Comparison of inductively coupled plasma mass spectrometry and colorimetric determination of total and extractable phosphorus in soils

Energy Technology Data Exchange (ETDEWEB)

Ivanov, Krasimir, E-mail: kivanov1@abv.bg [Department of Chemistry, University of Agriculture, Plovdiv (Bulgaria); Zaprjanova, Penka [Tobacco and Tobacco Products Institute, Plovdiv (Bulgaria); Petkova, Milena [Department of Chemistry, University of Agriculture, Plovdiv (Bulgaria); Stefanova, Violeta; Kmetov, Veselin; Georgieva, Deyana [Department of Analytical Chemistry, Plovdiv University ' Paisii Hilendarski,' Plovdiv (Bulgaria); Angelova, Violina [Department of Chemistry, University of Agriculture, Plovdiv (Bulgaria)

2012-05-15

The most widely used method for determination of total phosphorus in soils is perchloric acid digestion, followed by a colorimetric assay to measure the concentration of P in solution. The first part of this study compares an alternative digestion method, using aqua regia (ISO 11466 and EPA Method 3052), with perchloric acid digestion procedure, and also compares inductively coupled plasma mass spectroscopy (ICP-MS) with colorimetry for the measurement of P on the basis of five internationally certified standard soils and 20 real-life soils with widely different extractability of phosphorus. The phosphorus concentration was determined by means of the reduced phosphomolybdenum blue and ICP-MS. The relationship between methods has been examined statistically. Good agreement of the results from colorimetry and ICP-MS was established for all certified soils. The microwave-assisted digestion with aqua regia was comparable, both in precision and accuracy, with the hot plate aqua regia method. The phosphorus concentration found with the HF + HClO{sub 4} digestion method was in good agreement with the certified mean values, while the superiority in extracting phosphorus, when compared to other methods, was obvious. Soil testing for plant-available phosphorus in Bulgaria and many European countries is most commonly conducted using acid Ca-lactate extraction (Egner-Riehm test) and alkaline sodium bicarbonate extraction (BDS ISO 11263:2002), based on Olsen test, followed by a colorimetric assay to measure the concentration of P in solution. The second part of this study reports the differences between Egner-Riehm test and BDS ISO 11263:2002 measured colorimetrically and by ICP-MS. Fifty soils were selected from South Bulgaria to represent a wide range of soil properties. It was established that ICP-MS consistently yielded significantly higher P concentrations than the colorimetric method in both extraction tests, and the relative differences were greatest in soils with lower

Total Value of Phosphorus Recovery.

Science.gov (United States)

Mayer, Brooke K; Baker, Lawrence A; Boyer, Treavor H; Drechsel, Pay; Gifford, Mac; Hanjra, Munir A; Parameswaran, Prathap; Stoltzfus, Jared; Westerhoff, Paul; Rittmann, Bruce E

2016-07-05

Phosphorus (P) is a critical, geographically concentrated, nonrenewable resource necessary to support global food production. In excess (e.g., due to runoff or wastewater discharges), P is also a primary cause of eutrophication. To reconcile the simultaneous shortage and overabundance of P, lost P flows must be recovered and reused, alongside improvements in P-use efficiency. While this motivation is increasingly being recognized, little P recovery is practiced today, as recovered P generally cannot compete with the relatively low cost of mined P. Therefore, P is often captured to prevent its release into the environment without beneficial recovery and reuse. However, additional incentives for P recovery emerge when accounting for the total value of P recovery. This article provides a comprehensive overview of the range of benefits of recovering P from waste streams, i.e., the total value of recovering P. This approach accounts for P products, as well as other assets that are associated with P and can be recovered in parallel, such as energy, nitrogen, metals and minerals, and water. Additionally, P recovery provides valuable services to society and the environment by protecting and improving environmental quality, enhancing efficiency of waste treatment facilities, and improving food security and social equity. The needs to make P recovery a reality are also discussed, including business models, bottlenecks, and policy and education strategies.

Modelling of in-stream nitrogen and phosphorus concentrations using different sampling strategies for calibration data

Science.gov (United States)

Jomaa, Seifeddine; Jiang, Sanyuan; Yang, Xiaoqiang; Rode, Michael

2016-04-01

It is known that a good evaluation and prediction of surface water pollution is mainly limited by the monitoring strategy and the capability of the hydrological water quality model to reproduce the internal processes. To this end, a compromise sampling frequency, which can reflect the dynamical behaviour of leached nutrient fluxes responding to changes in land use, agriculture practices and point sources, and appropriate process-based water quality model are required. The objective of this study was to test the identification of hydrological water quality model parameters (nitrogen and phosphorus) under two different monitoring strategies: (1) regular grab-sampling approach and (2) regular grab-sampling with additional monitoring during the hydrological events using automatic samplers. First, the semi-distributed hydrological water quality HYPE (Hydrological Predictions for the Environment) model was successfully calibrated (1994-1998) for discharge (NSE = 0.86), nitrate-N (lowest NSE for nitrate-N load = 0.69), particulate phosphorus and soluble phosphorus in the Selke catchment (463 km2, central Germany) for the period 1994-1998 using regular grab-sampling approach (biweekly to monthly for nitrogen and phosphorus concentrations). Second, the model was successfully validated during the period 1999-2010 for discharge, nitrate-N, particulate-phosphorus and soluble-phosphorus (lowest NSE for soluble phosphorus load = 0.54). Results, showed that when additional sampling during the events with random grab-sampling approach was used (period 2011-2013), the hydrological model could reproduce only the nitrate-N and soluble phosphorus concentrations reasonably well. However, when additional sampling during the hydrological events was considered, the HYPE model could not represent the measured particulate phosphorus. This reflects the importance of suspended sediment during the hydrological events increasing the concentrations of particulate phosphorus. The HYPE model could

Determinants of total and available phosphorus in forested Alfisols and Ultisols of the Ozark Highlands, USA

Science.gov (United States)

Gurbir Singh; Keith W. Goyne; John M. Kabrick

2015-01-01

Phosphorus is an important nutrient limiting forest growth in many parts of world, and soil P forms and concentrations may be associated with a host of soil and environmental attributes in a complex soil landscape. The objective of this study was to identify key environmental and soil properties influencing total and available soil P concentrations in a mixed oak (

Impacts of anthropic pressures on soil phosphorus availability, concentration, and phosphorus forms in sediments in a Southern Brazilian watershed

Energy Technology Data Exchange (ETDEWEB)

Pellegrini, Joao Batista Rossetto; Rheinheimer dos Santos, Danilo; Goncalves, Celso Santos; Copetti, Andre Carlos Cruz [Dept. de Solos, Univ. Federal de Santa Maria, Centro de Ciencias Rurais, Santa Maria, RS (Brazil); Bortoluzzi, Edson Campanhola [Faculdade de Agronomia e Medicina Veterinaria da Univ. de Passo Fundo, RS (Brazil); Tessier, Daniel [Inst. National de la Recherche Agronomique, Versailles (France)

2010-04-15

Purpose: The transfer of soil sediments and phosphorus from terrestrial to aquatic systems is a common process in agricultural lands. The aims of this paper are to quantify the soil phosphorus availability and to characterize phosphorus forms in soil sediments as contaminant agents of waters as a function of anthropic pressures. Materials and methods On three subwatersheds with different anthropic pressure, water and sediment samples were collected automatically in upstream and downstream discharge points in six rainfall events during the tobacco growing season. Phosphorus desorption capacity from soil sediments was estimated by successive extractions with anion exchange resins. First-order kinetic models were adjusted to desorption curves for estimating potentially bioavailable particulate phosphorus, desorption rate constant, and bioavailable particulate phosphorus. Results and discussion The amount of bioavailable particulate phosphorus was directly correlated with the iron oxide content. The value of desorption rate constant was directly related with the total organic carbon and inversely with the iron oxide contents. Phosphate ions were released to solution, on average, twice as rapidly from sediments collected in subwatersheds with low anthropic activity than from those ones of highly anthropic subwatersheds. Anthropic pressure on watershed can engender high sediment discharge, but these solid particles seem to present low phosphorus-releasing capacity to water during transport due to the evidenced high affinity between phosphorus and iron oxide from sediments. Conclusions Anthropic pressure was related with sediment concentration and phosphorus release to aquatic systems. While natural vegetation along streams plays a role on soil and water depuration, it is unable to eliminate the phosphorus inputs intrinsic to the agricultural-intensive systems. Recommendations and perspectives The contamination of water in watershed by phosphates is facilitated by the

Recycling phosphorus by fast pyrolysis of pig manure: concentration and extraction of phosphorus combined with formation of value-added pyrolysis products

NARCIS (Netherlands)

Azuara, M.; Kersten, Sascha R.A.; Kootstra, A.M.J.

2013-01-01

In order to recycle phosphorus from the livestock chain back to the land, fast pyrolysis of concentrated pig manure at different temperatures (400 °C, 500 °C, 600 °C), was undertaken to concentrate the phosphorus in the char fraction for recovery. Results show that 92%–97% of the phosphorus present

Relationship among Phosphorus Circulation Activity, Bacterial Biomass, pH, and Mineral Concentration in Agricultural Soil

Directory of Open Access Journals (Sweden)

Dinesh Adhikari

2017-12-01

Full Text Available Improvement of phosphorus circulation in the soil is necessary to enhance phosphorus availability to plants. Phosphorus circulation activity is an index of soil’s ability to supply soluble phosphorus from organic phosphorus in the soil solution. To understand the relationship among phosphorus circulation activity; bacterial biomass; pH; and Fe, Al, and Ca concentrations (described as mineral concentration in this paper in agricultural soil, 232 soil samples from various agricultural fields were collected and analyzed. A weak relationship between phosphorus circulation activity and bacterial biomass was observed in all soil samples (R2 = 0.25, and this relationship became significantly stronger at near-neutral pH (6.0–7.3; R2 = 0.67. No relationship between phosphorus circulation activity and bacterial biomass was observed at acidic (pH < 6.0 or alkaline (pH > 7.3 pH. A negative correlation between Fe and Al concentrations and phosphorus circulation activity was observed at acidic pH (R2 = 0.72 and 0.73, respectively, as well as for Ca at alkaline pH (R2 = 0.64. Therefore, bacterial biomass, pH, and mineral concentration should be considered together for activation of phosphorus circulation activity in the soil. A relationship model was proposed based on the effects of bacterial biomass and mineral concentration on phosphorus circulation activity. The suitable conditions of bacterial biomass, pH, and mineral concentration for phosphorus circulation activity could be estimated from the relationship model.

Concentration, flux, and trend estimates with uncertainty for nutrients, chloride, and total suspended solids in tributaries of Lake Champlain, 1990–2014

Science.gov (United States)

Medalie, Laura

2016-12-20

The U.S. Geological Survey, in cooperation with the New England Interstate Water Pollution Control Commission and the Vermont Department of Environmental Conservation, estimated daily and 9-month concentrations and fluxes of total and dissolved phosphorus, total nitrogen, chloride, and total suspended solids from 1990 (or first available date) through 2014 for 18 tributaries of Lake Champlain. Estimates of concentration and flux, provided separately in Medalie (2016), were made by using the Weighted Regressions on Time, Discharge, and Season (WRTDS) regression model and update previously published WRTDS model results with recent data. Assessment of progress towards meeting phosphorus-reduction goals outlined in the Lake Champlain management plan relies on annual estimates of phosphorus flux. The percent change in annual concentration and flux is provided for two time periods. The R package EGRETci was used to estimate the uncertainty of the trend estimate. Differences in model specification and function between this study and previous studies that used WRTDS to estimate concentration and flux using data from Lake Champlain tributaries are described. Winter data were too sparse and nonrepresentative to use for estimates of concentration and flux but were sufficient for estimating the percentage of total annual flux over the period of record. Median winter-to-annual fractions ranged between 21 percent for total suspended solids and 27 percent for dissolved phosphorus. The winter contribution was largest for all constituents from the Mettawee River and smallest from the Ausable River. For the full record (1991 through 2014 for total and dissolved phosphorus and chloride and 1993 through 2014 for nitrogen and total suspended solids), 6 tributaries had decreasing trends in concentrations of total phosphorus, and 12 had increasing trends; concentrations of dissolved phosphorus decreased in 6 and increased in 8 tributaries; fluxes of total phosphorus decreased in 5 and

Competition between Free-Floating Plants Is Strongly Driven by Previously Experienced Phosphorus Concentrations in the Water Column.

Science.gov (United States)

Peeters, Edwin T H M; Neefjes, Rozemarijn E M; Zuidam, Bastiaan G van

2016-01-01

Nutrients can determine the outcome of the competition between different floating plant species. The response of floating plants to current phosphorus levels may be affected by previously experienced phosphorus concentrations because some species have the ability to store excess phosphorus for later use. This might have an impact on their competition. Here, we investigate the effect of previous and actual phosphorus concentrations on the growth rate of free-floating plant species (Azolla filiculoides, Lemna minor/gibba and Ricciocarpus natans)and the effect of phosphorus history on the competition between L. minor/gibba and A. filiculoides and between L. minor/gibba and R. natans. As expected, plant growth was lower when previously kept at low instead of high phosphorus concentrations. Growth of L. minor/gibba and A. filiculoides with a phosphorus rich history was comparable for low and high actual phosphorus concentrations, however, internal phosphorus concentrations were significantly lower with low actual phosphorus concentration. This indicates that both species perform luxury phosphorus uptake. Furthermore, internal P concentration in Azolla and Lemna increased within two weeks after a period of P deficit without a strong increase in growth. A. filiculoides in a mixture with L. minor/gibba grew faster than its monoculture. Morphological differences may explain why A. filiculoides outcompeted L. minor/gibba and these differences may be induced by phosphorus concentrations in the past. Growth of L. minor/gibba was only reduced by the presence of A. filiculoides with a high phosphorus history. Growth of L. minor/gibba and R. natans in mixtures was positively affected only when they had a high phosphorus history themselves and their competitor a low phosphorus history. These observations clearly indicate that phosphorus history of competing plants is important for understanding the outcome of the competition. Therefore, actual and previously experienced phosphorus

Changes in Olsen Phosphorus Concentration and Its Response to Phosphorus Balance in Black Soils under Different Long-Term Fertilization Patterns

Science.gov (United States)

Zhan, Xiaoying; Zhang, Li; Zhou, Baoku; Zhu, Ping; Zhang, Shuxiang; Xu, Minggang

2015-01-01

The Olsen phosphorus (P) concentration of a soil is a key index that can be used to evaluate the P supply capacity of the soil and to estimate the optimal P fertilization rate. A study of the relationship between the soil Olsen P concentration and the P balance (P input minus P output) and their variations among different fertilization patterns will help to provide useful information for proper management of P fertilization. In this paper, the two investigated long-term experiments were established on black soils in the northeast region of China. Six fertilization treatments were selected: (1) unfertilized (CK); (2) nitrogen only (N); (3) nitrogen and potassium (NK); (4) nitrogen and phosphorus (NP); (5) nitrogen, phosphorus, and potassium (NPK); and (6) nitrogen, phosphorus, potassium and manure (NPKM). The results showed that the average Olsen P concentrations in the black soils at Gongzhuling and Harbin (16- and 31-year study periods, respectively), decreased by 0.49 and 0.56 mg kg-1 a-1, respectively, without P addition and increased by 3.17 and 1.78 mg kg-1 a-1, respectively, with P fertilization. The changes in soil Olsen P concentrations were significantly (P<0.05) correlated with the P balances at both sites except for the NP and NPK treatments at Gongzhuling. Under an average deficit of 100 kg ha-1 P, the soil Olsen P concentration at both sites decreased by 1.36~3.35 mg kg-1 in the treatments without P addition and increased by 4.80~16.04 mg kg-1 in the treatments with 100 kg ha-1 of P accumulation. In addition, the changes in Olsen P concentrations in the soil with 100 kg ha-1of P balance were significantly correlated with the P activation coefficient (PAC, percentage of Olsen P to total P, r=0.99, P<0.01) and soil organic matter content (r=0.91, P<0.01). A low pH was related to large changes of Olsen P by 1 kg ha-1 of P balance. These results indicated that soil organic matter and pH have important effects on the change in soil Olsen P by 1 kg ha-1 of P

Competition between Free-Floating Plants Is Strongly Driven by Previously Experienced Phosphorus Concentrations in the Water Column.

Directory of Open Access Journals (Sweden)

Edwin T H M Peeters

Full Text Available Nutrients can determine the outcome of the competition between different floating plant species. The response of floating plants to current phosphorus levels may be affected by previously experienced phosphorus concentrations because some species have the ability to store excess phosphorus for later use. This might have an impact on their competition. Here, we investigate the effect of previous and actual phosphorus concentrations on the growth rate of free-floating plant species (Azolla filiculoides, Lemna minor/gibba and Ricciocarpus natansand the effect of phosphorus history on the competition between L. minor/gibba and A. filiculoides and between L. minor/gibba and R. natans. As expected, plant growth was lower when previously kept at low instead of high phosphorus concentrations. Growth of L. minor/gibba and A. filiculoides with a phosphorus rich history was comparable for low and high actual phosphorus concentrations, however, internal phosphorus concentrations were significantly lower with low actual phosphorus concentration. This indicates that both species perform luxury phosphorus uptake. Furthermore, internal P concentration in Azolla and Lemna increased within two weeks after a period of P deficit without a strong increase in growth. A. filiculoides in a mixture with L. minor/gibba grew faster than its monoculture. Morphological differences may explain why A. filiculoides outcompeted L. minor/gibba and these differences may be induced by phosphorus concentrations in the past. Growth of L. minor/gibba was only reduced by the presence of A. filiculoides with a high phosphorus history. Growth of L. minor/gibba and R. natans in mixtures was positively affected only when they had a high phosphorus history themselves and their competitor a low phosphorus history. These observations clearly indicate that phosphorus history of competing plants is important for understanding the outcome of the competition. Therefore, actual and previously

Competition between Free-Floating Plants Is Strongly Driven by Previously Experienced Phosphorus Concentrations in the Water Column

Science.gov (United States)

Peeters, Edwin T. H. M.; Neefjes, Rozemarijn E. M.; van Zuidam, Bastiaan G.

