014 mg m -2 d -1 ) (He et al, 2017) and Yangtze river (0.105 to 0.143 mg m -2 d -1 ) (Zhu et al, 2012). This variation in values of sediment release rates demonstrates how complex the internal loading process is, which can be the result of many variables: pollution level of environment (external loading), soil composition, water physicochemical parameters, sedimentation rates and other factors.…”

“…The removed water was replaced with filtered (Ø=0.6 µm) reservoir water (kept in incubators together with the microcosms). Based on the TP concentrations in the water per the day of analysis, it was possible to calculate the P flux from the sediment to the water, that is, the release rate of the P (Equation 1) (He et al, 2017).…”

Phosphorus migration from sediment to phosphorus-inactivating material: A key process neglected by common phosphorus immobilization assessments for lake geoengineering

“…Various types of P-inactivating materials have been developed ( Wu et al., 2022a ; Lin et al., 2019c ), but adsorption of soluble P by these materials is typically a rapid process ( Wang and Jiang, 2016 ). Sediment P release is mainly regulated by sediment properties and environmental conditions ( Wu et al., 2022b ; He et al., 2017 ). Therefore, the observed mechanisms, in which P immobilization efficiencies depend on the timeliness of sediment P release, could be common features of sediment P immobilization methods.…”