Assessment of sediment and porewater after one year of subaqueous capping of contaminated sediments in Hamilton Harbour, Canada

1998 ◽  
Vol 37 (6-7) ◽  
pp. 323-329 ◽  
Author(s):  
José M. Azcue ◽  
Alex J. Zeman ◽  
Alena Mudroch ◽  
Fernando Rosa ◽  
Tim Patterson
Keyword(s):  
Soluble Reactive Phosphorus ◽  
Coarse Sand ◽  
Contaminated Sediments ◽  
Overlying Water ◽  
Hamilton Harbour ◽  
Vertical Fluxes ◽  
Reactive Phosphorus ◽  
One Year ◽  
In Situ Capping

In this manuscript, we present data from a demonstration in situ capping site (100 m × 100 m) in Hamilton Harbour, Lake Ontario, Canada. A layer of clean medium to coarse sand with the average thickness of 35 cm was placed at the site in the summer of 1995. Concentration of Zn, Cr, and Cd in the original sediments reached values over 6000, 300 and 15 μg/g, respectively. The predicted consolidation of the uppermost one meter of sediment was about 14 cm, which was in good agreement with values obtained from comparisons of moisture content values of pre-capping and post-capping cores. A thin layer of fresh moderately contaminated sediments has started to develop on the top of the cap. In general, the concentrations of elements were greater in porewater than in the overlying water, e.g., the concentration of Fe and soluble reactive phosphorus were 1000 times, and those of Mn 100 times greater. There was a significant reduction in the vertical fluxes of all the trace elements after the capping of the contaminated sediments.

Hypolimnetic Aeration: An Overview

1986 ◽  
Vol 21 (2) ◽  
pp. 205-217 ◽  
Author(s):  
D.J. McQueen ◽  
D.R.S. Lean
Keyword(s):  
Ammonia Volatilization ◽  
Cold Water ◽  
Soluble Reactive Phosphorus ◽  
Eutrophic Lakes ◽  
Hypolimnetic Oxygen ◽  
Dissolved Hydrogen ◽  
Phosphorus Sedimentation ◽  
Reactive Phosphorus ◽  
Maximum Removal

Abstract Hypolimnetic aerators are now being widely used throughout Europe and are beginning to appear in small and medium sized eutrophic lakes in temperate North America. This activity has produced approximately 42 published reports dealing with experiments conducted at 16 lakes. Taken together, the evidence from these experiments suggests that well designed aerators do not cause significant destratification or warming of hypolimnetic water, but do result in measurable Increases in hypolimnetic oxygen concentration and decreases in dissolved hydrogen sulfide, methane and ammonia. Early experiments suggested that phosphorus sedimentation was unpredictable, but recent work has demonstrated that when the ratio of total iron to soluble reactive phosphorus exceeds 10:1 and pH is < 7.5, phosphorus sedimentation is assured and internal loading greatly reduced. Early experiments also showed that ammonia volatilization was unpredictable, but at pH > 8.0, ammonia volatilization will occur. Because both phosphorus sedimentation and nitrogen reduction are pH dependent, both cannot be optimally removed during the same period of time and so the experimenter is advised to select for the maximum removal of one or the other through pH manipulation. Hypolimnetic aeration induces oxygen consumption and this must be considered when choosing an appropriate compressor size. Most studies show little impact on phytoplankton blomass, but one recent experiment showed that aeration during spring turnover resulted in reduced concentrations of chlorophyll a and TP. Zooplankton populations are, for the most part, unaffected and a number of American studies have shown that hypolimnetically aerated lakes can support cold water fish populations. The aggregate practical and experimental experience suggests that well designed hypolimnetic aeration systems yield measurable improvements in water quality and will almost certainly prove to be one of the major methods used for future in situ lake restoration.

Spatial and Temporal Evolution of Biogeochemical Processes Following In Situ Capping of Contaminated Sediments

2008 ◽  
Vol 42 (11) ◽  
pp. 4113-4120 ◽  
Author(s):  
David W. Himmelheber ◽  
Martial Taillefert ◽  
Kurt D. Pennell ◽  
Joseph B. Hughes
Keyword(s):  
Temporal Evolution ◽  
Contaminated Sediments ◽  
Biogeochemical Processes ◽  
In Situ Capping

Adsorption-Desorption of Phosphate on Hohhot Dust in Yellow River Water

2013 ◽  
Vol 807-809 ◽  
pp. 219-222
Author(s):  
Xiao Li Wang ◽  
Hui Juan Wang
Keyword(s):  
River Water ◽  
Yellow River ◽  
Soluble Reactive Phosphorus ◽  
Phosphorus Concentration ◽  
Overlying Water ◽  
P Adsorption ◽  
Isotherm Equation ◽  
Langmuir Isotherm Equation ◽  
Reactive Phosphorus ◽  
Adsorption Desorption

The Equilibrium Phosphorus Concentration (EPC0) of Hohhot dust (HD) of Inner mongolia was measured to examine whether the HD acted as sources or sinks of soluble reactive phosphorus (SRP) to the Yellow River water column. The modified Langmuir isotherm equation was modified to describe phosphorus (P) adsorption on the HD in Yellow River water. The EPC0 was higher than P concentration in the overlying water, which indicates that the HD acted as sources of phosphate. In addition, solid concentration (Cs) effect existed obviously in P adsorption experiment and the hysteresis got bigger as Cs increased.

Submerged macrophyte Ceratophyllum demersum affects phosphorus exchange at the sediment–water interface

2015 ◽  
Vol 71 (6) ◽  
pp. 913-921 ◽  
Author(s):  
Yanran Dai ◽  
Shuiping Cheng ◽  
Wei Liang ◽  
Zhenbin Wu
Keyword(s):  
Submerged Macrophytes ◽  
Soluble Reactive Phosphorus ◽  
Mean Value ◽  
Submerged Macrophyte ◽  
Ceratophyllum Demersum ◽  
Phosphorus Concentration ◽  
Water Interface ◽  
Adsorption Parameters ◽  
Overlying Water ◽  
Reactive Phosphorus

Substantial research efforts were made to assess the effects of submerged macrophytes on water quality improvement, but information on the mechanism of submerged macrophytes relative to the exchange of phosphorus (P) at the sediment–water interface is very limited. To help fill the void, a popular species, Ceratophyllum demersum L. was chosen to address the effects and mechanisms of submerged macrophyte growth on the processes of P exchange across the sediment­–water interface. In treatment mesocosms (planted), equilibrium phosphorus concentration (EPC0) value falls from 68.4 to 36.0 µg/L, with a mean value of 52.5 µg/L. Conversely, the distribution coefficient (Kd) value has a predominantly increasing trend. But they are both significantly higher than an unplanted control (p < 0.05). Also, in the planted mesocosm, maximum phosphate sorption capacity (Qmax) was significantly reduced (4,721–3,845 mg/kg), and most of the linear correlations between different forms of phosphorus and sediment P adsorption parameters were affected (p < 0.05). The EPC0 Percentage Saturation percentages (EPCsat) in planted groups were 325% higher than that in control (p < 0.05). We conclude that C. demersum could promote the release of P from sediments, and soluble reactive phosphorus concentration in overlying water is probably the driving force for P exchange at the sediment–water interface.

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