2016-01-01

Nutrients can determine the outcome of the competition between different floating plant species. The response of floating plants to current phosphorus levels may be affected by previously experienced phosphorus concentrations because some species have the ability to store excess phosphorus for later use. This might have an impact on their competition. Here, we investigate the effect of previous and actual phosphorus concentrations on the growth rate of free-floating plant species (Azolla filiculoides, Lemna minor/gibba and Ricciocarpus natans)and the effect of phosphorus history on the competition between L. minor/gibba and A. filiculoides and between L. minor/gibba and R. natans. As expected, plant growth was lower when previously kept at low instead of high phosphorus concentrations. Growth of L. minor/gibba and A. filiculoides with a phosphorus rich history was comparable for low and high actual phosphorus concentrations, however, internal phosphorus concentrations were significantly lower with low actual phosphorus concentration. This indicates that both species perform luxury phosphorus uptake. Furthermore, internal P concentration in Azolla and Lemna increased within two weeks after a period of P deficit without a strong increase in growth. A. filiculoides in a mixture with L. minor/gibba grew faster than its monoculture. Morphological differences may explain why A. filiculoides outcompeted L. minor/gibba and these differences may be induced by phosphorus concentrations in the past. Growth of L. minor/gibba was only reduced by the presence of A. filiculoides with a high phosphorus history. Growth of L. minor/gibba and R. natans in mixtures was positively affected only when they had a high phosphorus history themselves and their competitor a low phosphorus history. These observations clearly indicate that phosphorus history of competing plants is important for understanding the outcome of the competition. Therefore, actual and previously experienced phosphorus

Influence of the detergent formulation on the concentration of phosphorus in the sewage inflows to the WWTPs: the Brazilian experience.

Science.gov (United States)

Quevedo, Claudia Maria Gomes de; Piveli, Roque Passos; Paganini, Wanderley da Silva

2018-05-01

This work seeks to discuss the presence of phosphorus in raw sewage considering the formulation of the powder detergent for cleaning fabrics currently sold in Brazil. Based on the results of laboratory analyses performed in the sewage inflows to three wastewater treatment plants (WWTPs) located in São Paulo state, it evaluates the different fractions of this element and sizes the impact caused by the product. The average concentration of total phosphorus (total-P) in sewage inflows has shown a reduction trend over the years, and it is currently between 5.3 and 7.6 mg/L. The participation of organic phosphorus (org-P) tends to be higher than that of the inorganic phosphorus (inorg-P) with average around 64% of total-P. This situation indicates a change from the default and it may be influenced by the reduced contribution of phosphorus in the powder detergents. It was concluded that the formulation of the Brazilian products, which have a very low phosphate content, less than 0.01% by weight, may have altered the phosphorus dynamics in sewage. In other respects, results have shown the need to enhance actions aimed at controlling the sources of phosphorus in sewage, with a view to assure preventive measures to water pollution processes.

Sewage-effluent phosphorus: A greater risk to river eutrophication than agricultural phosphorus?

International Nuclear Information System (INIS)

Jarvie, Helen P.; Neal, Colin; Withers, Paul J.A.

2006-01-01

Phosphorus (P) concentrations from water quality monitoring at 54 UK river sites across seven major lowland catchment systems are examined in relation to eutrophication risk and to the relative importance of point and diffuse sources. The over-riding evidence indicates that point (effluent) rather than diffuse (agricultural) sources of phosphorus provide the most significant risk for river eutrophication, even in rural areas with high agricultural phosphorus losses. Traditionally, the relative importance of point and diffuse sources has been assessed from annual P flux budgets, which are often dominated by diffuse inputs in storm runoff from intensively managed agricultural land. However, the ecological risk associated with nuisance algal growth in rivers is largely linked to soluble reactive phosphorus (SRP) concentrations during times of ecological sensitivity (spring/summer low-flow periods), when biological activity is at its highest. The relationships between SRP and total phosphorus (TP; total dissolved P + suspended particulate P) concentrations within UK rivers are evaluated in relation to flow and boron (B; a tracer of sewage effluent). SRP is the dominant P fraction (average 67% of TP) in all of the rivers monitored, with higher percentages at low flows. In most of the rivers the highest SRP concentrations occur under low-flow conditions and SRP concentrations are diluted as flows increase, which is indicative of point, rather than diffuse, sources. Strong positive correlations between SRP and B (also TP and B) across all the 54 river monitoring sites also confirm the primary importance of point source controls of phosphorus concentrations in these rivers, particularly during spring and summer low flows, which are times of greatest eutrophication risk. Particulate phosphorus (PP) may form a significant proportion of the phosphorus load to rivers, particularly during winter storm events, but this is of questionable relevance for river eutrophication

Selenium and phosphorus interaction in pea (pisum sativum L.)

International Nuclear Information System (INIS)

Singh, Mahendra; Bhandari, D.K.

1975-01-01

The interaction of selenium and phosphorus on the dry matter yield and concentration and uptake of phosphorus, sulfur and selenium was studied in pea (Pisum sativnum) var. T 163. The fertilizer was tagged with P 32 . It was observed that increased concentration of applied selenium in soil decreased the dry matter yield and increased the concentration and uptake of total P, soil P and selenium in pea plants. Increased concentration of P alone increased dry matter yield, concentration and uptake of total, soil and fertilizer P and selenium which was beyond safe limits, and decreased concentration and uptake of sulphur. Selenium and phosphorus showed strong synergetic relationship by increasing the concentration of each other in plants while both showed antagonistic effect on the concentration of sulphur. Phosphorus compensated the toxic effect of selenium and improved the growth and dry matter yield of pea plants. The highest selenium concentration of 22.4 ppm was observed in 100 ppm phosphorus with 5 ppm selenium treated pots while lowest (0.10 ppm) in control. (author)

Assessment of Non-Point Source Total Phosphorus Pollution from Different Land Use and Soil Types in a Mid-High Latitude Region of China

Directory of Open Access Journals (Sweden)

Zhiwei Wang

2016-11-01

Full Text Available The transport characteristics of phosphorus in soil and the assessment of its environmental risk have become hot topics in the environmental and agricultural fields. The Sanjiang Plain is an important grain production base in China, and it is characterised by serious land use change caused by large-scale agricultural exploitation. Agricultural inputs and tillage management have destroyed the soil nutrient balance formed over long-term conditions. There are few studies on non-point source phosphorus pollution in the Sanjiang Plain, which is the largest swampy low plain in a mid-high-latitude region in China. Most studies have focused on the water quality of rivers in marsh areas, or the export mechanism of phosphorus from specific land uses. They were conducted using experimental methods or empirical models, and need further development towards mechanism models and the macro-scale. The question is how to find a way to couple processes in phosphorus cycling and a distributed hydrological model considering local hydrological features. In this study, we report an attempt to use a distributed phosphorus transport model to analyse non-point source total phosphorus pollution from different land uses and soil types on the Sanjiang Plain. The total phosphorus concentration generally shows an annually increasing trend in the study area. The total phosphorus load intensity is heterogeneous in different land use types and different soil types. The average total phosphorus load intensity of different land use types can be ranked in descending order from paddy field, dry land, wetlands, grassland, and forestland. The average total phosphorus load intensity of different soil types can be ranked in descending order: paddy soil, bog soil, planosol, meadow soil, black soil, and dark brown earth. The dry land and paddy fields account for the majority of total phosphorus load in the study area. This is mainly caused by extensive use of phosphate fertilizer on the

Distribution of total phosphorus in the Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Rao, V.C.; Rao, T.S.S.

The total phosphorus content in the sediment samples collected from different stations on the continental shelf along five sections normal to the coast near Bombay, Karwar, Mangalore, Cochin and Alleppey has been determined and the distribution...

Sensitive determination of total particulate phosphorus and particulate inorganic phosphorus in seawater using liquid waveguide spectrophotometry.

Science.gov (United States)

Ehama, Makoto; Hashihama, Fuminori; Kinouchi, Shinko; Kanda, Jota; Saito, Hiroaki

2016-06-01

Determining the total particulate phosphorus (TPP) and particulate inorganic phosphorus (PIP) in oligotrophic oceanic water generally requires the filtration of a large amount of water sample. This paper describes methods that require small filtration volumes for determining the TPP and PIP concentrations. The methods were devised by validating or improving conventional sample processing and by applying highly sensitive liquid waveguide spectrophotometry to the measurements of oxidized or acid-extracted phosphate from TPP and PIP, respectively. The oxidation of TPP was performed by a chemical wet oxidation method using 3% potassium persulfate. The acid extraction of PIP was initially carried out based on the conventional extraction methodology, which requires 1M HCl, followed by the procedure for decreasing acidity. While the conventional procedure for acid removal requires a ten-fold dilution of the 1M HCl extract with purified water, the improved procedure proposed in this study uses 8M NaOH solution for neutralizing 1M HCl extract in order to reduce the dilution effect. An experiment for comparing the absorbances of the phosphate standard dissolved in 0.1M HCl and of that dissolved in a neutralized solution [1M HCl: 8M NaOH=8:1 (v:v)] exhibited a higher absorbance in the neutralized solution. This indicated that the improved procedure completely removed the acid effect, which reduces the sensitivity of the phosphate measurement. Application to an ultraoligotrophic water sample showed that the TPP concentration in a 1075mL-filtered sample was 8.4nM with a coefficient of variation (CV) of 4.3% and the PIP concentration in a 2300mL-filtered sample was 1.3nM with a CV of 6.1%. Based on the detection limit (3nM) of the sensitive phosphate measurement and the ambient TPP and PIP concentrations of the ultraoligotrophic water, the minimum filtration volumes required for the detection of TPP and PIP were estimated to be 15 and 52mL, respectively. Copyright © 2016

An Analysis of Total Phosphorus Dispersion in Lake Used As a Municipal Water Supply.

Science.gov (United States)

Lima, Rômulo C; Mesquita, André L A; Blanco, Claudio J C; Santos, Maria de Lourdes S; Secretan, Yves

2015-09-01

In Belém city is located the potable water supply system of its metropolitan area, which includes, in addition to this city, four more municipalities. In this water supply complex is the Água Preta lake, which serves as a reservoir for the water pumped from the Guamá river. Due to the great importance of this lake for this system, several works have been devoted to its study, from the monitoring of the quality of its waters to its hydrodynamic modeling. This paper presents the results obtained by computer simulation of the phosphorus dispersion within this reservoir by the numerical solution of two-dimensional equation of advection-diffusion-reaction by the method θ/SUPG. Comparing these results with data concentration of total phosphorus collected from November 2008 to October 2009 and from satellite photos show that the biggest polluters of the water of this lake are the domestic sewage dumps from the population living in its vicinity. The results obtained indicate the need for more information for more precise quantitative analysis. However, they show that the phosphorus brought by the Guamá river water is consumed in an area adjacent to the canal that carries this water into the lake. Phosphorus deposits in the lake bottom should be monitored to verify their behavior, thus preventing the quality of water maintained therein.

Simultaneous denitrification and phosphorus removal by Agrobacterium sp. LAD9 under varying oxygen concentration.

Science.gov (United States)

Ma, Tao; Chen, Qian; Gui, Mengyao; Li, Can; Ni, Jinren

2016-04-01

Although efficient aerobic denitrification has received increasing attention, few studies have been made on simultaneous denitrification and phosphorus removal (SDPR) under aerobic condition. In this study, SDPR by an efficient aerobic denitrifier, Agrobacterium sp. LAD9, was firstly demonstrated. High nitrate and phosphorus removal rates of 7.50 and 1.02 mg L(-1) h(-1) were achieved in wide range of O2 concentration from 5.92 to 20.02 mg L(-1). The N2O production would be inhibited as O2 concentration exceeded 11.06 mg L(-1), while the phosphorus removal efficiency would be generally improved with increasing O2 concentration. (15)N mass spectrometry revealed that nitrogen removal accorded with the typical aerobic denitrification pathway, while (31)P nuclear magnetic resonance spectroscopy ((31)P NMR) indicated the fate of phosphorus to cells, extracellular polymeric substances (EPS), and polyphosphate (poly-P) of the denitrifier. EPS acted as a reservoir of phosphorus and the transformation of poly-P was dynamic and depended on initial orthophosphate (ortho-P) content. The aerobic SDPR would greatly simplify the conventional wastewater treatment processes which required separated considerations of nitrogen and phosphorus removal.

Occurrence of phosphorus in groundwater and surface water of northwestern Mississippi

Science.gov (United States)

Welch, Heather L.; Kingsbury, James A.; Coupe, Richard H.

2010-01-01

Previous localized studies of groundwater samples from the Mississippi River Valley alluvial (MRVA) aquifer have demonstrated that dissolved phosphorus concentrations in the aquifer are much higher than the national background concentration of 0.03 milligram per liter (mg/L) found in 400 shallow wells across the country. Forty-six wells screened in the MRVA aquifer in northwestern Mississippi were sampled from June to October 2010 to characterize the occurrence of phosphorus in the aquifer, as well as the factors that might contribute to high dissolved phosphorus concentrations in groundwater. Dissolved phosphorus concentrations ranged from 0.12 to 1.2 mg/L with a median concentration of 0.62 mg/L. The predominant subunit of the MRVA aquifer in northwestern Mississippi is the Holocene alluvium in which median dissolved phosphorus concentrations were higher than the Pleistocene valley trains deposits subunit. Highest phosphorus concentrations occurred in water from wells located along the Mississippi River. A general association between elevated phosphorus concentrations and dissolved iron concentrations suggests that reducing conditions that mobilize iron in the MRVA aquifer also might facilitate transport of phosphorus. Using baseflow separation to estimate the contribution of baseflow to total streamflow, the estimated contribution to the total phosphorus load associated with baseflow at the Tensas River at Tendal, LA, and at the Bogue Phalia near Leland, MS, was 23 percent and 8 percent, respectively. This analysis indicates that elevated concentrations of dissolved phosphorus in the MRVA aquifer could be a possible source of phosphorus to streams during baseflow conditions. However, the fate of phosphorus in groundwater discharge and irrigation return flow to streams is not well understood.

Spatial temporal determination of phosphorus concentration in Lake Tota

International Nuclear Information System (INIS)

Cordero, Ruben D; Ruiz, J Efraim; Vargas, Edgar F

2005-01-01

The lapse from July to November of 2003 a study was made to determine the spatial and temporal concentration of phosphorus in the lake of Tota (Boyaca, Colombia). Samples were taken with a Van-Dorn bottle of the horizontal type of two-liter capacity in the superficial stratum up to 20 cm in the water column and at 10 m depth. The different forms of phosphorus studied, show that there are significant differences in their concentrations, the highest values being found in the sector known as Lago Chico and the lowest in the area of Lago Grande; this behavior is found to be closely related to the agricultural uses of the land in the littoral zone and additionally with the climatic factors especially the precipitation in the area investigated

Relations between total phosphorus and orthophosphorus concentrations and rainfall, surface-water discharge, and groundwater levels in Big Cypress Seminole Indian Reservation, Florida, 2014–16

Science.gov (United States)

McBride, W. Scott; Sifuentes, Dorothy F.

2018-02-06

The Seminole Tribe of Florida (the Tribe) is partnering with the U.S. Environmental Protection Agency to develop a numeric phosphorus criterion for the 52,000-acre Big Cypress Seminole Indian Reservation (BCSIR), which is located downgradient of the Everglades Agricultural Area, and of other public and private lands, in southeastern Hendry County and northwestern Broward County in southern Florida. The U.S. Geological Survey (USGS), in cooperation with the Tribe, used water-quality data collected between October 2014 and September 2016 by the Tribe and the South Florida Water Management District (SFWMD), along with data from rainfall gages, surface-water stage and discharge gages, and groundwater monitoring wells, to (1) examine the relations between local hydrology and measured total phosphorus (TP) and orthophosphorus (OP) concentrations and (2) identify explanatory variables for TP concentrations. Of particular concern were conditions when TP exceeded 10 parts per billion (ppb) (0.01 milligram per liter [mg/L]) given that the State of Florida and the Miccosukee Tribe of Indians Alligator Alley Reservation (located downstream of the BCSIR) have adopted a 10-ppb maximum TP criterion for surface waters.From October 2014 to September 2016, the Tribe collected 47–52 samples at each of nine water-quality sites for analysis of TP and OP, except at one site where 28 samples were collected. For all sites sampled, concentrations of TP (as phosphorus [P]) ranged from less than 0.002 mg/L (2 ppb) to a maximum of nearly 0.50 mg/L (500 ppb), whereas concentrations of OP (as P), the reactive form of inorganic phosphorus readily absorbed by plants and (or) abiotically absorbed, ranged from less than 0.003 mg/L (3 ppb) to a maximum of 0.24 mg/L (240 ppb). The median and interquartile ranges of concentrations of TP and OP in the samples collected in 2014–16 by the Tribe were similar to the median and interquartile ranges of concentrations in samples collected by the SFWMD at

Estimating and mapping grass phosphorus concentration in an African savanna using hyperspectral image data

NARCIS (Netherlands)

Mutanga, O.; Kumar, L.

2007-01-01

We tested the utility of imaging spectroscopy and neural networks to map phosphorus concentration in savanna grass using airborne HyMAP image data. We also sought to ascertain the key wavelengths for phosphorus prediction using hyperspectral remote sensing. The remote sensing of foliar phosphorus

Photometric determination of phosphorus in zircon concentrate and potassium hexafluorozirconate

International Nuclear Information System (INIS)

Polonskaya, I.A.; Fominykh, N.L.

1978-01-01

A method for direct photometric phosphorus determination in the materials, containing considerable zirconium amounts is developed. Phosphorus is determined in a form of reduced heteropolyacid with the use of ascorbic acid and potassium antimonyltartrate in sulfuric acid medium. To remove zirconium effect, a graduation diagram is drawn at the background of zirconium, which is bound into a stable fluoride complex in the presence of H 3 BO 3 . Under the above conditions the coloring developes after 30-40 min and remains stable for 24 hrs. A proportional dependence between phosphorus concentration and optical density is observed in the range of 10-160 mg of Zr. The method sensitivity is 5x10 -5 %

The study of Phosphorus distribution at Putrajaya Wetland

Science.gov (United States)

Mubin Zahari, Nazirul; Malek, Nur Farzana Fasiha Abdul; Fai, Chow Ming; Humaira Haron, Siti; Hafiz Zawawi, Mohd; Nazmi Ismail, Iszmir; Mohamad, Daud; Syamsir, Agusril; Sidek, Lariyah Mohd; Zakwan Ramli, Mohd; Ismail, Norfariza; Zubir Sapian, Ahmad; Noordin, Normaliza; Rahaman, Nurliyana Abdul; Muhamad, Yahzam; Mat Saman, Jarina

2018-04-01

This study is concerning phosphorus distribution in Putrajaya Wetland. Phosphorus is one of the important component in nutrients for living things be it aquatic or non – aquatic organisms. Total phosphorus (TP) results will give some information on the trophic status of surface water in water bodies. The focus of this study is to determine the total phosphorus concentration in Putrajaya Wetland which is in the inlet of the wetland then outlet of the wetland (Central Wetland Lake). The water sample is taken from Putrajaya Wetland and the test was conducted in the laboratory. The result from this study shows the results for total phosphorus according to month, sampling station and cells. Lowest total phosphate at the Central Wetland compare with all the wetland arms cells.

The Spatial-temperal Distribution of Phosphorus Species and the Main Factors Influencing on Phosphorus Transportation in Middle Reaches of the Yarlung Zangbo River, China

Science.gov (United States)

Pu, X.; An, R.; Li, R.; Huang, W.; Li, J.

