scholarly journals Estimation of Phosphorus Release Rate by Bacterivorous Flagellates in Lake Biwa.

1994 ◽  
Vol 55 (3) ◽  
pp. 201-211 ◽  
Author(s):  
Shin-ichi NAKANO
Keyword(s):  
Release Rate ◽  
Lake Biwa ◽  
Phosphorus Release

Phosphate release from waste stabilisation pond sludge: significance and fate of polyphosphate

2011 ◽  
Vol 63 (8) ◽  
pp. 1689-1694 ◽  
Author(s):  
N. Powell ◽  
A. Shilton ◽  
S. Pratt ◽  
Y. Chisti
Keyword(s):  
Release Rate ◽  
Phosphorus Removal ◽  
Algal Bloom ◽  
Chemical Precipitation ◽  
Phosphorus Release ◽  
Common View ◽  
Phosphate Release ◽  
Initial Release ◽  
Polyphosphate Accumulation ◽  
The Common

Net phosphorus removal from waste stabilisation pond (WSP) systems is governed by the rate of phosphorus incorporation into the sludge layer and the rate of phosphorus release from this sludge back to the overlying wastewater. Luxury uptake of phosphorus by microalgae has been shown to occur under WSP conditions in the laboratory; however, the significance of this mechanism and the fate of polyphosphate contained in the settled solids have not previously been investigated. In this work the analysis of sludge samples from three WSP showed that up to 71% of the total phosphorus in the sludge was in the form of polyphosphate. This indicates that polyphosphate accumulation could potentially be an important mechanism for phosphorus sequestration in WSP and challenges the common view that chemical precipitation is the predominant phosphorus removal mechanism in these systems. The release of phosphate from WSP sludge samples was monitored in the laboratory. The samples from two different pond systems had release rates in the order of 4.3 μgP/gTSS.d. However, the third sample which was collected during an algal bloom had a release rate of 12.4 μgP/gTSS.d. Phosphate release from fresh microalgal sludge grown under laboratory conditions was also studied and was shown to have a release rate of 160 μgP/gTSS.d. Analysis of polyphosphate during the experiments on laboratory grown microalgal sludge showed that polyphosphate was indeed degraded resulting in phosphate release. Interestingly, after the initial release phase phosphorus was assimilated by the biomass and some polyphosphate was reformed. It is likely that this is due to bacterial growth in the sludge.

Phosphorus release rate and plant response in some calcareous soils

2009 ◽  
Vol 55 (1) ◽  
pp. 91-103 ◽  
Author(s):  
Farzaneh Sadate Biabanaki ◽  
Alireza R. Hosseinpur
Keyword(s):  
Release Rate ◽  
Calcareous Soils ◽  
Phosphorus Release ◽  
Plant Response

Use of phosphorus release batch tests for modelling an EBPR pilot plant

2002 ◽  
Vol 45 (6) ◽  
pp. 99-106 ◽  
Author(s):  
E. Tykesson ◽  
H. Aspegren ◽  
M. Henze ◽  
P.H. Nielsen ◽  
J. Ia C. Jansen
Keyword(s):  
Release Rate ◽  
Phosphorus Removal ◽  
Pilot Plant ◽  
Phosphorus Content ◽  
Phosphorus Release ◽  
Biological Phosphorus Removal ◽  
Batch Tests ◽  
Initial Release ◽  
Analysis Programme ◽  
Biological Phosphorus

The aim of this study was to evaluate how routinely performed phosphorus release tests could be used when modelling enhanced biological phosphorus removal (EBPR) using activated sludge models such as ASM2d. A pilot plant with an extensive analysis programme was used as basis for the simulations. Without any calibration the prediction of phosphorus removal was poor and the initial release rates from the simulations were not similar to those found from the laboratory tests. A period with low organic loading was chosen as a calibration period. In this period averages of daily influent measurements were used as influent parameters. First, calibration was performed in order to fit effluent COD and MLVSS in the sludge. Next, the phosphorus content in the sludge was decreased to the measured level by decreasing the fermentation rate. Finally, the initial phosphorus release rate was calculated from a simulated batch test and the PHA uptake rate was increased to fit this release rate with the average initial rates from laboratory batch tests performed during the period. The calibrated model was verified with data from the subsequent period where acetate was dosed.

