Overestimation of Orthophosphorus Concentrations in Surface Waters of Southern Lake Michigan: Effects of Acid and Ammonium Molybdate

1982 ◽  
Vol 39 (2) ◽  
pp. 296-304 ◽  
Author(s):  
Stephen J. Tarapchak ◽  
Sylvia M. Bigelow ◽  
Cora Rubitschun
Keyword(s):  
Surface Waters ◽  
Extraction Method ◽  
Time Course ◽  
Lake Michigan ◽  
Soluble Reactive Phosphorus ◽  
Particulate Material ◽  
Ammonium Molybdate ◽  
Molybdenum Blue ◽  
P Release ◽  
Reactive Phosphorus

Water from southern Lake Michigan was analyzed to determine if orthophosphorus (PO4-P) concentrations are overestimated by molybdenum blue methods and to assess the potential effects of ammonium molybdate on soluble reactive phosphorus (SRP) determinations. Time-course "hydrolysis" tests, based on the Chamberlain–Shapiro extraction method, showed that large amounts of PO4-P were released from bound sources into solution within seconds after acid molybdate was added, and that molybdate-reactive PO4-P could be retained by filters or released from particulate material into filtrates during filtration. PO4-P concentrations obtained by using the prescribed exposure of 30 s were overestimated minimally by up to 86%, and ammonium molybdate dramatically accelerated PO4-P release in filtered samples. Tests using up to a fourfold range in ammonium molybdate concentrations also showed that the extraction method and Harvey's method yielded SRP values that varied two- to three-fold or more, and that most of the PO4-P was released from "particles" in filtrates. Analytical methods, therefore, can yield substantially different SRP estimates because of differences in the length of time samples are exposed to acid molybdate and because of differences in molybdate concentrations.Key words: ammonium molybdate, hydrolysis, phosphorus, soluble reactive phosphorus, orthophosphorus

Silica and Phosphorus Flux from Sediments: Importance of Internal Recycling in Lake Michigan

1988 ◽  
Vol 45 (6) ◽  
pp. 1030-1035 ◽  
Author(s):  
Daniel J. Conley ◽  
Michael A. Quigley ◽  
Claire L. Schelske
Keyword(s):  
Lake Michigan ◽  
Water Mass ◽  
Sediment Cores ◽  
Soluble Reactive Phosphorus ◽  
Dissolved Silica ◽  
Sediment Fluxes ◽  
Species Succession ◽  
Reactive Phosphorus ◽  
Annual Primary Production ◽  
Total P

Estimated lake-wide sediment fluxes of silica and phosphorus (P) were determined and then compared with other components in the biogeochemical cycle to investigate the importance of sediment regeneration in Lake Michigan. Dissolved silica (Si) and soluble reactive phosphorus (SRP) fluxes from sediments were measured by the incubation of intact sediment cores. Estimated Si flux from sediments can supply 21% of the total mass of silica in the water annually and 26% of the Si used during annual diatom production. By contrast, estimated SRP flux from lake sediments can supply only 4.1% of the mass of total P in the water annually and <1% of the P utilized for annual primary production. Because the internal regeneration of P occurs rapidly in the water column, compared with the much slower regeneration of Si (0.8∙yr−1), P can be used many times during an annual cycle whereas Si is used only once. Thus, differences in the supply rates and in the biogeochemical recycling rates of Si and P can lead to seasonal Si depletion in the water mass and influence the outcome of seasonal phytoplankton species succession by limiting Si availability necessary for diatom production.

scholarly journals Sediment phosphorus fractionation and flux in a tropical shallow lake

2021 ◽  
Vol 33 ◽  
Author(s):  
Jéssica Papera ◽  
Fabiana Araújo ◽  
Vanessa Becker
Keyword(s):  
Shallow Lake ◽  
Organic Phosphorus ◽  
Soluble Reactive Phosphorus ◽  
Oxygen Depletion ◽  
Phosphorus Fractionation ◽  
P Fractions ◽  
P Release ◽  
Water And Sediment ◽  
Mobile Fraction ◽  
Reactive Phosphorus