2017-12-01

The objectives of the current study are to investigate the spatial, temperal variation of phisphorus (P) fraction in middle reaches of the Yarlung Zangbo River of China. Samples were collected in April (dry season), August (wet season), and Octber (normal season) along with the middle reaches from Lazi site to Nuxia sitewhich which is about 1000km long. Sequential extraction were applied to determine the forms of phosphorus in suspended particles and to assess the potential bioavailability of particulate P. The results indicated that the distribution of suspended particle size inflenced not only the total phosphorus concentration, but also the proportions of different forms of phosphorus. The exchangeable phosphorus (Ex-P), Fe-bound-P, Ca-bound-P were the most aboundant forms and the highest proportions of total P. The total P concentrations were closely relative to the concentration of suspended particles. According to the characteristics of suspended particles in the Yarlung Zangbo River, the relationship between the suspended particles size and species of phosphorus was established though statistical analysis. The Ex-P increased with the decreasing of suspended particulate size. The content of bioavailable particulate phosphorus varied greatly with the proportions of particulate size. In genral, the higher the proportion of smaller particle size, the higher the content of bioavailable phosphorus. The main factors which affect the phosphorus transportation in Yarlung Zangbo River had also been discussed.

Effect of phosphorus dopant concentration on the carrier mobility in ...

African Journals Online (AJOL)

This study investigated the effect of phosphorus dopant concentration on mobility of crystalline silicon (c-Si). It considers different temperature ranges, from 100 K to 500 K, and dopant concentration from 1012 cm-3 to 1020 cm-3 in relation to its effect on the mobility of the crystalline silicon. This study indicates that the ...

Determination of total organic phosphorus in samples of mineral soils

Directory of Open Access Journals (Sweden)

Armi Kaila

1962-01-01

Full Text Available In this paper some observations on the estimation of organic phosphorus in mineral soils are reported. The fact is emphasized that the accuracy of all the methods available is relatively poor. Usually, there are no reasons to pay attention to differences less than about 20 ppm. of organic P. Analyses performed on 345 samples of Finnish mineral soils by the extraction method of MEHTA et. al. (10 and by a simple procedure adopted by the author (successive extractions with 4 N H2SO4 and 0.5 N NaOH at room temperature in the ratio of 1 to 100 gave, on the average, equal results. It seemed to be likely that the MEHTA method removed the organic phosphorus more completely than did the less vigorous method, but in the former the partial hydrolysis of organic phosphorus compounds tends to be higher than in the latter. An attempt was made to find out whether the differences between the respective values for organic phosphorus obtained by an ignition method and the simple extraction method could be connected with any characteristics of the soil. No correlation or only a low correlation coefficient could be calculated between the difference in the results of these two methods and e. g. the pH-value, the content of clay, organic carbon, aluminium and iron soluble in Tamm’s acid oxalate, the indicator of the phosphate sorption capacity, or the »Fe-bound» inorganic phosphorus, respectively. The absolute difference tended to increase with an increase in the content of organic phosphorus. For the 250 samples of surface soils analyzed, the ignition method gave values which were, on the average, about 50 ppm. higher than the results obtained by the extraction procedure. The corresponding difference for the 120 samples from deeper layers was about 20 ppm of organic P. The author recommends, for the present, the determination of the total soil organic phosphorus as an average of the results obtained by the ignition method and the extraction method.

Phosphorus Export Model Development in a Terminal Lake Basin using Concentration-Streamflow Relationship

Science.gov (United States)

Jeannotte, T.; Mahmood, T. H.; Matheney, R.; Hou, X.

2017-12-01

Nutrient export to streams and lakes by anthropogenic activities can lead to eutrophication and degradation of surface water quality. In Devils Lake, ND, the only terminal lake in the Northern Great Plains, the algae boom is of great concern due to the recent increase in streamflow and consequent rise in phosphorus (P) export from prairie agricultural fields. However, to date, very few studies explored the concentration (c) -streamflow (q) relationship in the headwater catchments of the Devils Lake basin. A robust watershed-scale quantitative framework would aid understanding of the c-q relationship, simulating P concentration and load. In this study, we utilize c-q relationships to develop a simple model to estimate phosphorus concentration and export from two headwater catchments of different size (Mauvais Coulee: 1032 km2 and Trib 3: 160 km2) draining to Devils Lake. Our goal is to link the phosphorus export model with a physically based hydrologic model to identify major drivers of phosphorus export. USGS provided the streamflow measurements, and we collected water samples (filtered and unfiltered) three times daily during the spring snowmelt season (March 31, 2017- April 12, 2017) at the outlets of both headwater catchments. Our results indicate that most P is dissolved and very little is particulate, suggesting little export of fine-grained sediment from agricultural fields. Our preliminary analyses in the Mauvais Coulee catchment show a chemostatic c-q relationship in the rising limb of the hydrograph, while the recession limb shows a linear and positive c-q relationship. The poor correlation in the rising limb of the hydrograph suggests intense flushing of P by spring snowmelt runoff. Flushing then continues in the recession limb of the hydrograph, but at a more constant rate. The estimated total P load for the Mauvais Coulee basin is 193 kg/km2, consistent with other catchments of similar size across the Red River of the North basin to the east. We expect

Weather conditions influencing phosphorus concentration in the growing period in the large shallow Lake Peipsi (Estonia/Russia)

OpenAIRE

Tammeorg, Olga; Möls, Tonu; Kangur, Külli

2014-01-01

The impact of water temperature (T), water level (L), photosynthetically active radiation (PAR), and wind speed (V) on the total phosphorus concentration (TP) in shallow eutrophic lake Peipsi, the fourth largest lake in Europe, was studied. We used a long-term dataset (1985-2010) of TP concentrations and weather factors. A Thin Plate Spline (TPS) model was used to predict TP by year, by day of the year, and by geographical coordinates. Deviations between observed and predicted TP values (resi...

Phosphorus fertilizer and grazing management effects on phosphorus in runoff from dairy pastures.

Science.gov (United States)

Dougherty, Warwick J; Nicholls, Paul J; Milham, Paul J; Havilah, Euie J; Lawrie, Roy A

2008-01-01

Fertilizer phosphorus (P) and grazing-related factors can influence runoff P concentrations from grazed pastures. To investigate these effects, we monitored the concentrations of P in surface runoff from grazed dairy pasture plots (50 x 25 m) treated with four fertilizer P rates (0, 20, 40, and 80 kg ha(-1) yr(-1)) for 3.5 yr at Camden, New South Wales. Total P concentrations in runoff were high (0.86-11.13 mg L(-1)) even from the control plot (average 1.94 mg L(-1)). Phosphorus fertilizer significantly (P pasture biomass (P dairy pastures should be the maintenance of soil P at or near the agronomic optimum by the use of appropriate rates of P fertilizer.

Characterization of suspended solids and total phosphorus loadings from small watersheds in Wisconsin

Science.gov (United States)

Danz, Mari E.; Corsi, Steven R.; Graczyk, David J.; Bannerman, Roger T.

2010-01-01

Knowledge of the daily, monthly, and yearly distribution of contaminant loadings and streamflow can be critical for the successful implementation and evaluation of water-quality management practices. Loading data for solids (suspended sediment and total suspended solids) and total phosphorus and streamflow data for 23 watersheds were summarized for four ecoregions of Wisconsin: the Driftless Area Ecoregion, the Northern Lakes and Forests Ecoregion, the North Central Hardwoods Ecoregion, and the Southeastern Wisconsin Till Plains Ecoregion. The Northern Lakes and Forests and the North Central Hardwoods Ecoregions were combined into one region for analysis due to a lack of sufficient data in each region. Urban watersheds, all located in the Southeastern Wisconsin Till Plains, were analyzed separately from rural watersheds as the Rural Southeastern Wisconsin Till Plains region and the Urban Southeastern Wisconsin Till Plains region. Results provide information on the distribution of loadings and streamflow between base flow and stormflow, the timing of loadings and streamflow throughout the year, and information regarding the number of days in which the majority of the annual loading is transported. The average contribution to annual solids loading from stormflow periods for the Driftless Area Ecoregion was 84 percent, the Northern Lakes and Forests/North Central Hardwoods region was 71 percent, the Rural Southeastern Wisconsin Till Plains region was 70 percent, and the Urban Southeastern Wisconsin Till Plains region was 90 percent. The average contributions to annual total phosphorus loading from stormflow periods were 72, 49, 61, and 76 percent for each of the respective regions. The average contributions to annual streamflow from stormflow periods are 20, 23, 31, and 50 percent for each of the respective regions. In all regions, the most substantial loading contributions for solids were in the late winter (February through March), spring (April through May), and

Simple, cost effective method for determination of phosphorus in uranium ore concentrate

International Nuclear Information System (INIS)

Misra, U.B.; Ramamurty, Vasantha; Dutta, M.; Balaji Rao, Y.; Subba Rao, Y.

2015-01-01

In this paper determination of phosphate as phosphorus in uranium ore concentrate has been described. The method used is spectrophotometric determination of phosphorus as phospho-molybdenum blue complex. As uranyl ion do not absorb in 600-900 nm range of visible region in the present medium, the phosphomolybdenum blue complex formation which is having maximum absorbance at 825 nm is exploited for determination of phosphorus. The molar absorptivity coefficient with and without the presence of uranium matrix are 2.6048 x 10 4 and 2.6730 x 10 4 lmol -1 cm -1 . The effect of matrix is not evident from the experiment carried out. (author)

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water

Science.gov (United States)

Patton, Charles J.; Kryskalla, Jennifer R.

2003-01-01

Alkaline persulfate digestion was evaluated and validated as a more sensitive, accurate, and less toxic alternative to Kjeldahl digestion for routine determination of nitrogen and phosphorus in surface- and ground-water samples in a large-scale and geographically diverse study conducted by U.S. Geological Survey (USGS) between October 1, 2001, and September 30, 2002. Data for this study were obtained from about 2,100 surface- and ground-water samples that were analyzed for Kjeldahl nitrogen and Kjeldahl phosphorus in the course of routine operations at the USGS National Water Quality Laboratory (NWQL). These samples were analyzed independently for total nitrogen and total phosphorus using an alkaline persulfate digestion method developed by the NWQL Methods Research and Development Program. About half of these samples were collected during nominally high-flow (April-June) conditions and the other half were collected during nominally low-flow (August-September) conditions. The number of filtered and whole-water samples analyzed from each flow regime was about equal.By operational definition, Kjeldahl nitrogen (ammonium + organic nitrogen) and alkaline persulfate digestion total nitrogen (ammonium + nitrite + nitrate + organic nitrogen) are not equivalent. It was necessary, therefore, to reconcile this operational difference by subtracting nitrate + nitrite concentra-tions from alkaline persulfate dissolved and total nitrogen concentrations prior to graphical and statistical comparisons with dissolved and total Kjeldahl nitrogen concentrations. On the basis of two-population paired t-test statistics, the means of all nitrate-corrected alkaline persulfate nitrogen and Kjeldahl nitrogen concentrations (2,066 paired results) were significantly different from zero at the p = 0.05 level. Statistically, the means of Kjeldahl nitrogen concentrations were greater than those of nitrate-corrected alkaline persulfate nitrogen concentrations. Experimental evidence strongly

[Effects of phosphorus sources on phosphorus fractions in rhizosphere soil of wild barley genotypes with high phosphorus utilization efficiency].

Science.gov (United States)

Cai, Qiu-Yan; Zhang, Xi-Zhou; Li, Ting-Xuan; Chen, Guang-Deng

2014-11-01

High P-efficiency (IS-22-30, IS-22-25) and low P-efficiency (IS-07-07) wild barley cultivars were chosen to evaluate characteristics of phosphorus uptake and utilization, and properties of phosphorus fractions in rhizosphere and non-rhizosphere in a pot experiment with 0 (CK) and 30 mg P · kg(-1) supplied as only Pi (KH2PO4), only Po (phytate) or Pi + Po (KH2PO4+ phytate). The results showed that dry matter and phosphorus accumulation of wild barley in the different treatments was ranked as Pi > Pi + Po > Po > CK. In addition, dry matter yield and phosphorus uptake of wild barley with high P-efficiency exhibited significantly greater than that with low P-efficiency. The concentration of soil available phosphorus was significantly different after application of different phosphorus sources, which was presented as Pi > Pi + Po > Po. The concentration of soil available phosphorus in high P-efficiency wild barley was significantly higher than that of low P-efficiency in the rhizosphere soil. There was a deficit in rhizosphere available phosphorus of high P-efficiency wild barley, especially in Pi and Pi+Po treatments. The inorganic phosphorus fractions increased with the increasing Pi treatment, and the concentrations of inorganic phosphorus fractions in soil were sorted as follows: Ca10-P > O-P > Fe-P > Al-P > Ca2-P > Ca8-P. The contents of Ca2-P and Ca8-P for high P-efficiency wild barley showed deficits in rhizosphere soil under each phosphorus source treatment. In addition, enrichment of Al-P and Fe-P was observed in Pi treatment in rhizosphere soil. The concentrations of organic phosphorus fractions in soil were sorted as follows: moderate labile organic phosphorus > moderate resistant, resistant organic phosphorus > labile organic phosphorus. The labile and moderate labile organic phosphorus enriched in rhizosphere soil and the greatest enrichment appeared in Pi treatment. Furthermore, the concentrations of moderate resistant organic phosphorus and resistant

Total Phosphorus in Surface Water

Data.gov (United States)

U.S. Environmental Protection Agency — Excess phosphorus in surface water can result in eutrophication. TOTALP is reported in kilograms/hectare/year. More information about these resources, including the...

Long-term trends of phosphorus concentrations in an artificial lake: Socio-economic and climate drivers.

Science.gov (United States)

Vystavna, Yuliya; Hejzlar, Josef; Kopáček, Jiří

2017-01-01

European freshwater ecosystems have undergone significant human-induced and environmentally-driven variations in nutrient export from catchments throughout the past five decades, mainly in connection with changes in land-use, agricultural practice, waste water production and treatment, and climatic conditions. We analysed the relations among concentration of total phosphorus (TP) in the Slapy Reservoir (a middle reservoir of the Vltava River Cascade, Czechia), and socio-economic and climatic factors from 1963 to 2015. The study was based on a time series analysis, using conventional statistical tools, and the identification of breaking points, using a segmented regression. Results indicated clear long-term trends and seasonal patterns of TP, with annual average TP increasing up until 1991 and decreasing from 1992 to 2015. Trends in annual, winter and spring average TP concentrations reflected a shift in development of sewerage and sanitary infrastructure, agricultural application of fertilizers, and livestock production in the early 1990s that was associated with changes from the planned to the market economy. No trends were observed for average TP in autumn. The summer average TP has fluctuated with increased amplitude since 1991 in connection with recent climate warming, changes in thermal stratification stability, increased water flow irregularities, and short-circuiting of TP-rich inflow during high flow events. The climate-change-induced processes confound the generally declining trend in lake-water TP concentration and can result in eutrophication despite decreased phosphorus loads from the catchment. Our findings indicate the need of further reduction of phosphorus sources to meet ecological quality standards of the EU Water Framework Directive because the climate change may lead to a greater susceptibility of the aquatic ecosystem to the supply of nutrients.

Competition between free-floating plants is strongly driven by previously experienced phosphorus concentrations in the water column

NARCIS (Netherlands)

Peeters, E.T.H.M.; Neefjes, Rozemarijn; Zuidam, van B.G.

2016-01-01

Nutrients can determine the outcome of the competition between different floating plant species. The response of floating plants to current phosphorus levels may be affected by previously experienced phosphorus concentrations because some species have the ability to store excess phosphorus for later

Associations of socioeconomic status and processed food intake with serum phosphorus concentration in community-living adults: the Multi-Ethnic Study of Atherosclerosis (MESA).

Science.gov (United States)

Gutiérrez, Orlando M; Katz, Ronit; Peralta, Carmen A; de Boer, Ian H; Siscovick, David; Wolf, Myles; Diez Roux, Ana; Kestenbaum, Bryan; Nettleton, Jennifer A; Ix, Joachim H

2012-09-01

Higher serum phosphorus concentrations are associated with cardiovascular disease events and mortality. Low socioeconomic status is linked with higher serum phosphorus concentration, but the reasons are unclear. Poor individuals disproportionately consume inexpensive processed foods commonly enriched with phosphorus-based food preservatives. Accordingly, we hypothesized that excess intake of these foods accounts for a relationship between lower socioeconomic status and higher serum phosphorus concentration. Cross-sectional analysis. We examined a random cohort of 2,664 participants with available phosphorus measurements in the Multi-Ethnic Study of Atherosclerosis, a community-based sample of individuals free of clinically apparent cardiovascular disease from across the United States. Socioeconomic status, the intake of foods commonly enriched with phosphorus-based food additives (processed meats, sodas), and frequency of fast-food consumption. Fasting morning serum phosphorus concentrations. In unadjusted analyses, lower income and lower educational achievement categories were associated with modestly higher serum phosphorus concentration (by 0.02 to 0.10 mg/dL, P fast-food consumption with serum phosphorus. In contrast, each serving per day higher soda intake was associated with 0.02 mg/dL lower serum phosphorus concentration (95% confidence interval, -0.04, -0.01). Greater intake of foods commonly enriched with phosphorus additives was not associated with higher serum phosphorus concentration in a community-living sample with largely preserved kidney function. These results suggest that excess intake of processed and fast foods may not impact fasting serum phosphorus concentrations among individuals without kidney disease. Copyright © 2012 National Kidney Foundation, Inc. All rights reserved.

Vertical distribution of total carbon, nitrogen and phosphorus in sediments of Drug Spring Lake, Wudalianchi

Science.gov (United States)

Zeng, Ying; Yang, Chen

2018-02-01

The content of total organic carbon, total nitrogen and total phosphorus in sediments of Drug Spring Lake was detected and their vertical distribution characteristic was analysed. Results showed that there were significant changes to the content of total organic carbon, total nitrogen and total phosphorus in different depth of the columnar sediments. Their highest content both appeared in the interval of 10cm to 25cm corresponding to the period of 1980s to 1990s, when the tourism of Wudalianchi scenic area began to develop. It reflected the impact of human activities on the Drug Spring Lake. That means the regulation was still not enough, although a series of pollution control measures adopted by the government in recent years had initial success.