Microbial effects on phosphorus release in aquatic sediments

2008 ◽  
Vol 58 (6) ◽  
pp. 1285-1289 ◽  
Author(s):  
Ting-Lin Huang ◽  
Xiao-Chun Ma ◽  
Hai-bing Cong ◽  
Bei-Bei Chai
Keyword(s):  
Ion Exchange ◽  
Release Rate ◽  
Phosphorus Release ◽  
Source Water ◽  
Aquatic Sediments ◽  
Iron Respiration ◽  
Microbial Effects

Microbial effects on phosphorus release were studied for the sediments of Tianjin source water by controlling DO and pH. The results show that: (1) In sterilised water, phosphorus began to release when pH = 9.1 and the stable release rate was 9.51 mg/(d·m2). It indicates that microorganisms may utilise anaerobic iron respiration to release Fe-P. (2) With unsterilised water, phosphorus release rate is 2.14 mg/(d·m2) when pH = 6.5, 8.60 mg/(d·m2) when pH is uncontrolled, and gets to 8.51 mg/(d·m2) when pH = 9.1. This indicates that microorganisms can dissolve insoluble phosphates to accelerate the ion exchange of OH− and PO43−, which are derived from iron-bound ortho-P and aluminium-bound ortho-P.

Internal Phosphorus Load in an Oligotrophic Precambrian Shield Lake with an Anoxic Hypolimnion

1986 ◽  
Vol 43 (3) ◽  
pp. 574-580 ◽  
Author(s):  
Gertrud K. Nürnberg ◽  
Margo Shaw ◽  
Peter J. Dillon ◽  
Don J. McQueen
Keyword(s):  
Release Rate ◽  
Lake Ontario ◽  
Phosphorus Release ◽  
Phosphorus Load ◽  
Release Rates ◽  
Eutrophic Lakes ◽  
Precambrian Shield ◽  
Anoxic Water ◽  
Internal Sources ◽  
External Loads

The release of phosphorus from sediments into the anoxic water of oligotrophic Chub Lake, Ontario, determined with three different methods, showed that the average release rate of 2.2 mg∙m−2∙d−1 is much smaller than release rates of more eutrophic lakes (14 mg∙m−2∙d−1). Our hypothesis that anoxic release rates depend on lake trophy was confirmed by the significant positive regression of release rates on lake phosphorus concentrations for 56 lakes from the literature. Despite a comparably small phosphorus release rate, the sediments play an important role in Chub Lake as a source of phosphorus because phosphorus from internal sources is in a highly available form and external loads are small.

Nutrient release from inundated land of a tropical reservoir (nanhua reservoir, Taiwan)

1998 ◽  
Vol 37 (2) ◽  
pp. 325-332 ◽  
Author(s):  
Shui-Ping Chang ◽  
Ching-Gung Wen
Keyword(s):  
Release Rate ◽  
Release Kinetics ◽  
Nutrient Release ◽  
Phosphorus Release ◽  
Nutrient Loads ◽  
Terrestrial Vegetation ◽  
Nitrogen And Phosphorus ◽  
Tropical Reservoir ◽  
Aerobic Conditions ◽  
Actual Operation

Nutrient release from land inundated by creation of a tropical reservoir (Nanhua Reservoir, Taiwan) is investigated. Both the magnitudes of nitrogen and phosphorus which might be released from inundated land are determined on the basis of measurements of biomass and nutrients content of terrestrial vegetation and the nutrients content of topsoil. The fresh biomass of the terrestrial vegetation was estimated at 48600 kg/ha, with an equivalent dry biomass of 15500 kg/ha. After complete decay following submergence, the terrestrial vegetation could potentially contribute 242 kg of nitrogen and 37 kg of phosphorus per hectare. The kinetics of nutrient release from topsoil is determined on a laboratory scale for 80 days, which showed that the phosphorus release rate is averaged at 5.25 mg TP/m2/day in anaerobic conditions and 1.34 mg TP/m2/day in aerobic conditions, also the nitrogen release rate is averaged at 78.31 mg TKN/m2/day in anaerobic condition and 35.71 mg TKN/m2/day in aerobic conditions. Based on the actual operation status of Nanhua Reservoir during the initial operation period of 21 months after construction (from August, 1993 to April, 19950 and nutrient release kinetics, the accumulated nutrient loads originating from the topsoil of the inundated land are about 81342 kg of nitrogen and 4701 kg of phosphorus.

