scholarly journals Ca–Fe oxide granules as potential phosphate barrier material for critical source areas: a laboratory study of P retention and release

2012 ◽  
Vol 21 (3) ◽  
pp. 224-236 ◽  
Author(s):  
Risto Uusitalo ◽  
Petri Ekholm ◽  
Jouni Lehtoranta ◽  
Aleksandar Klimeski ◽  
Olli Konstari ◽  
...  
Keyword(s):  
Barrier Material ◽  
Retention Capacity ◽  
Critical Source Areas ◽  
Fe Oxide ◽  
Source Areas ◽  
Batch Tests ◽  
P Concentration ◽  
Phosphate Retention ◽  
Flow Through ◽  
P Retention

Phosphate barriers may mitigate dissolved P losses from critical source areas. We studied P retention of industrially produced Ca–Fe oxide as potential P barrier material. In batch tests with 1 mg l−1 P solution, P retention was 85% efficient in 5 min. In a flow-through system, the granule phosphate-retention capacity was 6–7 mg g−1, being largely unaffected by pre-leaching. Phosphate release from P-saturated granules was pH-dependant and suggested P association with Fe oxides, and as Ca-phosphate precipitates. In a sequential extraction of P-saturated granules, about 25% of retained P was released, whereas a separate anaerobic incubation resulted in negligible release of P. Immersion of unleached, P-saturated granules for 16 days in a low-P–concentration lake resulted in more than 80% Ca loss, but no loss of metals, and about 25% loss of P accumulated earlier in granules. These granules are promising for P retention and merit a field-scale study.

scholarly journals Potential and limitations of phosphate retention media in water protection: A process-based review of laboratory and field-scale tests

2012 ◽  
Vol 21 (3) ◽  
pp. 206-223 ◽  
Author(s):  
Aleksandar Klimeski ◽  
Wim J. Chardon ◽  
Eila Turtola ◽  
Risto Uusitalo
Keyword(s):  
High Capacity ◽  
Agricultural Runoff ◽  
Solution Chemistry ◽  
Field Scale ◽  
Test Procedures ◽  
Retention Capacity ◽  
Batch Tests ◽  
Phosphate Retention ◽  
Alkaline Conditions ◽  
P Retention

The application of phosphorus (P)-sorbing materials offers a possible solution for treating municipal wastewaterand agricultural runoff. In this paper we discuss P retention and release mechanisms, and review studies on the Pretention of different materials and their use as reactive media in filter beds. The main mechanisms for P retentionare sorption on metal (mostly Fe or Al) hydroxide surfaces and, in alkaline conditions, the formation of Ca-Pprecipitates. The retention of P is strongly affected by the chemical composition of a material, its particle size andpH-related effects on sorption and precipitation both during testing and in practical operation. Laboratory testsare sensitive to solution chemistry (pH, alkalinity, ionic strength and composition, P concentration) and affected bymaterial-to-solution ratio, contact time and agitation. Moreover, due to deviations from realistic field conditions,laboratory tests may produce imprecise estimates of the retention capacity and retention kinetics. In particular,materials that contain soluble substances (e.g., CaO) that elevate the pH of the ambient solution to high levels mayin batch tests suggest a high capacity for P retention, but will most probably show much lower retention in fieldsettings. On the other hand, materials containing metal oxides also retain P via slow reactions, and their retentioncapacity may be underestimated in short equilibrations. Appropriate laboratory test procedures will dependon their intended applications and material properties. Long-term field-scale tests are few in number, but some ofthem have shown promising results. Field-scale tests have, however, highlighted the design of the filters as a criticalfactor in their efficiency. 

scholarly journals Phosphorus retention in drainage soils of commercial greenhouses.

1969 ◽  
Vol 95 (1-2) ◽  
pp. 1-14
Author(s):  
José A. Dumas ◽  
Joaquín A. Chong ◽  
Magaly Cintrón ◽  
Luis Reinaldo Santiago
Keyword(s):  
Phosphorus Retention ◽  
Organic Residues ◽  
Soil Factors ◽  
Retention Capacity ◽  
Soil P ◽  
Al Content ◽  
P Concentration ◽  
Highly Correlated ◽  
Retention Parameters ◽  
P Retention

Five commercial greenhouses in the central mountainous zone of Puerto Rico were studied in order to identify changes in soil factors that affect P retention. Soils were collected both within and outside drainages at a 0- to 15-cm depth. Soil physicochemical properties varied in samples taken both within and outside drainages. The high Fe and Al content in the soils of this study suggested a high phosphorus retention capacity. Laboratory estimates of P retention parameters indicated differences in P sorption capacity among soils. Phosphorus retention parameters were highly correlated with citrate dithionite extractable Fe. The equilibrium P concentration was also correlated with citrate dithionate Al in soils outside drainages. This finding was due to the higher soil organic matter counterbalancing the soil P retention capability of Al, all of which indicates the importance of clearing all drainages of organic residues in order to avoid excessive movement of P outside the greenhouse premises.

