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.

scholarly journals Phosphorus Inactivation in Lake Sediments Using Calcite Materials and Controlled Resuspension—Mechanism and Efficiency

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 223
Author(s):  
Agnieszka Bańkowska-Sobczak ◽  
Aurelia Blazejczyk ◽  
Elisabeth Eiche ◽  
Uwe Fischer ◽  
Zbigniew Popek
Keyword(s):  
Adsorption Capacity ◽  
Soluble Reactive Phosphorus ◽  
High Dose ◽  
Eutrophic Lakes ◽  
Precipitated Calcium Carbonate ◽  
Anoxic Conditions ◽  
P Fraction ◽  
Reactive Phosphorus ◽  
High Doses

The efficiency and mechanism of orthophosphate—soluble reactive phosphorus (SRP)—inactivation in eutrophic lakes using controlled resuspension and calcite application into the sediment were investigated in this study. Two calcite materials, industrially produced precipitated calcium carbonate (PCC) and natural ground limestone (GCC), were tested in short-term batch experiments and long-term sediment incubations under oxic and anoxic conditions. Maximum SRP adsorption capacity calculated using Langmuir model for PCC (3.11 mg PO43− g−1) was 6 times higher than of GCC (0.43 mg PO43− g−1), reflecting substantial difference in the surface area of calcite materials (12.36 and 1.72 m2 g−1, respectively). PCC applied into the sediment during controlled resuspension reduced SRP release by 95% (oxic) and 78% (anoxic incubation) at medium dose (0.75 kg m−2) and suppressed it completely at high dose (1.5 kg m−2) for at least 3 months, irrespectively of incubation conditions. The maximum achieved reduction of SRP release using GCC was also meaningful: 78% under oxic and 56% under anoxic conditions, but this required very high doses of this material (6 kg m−2). Mechanisms of SRP inactivation by calcites were: (1) adsorption of SRP during application into the resuspended sediment and (2) precipitation of calcium-phosphate compounds (Ca-PO4) during subsequent incubation, which was reflected in a substantial increase in the HCl-P fraction (phosphorus extractable in 0.5 M HCl) in sediments enriched with calcite, irrespectively of oxygen presence. However, anoxia strongly promoted the formation of this fraction: the rise of HCl-P was 2–6 times higher in anoxic than in oxic conditions, depending on the dose and form of calcite applied. The results showed that SRP inactivation using the controlled resuspension method is only successful if highly efficient reactive materials are used, due to large amount of SRP being released from sediment during resuspension. Thus, calcite materials exhibiting high adsorption capacity should be used in this lakes’ restoration technology to ensure fast and sufficient SRP inactivation. The rise in the HCl-P fraction in sediment suggests SRP inactivation through precipitation of relatively stable Ca-PO4 minerals, which makes calcite a suitable agent for sustainable, long term SRP inactivation. As anoxic conditions promoted formation of these compounds, calcite seems to be a promising SRP inactivation agent in highly reductive sediments.

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.

Nutrient excretion by crustacean zooplankton in the deep chlorophyll layer of Lake Superior

2015 ◽  
Vol 72 (3) ◽  
pp. 390-399 ◽  
Author(s):  
Samantha K. Oliver ◽  
Donn K. Branstrator ◽  
Thomas R. Hrabik ◽  
Stephanie J. Guildford ◽  
Robert E. Hecky
Keyword(s):  
Cold Water ◽  
Lake Superior ◽  
Soluble Reactive Phosphorus ◽  
Zooplankton Community ◽  
Crustacean Zooplankton ◽  
Nutrient Excretion ◽  
Mysis Diluviana ◽  
Incubation Experiments ◽  
Limnocalanus Macrurus ◽  
Reactive Phosphorus