The regularity of wind-induced sediment resuspension in Meiliang Bay of Lake Taihu

2014 ◽  
Vol 70 (1) ◽  
pp. 167-174 ◽  
Author(s):  
Jianjian Wang ◽  
Yong Pang ◽  
Yiping Li ◽  
Yawen Huang ◽  
Junjie Jia ◽  
...  
Keyword(s):  
Wind Speed ◽  
Release Rate ◽  
Lake Taihu ◽  
Sediment Resuspension ◽  
Quantitative Relationship ◽  
Phosphorus Release ◽  
Hydrodynamic Conditions ◽  
Wind Speeds ◽  
Resuspension Rate ◽  
Meiliang Bay

Contaminants released by wind-induced sediment resuspension could influence the water quality in shallow lakes. This study aims to reveal the quantitative relationship between wind speed (v) and sediment resuspension rate (r) in Meiliang Bay of Lake Taihu. The study was conducted in three steps. First, the in situ wind speed and current velocity were measured over a period of 2 days in Meiliang Bay to establish the relationship between wind and hydrodynamic conditions; second, an indoor experiment was conducted in a cylindrical simulator with sediment from the study area to determine sediment resuspension rates under different hydrodynamic conditions; and third, linkages between sediment resuspension and wind were determined. The average sediment resuspension rate was highly correlated with the wind speed (R2 = 0.99), and was expressed by r = 20.72v2.034 at wind speeds in the range of 0–14 m/s. The critical wind speed for sediment resuspension is about 7 m/s. Under these conditions, the average resuspension rate could reach 1,000 g/(m2d), with a total phosphorus release rate of 1.1 g/(m2d) and a total nitrogen release rate of 18.1 g/(m2d).

scholarly journals Comparison of anaerobic phosphorus release from activated sludge with three carbon sources

2021 ◽  
Vol 83 (6) ◽  
pp. 1327-1334
Author(s):  
Xiaohu Dai ◽  
Zhanbei Gu ◽  
Lingling Dai ◽  
Changming Shen ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Carbon Source ◽  
Release Rate ◽  
Sodium Acetate ◽  
Sewage Treatment ◽  
Carbon Sources ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Phosphorus Release ◽  
The Stability

Abstract Three carbon sources, namely sodium acetate, sewage and effluent, were used to simulate the process of phosphorus release in an actual sewage treatment plant, in order to explore the phosphorus release performance of the sludge, the relationship between phosphorus release and chemical oxygen demand (COD) in sewage, and the stability of phosphorus-rich sludge. The results showed that the type and concentration of carbon sources had significant effects on the rate of phosphorus release, reaction equilibrium time and phosphorus release amount. When sodium acetate was used as the carbon source, the phosphorus release rate reached 12.54 mg P (g VSS·h)−1, and tended to be stable at 4.0 hours. The phosphorus release amount in the first 2.5 hours accounted for 36.88% of the total phosphorus in the sludge. When sewage was used as the carbon source, the phosphorus release rate did not reach equilibrium even at 5.0 hours, and the phosphorus release amount increased by 1.0 mg L−1 for every 10.5 mg L−1 increase sewage COD within a certain range. When effluent was used as the carbon source, the visual phosphorus release amount was only 0.83 mg L−1 after standing for 24 hours and the actual phosphorus release amount was 17.98 mg L−1. These conclusions can provide technical support for the optimization of phosphorus removal in sewage treatment plants.

Discrete release rate impact on ramp metering performance

2006 ◽  
Vol 153 (1) ◽  
pp. 85 ◽  
Author(s):  
A. Kotsialos ◽  
M. Papageorgiou ◽  
J. Hayden ◽  
R. Higginson ◽  
K. McCabe ◽  
...  
Keyword(s):  
Release Rate ◽  
Ramp Metering
Sign in / Sign up

Export Citation Format

Share Document