Predicting critical source areas of sediment in headwater catchments

2013 ◽  
Vol 179 ◽  
pp. 41-52 ◽  
Author(s):  
Joshua Thompson ◽  
Rachel Cassidy ◽  
Donnacha G. Doody ◽  
Ray Flynn
Keyword(s):  
Critical Source Areas ◽  
Headwater Catchments ◽  
Source Areas

Identification of critical source areas under present and projected land use for effective management of diffuse pollutants in an urbanized watershed

2018 ◽  
Vol 17 (2) ◽  
pp. 171-184 ◽  
Author(s):  
Al-amin Danladi Bello ◽  
Mohd Ridza Mohd Haniffah ◽  
Muhammad Nassir Hanapi ◽  
Aliyu Bamaiyi Usman
Keyword(s):  
Land Use ◽  
Effective Management ◽  
Critical Source Areas ◽  
Source Areas

scholarly journals Phosphorus and Metals Leaching from Green Roof Substrates and Aggregates Used in Their Composition

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 112 ◽  
Author(s):  
Agnieszka Karczmarczyk ◽  
Anna Baryła ◽  
Joanna Fronczyk ◽  
Agnieszka Bus ◽  
Józef Mosiej
Keyword(s):  
Heavy Metals ◽  
Green Roof ◽  
Green Roofs ◽  
Point Of View ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Batch Tests ◽  
Quality Literature ◽  
Materials Used ◽  
Runoff Quality

Green roofs are constructions made of different layers, each serving a dedicated function. Substrates and materials used in their composition are essential from the point of view of rainwater retention and plant development, but they may have an adverse effect on runoff quality. Literature studies show that phosphorus and heavy metals are of main importance. The total roofs area covered with green increased in the last years in cities as they are efficient in retention of rainwater and delaying of the runoff, therefore, protecting the cities against floods. As green roofs filtrate a significant amount of rainwater, materials used in substrates composition should be carefully selected to protect urban receivers against pollution. The aim of this study was to assess phosphorus and heavy metals leaching from different green roof substrates and their components with the focus on green roof runoff quality. Both commercially made green roof substrates and often used compounds (construction aggregates) were tested in laboratory batch tests for P, Cu, Ni, Cd, and Zn content in extracts. Based on the results of this study, it could be emphasized that a large part of commonly used construction aggregates can be a source of phosphorus, some also can release elevated values of nickel. Therefore, the materials should be carefully tested before use in the green roof substrate composition, not only for their physical properties reflecting water retention capacity, but also for chemical composition.

Effective pollutant retention capacity of permeable pavements for infiltrated road runoffs determined by laboratory tests

2005 ◽  
Vol 51 (2) ◽  
pp. 37-45 ◽  
Author(s):  
S. Fach ◽  
W.F. Geiger
Keyword(s):  
Large Scale ◽  
Urban Runoff ◽  
Assessment Procedure ◽  
Retention Capacity ◽  
Test Installation ◽  
Permeable Pavements ◽  
Batch Tests ◽  
Different Types ◽  
Stormwater Infiltration

The infiltration of urban runoff always implies an entrance of pollutants into the soil and ground water. Due to legal regulations in many communes there is no longer any permission needed for stormwater infiltration, if administrative regulations and the requirements of standards are observed. The results of a research project carried out under the heading “Development of an assessment procedure for permeable pavements” show, that the pollutant retention capacity of permeable pavements varies considerably, depending on the material and the specific reactive surface. The objective of the study was to work out recommendations of suitable permeable pavements for different types of urban runoff. Selected data about the quality of urban runoff was compiled into a runoff matrix, which was used for defining characteristic dilutions. In batch tests, the material of the infiltration devices is penetrated with the dilutions. A test installation in large scale is used to calibrate the sorption coefficients derived from the batch experiment.

