scholarly journals Migration mechanism of biogenic elements and their quantification on the sediment-water interface of Lake Taihu:Ⅱ. chemical thermodynamic mechanism of phosphorus release and its source-sink transition

2006 ◽  
Vol 18 (3) ◽  
pp. 207-217 ◽  
Author(s):  
FAN Chengxin ◽  
◽  
ZHANG Lu ◽  
BAO Xianming ◽  
YOU Bensheng ◽  
...  
Keyword(s):  
Phosphorus Release ◽  
Biogenic Elements ◽  
Water Interface ◽  
Chemical Thermodynamic ◽  
Migration Mechanism ◽  
Thermodynamic Mechanism ◽  
Source Sink

scholarly journals Hydrodynamic disturbance on phosphorus release across the sediment–water interface in Xuanwu Lake, China

2018 ◽  
Vol 19 (3) ◽  
pp. 735-742 ◽  
Author(s):  
Yu Bai ◽  
Yuhong Zeng ◽  
Bei Nie ◽  
Helong Jiang ◽  
Xiaofeng Zhang
Keyword(s):  
Lattice Boltzmann ◽  
Shear Velocity ◽  
Phosphorus Release ◽  
Water Interface ◽  
Hydrodynamic Conditions ◽  
Overlying Water ◽  
Important Index ◽  
Hydrodynamic Disturbance ◽  
Predicted Values ◽  
Boltzmann Method

Abstract Excess phosphorus in lakes may cause algal blooming, and total phosphorus (TP) is an important index for lake eutrophication. As an important source of TP, lake sediment contributes a lot to TP release. TP release across the sediment–water interface varies with the hydrodynamic conditions of the overlying water, and in this paper the release characteristics of TP under hydrodynamic disturbance has been investigated. The sediment samples from Xuanwu Lake are collected and their release characteristics of TP under varying shear velocity are simulated in laboratory apparatus. Results show that increasing shear velocity contributes to the release of TP from sediment and the combination of varying shear velocity in different stages has a significant influence on the distribution of TP concentration. Further, the lattice Boltzmann method (LBM) is used to simulate the process of TP release from the sediment–water interface and the predicted values agree well with the measured data, which proves that the LBM can be used in simulating the process of TP release from sediment.

Seasonality in phosphorus release rates from the sediments of a hypereutrophic lake under a matrix of pH and redox conditions

2000 ◽  
Vol 57 (5) ◽  
pp. 1033-1041 ◽  
Author(s):  
Michael R Penn ◽  
Martin T Auer ◽  
Susan M Doerr ◽  
Charles T Driscoll ◽  
Carol M Brooks ◽  
...  
Keyword(s):  
Average Rate ◽  
Sediment Cores ◽  
Redox Status ◽  
Phosphorus Release ◽  
Water Interface ◽  
Concentration Gradients ◽  
Release Rates ◽  
Release Process ◽  
P Release

Phosphorus release rates were measured on intact sediment cores collected from the major depositional basin of Onondaga Lake, a dimictic, calcareous, hypereutrophic system in Syracuse, N.Y., U.S.A. Release experiments were conducted under a matrix of redox and pH conditions to investigate the importance of Ca- and Fe-related physicochemistry on sediment cores collected seasonally, i.e., during the spring, summer, fall, and winter periods. Strong seasonal variation in P release was observed, with rates ranging from ~3 to 38 mg P·m-2·day-1. This variation is attributed to changes in redox status and P concentration gradients at the sediment-water interface. An oxidized microlayer at the sediment-water interface partially inhibits sediment P release under isothermal, well-mixed conditions in the spring and fall. Phosphorus trapped in the oxic microlayer (sorption) is freed when the microlayer is chemically reduced at the onset of anoxia and high P release rates are observed. The oxidized microlayer serves to regulate seasonality in rates of sediment P release but does not influence long-term sediment-water exchange. It is proposed that the long-term P release process is best represented by a time-weighted annual average rate, calculated here to be ~10 mg P·m-2·day-1.

Nitrate applications to control phosphorus release from sediments of a shallow eutrophic estuary: an experimental evaluation

1998 ◽  
Vol 49 (6) ◽  
pp. 463 ◽  
Author(s):  
T. F. McAuliffe ◽  
R. J. Lukatelich ◽  
A. J. McComb ◽  
S. Qiu
Keyword(s):  
Dissolved Oxygen ◽  
Water Column ◽  
Oxygen Demand ◽  
Phosphorus Release ◽  
Carbon Limitation ◽  
Water Interface ◽  
Phosphate Release ◽  
Soluble Reactive Phosphate ◽  
Reactive Phosphate ◽  
Nitrate Consumption

Effects of nitrate on phosphate release from sediments of a eutrophic estuary were investigated under laboratory conditions, using reconstituted sediment–water cores. Application of nitrate (5–100 mg L-1 NO3-N) increased redox potential near the sediment–water interface from –200 mV to about 200 mV during 25 days of incubation. The effective concentration of nitrate differed between sediments, reflecting differences in sediment properties, particularly bioavailable carbon. Reduced phosphate after nitrate application is attributed mainly to: (1) increased iron (III) binding near the sediment–water interface; and (2) increased dissolved oxygen in the water column due to lowered oxygen demand, with increased oxidation of ferrous iron and substances binding soluble reactive phosphate. High nitrate concentrations (50 and 100 mg L-1 NO3-N) did not persist through a 155-day incubation, suggesting that without carbon limitation added nitrate will eventually be consumed by microbial activity, and increased phosphate release may occur. Nitrate application directly into the surface sediment increased nitrate consumption, and so was less effective than application to the water column. Frequent resuspension increased dissolved oxygen concentration, so reduced nitrate consumption and lowered concentration of soluble reactive phosphate.

Estimation of Nitrogen and Phosphorus Release Rates at Sediment-Water Interface of Nansi Lake, China

2012 ◽  
Vol 573-574 ◽  
pp. 573-577
Author(s):  
Bao Li ◽  
Zhi Qi Wang
Keyword(s):  
Water Body ◽  
Lake Restoration ◽  
Sediment Cores ◽  
Sampling Period ◽  
Phosphorus Release ◽  
Water Interface ◽  
Nansi Lake ◽  
Release Rates ◽  
Nitrogen And Phosphorus ◽  
Overlying Water

At present, Nansi Lake restoration is maily focused on reducing extraneous pollution, however, it is unclear about the endogenous pollution. In this study, twelve intact sediment cores were collected from four sub-lakes (Nanyang Lake, Dushan Lake, Zhaoyang Lake and Weishan Lake) in Nansi Lake, and the fluxes of NH4+-N, PO43--P, NO3--N, TN and TP at sediment-water interface were calculated based on static incubation of sediment cores with a laboratory-scale benthic chamber. The incubation results showed fluxes of PO43--P, NO3--N, TN and TP in Nanyang Lake were the highest and as follows: 2.73, 7.55, 44.43 and 3.06 mg/m2.d, respectivly, and the flux of NH4+-N in Nanyang Lake, Dushan Lake and Zhaoyang Lake had little difference ranged from 8.99 to 10.19 mg/m2.d. This study indicated that during the sampling period sediment acted as a source of nitrogen as well as phosphorus to the overlying water body in Nansi Lake.

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