We hypothesized that the resident and migrating cold-water zooplankton in Lake Superior concentrate beneath the thermocline and elevate nutrient availability via mineralization in the deep chlorophyll layer (DCL). In August 2010 and 2011, diel vertical net tows and incubation experiments were conducted in the western arm of Lake Superior to measure zooplankton distribution and excretion of dissolved nutrients. Limnocalanus macrurus showed the strongest spatial overlap with the DCL, and the broader crustacean community excreted P at 0.145 μg·mg−1·h−1 and N at 0.617 μg·mg−1·h−1 as soluble reactive phosphorus (SRP) and ammonia, respectively. Mysis diluviana displayed strong diel vertical migration into the DCL and excreted P at 0.013 μg·mg−1·h−1 and N at 0.116 μg·mg−1·h−1 as SRP and ammonia, respectively. Based on primary productivity estimates, the zooplankton community has the potential to meet the daily phosphorus demand by phytoplankton in the DCL during late-season stratification. Our excretion estimates indicate a possible coupling between the cold-water zooplankton community and production in the DCL of Lake Superior.

Effects of Large-Scale Metalimnetic Migration Events on Phosphorus Dynamics In a North-Temperate Reservoir

1990 ◽  
Vol 47 (1) ◽  
pp. 156-162 ◽  
Author(s):  
William F. James ◽  
Robert H. Kennedy ◽  
Robert F. Gaugush
Keyword(s):  
Total Phosphorus ◽  
Large Scale ◽  
Soluble Reactive Phosphorus ◽  
Phosphorus Loading ◽  
Sediment Surface ◽  
Anoxic Water ◽  
Oxidized Iron ◽  
Phosphorus Sedimentation ◽  
Reactive Phosphorus ◽  
Large Wind

In Eau Galle Reservoir, Wisconsin, early in the stratified period of 1982, hypolimnetic anoxia developed, soluble reactive phosphorus concentrations increased above the profundal sediment surface, and internal total phosphorus loading was high. Shortly thereafter, the passage of a cold front with high wind power resulted in mixing and a pronounced descent of the metalimnion. During this event, previously anoxic water within the metalimnion and upper hypolimnion became reoxygenated, internal total phosphorus loading declined to a minimum, and a loss of total phosphorus mass occurred from the metalimnion and hypolimnion. Total phosphorus mass in the epilimnion remained constant during this period. A similar pattern occurred during a large, wind-driven migration of the metalimnion in early August. During such events, phosphorus sedimentation rates increased in the hypolimnion, reflecting the loss of total phosphorus mass from the water column. In contrast, other investigations of lakes have reported that phosphorus is entrained into the epilimnion during metalimnetic migrations, rather than lost through sedimentation. Phosphorus sedimentation during large metalimnetic migration events in Eau Galle Reservoir may occur because previously anoxic water containing iron becomes reoxygenated, causing the coprecipitation and sedimentation of oxidized iron and phosphorus.

scholarly journals Under-ice mesocosms reveal the primacy of light but the importance of zooplankton in winter phytoplankton dynamics

2019 ◽  
Author(s):  
Allison R. Hrycik ◽  
Jason D. Stockwell
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Food Webs ◽  
Soluble Reactive Phosphorus ◽  
Open Water ◽  
Light Environment ◽  
Zooplankton Grazing ◽  
Ice Dynamics ◽  
Reactive Phosphorus

AbstractFactors that regulate planktonic communities under lake ice may be vastly different than the open-water season. However, under-ice food webs in temperate lakes are poorly understood, despite expected changes in light availability, ice cover, and snowfall associated with climate change. We hypothesized that light limitation (bottom-up control) outweighs zooplankton grazing (top-down control) on phytoplankton biovolume and community structure under ice in a north temperate lake. Using in situ under-ice mesocosms, we found that light had stronger effects on phytoplankton abundance than zooplankton, as expected. Specifically, low light limited growth of diatoms, cryptophytes, chrysophytes, and chlorophytes. Zooplankton, however, also significantly affected phytoplankton by decreasing diatoms and cryptophytes, in contrast to the common assumption that zooplankton grazing has negligible effects under ice. Ammonia and soluble reactive phosphorus decreased in high light treatments presumably through uptake by phytoplankton, whereas ammonia and soluble reactive phosphorus increased in high zooplankton treatments, likely through excretion. In situ experimental studies are commonly applied to understand food web dynamics in open-water conditions, but are extremely rare under ice. Our results suggest that changes in the light environment under ice have significant, rapid effects on phytoplankton growth and community structure and that zooplankton may play a more active role in winter food webs than previously thought. Changes in snow and ice dynamics associated with climate change may alter the light environment in ice-covered systems and significantly influence community structure.