Effects of salinity, temperature and phosphorus concentration on the chemical composition of Gelidium crinale (Turner Lamouroux (Gelidiaceae, Rhodophyta

Directory of Open Access Journals (Sweden)

Lúcia Rebello Dillenburg

2005-05-01

Full Text Available The effects of different culture conditions (temperature, salinity and dissolved inorganic phosphorus were investigated for seven days, under controlled conditions. The maximum production of proteins occurred in cultures where the temperature was 25°C, with concentrations of 5.0 and 10.0 µM of dissolved inorganic phosphorus and salinity between 15 and 20 psu, with values varying from 2.62 to 2.83% of algae dry weight. For carbohydrates, a third-order interaction was not observed in the statistical analysis; only a second order interaction was observed between temperature and inorganic phosphorus concentrations Efeito dos parâmetros abióticos em cultivo de G. crinale (P < 0.005 and between temperature and salinity (P < 0.000. The greatest phosphorus increase in the thalli (0.80 % occurred in the lowest temperature (15 °C, associated with low salinity (10 psu and high inorganic phosphorus concentration (10.0 µM. The Pearson’s correlation coefficient revealed positive correlations (P < 0.001 among protein content, temperature and inorganic phosphorus available in the growth medium. For carbohydrates, correlations were positive with all three abiotic parameters. For tissue phosphorus, a positive correlation occurred only with dissolved inorganic phosphorus; with temperature and salinity, the correlations were negative. Among the chemical components present in the algae, proteins and carbohydrates showed a positive correlation, while tissue phosphorus presented a negative correlation with both, although this correlation was not significant with regard to protein.

Estimation of phosphorus flux in rivers during flooding.

Science.gov (United States)

Chen, Yen-Chang; Liu, Jih-Hung; Kuo, Jan-Tai; Lin, Cheng-Fang

2013-07-01

Reservoirs in Taiwan are inundated with nutrients that result in algal growth, and thus also reservoir eutrophication. Controlling the phosphorus load has always been the most crucial issue for maintaining reservoir water quality. Numerous agricultural activities, especially the production of tea in riparian areas, are conducted in watersheds in Taiwan. Nutrients from such activities, including phosphorus, are typically flushed into rivers during flooding, when over 90% of the yearly total amount of phosphorous enters reservoirs. Excessive or enhanced soil erosion from rainstorms can dramatically increase the river sediment load and the amount of particulate phosphorus flushed into rivers. When flow rates are high, particulate phosphorus is the dominant form of phosphorus, but sediment and discharge measurements are difficult during flooding, which makes estimating phosphorus flux in rivers difficult. This study determines total amounts of phosphorus transport by measuring flood discharge and phosphorous levels during flooding. Changes in particulate phosphorus, dissolved phosphorus, and their adsorption behavior during a 24-h period are analyzed owing to the fact that the time for particulate phosphorus adsorption and desorption approaching equilibrium is about 16 h. Erosion of the reservoir watershed was caused by adsorption and desorption of suspended solids in the river, a process which can be summarily described using the Lagmuir isotherm. A method for estimating the phosphorus flux in the Daiyujay Creek during Typhoon Bilis in 2006 is presented in this study. Both sediment and phosphorus are affected by the drastic discharge during flooding. Water quality data were collected during two flood events, flood in June 9, 2006 and Typhoon Bilis, to show the concentrations of suspended solids and total phosphorus during floods are much higher than normal stages. Therefore, the drastic changes of total phosphorus, particulate phosphorus, and dissolved phosphorus in

Increasing Dietary Phosphorus Intake from Food Additives: Potential for Negative Impact on Bone Health123

OpenAIRE

Takeda, Eiji; Yamamoto, Hironori; Yamanaka-Okumura, Hisami; Taketani, Yutaka

2014-01-01

It is important to consider whether habitual high phosphorus intake adversely affects bone health, because phosphorus intake has been increasing, whereas calcium intake has been decreasing in dietary patterns. A higher total habitual dietary phosphorus intake has been associated with higher serum parathyroid hormone (PTH) and lower serum calcium concentrations in healthy individuals. Higher serum PTH concentrations have been shown in those who consume foods with phosphorus additives. These fi...

Characteristics of Phosphorus Runoff Losses from Typical Paddy Fields in Guangdong Province, China

Directory of Open Access Journals (Sweden)

NING Jian-feng

2018-03-01

Full Text Available Three experimental paddy fields located in the city of Zengcheng, Qingyuan and Gaozhou in Guangdong Province were selected to monitor the runoff losses of phosphorus from the year of 2008 to 2012. The results showed that runoff event in paddy field occurred mainly in the early rice season. The runoff concentration of total phosphorus(TP under conventional fertilization treatment was in the range of 0.02~1.56 mg·L-1. It was recorded that TP concentration in 11%~18% of the total runoff samples exceeded the grade Ⅴ of the national surface water environmental quality(0.4 mg·L-1. Peak concentration of different phosphorus forms[TP, dissolved total P(DTP and particulate P(PP] were observed within 14 days after fertilization, which indicated the high environmental pollution risk of phosphorus during this period. Application of phosphorus fertilizer increased runoff load of DTP in paddy field and showed no effect on that of PP and TP. The annual runoff loads of 0.63~4.05, 0.33~2.91 kg·hm-2 and 1.10~6.68 kg·hm-2 for DTP, PP and TP, respectively, were recorded under conventional fertilizer model. Runoff load of phosphorus exhibited wide spatial and temporal variation during experimental period. Runoff coefficient of 0.06%~6.81% of phosphorus was recorded. It was observed that DTP dominated the phosphorus runoff load. Phosphorus runoff losses from paddy field was affected by a variety of natural and human factors, and fertilization, precipitation and runoff volume were identified as the main factors.

Total nitrogen and total phosphorus removal from brackish aquaculture wastewater using effective microorganism

Science.gov (United States)

Mohamad, K. A.; Mohd, S. Y.; Sarah, R. S.; Mohd, H. Z.; Rasyidah, A.

2017-09-01

Aquaculture is one of dominant food based industry in the world with 8.3% annual growth rate and its development had led to adverse effect on the environment. High nutrient production in form of nitrogenous compound and phosphorus contributed to environmental deterioration such as eutrophication and toxicity to the industry. Usage of Effective Microorganism (EM), one of the biological approaches to remove Total Nitrogen (TN) and Total Phosphorus (TP) in aquaculture pond was proposed. Samples were obtained from the Sea Bass intensive brackish aquaculture wastewater (AW) from fish farm at Juru, Penang and the parameters used to measure the removal of nitrogenous compounds include, pH, EM dosage, shaking, contact time and optimum variable conditions. From the study, for effective contact time, day 6 is the optimum contact time for both TN and TP with 99.74% and 62.78% removal respectively while in terms of optimum pH, the highest TN removal was at pH 7 with 66.89 %. The optimum dosage of EM is 1.5 ml with ratio 1:166 for 81.5 % TN removal was also found appropriate during the experiment. At varied optimum conditions of EM, the removal efficiency of TN and TP were 81.53% and 38.94% respectively while the removal mechanism of TN was highly dependent on the decomposition rate of specific bacteria such as Nitrobacter bacteria, Yeast and Bacillus Subtilis sp. The study has established the efficacy of EM's ability to treat excessive nutrient of TN and TP from AW.

Factors affecting phosphorus transport at a conventionally-farmed site in Lancaster County, Pennsylvania, 1992-95

Science.gov (United States)

Galeone, Daniel G.

1996-01-01

The U.S. Geological Survey and the Bureau of Land and Water Conservation of the Pennsylvania Department of Environmental Protection conducted a cooperative study to determine the effects of manure application and antecedent soil-phosphorus concentrations on the transport of phosphorus from the soil of a typical farm site in Lancaster County, Pa., from September 1992 to March 1995. The relation between concentrations of soil phosphorus and phosphorus transport needs to be identified because excessive phosphorus concentrations in surface-water bodies promote eutrophication.The objective of the study was to quantify and determine the significance of chemical, physical, and hydrologic factors that affected phosphorus transport. Three study plots less than 1 acre in size were tilled and planted in silage corn. Phosphorus in the form of liquid swine and dairy manure was injected to a depth of 6-8 inches on two of the three study plots in May 1993 and May 1994. Plot 1 received no inputs of phosphorus from manure while plots 2 and 3 received an average of 56 and 126 kilograms of phosphorus per acre, respectively, from the two manure applications. No other fertilizer was applied to any of the study plots. From March 30, 1993, through December 31, 1993, and March 10, 1994, through August 31, 1994 (the study period), phosphorus and selected cations were measured in precipitation, manure, soil, surface runoff, subsurface flow (at 18 inches below land surface), and corn plants before harvest. All storm events that yielded surface runoff and subsurface flow were sampled. Surface runoff was analyzed for dissolved (filtered through a 0.45-micron filter) and total concentrations. Subsurface flow was only analyzed for dissolved constituents. Laboratory soil-flask experiments and geochemical modeling were conducted to determine the maximum phosphate retention capacity of sampled soils after manure applications and primary mineralogic controls in the soils that affect phosphate

Loads of nitrate, phosphorus, and total suspended solids from Indiana watersheds

Science.gov (United States)

Bunch, Aubrey R.

2016-01-01

Transport of excess nutrients and total suspended solids (TSS) such as sediment by freshwater systems has led to degradation of aquatic ecosystems around the world. Nutrient and TSS loads from Midwestern states to the Mississippi River are a major contributor to the Gulf of Mexico Hypoxic Zone, an area of very low dissolved oxygen concentration in the Gulf of Mexico. To better understand Indiana’s contribution of nutrients and TSS to the Mississippi River, annual loads of nitrate plus nitrite as nitrogen, total phosphorus, and TSS were calculated for nine selected watersheds in Indiana using the load estimation model, S-LOADEST. Discrete water-quality samples collected monthly by the Indiana Department of Environmental Management’s Fixed Stations Monitoring Program from 2000–2010 and concurrent discharge data from the U. S. Geological Survey streamflow gages were used to create load models. Annual nutrient and TSS loads varied across Indiana by watershed and hydrologic condition. Understanding the loads from large river sites in Indiana is important for assessing contributions of nutrients and TSS to the Mississippi River Basin and in determining the effectiveness of best management practices in the state. Additionally, evaluation of loads from smaller upstream watersheds is important to characterize improvements at the local level and to identify priorities for reduction.

Low-to-moderate nitrogen and phosphorus concentrations accelerate microbially driven litter breakdown rates

Science.gov (United States)

John S. Kominoski; Amy D. Rosemond; Jonathan P. Benstead; Vladislav Gulis; John C. Maerz; David Manning

2015-01-01

Particulate organic matter (POM) processing is an important driver of aquatic ecosystem productivity that is sensitive to nutrient enrichment and drives ecosystem carbon (C) loss. Although studies of single concentrations of nitrogen (N) or phosphorus (P) have shown effects at relatively low concentrations, responses of litter breakdown rates along gradients of low-to-...

Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

International Nuclear Information System (INIS)

Eltayeb, M. A. H.; Mohammed, A. A.

2003-01-01

In the present work uranium content and total phosphorus were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba Mountains in Sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (Vi) is kept in solution as its carbonate complex. The ion exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of absorbance of the yellow uranium (Vi)-8-hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the total liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples from uro area, which contain 200 ppm uranium in average. (Author)

Spatial variability of arsenic concentration in soils and plants, and its relationship with iron, manganese and phosphorus

International Nuclear Information System (INIS)

Hossain, M.B.; Jahiruddin, M.; Panaullah, G.M.; Loeppert, R.H.; Islam, M.R.; Duxbury, J.M.

2008-01-01

Spatial distribution of arsenic (As) concentrations of irrigation water, soil and plant (rice) in a shallow tube-well (STW) command area (8 ha), and their relationship with Fe, Mn and P were studied. Arsenic concentrations of water in the 110 m long irrigation channel clearly decreased with distance from the STW point, the range being 68-136 μg L -1 . Such decreasing trend was also noticed with Fe and P concentrations, but the trend for Mn concentrations was not remarkable. Concerning soil As, the concentration showed a decreasing tendency with distance from the pump. The NH 4 -oxalate extractable As contributed 36% of total As and this amount of As was associated with poorly crystalline Fe-oxides. Furthermore only 22% of total As was phosphate extractable so that most of the As was tightly retained by soil constituents and was not readily exchangeable by phosphate. Soil As (both total and extractable As) was significantly and positively correlated with rice grain As (0.296 ± 0.063 μg g -1 , n = 56). Next to drinking water, rice could be a potential source of As exposure of the people living in the As affected areas of Bangladesh. - Arsenic concentrations of irrigation water, soil and rice decreased with distance from STW point and it was related with iron and phosphorus concentrations

Estimation of Total Nitrogen and Phosphorus in New England Streams Using Spatially Referenced Regression Models

Science.gov (United States)

Moore, Richard Bridge; Johnston, Craig M.; Robinson, Keith W.; Deacon, Jeffrey R.

2004-01-01

The U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (USEPA) and the New England Interstate Water Pollution Control Commission (NEIWPCC), has developed a water-quality model, called SPARROW (Spatially Referenced Regressions on Watershed Attributes), to assist in regional total maximum daily load (TMDL) and nutrient-criteria activities in New England. SPARROW is a spatially detailed, statistical model that uses regression equations to relate total nitrogen and phosphorus (nutrient) stream loads to nutrient sources and watershed characteristics. The statistical relations in these equations are then used to predict nutrient loads in unmonitored streams. The New England SPARROW models are built using a hydrologic network of 42,000 stream reaches and associated watersheds. Watershed boundaries are defined for each stream reach in the network through the use of a digital elevation model and existing digitized watershed divides. Nutrient source data is from permitted wastewater discharge data from USEPA's Permit Compliance System (PCS), various land-use sources, and atmospheric deposition. Physical watershed characteristics include drainage area, land use, streamflow, time-of-travel, stream density, percent wetlands, slope of the land surface, and soil permeability. The New England SPARROW models for total nitrogen and total phosphorus have R-squared values of 0.95 and 0.94, with mean square errors of 0.16 and 0.23, respectively. Variables that were statistically significant in the total nitrogen model include permitted municipal-wastewater discharges, atmospheric deposition, agricultural area, and developed land area. Total nitrogen stream-loss rates were significant only in streams with average annual flows less than or equal to 2.83 cubic meters per second. In streams larger than this, there is nondetectable in-stream loss of annual total nitrogen in New England. Variables that were statistically significant in the total

[Response of Algae to Nitrogen and Phosphorus Concentration and Quantity of Pumping Water in Pumped Storage Reservoir].

Science.gov (United States)

Wan, You-peng; Yin, Kui-hao; Peng, Sheng-hua

2015-06-01

Taking a pumped storage reservoir located in southern China as the research object, the paper established a three-dimensional hydrodynamic and eutrophication model of the reservoir employing EFDC (environmental fluid dynamics code) model, calibrated and verified the model using long-term hydraulic and water quality data. Based on the model results, the effects of nitrogen and phosphorus concentrations on the algae growth were analyzed, and the response of algae to nitrogen and phosphorus concentration and quantity of pumping water was also calculated. The results showed that the nitrogen and phosphorus concentrations had little limit on algae growth rate in the reservoir. In the nutrients reduction scenarios, reducing phosphorus would gain greater algae biomass reduction than reducing nitrogen. When reducing 60 percent of nitrogen, the algae biomass did not decrease, while 12.4 percent of algae biomass reduction could be gained with the same reduction ratio of phosphorus. When the reduction ratio went to 90 percent, the algae biomass decreased by 17.9 percent and 35.1 percent for nitrogen and phosphorus reduction, respectively. In the pumping water quantity regulation scenarios, the algae biomass decreased with the increasing pumping water quantity when the pumping water quantity was greater than 20 percent of the current value; when it was less than 20 percent, the algae biomass increased with the increasing pumping water quantity. The algae biomass decreased by 25.7 percent when the pumping water quantity was doubled, and increased by 38.8 percent when it decreased to 20 percent. The study could play an important role in supporting eutrophication controlling in water source area.

Fósforo total, fósforo fítico y actividad fitásica en los frutos de árboles forrajeros de los Llanos Centrales de Venezuela Total phosphorus, phytic phosphorus and phytase activity in the fruits of forage trees from the Central Plains, Venezuela

Directory of Open Access Journals (Sweden)

P Pizzani

2009-06-01

Full Text Available Con el objetivo de conocer la concentración de fósforo total (PT, fósforo fítico (PF y la actividad fitásica intrínseca (AFi de algunos frutos de árboles de interés forrajero de los Llanos Centrales de Venezuela: samán (Pithecellobium saman, carocaro (Enterolobium cyclocarpum, cují hediondo (Acacia macracantha, cañafistolillo (Cassia emarginata, caruto (Genipa americana, dividive (Caesalpinia coriaria, granadillo (Caesalpinia granadillo, guamacho (Pereskia guamacho, tiamo (Acacia glomerosa, guácimo (Guazuma ulmifolia, merecure (Licania pyrifolia y cují blanco (Prosopis juliflora, se realizó un ensayo mediante un diseño totalmente aleatorizado y diez réplicas. Los resultados indicaron valores de PT entre 0,08 y 0,38% y los contenidos de PF oscilaron entre 0,02 y 0,28%; ambas variables presentaron diferencias significativas entre especies (PWith the objective of learning the total phosphorus (TP and phytic phosphorus (PP concentrations and the intrinsic phytase activity (PAi in some fruits of forage trees from the Central Plains, Venezuela: Pithecellobium saman, Enterolobium cyclocarpum, Acacia macracantha, Cassia emarginata, Genipa americana, Caesalpinia coriaria, Caesalpinia granadillo, Pereskia guamacho, Acacia glomerosa, Guazuma ulmifolia, Licania pyrifolia and Prosopis juliflora, a trial was conducted by means of a completely randomized design and ten replications. The results indicated TP values between 0,08 and 0,38% and the PP contents oscillated between 0,02 and 0,28%; both variables showed significant differences among species (P<0,05. P. guamacho had the highest TP and PP concentration. The PAi of 91,7% of the fruits was higher than 100 Ukg-1; the rest showed values between 94 and 95 Ukg-1. The PP content was highly correlated to TP concentration (r = 0,97; P<0,01. However, the PAi did not show significant relationship to the TP and PP values. Only L. pyrifolia recorded a lower value (0,08%. The PP content, as percentage

Exploring the Modes of Action of Phosphorus-Based Flame Retardants in Polymeric Systems

Directory of Open Access Journals (Sweden)

Sebastian Rabe

2017-04-01

Full Text Available Phosphorus-based flame retardants were incorporated into different, easily preparable matrices, such as polymeric thermoset resins and paraffin as a proposed model for polyolefins and investigated for their flame retardancy performance. The favored mode of action of each flame retardant was identified in each respective system and at each respective concentration. Thermogravimetric analysis was used in combination with infrared spectroscopy of the evolved gas to determine the pyrolysis behavior, residue formation and the release of phosphorus species. Forced flaming tests in the cone calorimeter provided insight into burning behavior and macroscopic residue effects. The results were put into relation to the phosphorus content to reveal correlations between phosphorus concentration in the gas phase and flame inhibition performance, as well as phosphorus concentration in the residue and condensed phase activity. Total heat evolved (fire load and peak heat release rate were calculated based on changes in the effective heat of combustion and residue, and then compared with the measured values to address the modes of action of the flame retardants quantitatively. The quantification of flame inhibition, charring, and the protective layer effect measure the non-linear flame retardancy effects as functions of the phosphorus concentration. Overall, this screening approach using easily preparable polymer systems provides great insight into the effect of phosphorus in different flame retarded polymers, with regard to polymer structure, phosphorus concentration, and phosphorus species.

