Factors influencing phosphate exchange across the sediment-water interface of eutrophic reservoirs

Abstract

The results of a survey of the sediment chemistry of 7 East Anglian reservoirs are presented as part of a regional study on the assessment and control of eutrophication . The influence of water quality (dissolved oxygen, pH, temperature) on phosphate (P0 4) adsorption by sediment from hypertrophic Ardleigh Reservoir is also examined . Extractable phosphate-P (extr .-P) varied between 92 and 383 mg kg -' dry matter. Extractable P varied between 5 .3 and 16 .6% of the total phosphate-P (Tot . P) content and increased with the concentration of dissolved reactive phosphate-P (DRP) in the overlying water column . Organically complexed iron (organic Fe) was the determinand which correlated most closely with phosphate adsorption capacity, PAC (r = 0.8). Organic Fe was also related inversely to Extr . P . The rate and extent of P0 4 adsorption by Ardleigh Reservoir sediment increased with the initial concentration of DRP and adsorption equilibria were reached after 24 h . The equilibrium DRP concentration, [DRP], was 0.7 mg P 1 -' under aerobic conditions indicative of a high potential for P04 exchange . The rate and extent of P0 4 adsorption was greater at 7 ° C than at 22 'C' P0 4 adsorption increased markedly with dissolved oxygen status. Ardleigh sediment exhibited a marked buffering capacity to a change in pH ; however, P0 4 adsorption was greatest at an equilibrium pH of 5 .6 and decreased progressively either side of this pH value.Options for the artificial control of sediment P0 4 release are discussed in relation to the seasonal variation in sediment P04 exchange observed for Ardleigh Reservoir .

Variability in adsorptive phosphorus removal by structural stormwater best management practices

“…The negative correlation with pH is consistent with the findings of Zeng et al (2004) and a field-based study by Redshaw et al (1990). Regarding the relative influence of the significant variables, "concentration gradient" had by far the largest effect, followed by pH, and lastly the diffusion-related, "antecedent dry period" variable.…”

The Comparison of Phosphorus Pools from the Sediment in Two Bays of Lake Dianchi for Cyanobacterial Bloom Assessment

“…The concrete method refers to the known literature (Redshaw et al, 1990, Perkins et al, 2001. Because the conclusions under the anaerobic condition and from the different pH have been very definite (Andersen, 1975;Jacoby et al, 1982;Boström et al, 1988), in the paper only the experiments of phosphorus adsorption from the differently initial concentrations of phosphate were carried out to evaluate the saturated status of phosphorus in the sediment.…”

Paleolimnological Records of Nutrient and Metal Profiles in Prehistoric, Historic and Modern Sediments of Three Lakes in North-eastern Germany

“…Higher primary production increases the autochthonic organic matter, but also the rate of sediment loss through degradation by oxidation or anoxic reduction. Redox conditions at the sediment-water interface are decisive for stable binding of P in the sediment (Bostroem et al 1982;Redshaw et al 1990 Fig. 5 Vertical distribution of phosphorus and metals in the sediment core of Lake Schulzensee -dating according calibrated 14 C-AMS analysis and pollenstratigraphic borders (letters -details show Fig.…”