scholarly journals Effects of Lanthanum Modified Bentonite and Polyaluminium Chloride on the Environmental Variables in the Water and Sediment Phosphorus Form in Lake Yanglan, China

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1947
Author(s):  
Ling Su ◽  
Chen Zhong ◽  
Lei Gan ◽  
Xiaolin He ◽  
Jinlei Yu ◽  
...  
Keyword(s):  
Suspended Solids ◽  
Soluble Reactive Phosphorus ◽  
Particulate Phosphorus ◽  
Modified Bentonite ◽  
Combined Application ◽  
Water And Sediment ◽  
Phosphorus Form ◽  
Labile P ◽  
Reactive Phosphorus ◽  
Polyaluminium Chloride

The application of lanthanum modified bentonite (Phoslock®) and polyaluminium chloride (PAC) is popular in the restoration of European temperate lakes; however, the effects of the application on the concentrations of phosphorus (P) in both the water and the sediments have been poorly evaluated to date. We studied the effects of the application of Phoslock® + PAC on the concentrations of total phosphorus (TP), particulate phosphorus (PP), soluble reactive phosphorus (SRP), total suspended solids (TSS) and chlorophyll a (Chla) in the water, and different P forms in the sediments, in an isolated part of Lake Yanglan. The results showed that the concentrations of TP, PP, SRP, TSS and Chla decreased significantly after the addition of Phoslock® + PAC. Moreover, the concentrations of labile-P, reductant-soluble-P and organic-P in the sediments were also significantly decreased after the Phoslock® + PAC application. However, the concentrations of both the stable apatite-P and residual-P in the sediments after application of Phoslock® + PAC were much higher than the pre-addition values, while the concentrations of metal-oxide-P did not differ significantly between the pre- and post- application conditions. Our findings imply that the combined application of Phoslock® and PAC can be used in the restoration of subtropical shallow lakes, to reduce the concentrations of P in the water and suppress the release of P from the sediments.

scholarly journals Seasonal Variations of Phosphorus Species in the Overlying and Pore Waters of the Tuohe River, China

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Qing Xu ◽  
Xiaoping Yu ◽  
Yafei Guo ◽  
Tianlong Deng ◽  
Yu-Wei Chen ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Yangtze River ◽  
Algal Bloom ◽  
Soluble Reactive Phosphorus ◽  
Pore Waters ◽  
Phosphorus Species ◽  
Dissolved Phosphorus ◽  
Vertical Distributions ◽  
Reactive Phosphorus ◽  
Main Factor

Overlying sediment and pore waters were collected in summer and winter at upstream (Jintang) and downstream (Neijiang) sites of the Tuohe River, which is one of the five largest tributaries of the Yangtze River in China. Phosphorus species, including soluble reactive phosphorus (SRP), soluble unreactive phosphorus (SUP), and total dissolved phosphorus (TDP), and some diagenetic constituents including dissolved Fe(II), Mn(II), and sulfide in overlying and pore waters, were measured systematically. The seasonal variations and vertical distributions of phosphorus species in overlying and pore waters at both sampling sites were obtained to elucidate some aspects of the transport and transformations of phosphorus. Based on the profiles of pore and overlying waters as well as the TDN/TDP data during an algal bloom in 2007, it was clearly demonstrated that phosphorus was the main factor limiting the phytoplankton growth in the Tuohe River.

Impact of hydro-sedimentary processes on the dynamics of soluble reactive phosphorus in the Seine River

2014 ◽  
Vol 122 (2-3) ◽  
pp. 229-251 ◽  
Author(s):  
Lauriane Vilmin ◽  
Najla Aissa-Grouz ◽  
Josette Garnier ◽  
Gilles Billen ◽  
Jean-Marie Mouchel ◽  
...  
Keyword(s):  
Soluble Reactive Phosphorus ◽  
Sedimentary Processes ◽  
Seine River ◽  
Reactive Phosphorus
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