Accumulation of phosphorus in coastal marine sediments: relationship to benthic and diffusive fluxes

Directory of Open Access Journals (Sweden)

Rocio Ponce

2010-11-01

Full Text Available Sedimentary phosphorus was characterized in sediment cores from 3 coastal ecosystems of the Gulf of Cadiz. High spatial variability was observed in total phosphorus (from 445 to 20291 μg g.sed-1 and in the other phosphorus phases studied. This variability correlates with the proximity of the 10 sampling stations to sources of urban and/or industrial effluent in the zone. The benthic and diffusive fluxes were measured concurrently with sediment collection at these stations. The measured values of benthic fluxes range between –14 and 6 mmol m-2 d-1. Generally, stations that showed increased interstitial phosphate concentrations with increasing depth were characterized by positive values in phosphate benthic fluxes and by high percentages of reactive forms of sedimentary phosphorus. Negative benthic fluxes were associated with stations receiving more anthropogenic matter, which showed progressively decreasing phosphate concentrations in the interstitial water with depth. In these anthropogenic areas, the non-reactive forms of phosphorus (those associated with ferric oxyhydroxide and authigenic carbonate fluorapatite are abundant, and reach values exceeding 75% of total phosphorus in sediment.

Distribution of total phosphorus in the shelf sediments off the west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Murty, P.S.N.; Reddy, C.V.G.; Varadachari, V.V.R.

The total phosphorus content in the sediment samples collected from different stations on the continental shelf along five sections normal to the coast near Bombay, Karwar, Mangalore, Cochin and Alleppey has been determined and the distribution...

Electrically-inactive phosphorus re-distribution during low temperature annealing

Science.gov (United States)

Peral, Ana; Youssef, Amanda; Dastgheib-Shirazi, Amir; Akey, Austin; Peters, Ian Marius; Hahn, Giso; Buonassisi, Tonio; del Cañizo, Carlos

2018-04-01

An increased total dose of phosphorus (P dose) in the first 40 nm of a phosphorus diffused emitter has been measured after Low Temperature Annealing (LTA) at 700 °C using the Glow Discharge Optical Emission Spectrometry technique. This evidence has been observed in three versions of the same emitter containing different amounts of initial phosphorus. A stepwise chemical etching of a diffused phosphorus emitter has been carried out to prepare the three types of samples. The total P dose in the first 40 nm increases during annealing by 1.4 × 1015 cm-2 for the sample with the highly doped emitter, by 0.8 × 1015 cm-2 in the middle-doped emitter, and by 0.5 × 1015 cm-2 in the lowest-doped emitter. The presence of surface dislocations in the first few nanometers of the phosphorus emitter might play a role as preferential sites of local phosphorus gettering in phosphorus re-distribution, because the phosphorus gettering to the first 40 nm is lower when this region is etched stepwise. This total increase in phosphorus takes place even though the calculated electrically active phosphorus concentration shows a reduction, and the measured sheet resistance shows an increase after annealing at a low temperature. The reduced electrically active P dose is around 0.6 × 1015 cm-2 for all the emitters. This can be explained with phosphorus-atoms diffusing towards the surface during annealing, occupying electrically inactive configurations. An atomic-scale visual local analysis is carried out with needle-shaped samples of tens of nm in diameter containing a region of the highly doped emitter before and after LTA using Atom Probe Tomography, showing phosphorus precipitates of 10 nm and less before annealing and an increased density of larger precipitates after annealing (25 nm and less).

Phosphorus vertical migration in aquic brown soil and light chernozem under different phosphorous application rate: a soil column leaching experiment.

Science.gov (United States)

Zhao, Muqiu; Chen, Xin; Shi, Yi; Zhou, Quanlai; Lu, Caiyan

2009-01-01

A soil column leaching experiment was conducted to study the vertical migration of phosphorus in aquic brown soil and light chernozem under different phosphorus fertilization rates. The results showed that total dissolved phosphorus concentration in the leachates from the two soils was nearly the same, but dissolved inorganic phosphorus concentration was obviously different. In all fertilization treatments, aquic brown soil had a higher content of phosphorus in calcium chloride extracts compared with light chernozem. But Olsen phosphorus content was higher at the soil depth beneath 0-20 cm, and increased with increasing phosphorus application rate.

Nutritional geometry of calcium and phosphorus nutrition in broiler chicks. The effect of different dietary calcium and phosphorus concentrations and ratios on nutrient digestibility.

Science.gov (United States)

Wilkinson, S J; Bradbury, E J; Thomson, P C; Bedford, M R; Cowieson, A J

2014-07-01

A total of 600 Ross 308-day-old male broiler chicks were used in a 28 day digestibility study to investigate the interaction between dietary calcium (Ca) and non-phytate phosphorus (nPP) on the digestibility of minerals and amino acids. Diets were formulated to be nutritionally adequate except for Ca and nPP. Fifteen mash diets based on corn and soya bean meal with varying concentrations of Ca (6.4 to 12.0 g/kg) and nPP (2.4 to 7.0 g/kg) were used. Diets were clustered around total densities of Ca and nPP of 12, 13.5 or 15.0 (g/kg) and within each density, a range of five Ca : nPP ratios (1.14 : 1, 1.5 : 1, 2.0 : 1, 2.75 : 1 and 4.0 : 1) were fed. Birds had free access to feed and water throughout the study. At day 28, birds were euthanised for the determination of apparent ileal mineral and amino acid digestibility. Data were modelled in R version 2.15 using a linear mixed-effects model and interrogation of the data was performed by fitting a low order polynomial function. At high Ca concentrations, increasing nPP led to an increase in the apparent digestibility of minerals. Apparent ileal digestibility of phosphorus (P) was enhanced with increasing dietary nPP up to 5.5 g/kg beyond which no improvements were found. Maximal Ca digestibility was found in diets with >8.0 g/kg Ca with concomitant low concentrations of nPP. Diets with a broader Ca : nPP ratio improved the digestibility of Ca but were deleterious to the digestibility of P. In this study, apparent digestibility of amino acids was broadly unaffected by dietary Ca and nPP concentrations. However, interactions between Ca and nPP were observed for the digestibility of glutamine, tyrosine and methionine (all P<0.001). Nitrogen digestibility showed discrete optima around 10.0 and 5.0 g/kg nPP and Na digestibility was maximised around 8 to 9.0 g/kg Ca and 4.5 to 5.4 g/kg nPP. These data show that the ratio of Ca : nPP is more influential to mineral digestibility than the absolute dietary concentration of each

Effect of phosphorus stress on Microcystis aeruginosa growth and phosphorus uptake.

Directory of Open Access Journals (Sweden)

Sajeela Ghaffar

Full Text Available This study was designed to advance understanding of phosphorus regulation of Microcystis aeruginosa growth, phosphorus uptake and storage in changing phosphorus (P conditions as would occur in lakes. We hypothesized that Microcystis growth and nutrient uptake would fit classic models by Monod, Droop, and Michaelis-Menten in these changing conditions. Microcystis grown in luxury nutrient concentrations was transferred to treatments with phosphorus concentrations ranging from 0-256 μg P∙L-1 and luxury nitrogen. Dissolved phosphorus concentration, cell phosphorus quota, P uptake rate and cell densities were measured at day 3 and 6. Results showed little relationship to predicted models. Microcystis growth was asymptotically related to P treatment from day 0-3, fitting Monod model well, but negatively related to P treatment and cell quota from day 3-6. From day 0-3, cell quota was negatively related to P treatments at <2 μg∙L-1, but increased slightly at higher P. Cell quota decreased greatly in low P treatments from day 3-6, which may have enabled high growths in low P treatments. P uptake was positively and linearly related to P treatment during both periods. Negative uptake rates and increases in measured culture phosphorus concentrations to 5 μg∙L-1 in the lowest P treatments indicated P leaked from cells into culture medium. This leakage during early stages of the experiment may have been sufficient to stimulate metabolism and use of intracellular P stores in low P treatments for rapid growth. Our study shows P regulation of Microcystis growth can be complex as a result of changing P concentrations, and this complexity may be important for modeling Microcystis for nutrient and ecosystem management.

A Compilation of Global Soil Microbial Biomass Carbon, Nitrogen, and Phosphorus Data

Data.gov (United States)

National Aeronautics and Space Administration — This data set provides the concentrations of soil microbial biomass carbon (C), nitrogen (N) and phosphorus (P), soil organic carbon, total nitrogen, and total...

Effects of high nitrogen concentrations on the growth of submersed macrophytes at moderate phosphorus concentrations.

Science.gov (United States)

Yu, Qing; Wang, Hong-Zhu; Li, Yan; Shao, Jian-Chun; Liang, Xiao-Min; Jeppesen, Erik; Wang, Hai-Jun

2015-10-15

Eutrophication of lakes leading to loss of submersed macrophytes and higher turbidity is a worldwide phenomenon, attributed to excessive loading of phosphorus (P). However, recently, the role of nitrogen (N) for macrophyte recession has received increasing attention. Due to the close relationship between N and P loading, disentanglement of the specific effects of these two nutrients is often difficult, and some controversy still exists as to the effects of N. We studied the effects of N on submersed macrophytes represented by Vallisneria natans (Lour.) Hara in pots positioned at three depths (0.4 m, 0.8 m, and 1.2 m to form a gradient of underwater light conditions) in 10 large ponds having moderate concentrations of P (TP 0.03 ± 0.04 mg L(-1)) and five targeted concentrations of total nitrogen (TN) (0.5, 2, 10, 20, and 100 mg L(-1)), there were two ponds for each treatment. To study the potential shading effects of other primary producers, we also measured the biomass of phytoplankton (ChlaPhyt) and periphyton (ChlaPeri) expressed as chlorophyll a. We found that leaf length, leaf mass, and root length of macrophytes declined with increasing concentrations of TN and ammonium, while shoot number and root mass did not. All the measured growth indices of macrophytes declined significantly with ChlaPhyt, while none were significantly related to ChlaPeri. Neither ChlaPhyt nor ChlaPeri were, however, significantly negatively related to the various N concentrations. Our results indicate that shading by phytoplankton unrelated to the variation in N loading and perhaps toxic stress exerted by high nitrogen were responsible for the decline in macrophyte growth. Copyright © 2015 Elsevier Ltd. All rights reserved.

Variations of Growth and Toxin Yield in Cylindrospermopsis raciborskii under Different Phosphorus Concentrations

Directory of Open Access Journals (Sweden)

Yiming Yang

2016-12-01

Full Text Available The bloom-forming cyanobacteria, Cylindrospermopsis raciborskii, is a producer of the cytotoxic cylindrospermopsin (CYN. In this study, the growth, toxin yield, and expression of CYN biosynthesis genes of C. raciborskii were examined under varying phosphorus (P concentrations. The results show the cell number at 0.00 and 0.01 mg·L−1 P was significantly lower than that at higher P concentrations (≥0.5 mg·L−1. The chlorophyll a content, filament length, heterocyst, and akinete numbers at P ≤ 0.05 mg·L−1 were also significantly reduced. The intracellular and extracellular CYN concentrations and the extracellular proportions increased during the culture period, and larger values were observed at higher P concentrations. Total CYN content reached 45.34–63.83 fg·cell−1 and extracellular CYN proportion reached 11.49%–20.44% at the stationary growth phase. A significantly positive correlation was observed between CYN production and cell growth rate. Three cyr genes were expressed constantly even at P-deficient conditions. The transcription of cyr genes at P-replete conditions or after P supplementation increased from 1.18-fold to 8.33-fold. In conclusion, C. raciborskii may rapidly reorganize metabolic processes as an adaptive response to environmental P fluctuations. CYN production and cyr gene expression were constitutive metabolic processes in toxic C. raciborskii.

Effect of high calcium concentration influents on enhanced biological phosphorus removal process

International Nuclear Information System (INIS)

Montoya Martinez, T.; Aguado Garcia, D.; Ferrer Polo, J.

2010-01-01

In this work, the effect of calcium concentration in wastewater on the polyphosphate accumulating organisms (PAO) is investigated as well as its influence in PAO metabolism, specifically in the Y P O4 (ratio between phosphorus release and acetic acid uptake). For this study a sequencing batch reactor (SBR) anaerobic-aerobic was used, in which the PAO enriched biomass was exposed to different calcium concentrations in the influent wastewater. The results indicate that until a given calcium level in the influent wastewater (35 mg Ca/l) the metabolism is not affect, but higher calcium concentrations lead to significant Y P O4 decline. (Author) 18 refs.

Absorption spectrum of neutral phosphorus (P I) in the range 7700-8256 A

International Nuclear Information System (INIS)

Deng Lunhua; Li Chuanliang; Zhang Junli; Yang Xiaohua; Chen Yangqin

2010-01-01

The absorption spectrum of neutral phosphorus was recorded in the range 7700-8256 A using optical heterodyne magnetic rotation concentration modulation spectroscopy with a tunable Ti:sapphire laser as the light source. Phosphorus atoms were excited by discharging the mixed gases of phosphorus vapor and neon gas. The phosphorus vapor was prepared by heating white phosphorus chips placed on a cylindrical copper electrode during discharge. In total, 234 lines of P I were observed, of which 127 were assigned. The transition frequencies were obtained with an uncertainty of 0.007 cm -1 . Empirical line intensities were provided covering four orders of magnitude.

Absorption spectrum of neutral phosphorus (P I) in the range 7700-8256 Å

Science.gov (United States)

Deng, Lunhua; Li, Chuanliang; Zhang, Junli; Yang, Xiaohua; Chen, Yangqin

2010-12-01

The absorption spectrum of neutral phosphorus was recorded in the range 7700-8256 Å using optical heterodyne magnetic rotation concentration modulation spectroscopy with a tunable Ti:sapphire laser as the light source. Phosphorus atoms were excited by discharging the mixed gases of phosphorus vapor and neon gas. The phosphorus vapor was prepared by heating white phosphorus chips placed on a cylindrical copper electrode during discharge. In total, 234 lines of P I were observed, of which 127 were assigned. The transition frequencies were obtained with an uncertainty of 0.007 cm-1. Empirical line intensities were provided covering four orders of magnitude.

[Pollution load and the first flush effect of phosphorus in urban runoff of Wenzhou City].

Science.gov (United States)

Zhou, Dong; Chen, Zhen-lou; Bi, Chun-juan

2012-08-01

Five typical rainfalls were monitored in two different research areas of Wenzhou municipality. The pH and concentrations of total phosphorus (TP), dissolved phosphorus (DP), particulate phosphorus (PP), total inorganic carbon (TIC), total organic carbon (TOC), total suspended substances (TSS), BOD5 and COD in six different kinds of urban runoff were measured. The results showed that, the concentrations of TP, DP and PP in different kinds of urban runoff of Wenzhou ranged from 0.01 to 4.32 mg x L(-1), ND to 0.88 mg x L(-1) and ND to 4.31 mg x L(-1), respectively. In the early stages of runoff process PP was dominated, while in the later, the proportion of DP in most of the runoff samples would show a rising trend, especially in roof and outlet runoff. Judged by the event mean concentration (EMC) of TP and DP in these five rainfalls, some kinds of urban runoff could cause environmental pressure to the next level receiving water bodies. Meanwhile, the differences among the TP and DP content (maximum, minimum and mean content) in various urban runoffs were significant, and so were the differences among various rainfall events. According to the M (V) curve, the first flush effect of TP in most kinds of urban runoff was common; while the first flush effect of DP was more difficult to occur comparing with TP. Not only the underlying surface types but also many physico-chemical properties of runoff could affect the concentration of TP in urban runoff. All the results also suggested that different best management plans (BMPs) should be selected for various urban runoff types for the treatment of phosphorus pollution, and reducing the concentration of TSS is considered as one of the effective ways to decrease the pollution load of phosphorus in urban runoff.

Phosphorus migration analysis using synchrotron radiation in soil treated with Brazilian granular fertilizers

International Nuclear Information System (INIS)

Castro, Robson C. de; Melo Benites, Vinícius de; César Teixeira, Paulo; Anjos, Marcelino José dos; Oliveira, Luis Fernando de

2015-01-01

The aim of this study was to evaluate the phosphorus (P) mobility in a tropical Brazilian soil type red Oxisol treated with three different forms of granular fertilizer. Total Reflection X-Ray Fluorescence (TXRF) was applied to determine the concentration of P at different distances from granular fertilizer application point. The results showed that most of the P from fertilizers tends to concentrate in a region of up to 10 mm around the place of the fertilizer deposition. - Highlights: • Phosphorus (P) mobility in a tropical Brazilian soil. • Total Reflection X-Ray Fluorescence was applied to determine the concentration of P. • Fertilizers used monoammonium phosphate and polymer coated monoammonium phosphate.

[Serum calcium and phosphorus concentration and alkaline phosphatase activity in healthy children during growth and development].

Science.gov (United States)

Savić, Ljiljana; Savić, Dejan

2008-01-01

Many changes happen during growth and development in an organism as a result of important hormon changes, especially biohumoral ones. These changes make a problem when interpreting biochemical results in pediatric population. The most important changes are intensive calcium and phosphorus metabolic turnover in bone tissue with changes in alkaline phosphatase activity as a result of osteoblast activity. The aim of this study was to follow the serum calcium and phosphorus concentration and alkaline phosphatase activity in children 1-15 years old in different growth and development period and of different sexes and to fortify the influence of growth and development dynamics on biohumoral status in healthy male and female children. We evaluated 117 healthy children of both sexes from 1-15 years of age and divided them into three age groups: 1-5, 6-10 and 11-15 years. We followed the serum calcium and phosphorus concentration and alkaline phosphatase activity in different groups and in different sexes. Our investigation found significantly higher values of serum calcium in boys than in girls with no important changes between the age groups and significantly higher values of serum phosphorus in the youngest age group in all children and in different sexes with no important sex differences. Alkaline phosphatase activity followed the growth spurt and was the biggest in 6-10 years group in girls and in 11-15 years group in boys.

New Method for Determination of Electrically Inactive Phosphorus in n-type Emitters

OpenAIRE

Steyer, Michael; Dastgheib-Shirazi, Amir; Hahn, Giso; Terheiden, Barbara

2015-01-01

The precise knowledge of the amount and the location in depth of inactive phosphorus in an n-type emitter is still a challenge. As a new approach, we determine the total amount of phosphorus (P dose) in the emitter stepwise in dependence of etching depth with the characterization tool ICP-OES. A comparison of the data with the electrically active P concentration profile measured by ECV allows to determine in which depths electrically inactive phosphorus is present. For a highly doped emitter,...

Species and biogeochemical cycles of organic phosphorus in sediments from a river with different aquatic plants located in Huaihe River Watershed, China.

