Riverine flux of dissolved phosphorus to the coastal sea may be overestimated, especially in estuaries of gated rivers: Implications of phosphorus adsorption/desorption on suspended sediments

Chemosphere ◽  
2022 ◽  
Vol 287 ◽  
pp. 132206
Author(s):  
Shiyu Wang ◽  
Rolf D. Vogt ◽  
Jacob Carstensen ◽  
Yan Lin ◽  
Jianfeng Feng ◽  
...  
2012 ◽  
Vol 599 ◽  
pp. 669-672 ◽  
Author(s):  
Qiu Lin Ouyang ◽  
Gui Qing Gao ◽  
Su Su Liu ◽  
Xiao Ling Shi ◽  
Hai Yan Ju

Based on isothermal adsorption experiment and adsorption/desorption kinetic experiment,the adsorption and desorption characteristics of suspended sediments in Ganjiang River to phophorus was studied.The results show the phosphorus adsorption of sediment reaches balance basically in 2~4h; the adsorption capacity is increased with the increment of the initial concentration of phosphorus,and decreased with the increment of sediment conentration. The isothermal adsorption of phosphorus by sediment can be fitted preferably by Langmuir and Freundlic model. The adsorption and desorption process can be fitted by Langmuir equation.The phosphorus desorption of sediment reaches balance basically in about 14h. The phosphorus desorption capacity of sediment is decreased with the increment of sediment concentration.


RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37441-37446 ◽  
Author(s):  
Qingzhi Wang ◽  
Jiankun Liu ◽  
Lingqing Wang

Freeze–thaw cycles (FTCs) can strongly influence the physical and chemical properties of soils in cold regions, which can in turn affect the adsorption–desorption characteristics of phosphorus (P) in the soil.


2014 ◽  
Vol 535 ◽  
pp. 293-297
Author(s):  
Wen Jun Yang ◽  
Jian Li ◽  
Zhong Wu Jin

These years the water quality deteriorated in Xiangxi River (XXR)---one tributary of Yangtze River in the Three Gorges Project reservoir area. Many components existed in XXR such as nutrients, suspended sediment (SS) and phytoplankton. The nutrients containing phosphorus could be adsorbed to the fine SS, which influenced the water quality components cycling obviously. For calculating the concentrations of different forms of phosphates (mainly the dissolved phosphate and particulate phosphate) more precisely, the formula was deduced based on the Langmuir equation and modified Langmuir equation. Then the field observed data were used to validate the deduced formula, which showed that the deduced formula can calculate the concentrations well. The formula could be applied for the water quality or ecological modeling, and also provide more information for water quality improvement. Keywords: Suspended sediment; Phosphorus; Adsorption-desorption; Xiangxi River


2020 ◽  
Vol 15 (No. 4) ◽  
pp. 220-227
Author(s):  
Jinquan Zhang ◽  
Weiguo Fu

In the initial stage of the rainfall, the nutrient element phosphorus (P) in the farmland, one of the most important factors causing agricultural non-point source pollution, flows into agriculture drainage ditches rapidly, and an instantaneous phosphorus peak value in the ditch water often occurs. Aerated concrete with high P adsorption properties was chosen as the experiment material in the laboratory to reduce the instantaneous P peak value in the drainage water in the initial stage of the rainfall. The three total P (TP) concentrations of the simulated drainage water (1.0, 2.0, and 3.0 mg/L) stood for three treatments were designed in the adsorption experiment; the same three TP concentrations of the simulated drainage water and the three TP concentrations of the simulated natural water (0.2, 0.3, and 0.4 mg/L) stood for nine treatments in the desorption experiment. The sponge effect of the aerated concrete on the P adsorption-desorption was explored by studying the dynamics of the P adsorption-desorption of the aerated concrete with an increase in the experiment’s time. The results showed the following details: (1) Both the adsorption rate and desorption rate of the aerated concrete decrease with an increase in the experiment’s time. The initial adsorption is dominant during the entire adsorption, as with the initial desorption during the entire desorption. (2) The adsorption capacity of the aerated concrete slightly decreases with the increase in the re-adsorption, whereas the desorption capacity of the aerated concrete significantly decreases with the increase in the re-desorption. Thus, the aerated concrete can be introduced into the agricultural drainage ditch to reduce the instantaneous P peak value in the drainage water in the initial stage of the rainfall, and potential further studies should explore the relationship between the different drainage water loads and the amount of the aerated concrete.


2003 ◽  
Vol 54 (1) ◽  
pp. 87 ◽  
Author(s):  
Kane T. Aldridge ◽  
George G. Ganf

Freshwater macrophytes may increase sediment redox potential and the affinity of sediments for phosphorus through radial oxygen loss from their below-ground biomass. This study demonstrated that the ability to alter sediment redox potential differs between macrophytes, according to their capacity to transport oxygen. Of the emergent macrophytes, Typha domingensis increased sediment redox potential (218 mV above bare sediment) to a greater extent than Bolboschoenus caldwellii (41 mV above bare sediment). However, the inhibition of convective flow in T. domingensis reduced its oxidizing ability by 78 mV. In contrast, Potamogeton crispus, a submerged macrophyte, had no influence on sediment redox potential. The presence of T. domingensis also increased phosphorus uptake from the water column by 0.88 mg P m−2 day−1, above that of bare sediments. In addition, inundation predictably decreased sediment redox potential from 175 mV to −176 mV over a 42-day period. Similarly, the addition of cellulose (10 mg L−1) decreased sediment redox potential by 42 mV. Consequently, deposition of organic debris may counteract the oxidizing effects of macrophytes that have a limited capacity to transport oxygen, such as P. crispus. Results suggest that macrophytes play an important role in facilitating the restoration of freshwater systems.


2020 ◽  
Vol 24 (4) ◽  
pp. 2401-2410
Author(s):  
Ying Mei ◽  
Xiao-Han Zhu ◽  
Long Gao ◽  
Hang Zhou ◽  
Ya-Jun Xiang ◽  
...  

A bioretention medium has considerable influence on the removal of pollutants, especially phosphorus pollutants. In this paper, the phosphorus adsorption properties of three bioretention media (sand, iron powder, and aluminum powder) are studied, and the effects of pH and ionic strength on the phosphorus adsorption are analyzed. Results show that the phosphorus adsorption isotherm can be well modeled by the Langmuir equation. The experimental results show the monolayer adsorption capacity of sand is the highest, while the iron powder the lowest. The pH of the solution has a considerable influence on the phosphorus adsorption of sand and iron powder, but has a minimal effect on aluminum powder.


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