Abstract: Aim The aim of the present study is to evaluate the potential phosphorus (P) release from the sediment to the water column of a tropical shallow lake in the northeast of Brazil, based on the sediment P fractions and on the flux of P between water and sediment. Methods We used a sequential extraction method to analyse the different P fractions of the sediment of Lake Extremoz. We also carried out a 40-day microcosm experiment to analyse the flux of P between water and sediment. We did so by flooding 200g of sediment from the lake with 800 mL of 1.2 µm filtered lake water in 1 L beakers. Every 5 days we analysed: soluble reactive phosphorus (SRP), total phosphorus (TP), organic phosphorus (Org-P), dissolved oxygen (DO), temperature, and pH of the water. Results The largest fraction of P in the sediment of Lake Extremoz is Refractory-P, which is non-mobile. The main mobile fraction of this lake’s sediment is composed of P bound to Fe and Mn oxides (BD-P) which is redox sensitive. During the P flux experiment, the water was always oxic and with nearly neutral pH, however the temperature increased by almost 4 °C due to the increase of the temperature of the air. SRP, TP and Org-P concentrations in the water had a general decrease in the first 20 days. But, on the second half of the experiment, those concentrations increased and the fluxes of P from sediment to water, mainly Org-P, were positive. Even with this increase in concentrations, indicating a period of P release, overall fluxes were negative. Conclusions The main mobile fraction of the sediment is redox sensitive, therefore it has the potential to be released in case of oxygen depletion. Under current conditions, most of the P released by the sediment is in organic forms, indicating that, in the presence of oxygen, the balance of P between water and sediment is controlled by the effects of organisms on P as well as temperature.

Phosphorus budget in the low-income, peri-urban area of Kibera in Nairobi (Kenya)

2009 ◽  
Vol 60 (10) ◽  
pp. 2669-2676 ◽  
Author(s):  
P. Kelderman ◽  
D. K. Koech ◽  
B. Gumbo ◽  
J. O'Keeffe
Keyword(s):  
Surface Waters ◽  
Low Income ◽  
Soluble Reactive Phosphorus ◽  
Pollution Levels ◽  
Consumption Values ◽  
Production And Consumption ◽  
Urine Separation ◽  
High Pollution ◽  
Reactive Phosphorus ◽  
P Budget

Kibera, located in Nairobi, Kenya is one of the largest (235,000 inhabitants) low-income areas in East Africa. Surface waters in Kibera show high pollution levels with respect to SRP (soluble reactive phosphorus; range: 2–10 mg P/L), coming from the uncontrolled wastewater discharges in the area. The different P production and consumption values in Kibera were estimated using interviews (155 interviewed) as well as detailed P house-keeping for five representative families. The results show that highest P consumption comes from food, in particular cereals. Highest P production came from urine (55% of the total) and faeces (31%), with relatively lower contributions from grey water and solid wastes. The overall P budget in Kibera amounted to around 9 × 103 kg P/month. This is equivalent to 0.47 g P/person yr, both for P production and consumption, with a relative error of 20%. Comparing with the estimated P outflows via the Kibera surface waters, around 65% of the P produced in Kibera will leave the area. In future ECOSAN techniques such as urine separation could well be applied for efficient recycling of these waste sources.

Major controls of base flow soluble reactive phosphorus losses in humid temperate headwater streams

2020 ◽  
Author(s):  
Michael Rode ◽  
Remi Dupas
Keyword(s):  
Land Use ◽  
Headwater Streams ◽  
Soluble Reactive Phosphorus ◽  
Low Flow ◽  
Temperate Climate ◽  
Redox Processes ◽  
Temperature Dependent ◽  
P Release ◽  
Reactive Phosphorus