Science.gov (United States)

Yuan, He Zhong; Pan, Wei; Ren, Li Jun; Liu, Eeng Feng; Shen, Ji; Geng, Qi Fang; An, Shu Qing

2015-01-01

The results of phosphorus fractionation in the sediments from a contaminated river containing different aquatic plants, analyzed by solution 31P-NMR for Organic Phosphorus, showed that the concentration of Inorganic Phosphorus dominated in all species and Organic Phosphorus accounted for over 20% of Total Phosphorus. In general, orthophosphate was dominant in all the sampling sites. The proportion of Organic Phosphorus accounting for the Total Phosphorus in the sediments with different plant decreased in the following order: Paspalum distichum>Typha orientalis>Hydrilla verticillata. Phosphorus-accumulation ability of Paspalum distichum was obviously stronger than Typha orientalis and Hydrilla verticillata. The Organic Phosphorus was in aquatic plants dominated by humic-associated P (Hu-P), which converted to Inorganic Ohosphorus more significantly in submerged plants than in emerged plants. The sediment dominated by Paspalum distichum abundantly accumulated Organic Phosphorus in the orthophosphate monoester fraction. The degradation and mineralization of orthophosphate monoester was the important source of high Inorganic Phosphorus concentration and net primary productivity in Suoxu River. The Organic Phosphorus derived from Typha orientalis and Hydrilla verticillata was dramatically converted to Inorganic Phosphorus when the environmental factors varied.

Viologen-Phosphorus Dendrimers Inhibit α-Synuclein Fibrillation.

Science.gov (United States)

Milowska, Katarzyna; Grochowina, Justyna; Katir, Nadia; El Kadib, Abdelkrim; Majoral, Jean-Pierre; Bryszewska, Maria; Gabryelak, Teresa

2013-03-04

Inhibition of α-synuclein (ASN) fibril formation is a potential therapeutic strategy in Parkinson's disease and other synucleinopathies. The aim of this study was to examine the role of viologen-phosphorus dendrimers in the α-synuclein fibrillation process and to assess the structural changes in α-synuclein under the influence of dendrimers. ASN interactions with phosphonate and pegylated surface-reactive viologen-phosphorus dendrimers were examined by measuring the zeta potential, which allowed determining the number of dendrimer molecules that bind to the ASN molecule. The fibrillation kinetics and the structural changes were examined using ThT fluorescence and CD spectroscopy. Depending on the concentration of the used dendrimer and the nature of the reactive groups located on the surface, ASN fibrillation kinetics can be significantly reduced, and even, in the specific case of phosphonate dendrimers, the fibrillation can be totally inhibited at low concentrations. The presented results indicate that viologen-phosphorus dendrimers are able to inhibit ASN fibril formation and may be used as fibrillar regulating agents in neurodegenerative disorders.

Impact of Phosphorus-Based Food Additives on Bone and Mineral Metabolism.

Science.gov (United States)

Gutiérrez, Orlando M; Luzuriaga-McPherson, Alexandra; Lin, Yiming; Gilbert, Linda C; Ha, Shin-Woo; Beck, George R

2015-11-01

Phosphorus-based food additives can substantially increase total phosphorus intake per day, but the effect of these additives on endocrine factors regulating bone and mineral metabolism is unclear. This study aimed to examine the effect of phosphorus additives on markers of bone and mineral metabolism. Design and Setting, and Participants: This was a feeding study of 10 healthy individuals fed a diet providing ∼1000 mg of phosphorus/d using foods known to be free of phosphorus additives for 1 week (low-additive diet), immediately followed by a diet containing identical food items; however, the foods contained phosphorus additives (additive-enhanced diet). Parallel studies were conducted in animals fed low- (0.2%) and high- (1.8%) phosphorus diets for 5 or 15 weeks. The changes in markers of mineral metabolism after each diet period were measured. Participants were 32 ± 8 years old, 30% male, and 70% black. The measured phosphorus content of the additive-enhanced diet was 606 ± 125 mg higher than the low-additive diet (P additive diet, consuming the additive-enhanced diet for 1 week significantly increased circulating fibroblast growth factor 23 (FGF23), osteopontin, and osteocalcin concentrations by 23, 10, and 11%, respectively, and decreased mean sclerostin concentrations (P foods can disturb bone and mineral metabolism in humans. The results of the animal studies suggest that this may compromise bone health.

Decline in Chinese lake phosphorus concentration accompanied by shift in sources since 2006

Science.gov (United States)

Tong, Yindong; Zhang, Wei; Wang, Xuejun; Couture, Raoul-Marie; Larssen, Thorjørn; Zhao, Yue; Li, Jing; Liang, Huijiao; Liu, Xueyan; Bu, Xiaoge; He, Wei; Zhang, Qianggong; Lin, Yan

2017-07-01

Domestic wastewater and agricultural activities are important sources of nutrient pollutants such as phosphorus and nitrogen. Upon reaching freshwater, these nutrients can lead to extensive growth of harmful algae, which results in eutrophication. Many Chinese lakes are subject to such eutrophication, especially in highly polluted areas, and as such, understanding nutrient fluxes to these lakes offers insights into the varying processes governing pollutant fluxes as well as lake water quality. Here we analyse water quality data, recorded between 2006 and 2014 in 862 freshwater lakes in four geographical regions of China, to assess the input of phosphorus from human activity. We find that improvements in sanitation of both rural and urban domestic wastewater have resulted in large-scale declines in lake phosphorus concentrations in the most populated parts of China. In more sparsely populated regions, diffuse sources such as aquaculture and livestock farming offset this decline. Anthropogenic deforestation and soil erosion may also offset decreases in point sources of pollution. In the light of these regional differences, we suggest that a spatially flexible set of policies for water quality control would be beneficial for the future health of Chinese lakes.

Sediment deposition and trends and transport of phosphorus and other chemical constituents, Cheney Reservoir watershed, south-central Kansas

Science.gov (United States)

Mau, D.P.

2001-01-01

Sediment deposition, water-quality trends, and mass transport of phosphorus, nitrogen, selected trace elements, and selected pesticides within the Cheney Reservoir watershed in south-central Kansas were investigated using bathymetric survey data and reservoir bottom-sediment cores. Sediment loads in the reservoir were investigated by comparing 1964 topographic data to 1998 bathymetric survey data. Approximately 7,100 acre-feet of sediment deposition occurred in Cheney Reservoir from 1965 through 1998. As of 1998, sediment had filled 27 percent of the reservoir's inactive conservation storage pool, which is less than the design estimate of 34 percent. Mean annual sediment deposition was 209 acre-feet per year, or 0.22 acre-feet per year per square mile, and the mean annual sediment load was 453 million pounds per year. During the 3-year period from 1997 through 1999, 23 sediment cores were collected from the reservoir, and subsamples were analyzed for nutrients (phosphorus and nitrogen species), selected trace elements, and selected organic pesticides. Mean concentrations of total phosphorus in reservoir bottom sediment ranged from 94 milligrams per kilogram at the upstream end of the reservoir to 710 milligrams per kilogram farther downstream near the reservoir dam. The mean concentration for all sites was 480 milligrams per kilogram. Total phosphorus concentrations were greatest when more silt- and clay-sized particles were present. The implications are that if anoxic conditions (inadequate oxygen) occur near the dam, phosphorus could be released from the sediment and affect the drinking-water supply. Analysis of selected cores also indicates that total phosphorus concentrations in the reservoir sediment increased over time and were probably the result of nonpoint-source activities in the watershed, such as increased fertilizer use and livestock production. Mean annual phosphorus loading to Cheney Reservoir was estimated to be 226,000 pounds per year on the basis

Increasing dietary phosphorus intake from food additives: potential for negative impact on bone health.

Science.gov (United States)

Takeda, Eiji; Yamamoto, Hironori; Yamanaka-Okumura, Hisami; Taketani, Yutaka

2014-01-01

It is important to consider whether habitual high phosphorus intake adversely affects bone health, because phosphorus intake has been increasing, whereas calcium intake has been decreasing in dietary patterns. A higher total habitual dietary phosphorus intake has been associated with higher serum parathyroid hormone (PTH) and lower serum calcium concentrations in healthy individuals. Higher serum PTH concentrations have been shown in those who consume foods with phosphorus additives. These findings suggest that long-term dietary phosphorus loads and long-term hyperphosphatemia may have important negative effects on bone health. In contrast, PTH concentrations did not increase as a result of high dietary phosphorus intake when phosphorus was provided with adequate amounts of calcium. Intake of foods with a ratio of calcium to phosphorus close to that found in dairy products led to positive effects on bone health. Several randomized controlled trials have shown positive relations between dairy intake and bone mineral density. In our loading test with a low-calcium, high-phosphorus lunch provided to healthy young men, serum PTH concentrations showed peaks at 1 and 6 h, and serum fibroblast growth factor 23 (FGF23) concentrations increased significantly at 8 h after the meal. In contrast, the high-calcium, high-phosphorus meal suppressed the second PTH and FGF23 elevations until 8 h after the meal. This implies that adequate dietary calcium intake is needed to overcome the interfering effects of high phosphorus intake on PTH and FGF23 secretion. FGF23 acts on the parathyroid gland to decrease PTH mRNA and PTH secretion in rats with normal kidney function. However, increased serum FGF23 is an early alteration of mineral metabolism in chronic kidney disease, causing secondary hyperthyroidism, and implying resistance of the parathyroid gland to the action of FGF23 in chronic kidney disease. These findings suggest that long-term high-phosphorus diets may impair bone health

Interaction of Peat Soil and Sulphidic Material Substratum: Role of Peat Layer and Groundwater Level Fluctuations on Phosphorus Concentration

Directory of Open Access Journals (Sweden)

Benito Heru Purwanto

2014-09-01

Full Text Available Phosphorus (P often becomes limiting factor for plants growth. Phosphorus geochemistry in peatland soil is associated with the presence of peat layer and groundwater level fluctuations. The research was conducted to study the role of peat layer and groundwater level fluctuations on P concentration in peatland. The research was conducted on deep, moderate and shallow peat with sulphidic material as substratum, peaty acid sulphate soil, and potential acid sulphate soil. While P concentration was observed in wet season, in transition from wet to dry season, and in dry season. Soil samples were collected by using peat borer according to interlayer and soil horizon. The results showed that peat layer might act as the main source of P in peatland with sulphidic material substratum. The upper peat layer on sulphidic material caused by groundwater level fluctuations had no directly effect on P concentration in the peat layers. Increased of P concentration in the lowest sulphidic layer might relate to redox reaction of iron in the sulphidic layer and precipitation process. Phosphorus concentration in peatland with sulphidic material as substratum was not influenced by peat thickness. However, depletion or disappearance of peat layer decreased P concentration in soil solution. Disappearance of peat layer means loss of a natural source of P for peatland with sulphidic material as substratum, therefore peat layer must be kept in order to maintain of peatlands.

Phosphorus Characteristics with Controlled Nitrogen in Fertile Soils in Protected Vegetable Field

Directory of Open Access Journals (Sweden)

WANG Heng

2014-06-01

Full Text Available There is an unreasonable phenomenon of fertilization in vegetable facility cultivation, with the serious imbalance of soil nutrient. In purpose of understanding the absorption characteristics of phosphorus from nitrogen-rich soil, a long-term nitrogen-controlled experiment was carried from the year 2004 to 2007, and a split plot experiment of leaching was carried in winter-spring season of 2007. The results showed that the content of phosphorus varied with different nitrogen control. The TP was decreased with nitrogen supply of none(NN 、organic manure(MN 、organic manure and straw(MN+S, and the decreased range was NN>MN>MN+S, meanwhile the increase range of TP was traditional-nitrogen(CN >traditional-nitrogen+straw(CN+S >optimized-nitrogen+straw(SN+S >optimized-nitrogen(SN. The available P with CN and CN+S reached to 213.7 mg· kg -1 、225.4 mg·kg -1, which increased by 17.1 percent and 23.5 percent, which declared the phosphorus was accumulated; The available P with other nitrogen controlled decreased with the range of NN>MN>MN+S>SN+S>SN跃CN>CN+S, which showed that the supply reduction of nitrogen could slowdown the phosphorus accumulated and promote the utilization ratio of phosphorus. The organophosphorus was increased except NN, with obvious increase with CN、CN+S（308.4 mg·kg -1 、331.4 mg·kg -1 by 28.5 percent and 38.2 percent. The absorption coefficient of phosphorus with SN+S(P 2 O 5，mg· 100 g -1 reached to 1 571, increased by 143.6 percent; Otherwise the absorption coefficient of phosphorus with CN、CN+S showed negative growth, the CN dipped to 416（P 2 O 5，mg·100 g -1 by 35.5 percent. Adding wheat straw could greatly improved the capacity of absorption of phosphorus and slow down the accumulation of available phosphorus to some extent. The concentrations of total phosphorus in the filtrate with SN+S were less than SN, contrary to the concentration of organophosphorus, thus the straw returning had a certain effect on

The adsorption/desorption of phosphorus in freshwater sediments from buffer zones: the effects of sediment concentration and pH.

Science.gov (United States)

Zhang, Liang; Du, Yun; Du, Chao; Xu, Meng; Loáiciga, Hugo A

2016-01-01

Riparian buffer zones adjacent to reservoirs and lakes protect aquatic ecosystems from polluted surface runoff. Sediments, collected from the buffer zones of Danjiangkou Reservoir (SR) and Honghu Lake (SL) in an ecologically fragile region in central China, were evaluated to reveal their phosphorus-adsorbing/desorbing properties and storage capacities. A nonlinear regression method was used to fit the pseudo-second-order kinetic and the modified crossover-type Langmuir isotherm models to the experimental data. It is shown that the adsorption of phosphorus onto the studied sediments followed the pseudo-second-order kinetic expression. The modified crossover-type Langmuir isotherm model was found to be a suitable method for describing adsorption/desorption processes in the experimental sediments. The maximum adsorption capacities (Q m), partitioning coefficients (K p), native adsorbed exchangeable phosphorus (NAP), and equilibrium phosphorus concentration (EPC0) were subsequently obtained for the experimental sediments. The effects of sediment concentration and pH were also investigated by batch experiments and Fourier transformation infrared and scanning electron microscopy analyses. The adsorption/desorption characteristics of different phosphate species on the sediments from reservoir and lake buffer zones were identified.

[Distribution characteristics and erosion risk of nitrogen and phosphorus in soils of Zhuangmu town in Lake Wabuhu basin].

Science.gov (United States)

Li, Ru-Zhong; Zou, Yang; Xu, Jing-Jing; Ding, Gui-Zhen

2014-03-01

To understand the loss risk of soil erosion in the Zhuangmu town in Lake Wabuhu watershed, concentration and spatial distribution of nitrogen and phosphorus in 162 surface soil samples collected from the farmlands in ten administrative villages of the town were investigated. The risk assessment was conducted by using the nitrogen and phosphorus index method after speciation analysis of soil nitrogen and phosphorus. Based on ArcGIS technology, the spatial interpolation of total nitrogen (TN), total phosphorus (TP), and bioavailable nitrogen and phosphorus contents as well as nitrogen and phosphorus index values were performed by means of Kriging interpolation. The results show that, generally, average contents of TN and TP were obtained at 1.67 g x kg(-1) and 0.71 g x kg(-1), respectively. And the mean concentration of bioavailable nitrogen and phosphorus were estimated at 0.26 g x kg(-1) and 0.33 g x kg(-1), accounting for 14.93% and 47.30% of TN and TP contents, respectively. Spatially, the samples with high concentration of TN were mostly from Houji, Yangwan and Liuqian villages, whereas the samples sites with higher contents of TP located in Houji, Yangwan and Zaolin villages. The mean values of nitrogen index (NI) and phosphorus index (PI) for the whole town are 2.11 and 2.13, respectively. According to the numeric size of NI and PI, ten villages ranged in the order of Yangwan > Zhuangmu > Xueqiao > Liuqian > Lizhuang > Jinqiao > Zaolin > Zhangwei > Houji > Xugang village. In general, the soil nitrogen loss is dominated by low and medium risks in the Zhuangmu town, and high risk sporadically appears in local area of the Yangwan village. Like the nitrogen, soil phosphorus loss risk also gives priority to low, and above medium risk concentrates in the Yangwan village as well.

Mapping watershed potential to contribute phosphorus from geologic materials to receiving streams, southeastern United States

Science.gov (United States)

Terziotti, Silvia; Hoos, Anne B.; Harned, Douglas; Garcia, Ana Maria

2010-01-01

As part of the southeastern United States SPARROW (SPAtially Referenced Regressions On Watershed attributes) water-quality model implementation, the U.S. Geological Survey created a dataset to characterize the contribution of phosphorus to streams from weathering and erosion of surficial geologic materials. SPARROW provides estimates of total nitrogen and phosphorus loads in surface waters from point and nonpoint sources. The characterization of the contribution of phosphorus from geologic materials is important to help separate the effects of natural or background sources of phosphorus from anthropogenic sources of phosphorus, such as municipal wastewater or agricultural practices. The potential of a watershed to contribute phosphorus from naturally occurring geologic materials to streams was characterized by using geochemical data from bed-sediment samples collected from first-order streams in relatively undisturbed watersheds as part of the multiyear U.S. Geological Survey National Geochemical Survey. The spatial pattern of bed-sediment phosphorus concentration is offered as a tool to represent the best available information at the regional scale. One issue may weaken the use of bed-sediment phosphorus concentration as a surrogate for the potential for geologic materials in the watershed to contribute to instream levels of phosphorus-an unknown part of the variability in bed-sediment phosphorus concentration may be due to the rates of net deposition and processing of phosphorus in the streambed rather than to variability in the potential of the watershed's geologic materials to contribute phosphorus to the stream. Two additional datasets were created to represent the potential of a watershed to contribute phosphorus from geologic materials disturbed by mining activities from active mines and inactive mines.

Increasing Dietary Phosphorus Intake from Food Additives: Potential for Negative Impact on Bone Health123

Science.gov (United States)

Takeda, Eiji; Yamamoto, Hironori; Yamanaka-Okumura, Hisami; Taketani, Yutaka

2014-01-01

It is important to consider whether habitual high phosphorus intake adversely affects bone health, because phosphorus intake has been increasing, whereas calcium intake has been decreasing in dietary patterns. A higher total habitual dietary phosphorus intake has been associated with higher serum parathyroid hormone (PTH) and lower serum calcium concentrations in healthy individuals. Higher serum PTH concentrations have been shown in those who consume foods with phosphorus additives. These findings suggest that long-term dietary phosphorus loads and long-term hyperphosphatemia may have important negative effects on bone health. In contrast, PTH concentrations did not increase as a result of high dietary phosphorus intake when phosphorus was provided with adequate amounts of calcium. Intake of foods with a ratio of calcium to phosphorus close to that found in dairy products led to positive effects on bone health. Several randomized controlled trials have shown positive relations between dairy intake and bone mineral density. In our loading test with a low-calcium, high-phosphorus lunch provided to healthy young men, serum PTH concentrations showed peaks at 1 and 6 h, and serum fibroblast growth factor 23 (FGF23) concentrations increased significantly at 8 h after the meal. In contrast, the high-calcium, high-phosphorus meal suppressed the second PTH and FGF23 elevations until 8 h after the meal. This implies that adequate dietary calcium intake is needed to overcome the interfering effects of high phosphorus intake on PTH and FGF23 secretion. FGF23 acts on the parathyroid gland to decrease PTH mRNA and PTH secretion in rats with normal kidney function. However, increased serum FGF23 is an early alteration of mineral metabolism in chronic kidney disease, causing secondary hyperthyroidism, and implying resistance of the parathyroid gland to the action of FGF23 in chronic kidney disease. These findings suggest that long-term high-phosphorus diets may impair bone health

Exploring spatiotemporal patterns of phosphorus concentrations in a coastal bay with MODIS images and machine learning models

Science.gov (United States)

Excessive nutrients, which may be represented as Total Nitrogen (TN) and Total Phosphorus (TP) levels, in natural water systems have proven to cause high levels of algae production. The process of phytoplankton growth which consumes the excess nutrients in a water body can also b...