Identifying critical source areas of nonpoint source pollution with SWAT and GWLF

2013 ◽  
Vol 268 ◽  
pp. 123-133 ◽  
Author(s):  
Rewati Niraula ◽  
Latif Kalin ◽  
Puneet Srivastava ◽  
Christopher J. Anderson
Keyword(s):  
Nonpoint Source Pollution ◽  
Nonpoint Source ◽  
Critical Source Areas ◽  
Source Areas

scholarly journals 288 Dietary calcium decreases digestibility of phosphorus in late gestating sows, but blood biomarkers may be used to predict bone formation and resorption

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 105-106
Author(s):  
Su A Lee ◽  
Mike R Bedford ◽  
Hans H Stein
Keyword(s):  
Bone Formation ◽  
Type I Collagen ◽  
Linear Increase ◽  
Type I ◽  
Serum Concentrations ◽  
Blood Biomarkers ◽  
Specific Alkaline Phosphatase ◽  
Bone Specific Alkaline Phosphatase ◽  
P Concentration ◽  
P Retention

Abstract The objective was to test the hypothesis that Ca levels in diets fed to late gestating sows affect apparent total tract digestibility (ATTD) and retention of Ca and P, blood Ca and P, and serum concentrations of hormones and blood biomarkers. Thirty-six sows (parity = 2.8) were divided in 3 blocks, housed individually in metabolism crates from d 91 to 105 of gestation and randomly allotted to 4 experimental diets containing 25, 50, 75, or 100% of the requirement for Ca with a constant P concentration. Fecal and urine samples were collected for 4 d after 5 d of adaptation. At the conclusion of the experiment, a blood sample from all sows was collected. The statistical model included diet as fixed effect and parity, block, and replicate within block as random effects. Values for the ATTD and retention of Ca increased quadratically (P < 0.05) as dietary Ca increased. Fecal P output increased linearly (P < 0.001) as dietary Ca increased, which resulted in a linear decrease (P < 0.001) in the ATTD of P. Urine P output decreased linearly (P < 0.001) as dietary Ca increased with a linear increase (P < 0.05) in P retention. Serum Ca and P and estrogen, calcitonin, and parathyroid hormone were not affected by dietary Ca. Carboxyterminal cross-linked telopeptide of type I collagen (CTX-I) in serum decreased linearly (P = 0.033) and bone-specific alkaline phosphatase tended to decrease linearly (P = 0.091) as Ca in diets increased. Osteocalcin in serum was not affected by Ca levels, but the ratio between osteocalcin and CTX-I tended to increase (P = 0.055) as dietary Ca increased. In conclusion, P digestibility decreases, but retention of P increases, as dietary Ca increases and blood biomarkers may be useful to predict bone formation and resorption by late gestating sows.

scholarly journals Identification of Critical Source Areas of Nitrogen Load in the Miyun Reservoir Watershed under Different Hydrological Conditions

2020 ◽  
Vol 12 (3) ◽  
pp. 964 ◽  
Author(s):  
Yingzhuang Guo ◽  
Xiaoyan Wang ◽  
Lili Zhou ◽  
Charles Melching ◽  
Zeqi Li
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Swat Model ◽  
Vegetation Coverage ◽  
Left Bank ◽  
Cultivated Land ◽  
Forest Land ◽  
Critical Source Areas ◽  
Source Areas ◽  
Hydrological Conditions

The spatiotemporal distribution of critical source areas (CSAs) will change with hydrological conditions. In this study, the CSAs of nitrogen load under different hydrological conditions in the Chaohe River watershed were identified using the cumulative pollution load curve method determined from the nitrogen pollution simulated using the Soil and Water Assessment Tool (SWAT) model. The results showed that: (1) The order of factors impacting nitrogen load intensity is as follows: fertilization intensity, rainfall, runoff, land use type, slope type, and soil type. (2) The primary and secondary CSAs are concentrated in the upper and lower areas of the watershed, where cultivated land (8.36%) and grassland (52.55%) are more abundant. The potential pollution source areas are concentrated in the upper and middle areas of the watershed, where cultivated land (6.99%), grassland (42.37%), and forest land (48.18%) are evenly distributed. The low-risk source areas are concentrated in the middle and left bank of the watershed, where forest land (67.65%) is dominant and the vegetation coverage is highest. The research results have significance for improving the accuracy of the implementation of best management practices, and can provide a reference for the formulation of drinking water protection policies for Beijing.

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