&lt;p&gt;Long-term Soluble Reactive Phosphorus (SRP) monitoring in headwater streams in central Europe revealed a seasonal pattern of SRP concentrations during low flow periods, with highest concentrations in summer and lowest in winter. These seasonal concentration amplitudes often exceed the eutrophication threshold during the summer eutrophication-sensitive period. It is assumed that temperature dependent biogeochemical processes control the underlying P release mechanism, where redox processes may be responsible for this increase. Several studies have highlighted the crucial role of reactive zones such as riparian wetlands in controlling solute export regimes. Moreover especially in forest headwater streams, in-stream assimilatory uptake shows a distinct seasonal behaviour because of varying shading conditions. This can also lead to seasonal SRP amplitudes. Furthermore sorption and desorption processes are temperature dependent which may alter in-stream SRP release during the year.&lt;/p&gt;&lt;p&gt;Often SRP concentrations are higher in agricultural streams than in more pristine headwaters. It is not clear how land use (e.g. P status of soils) may impact the baseline SRP concentrations and which factors control the seasonal change in SRP stream concentration (riparian groundwater heads and redox processes, temperature, in-stream release and uptake processes). Therefore the objective of this study is to disentangle land use impacts from hydrological and biogeochemical controls of low flow SRP losses.&amp;#160; A comparative study on seasonal SRP concentration patterns will be presented comprising around 53 long term monitored headwater catchments in humid temperate climate of northern Europe and the United States. Based on hydrological and SRP headwater signals and catchment properties, P release processes are discussed. The results of the study will allow to target SRP mitigation strategies based on knowledge of the dominating control of SRP loss from headwater streams.&amp;#160;&lt;/p&gt;

A Comparison of Different Phosphorus Fractions as Predictors of Particulate Pigment Levels in Lake Memphremagog and its Tributaries

1982 ◽  
Vol 39 (5) ◽  
pp. 785-790 ◽  
Author(s):  
Robert Henry Peters ◽  
Martin Bergmann
Keyword(s):  
Molecular Weight ◽  
Soluble Reactive Phosphorus ◽  
Particulate Material ◽  
Phosphorus Fractions ◽  
Particulate Phosphorus ◽  
Small Molecular Weight ◽  
Large Molecular Weight ◽  
Reactive Phosphorus ◽  
Lake Waters ◽  
Total P

The amounts of colored particulate material (measured by reflectance) in surface waters of Lake Memphremagog and its tributaries were regressed against concentrations of total phosphorus and several of its component fractions: soluble phosphorus, particulate phosphorus, soluble reactive phosphorus, orthophosphate, large molecular weight phosphorus (> 5000 mol wt) and small molecular weight phosphorus (< 400 mol wt). The correlations were examined to see if one of these fractions was a better predictor of seston concentration, and presumably of other biologically related lake properties, than total P, and to determine if riverine samples differed from lake waters in the relation between concentrations of P and suspended particulates. Total P correlated with colored particulates in both lotic and lentic samples as well as or better than any other fraction. Although river samples showed greater variation than lake samples, the regression lines describing the relations were similar in both lakes and rivers.Key words: phosphorus fractions, lakes, rivers, empirical models, particulate concentration, seston

Soluble Reactive Phosphorus Measurements in Lake Michigan: Filtration Artifacts

1982 ◽  
Vol 8 (3) ◽  
pp. 550-557 ◽  
Author(s):  
Stephen J. Tarapchak ◽  
Sylvia M. Bigelow ◽  
Cora Rubitschun
Keyword(s):  
Lake Michigan ◽  
Soluble Reactive Phosphorus ◽  
Reactive Phosphorus

Soluble Reactive Phosphorus Measurements in Lake Michigan: Causes of Method-Specific Differences

1982 ◽  
Vol 8 (4) ◽  
pp. 700-710 ◽  
Author(s):  
Stephen J. Tarapchak ◽  
Richard L. Chambers ◽  
Sylvia M. Bigelow
Keyword(s):  
Lake Michigan ◽  
Soluble Reactive Phosphorus ◽  
Reactive Phosphorus

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.

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