Sargasso Sea phosphorus biogeochemistry: an important role for dissolved organic phosphorus (DOP

Directory of Open Access Journals (Sweden)

M. W. Lomas

2010-02-01

Full Text Available Inorganic phosphorus (SRP concentrations in the subtropical North Atlantic are some of the lowest in the global ocean and have been hypothesized to constrain primary production. Based upon data from several transect cruises in this region, it has been hypothesized that dissolved organic phosphorus (DOP supports a significant fraction of primary production in the subtropical North Atlantic. In this study, a time-series of phosphorus biogeochemistry is presented for the Bermuda Atlantic Time-series Study site, including rates of phosphorus export. Most parameters have a seasonal pattern, although year-over-year variability in the seasonal pattern is substantial, likely due to differences in external forcing. Suspended particulate phosphorus exhibits a seasonal maximum during the spring bloom, despite the absence of a seasonal peak in SRP. However, DOP concentrations are at an annual maximum prior to the winter/spring bloom and decline over the course of the spring bloom while whole community alkaline phosphatase activities are highest. As a result of DOP bioavailability, the growth of particles during the spring bloom occurs in Redfield proportions, though particles exported from the euphotic zone show rapid and significant remineralization of phosphorus within the first 50 m below the euphotic zone. Based upon DOP data from transect cruises in this region, the southward cross gyral flux of DOP is estimated to support ~25% of annual primary production and ~100% of phosphorus export. These estimates are consistent with other research in the subtropical North Atlantic and reinforce the hypothesis that while the subtropics may be phosphorus stressed (a physiological response to low inorganic phosphorus, utilization of the DOP pool allows production and accumulation of microbial biomass at Redfield proportions.

III. Quantitative aspects of phosphorus excretionin ruminants

OpenAIRE

Bravo , David; Sauvant , Daniel; Bogaert , Catherine; Meschy , François

2003-01-01

International audience; Ruminant phosphorus excretion and metabolism were studied through a database. Faecal endogenous phosphorus is the main pathway of phosphorus excretion and averages 0.85 of total faecal phosphorus. The remaining 0.15 is unabsorbed dietary phosphorus. Faecal endogenous phosphorus is mainly unabsorbed phosphorus, with saliva being the major source, and is correlated to factors influencing saliva secretion (DM intake, physical dietary characteristics and dietary phosphorus...

Phosphorus solubility in an acid forest soil as influenced by form of applied phosphorus and liming

International Nuclear Information System (INIS)

Fransson, Ann-Mari; Bergkvist, Bo; Tyler, Germund

1999-01-01

Sedimentary phosphorus, superphosphate, and wood-ash, as well as either sedimentary phosphorus. superphosphate or ash combined with lime, were distributed in selected plots in an 80-yr-old Norway spruce forest [Picea abies (L.) Karst]. After 2 yrs, the sedimentary phosphorus had increased the oxalate/oxalic acid-extractable P in the O-horizon, and the superphosphate had increased the oxalate/oxalic acid-extractable P in the E-horizon. At first, the percolation water from the superphosphate treatment showed high P concentrations. It soon returned to control levels, however. The percolation water from the sedimentary phosphorus treatment gradually showed increased phosphate concentrations. The wood-ash increased neither the amount of extractable P nor the P concentration in the percolation water. The oxalate/oxalic acid-extractable P from the sedimentary P treatment was reduced by liming. The P concentration in the percolation water also tended to be reduced. This was perhaps due to formation of Ca phosphates in the vicinity of the lime particles. In addition, if the solubility rate was similar to the uptake rate, it could account for the decreased P concentration

Effect of phosphorus level on nitrogen accumulation and yield in soybean

International Nuclear Information System (INIS)

You Yubo; Wu Dongmei; Gong Zhenping; Ma Chunmei

2012-01-01

In this paper, the 15 N labeling with sand culture was conducted to study effects of phosphorus level on nitrogen accumulation, nodule nitrogen fixation and yield of soybean plants. Results showed that nitrogen accumulation, fixation and yield of soybean plants all presented a single peak curve with improvement of phosphorus nutrition level, with the peak value of phosphorus concentration in nutrient solution of 31 mg/L. When phosphorus concentration of nutrient solution was 11 mg/L, no obvious promotion was found on the ratio of nodule nitrogen fixation when increasing phosphorus concentration again, However, when phosphorus concentration of nutrient solution was 21 mg/L, increasing phosphorus concentration again had no obvious promotion on soybean plant nitrogen accumulation, nodule nitrogen fixation accumulation and yield, indicating that effect of phosphorus nutrition level on nitrogen fixation was lower than that on yield formation level. (authors)

Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

International Nuclear Information System (INIS)

Mohammed, A.A.; Eltayeb, M.A.H.

2003-01-01

In the present work uranium content and total phosphorous were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba mountains in sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (VI) is kept in solution as its carbonate complex. The ion-exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of the absorbance of the yellow uranium (VI) - 8- hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the leach liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from Kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples samples from Uro area, which contain 200 ppm uranium in average

Phosphorus vacancy cluster model for phosphorus diffusion gettering of metals in Si

Energy Technology Data Exchange (ETDEWEB)

Chen, Renyu; Trzynadlowski, Bart; Dunham, Scott T. [Department of Electrical Engineering, University of Washington, Seattle, Washington 98195 (United States)

2014-02-07

In this work, we develop models for the gettering of metals in silicon by high phosphorus concentration. We first performed ab initio calculations to determine favorable configurations of complexes involving phosphorus and transition metals (Fe, Cu, Cr, Ni, Ti, Mo, and W). Our ab initio calculations found that the P{sub 4}V cluster, a vacancy surrounded by 4 nearest-neighbor phosphorus atoms, which is the most favorable inactive P species in heavily doped Si, strongly binds metals such as Cu, Cr, Ni, and Fe. Based on the calculated binding energies, we build continuum models to describe the P deactivation and Fe gettering processes with model parameters calibrated against experimental data. In contrast to previous models assuming metal-P{sub 1}V or metal-P{sub 2}V as the gettered species, the binding of metals to P{sub 4}V satisfactorily explains the experimentally observed strong gettering behavior at high phosphorus concentrations.

[Output characteristics of rainfall runoff phosphorus pollution from a typical small watershed in Yimeng mountainous area].

Science.gov (United States)

Yu, Xing-xiu; Li, Zhen-wei; Liu, Qian-jin; Jing, Guang-hua

2012-08-01

Relationships between phosphorus pollutant concentrations and precipitation-runoff were analyzed by monitoring pollutant losses at outlets of the Menglianggu watershed in 2010. A typical small watershed was selected to examine the runoff and quality parameters such as total phosphorus (TP), particle phosphorus (PP), dissolve phosphorus (DP) and dissolve inorganic phosphorus (DIP) in rainfall-runoff of 10 rainfall events. Precipitation was above 2 mm for all the 10 rainfall events. The results showed that the peak of phosphorus concentrations occurred before the peak of water flows, whereas change processes of the phosphorus fluxes were consistent with that of the water flows and the phosphorus flux also have a strong linear relationship with the water flows. The minimums of the phosphorus concentrations in every 10 natural rainfall events have small differences with each other, but the maximum and EMCs of the phosphorus concentrations have significant differences with each rainfall event. This was mainly influenced by the precipitation, maximum rainfall intensity and mean rainfall intensity (EMCs) and was less influenced by rainfall duration. DP and TP were mainly composed of DIP and PP, respectively. There were no significant correlations between DIP/DP dynamic changes and rainfall characteristics, whereas significant correlations between PP/TP dynamic changes and maximum rainfall intensity were detected. The production of DIP, DP, AND TP were mainly influenced by the direct runoff (DR) and base flow (BF). The EMCs of DIP, DP, TP and the variations of DIP/DP were all found to have significant polynomial relationships with DR/TR., but the dynamic changes of PP/ TP and the EMCS of PP were less influenced by the DR/TR.

Phosphorus Dynamics along River Continuum during Typhoon Storm Events

Directory of Open Access Journals (Sweden)

Ming Fai Chow

2017-07-01

Full Text Available Information on riverine phosphorus (P dynamics during typhoon storm events remains scarce in subtropical regions. Thus, this study investigates the spatial and temporal dynamics of riverine phosphorus in a headwater catchment during three typhoon events. Continuous sampling (3 h intervals of stormwater samples and discharge data were conducted at five locations, which represent the upstream, transitional zone, and downstream areas of the main inflow river. The results revealed that the average event mean concentrations (EMCs for total dissolved phosphorus (TDP and particulate phosphorus (PP in the upstream catchment of Fei-Tsui reservoir were 15.66 μg/L and 11.94 μg/L, respectively. There was at least a 1.3-fold increase in flow-weighted concentrations of TDP and PP from the upper to lower reaches of the main stream. PP and TDP were transported either in clockwise or anticlockwise directions, depending on storm intensity and source. The transport of TDP was primarily regulated by the subsurface flow during the storm event. Soluble reactive phosphorus (SRP contributes more than 50% of the TDP load in moderate storms, while extreme storms supply a greater dissolved organic phosphorus (DOP load into the stream. TDP accounted for approximately 50% of TP load during typhoon storms. Mobilization of all P forms was observed from upstream to downstream of the river, except for DOP. A decrease of DOP load on passing downstream may reflect the change in phosphorus form along the river continuum. Peak discharge and antecedent dry days are correlated positively with P fluxes, indicating that river bank erosion and re-suspension of within-channel sediment are the dominant pathways of P during typhoon storm periods.

Study on the Varying Patterns of Total Phospholipids, Selenium, Phosphorus, Reducing Sugar and Total Sugar, Hydrolyzed Amino Acids in the Velvet Antler of Northeast Sika Deer in Growth Period

Directory of Open Access Journals (Sweden)

Wang Shu-li

2016-01-01

Full Text Available In this study, the varying patterns of total phospholipids, selenium, phosphorus, reducing sugar and total sugar, hydrolyzed amino acids in the velvet antler of Northeast sika deer in growth period were evaluated. Eighteen Northeast sika deer were allocated into 6 groups according to the antler shedding time. Results indicated that there was significant difference of the selenium content between any two of the six groups (P<0.05 except that of Group 1 and Group 2 or Group 5 and Group 6. About the phosphorus there was significant difference between any two of the six groups (P<0.05 except that of Group 4 and Group 5 or Group 2 and Group 3 or Group 1 and Group 2. Group 6 had the lowest total Phospholipids content. Both of the reducing sugar and total sugar showed an increasing pattern initially and then decrease gradually.

Absolute concentration determination of phosphorus metabolites in the Langendorff-perfused rabbit heart by phosphorus-31 nuclear magnetic resonance

International Nuclear Information System (INIS)

Gard, J.K.

1984-01-01

The concentrations of mobile high energy phosphorus metabolites and intracellular pH of Langendorff-perfused rabbit heart have been determined under control and reduced flow conditions. Absolute concentration determination was accomplished by Lorentzian lineshape analysis after development of hexachlorocyclotriphosphazene as an external intensity standard. Hearts were demonstrated to be biochemically and physiologically competent during control perfusion periods and compromised during reduced flow conditions by independent hemodynamic and metabolic measurements coincident with the NMR experiment. Reduction in perfusate flow from 20 mL/min to 5.0 mL/min (25% flow) or 2.5 mL/min (12.5% flow) demonstrated a fall in phosphocreatine and adenosine triphosphate concentrations, a rise in cytosolic inorganic phosphate concentrations, and drops in pH. Subsequent recovery upon reflow was observed. The derived values for the free concentration of ADP were very close to the reported values of the Michaelis constant for respiratory stimulation, implicating a regulatory role for this molecule in cellular respiration. Strong evidence that the creating kinase reaction was in equilibrium in the 25% flow study was seen. The NMR observable correlated closely with myocardial performance and biochemical indices of metabolic function, and supported the use of phosphocreatine as an indicator of current metabolic integrity

Phosphorus run-off assessment in a watershed.

Science.gov (United States)

Chebud, Yirgalem; Naja, Ghinwa M; Rivero, Rosanna

2011-01-01

The Watershed Assessment Model was used to simulate the runoff volume, peak flows, and non-point source phosphorus loadings from the 5870 km(2) Lake Okeechobee watershed as a case study. The results were compared to on-site monitoring to verify the accuracy of the method and to estimate the observed/simulated error. In 2008, the total simulated phosphorus contribution was 9634, 6524 and 3908 kg (P) y(-1) from sod farms, citrus farms and row crop farmlands, respectively. Although the dairies represent less than 1% of the total area of Kissimmee basin, the simulated P load from the dairies (9283 kg (P) y(-1) in 2008) made up 5.4% of the total P load during 2008. On average, the modeled P yield rates from dairies, sod farms and row crop farmlands are 3.85, 2.01 and 0.86 kg (P) ha(-1) y(-1), respectively. The maximum sediment simulated phosphorus yield rate is about 2 kg (P) ha(-1) and the particulate simulated phosphorus contribution from urban, improved pastures and dairies to the total phosphorus load was estimated at 9%, 3.5%, and 1%, respectively. Land parcels with P oversaturated soil as well as the land parcels with high phosphorus assimilation and high total phosphorus contribution were located. The most critical sub-basin was identified for eventual targeting by enforced agricultural best management practices. Phosphorus load, including stream assimilation, incoming to Lake Okeechobee from two selected dairies was also determined.

[Spatiotemporal characteristics of nitrogen and phosphorus in a mountainous urban lake].

Science.gov (United States)

Bao, Jing-Yue; Bao, Jian-Guo; Li, Li-Qing

2014-10-01

Longjing Lake in Chongqing Expo Garden is a typical representative of mountainous urban lake. Based on water quality monitoring of Longjing Lake, spatiotemporal characteristics of nitrogen and phosphorus and their relations were analyzed, combined with natural and human factors considered. The results indicated that annual average concentrations of TN and TP in overall lake were (1.42 ± 0.46) mg · L(-1) and (0.09 ± 0.03) mg · L(-1), nitrogen and phosphorus concentrations fluctuated seasonally which were lower during the flooding season than those during the dry season. Nitrogen and phosphorus concentration in main water area, open water areas and bay areas of Longjing Lake were distributed with temporal and spatial heterogeneity by different regional influencing factors. The seasonal variation of the main water area was basically consistent with overall lake. Two open water areas respectively connected the main water area with the upstream region, bay areas. TN and TP concentrations were gradually reduced along the flow direction. Upstream water quality and surrounding park functional layout impacted nitrogen and phosphorus nutrient concentrations of open water areas. Nutrient concentrations of typical bay areas were higher than those of main water area and open water areas. The mean mass fraction of PN/TN and PP/TP accounted for a large proportion (51.7% and 72.8%) during the flooding season, while NO(3-)-N/TN and SRP/TP accounted for more (42.0% and 59.4%) during the dry season. The mass fraction of ammonia nitrogen and dissolved organic nitrogen in total nitrogen were relatively stable. The annual mean of N/P ratio was 18.429 ± 7.883; the period of nitrogen limitation was 5.3% while was 21.2% for phosphorus limitation.

Increasing phytoplankton-available phosphorus and inhibition of macrophyte on phytoplankton bloom.

Science.gov (United States)

Dai, Yanran; Wu, Juan; Ma, Xiaohang; Zhong, Fei; Cui, Naxin; Cheng, Shuiping

2017-02-01

We assembled mesocosms to address the coherent mechanisms that an increasing phosphorus (P) concentration in water columns coupled with the phytoplankton bloom and identify the performance gap of regulating phytoplankton growth between two macrophyte species, Ceratophyllum demersum L. and Vallisneria spiralis L. Intense alkaline phosphatase activities (APA) were observed in the unplanted control, with their predominant part, phytoplankton APA (accounting for up to 44.7% of the total APA), and another large share, bacterial APA. These correspond with the large average concentration of total phosphorus (TP), total dissolved phosphorus (TDP) and soluble reactive (SRP) as well as high phytoplankton density in the water column. The consistency among P concentrations, phytoplankton density and APA, together with the positive impact of phytoplankton density on total APA revealed by the structural equation modelling (SEM), indicates that facilitated APA levels in water is an essential strategy for phytoplankton to enhance the available P. Furthermore, a positive interaction between phytoplankton APA and bacteria APA was detected, suggesting a potential collaboration between phytoplankton and bacteria to boost available P content in the water column. Both macrophyte species had a prominent performance on regulating phytoplankton proliferation. The phytoplankton density and quantum yield in C. demersum systems were all significantly lower (33.8% and 24.0%) than those in V. spiralis systems. Additionally, a greater decoupling effect of C. demersum on the relationship between P, APA, phytoplankton density, bacteria dynamic and quantum yield was revealed by SEM. These results imply that the preferred tactic of different species could lead to the performance gap. Copyright © 2016 Elsevier B.V. All rights reserved.

Phosphorus containing sintered alloys (review)

International Nuclear Information System (INIS)

Muchnik, S.V.

1984-01-01

Phosphorus additives are considered for their effect on the properties of sintered alloys of different applications: structural, antifriction, friction, magnetic, hard, superhard, heavy etc. Data are presented on compositions and properties of phosphorus-containing materials produced by the powder metallurgy method. Phosphorus is shown to be an effective activator of sintering in some cases. When its concentration in the material is optimal it imparts the material such properties as strength, viscosity, hardness, wear resistance. Problems concerning powder metallurgy of amorphous phosphorus-containing alloys are reported

Influence of integrated phosphorus supply and plant growth ...

African Journals Online (AJOL)

To guarantee a sufficient phosphorus supply for plants, a rapid and permanent mobilization of phosphorus from the labile phosphorus fractions is necessary, because phosphorus concentrations in soil solution are generally low. Several plant growth-promoting rhizobacteria (PGPR) have shown potential to enhance ...

Physical and chemical characteristics including total and geochemical forms of phosphorus in sediment from the top 30 centimeters of cores collected in October 2006 at 26 sites in Upper Klamath Lake, Oregon

Science.gov (United States)

Simon, Nancy S.; Ingle, Sarah N.

2011-01-01

μThis study of phosphorus (P) cycling in eutrophic Upper Klamath Lake (UKL), Oregon, was conducted by the U.S. Geological Survey in cooperation with the U.S. Bureau of Reclamation. Lakebed sediments from the upper 30 centimeters (cm) of cores collected from 26 sites were characterized. Cores were sampled at 0.5, 1.5, 2.5, 3.5, 4.5, 10, 15, 20, 25, and 30 cm. Prior to freezing, water content and sediment pH were determined. After being freeze-dried, all samples were separated into greater than 63-micron (μm) particle-size (coarse) and less than 63-μm particle-size (fine) fractions. In the surface samples (0.5 to 4.5 cm below the sediment water interface), approximately three-fourths of the particles were larger than 63-μm. The ratios of the coarse particle-size fraction (>63 μm) and the fine particle-size fraction (determination of total concentrations of aluminum (Al), calcium (Ca), carbon (C), iron (Fe), poorly crystalline Fe, nitrogen (N), P, and titanium (Ti). Total Fe concentrations were the largest in sediment from the northern portion of UKL, Howard Bay, and the southern portion of the lake. Concentrations of total Al, Ca, and Ti were largest in sediment from the northern, central, and southernmost portions of the lake and in sediment from Howard Bay. Concentrations of total C and N were largest in sediment from the embayments and in sediment from the northern arm and southern portion of the lake in the general region of Buck Island. Concentrations of total C were larger in the greater than 63-μm particle-size fraction than in the less than 63-μm particle-size fraction. Sediments were sequentially extracted to determine concentrations of inorganic forms of P, including loosely sorbed P, P associated with poorly crystalline Fe oxides, and P associated with mineral phases. The difference between the concentration of total P and sum of the concentrations of inorganic forms of P is referred to as residual P. Residual P was the largest fraction of P in all

Relative efficiency of different methods of phosphorus (32P) application on fertilizer phosphorus uptake by maize (zea may L.)

International Nuclear Information System (INIS)

Chaudhary, M.L.; Gupta, A.P.

1975-01-01

A green house study was conducted for comparing four methods of phosphorus application (broad cast, below the seed, one side and both sides of the seeds) at the rate of 60 ppm in sierozem soil of H issar (Haryana). Maize crop was planted in 50 cm. bottomless bitumin drums for 70 days i.e. upto tasseling stage. The plant samples were collected at jointing and tasseling stages of plant growth. The results revealed that the highest dry matter yield, total and fertilizer phosphorus uptake was observed when the phosphorus was applied below the seed, followed by both side application of phosphorus. The least yield, total and fertilizer phosphorus uptake were recorded when the phosphorus was broadcast at the time of sowing. (author)

[Influence of submerged macrophytes on phosphorus transference between sediment and overlying water in the growth period].

Science.gov (United States)

Wang, Li-Zhi; Wang, Guo-Xiang; Yu, Zhen-Fei; Zhou, Bei-Bei; Chen, Qiu-Min; Li, Zhen-Guo

2012-02-01

In order to study the process of phosphorus transfer between sediment and overlying water, Hydrilla verticillata and Vallisneria natans were cultured in spring, Potamogeton crispus was cultured in winter. Changes of environmental factors and phosphorus concentrations in water and sediment were investigated. The results indicated that: submerged macrophytes could reduce all phosphorus fractions in the overlying water. Phosphorus concentrations in overlying water maintained in a relative low level in the growth period of submerged macrophytes. The concentrations of total phosphorus (TP) in overlying water of H. verticillata, V. natans and P. crispus were 0.03-0.05, 0.04-0.12, 0.02-0.11 mg x L(-1), respectively. All phosphorus fractions in sediment were reduced. The maximum value between submerged macrophyte and control of H. verticillata, V. natans and P. crispus were 35.34, 60.67 and 25.92 mg x kg(-1), respectively. Dissolved oxygen (DO), redox potential (Eh) and pH in overlying water increased (DO 10.0-14.0 mg x L(-1), Eh 185-240 mV, pH 8.0-11.0) in the submerged macrophytes groups. Submerged macrophytes increased Eh( -140 - -23 mV) and maintained pH(7.2-8.0) in neutral range. The results indicated that submerged macrophytes affected phosphorus transferring between sediment and overlying water through increasing DO, Eh and pH in overlying water, and Eh in sediment.

Impact of upstream river inputs and reservoir operation on phosphorus fractions in water-particulate phases in the Three Gorges Reservoir.

Science.gov (United States)

Han, Chaonan; Zheng, Binghui; Qin, Yanwen; Ma, Yingqun; Yang, Chenchen; Liu, Zhichao; Cao, Wei; Chi, Minghui

2018-01-01

The impoundment of the Three Gorges Reservoir (TGR) has changed water-sand transport regime, with inevitable effects on phosphorus transport behavior in the TGR. In this study, we measured phosphorus fractions in water and suspended particles transported from upstream rivers of the TGR (the Yangtze River, the Jialing River and the Wu River) to reservoir inner region over the full operation schedule of the TGR. The aim was to determine how phosphorus fractions in water and particulate phases varied in response to natural hydrological processes and reservoir operations. The results showed that total phosphorus concentration (TP) in water in the TGR inner region was 0.17±0.05mg/L, which was lower than that in the Yangtze River (0.21±0.04mg/L) and the Wu River (0.23±0.03mg/L), but higher than that in the Jialing River (0.12±0.07mg/L). In the TGR inner region, there was no clear trend of total dissolved phosphorus (TDP), but total particulate phosphorus (TPP) showed a decreasing trend from tail area to head area because of particle deposition along the TGR mainstream. In addition, the concentrations of TPP in water and particulate phosphorus in a unit mass of suspended particles (PP) in the TGR inner region were higher in October 2014 and January 2015 (the impounding period and high water level period) than that in July 2015 (the low water level period). The temporal variations of PP and TPP concentrations in the TGR may be linked to the change of particle size distribution of suspended particles in the TGR. The particle size tended to be finer due to large-size particle deposition under stable hydrodynamic conditions in the process of TGR impoundment, resulting in high adsorption capacities of phosphorus in suspended particles. The results implied that phosphorus temporal variations in the TGR could exert different impacts on water quality in the TGR tributaries. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of lake surface area and total phosphorus on annual bluegill growth in small impoundments of central Georgia

Science.gov (United States)

Jennings, Cecil A.; Sundmark, Aaron P.

2017-01-01

The relationships between environmental variables and the growth rates of fishes are important and rapidly expanding topics in fisheries ecology. We used an informationtheoretic approach to evaluate the influence of lake surface area and total phosphorus on the age-specific growth rates of Lepomis macrochirus (Bluegill) in 6 small impoundments in central Georgia. We used model averaging to create composite models and determine the relative importance of the variables within each model. Results indicated that surface area was the most important factor in the models predicting growth of Bluegills aged 1–4 years; total phosphorus was also an important predictor for the same age-classes. These results suggest that managers can use water quality and lake morphometry variables to create predictive models specific to their waterbody or region to help develop lake-specific management plans that select for and optimize local-level habitat factors for enhancing Bluegill growth.

Leaching behavior of total organic carbon, nitrogen, and phosphorus from banana peel.

Science.gov (United States)

Jiang, Ruixue; Sun, Shujuan; Xu, Yan; Qiu, Xiudong; Yang, Jili; Li, Xiaochen

2015-01-01

The leaching behavior of organic carbon and nutrient compounds from banana peel (BP) was investigated in batch assays with respect to particle size, contact time, pH value, and temperature. The granularity, contact time, pH, and temperature caused no significant effects on the leaching of total phosphorus (TP) from the BP. The maximum leached total nitrogen (TN) content was found at pH 5.0 and 90 minutes, while no significant effects were caused by the granularity and temperature. The maximum leached total organic carbon (TOC) content was found by using a powder of 40 mesh, 150 minutes and at pH 6.0, while the temperature had no effect on the TOC leaching. The proportions of the TN, TP, and TOC contents leached from the dried BP ranged from 33.6% to 40.9%, 60.4% to 72.7%, and 8.2% to 9.9%, respectively, indicating that BP could be a potential pollution source for surface and ground water if discharged as domestic waste or reutilized without pretreatment.

Land-use impact on selected forms of arsenic and phosphorus in soils of different functions

Science.gov (United States)

Plak, Andrzej; Bartmiński, Piotr; Dębicki, Ryszard

2017-10-01

The aim of the study was to assess the impact of technosols and geomechanically unchanged soils of the Lublin agglomeration on the concentrations of arsenic and phosphorus, and on selected forms of these elements. Arsenic and phosphorus concentrations were determined in the urban soils of Lublin (Poland), and the relationship between their degree of contamination and different types of land use was estimated. The samples collected were subjected to sequential analysis, using ammonium sulphate, acid ammonium phosphate, oxalate buffer (also with ascorbic acid) and aqua regia for arsenic, and ammonium chloride, sodium hydroxide, hydrochloric acid and aqua regia for phosphorus. The influence of the land use forms was observed in the study. The greatest amount of arsenic (19.62 mg kg-1) was found in the industrial soils of Lublin, while the greatest amount of phosphorus (580.4 mg kg-1) was observed in non-anthropogenic soils (mainly due to the natural accumulation processes of this element). Fractions of arsenic and phosphorus obtained during analysis showed strong differentiation. Amorphic and crystalline fractions of arsenic, bound with iron oxides, proved to have the highest share in the total arsenic pool. The same situation was noted for phosphorus.

Combined effects of nitrogen to phosphorus ratios and nitrogen speciation on cyanobacterial metabolite concentrations in eutrophic Midwestern USA reservoirs.

NARCIS (Netherlands)

Harris, T.D.; Smith, V.H.; Graham, J.L.; Van de Waal, D.B.; Tedesco, L.P.; Clercin, N.

2016-01-01

Recent studies have shown that the total nitrogen to total phosphorus (TN:TP) ratio and nitrogen oxidation state may have substantial effects on secondary metabolite (e.g., microcystins) production in cyanobacteria. We investigated the relationship between the water column TN:TP ratio and the

Determination of phosphorus distribution in the region of a SiO2-Si interface by substoichiometric analysis

International Nuclear Information System (INIS)

Shigematsu, T.; Yonezawa, H.

1994-01-01

A simplified method for the substoichiometric analysis of phosphorus has been developed and applied to determine the concentration distribution of phosphorus in the region of a SiO 2 -Si interface in order to explain why phosphorus is lost from the ion-implanted silicon surface throughout the oxidation and oxide removal processes. It is revealed that phosphorus piles up on the SiO 2 side at the interface by the thermal oxidation of silicon surface and is removed with the oxide by wet etching and with the resulting silicon by RCA cleaning. This results in a total loss of ion-implanted phosphorus of 3.5%. (author) 11 refs.; 2 figs.; 3 tabs

A randomized, double-blind, placebo-controlled trial of calcium acetate on serum phosphorus concentrations in patients with advanced non-dialysis-dependent chronic kidney disease

Directory of Open Access Journals (Sweden)

Ho Chiang-Hong

2011-02-01

Full Text Available Abstract Background Hyperphosphatemia in patients with chronic kidney disease (CKD contributes to secondary hyperparathyroidism, soft tissue calcification, and increased mortality risk. This trial was conducted to examine the efficacy and safety of calcium acetate in controlling serum phosphorus in pre-dialysis patients with CKD. Methods In this randomized, double-blind, placebo-controlled trial, 110 nondialyzed patients from 34 sites with estimated GFR 2 and serum phosphorus > 4.5 mg/dL were randomized to calcium acetate or placebo for 12 weeks. The dose of study drugs was titrated to achieve target serum phosphorus of 2.7-4.5 mg/dL. Serum phosphorus, calcium, iPTH, bicarbonate and serum albumin were measured at baseline and every 2 weeks for the 12 week study period. The primary efficacy endpoint was serum phosphorus at 12 weeks. Secondary endpoints were to measure serum calcium and intact parathyroid hormone (iPTH levels. Results At 12 weeks, serum phosphorus concentration was significantly lower in the calcium acetate group compared to the placebo group (4.4 ± 1.2 mg/dL vs. 5.1 ± 1.4 mg/dL; p = 0.04. The albumin-adjusted serum calcium concentration was significantly higher (9.5 ± 0.8 vs. 8.8 ± 0.8; p p Conclusions In CKD patients not yet on dialysis, calcium acetate was effective in reducing serum phosphorus and iPTH over a 12 week period. Trial Registration www.clinicaltrials.gov NCT00211978.

Transport of phosphorus, wash load and suspended sediment in the River Varde A in southwest Jutland, Denmark

DEFF Research Database (Denmark)

Thodsen, Hans; Hasholt, Bent; Pejrup, Morten

2004-01-01

Total phosphorus (TP) concentrations, suspended sediment concentrations (SSC) and wash load have been measured at three river monitoring stations in the River Varde Angstrom system since 1998. This provides the possibility of studying the link between SSC and wash load and concentrations of TP...... at the end of a small impoundment. Transport rates at the upstream stations were 57% higher for suspended sediment and 27% higher for wash load than at the downstream station, while transport of TP was the same. This indicates that phosphorus is transported adhered to the finest grain size fractions that do...

Occurrence of phosphorus, other nutrients, and triazine herbicides in water from the Hillsdale Lake basin, Northeast Kansas, May 1994 through May 1995

Science.gov (United States)

Putnam, J.E.

1997-01-01

An investigation of the occurrence of phosporus, other nutrients, and triazine herbicides in water samples from the Hillsdale Lake Basin in northeast Kansas was conducted from May 1994 through May 1995. Point-source and nonpoint-source contributions of these water-quality constituents were estimated by conducting synoptic sampling at 48 sites in the basin during five periods of low- flow conditions. Samples were collected for the determination of nutrients, including total phosphorus as phosphorus, dissolved orthophosphate as phosphorus, total nitrite plus nitrate as nitrogen, and total ammonia plus organic nitrogen as nitrogen, and for selected triazine herbicides. On the basis of criteria developed by the Kansas Department of Health and Environment, the Hillsdale Water-Quality Protection Project established a goal to maintain water quality in the tributaries of the Hillsdale Lake Basin at a mean annual low-flow total phosphorus concentration of 0.05 mg/L (milligrams per liter). The mean low- flow total phosphorus concentration of water samples collected in the Big Bull Creek (which includes drainage from Martin Creek), Rock Creek, Little Bull Creek, Wade Branch, and Smith Branch subbasins during low-flow conditions ranged from 0.05 to 4.9 mg/L during this study. Of the 44 sites sampled during low flow, 95 percent had low-flow total phosphorus concentrations larger than the 0.05-mg/L criterion. Discharges from wastewater- treatment plants located in Big Bull Creek and Martin Creek subbasins and the Little Bull Creek subbasin affected nutrient concentrations. Nutrient concentrations in water samples collected from the subbasins not affected by point-source discharges generally were smaller than those in the Big Bull Creek and Little Bull Creek subbasins. Estimated annual low-flow phosphorus loads computed at sampling sites located at the outlet of the subbasins show that the Big Bull Creeksubbasin, which includes drainage from the Martin Creek subbasin, had the

Plasma concentration of ionized calcium in healthy iguanas.

Science.gov (United States)

Dennis, P M; Bennett, R A; Harr, K E; Lock, B A

2001-08-01

To measure plasma concentration of ionized calcium in healthy green iguanas. Prospective study. 9 juvenile and 21 (10 male, 11 female) adult iguanas. Blood samples were obtained from each iguana, and plasma calcium, glucose, phosphorus, uric acid, total protein, albumin, globulin, potassium, and ionized calcium concentrations, aspartate transaminase (AST) activity, and pH were measured. Heparinized blood was used for measurement of ionized calcium concentration and blood pH. A CBC was also performed to assess the health of the iguanas. Significant differences were not detected among the 3 groups (juveniles, males, and females) with regard to ionized calcium concentration. Mean ionized calcium concentration measured in blood was 1.47 +/- 0.105 mmol/L. Significant differences were detected between juveniles and adults for values of phosphorus, glucose, total protein, albumin, globulin, and AST activity. Ionized calcium concentration provides a clinical measurement of the physiologically active calcium in circulation. Evaluation of physiologically active calcium in animals with suspected calcium imbalance that have total plasma calcium concentrations within reference range or in gravid animals with considerably increased total plasma calcium concentrations is vital for determining a therapeutic plan. Accurate evaluation of calcium status will provide assistance in the diagnosis of renal disease and seizures and allow for better evaluation of the health status of gravid female iguanas.

Refractometric total protein concentrations in icteric serum from dogs.

Science.gov (United States)

Gupta, Aradhana; Stockham, Steven L

2014-01-01

To determine whether high serum bilirubin concentrations interfere with the measurement of serum total protein concentration by refractometry and to assess potential biases among refractometer measurements. Evaluation study. Sera from 2 healthy Greyhounds. Bilirubin was dissolved in 0.1M NaOH, and the resulting solution was mixed with sera from 2 dogs from which food had been withheld to achieve various bilirubin concentrations up to 40 mg/dL. Refractometric total protein concentrations were estimated with 3 clinical refractometers. A biochemical analyzer was used to measure biuret assay-based total protein and bilirubin concentrations with spectrophotometric assays. No interference with refractometric measurement of total protein concentrations was detected with bilirubin concentrations up to 41.5 mg/dL. Biases in refractometric total protein concentrations were detected and were related to the conversion of refractive index values to total protein concentrations. Hyperbilirubinemia did not interfere with the refractometric estimation of serum total protein concentration. The agreement among total protein concentrations estimated by 3 refractometers was dependent on the method of conversion of refractive index to total protein concentration and was independent of hyperbilirubinemia.

Influence of lead-doped hydroponic medium on the adsorption/bioaccumulation processes of lead and phosphorus in roots and leaves of the aquatic macrophyte Eicchornia crassipes.

Science.gov (United States)

Espinoza-Quiñones, Fernando R; Módenes, Aparecido Nivaldo; de Oliveira, Ana Paula; Trigueros, Daniela Estelita Goes

2013-11-30

In this study, lead bioaccumulation by the living free-floating aquatic macrophyte Eicchornia crassipes in different hydroponic conditions with variations in phosphorus and lead concentrations was investigated. A set of growth experiments in hydroponic media doped with lead and phosphorus within a wide concentration range was performed for 32 days in a greenhouse. All experiments were carried out with periodic replacement of all nutrients and lead. The concentration of lead and nutrients in biomass was determined by synchrotron radiation-excited total reflection X-ray fluorescence. By increasing the lead concentration in the medium, a reduction in biomass growth was observed, but a higher phosphorus retention in roots and leaves was shown at lower lead concentrations. In addition, an increase in the amount of bioaccumulated lead and phosphorus in roots was observed for higher lead and phosphorus concentrations in the medium, reaching saturation values of 4 mg Pb g(-1) and 7 mg P g(-1), respectively. Four non-structural kinetic models were tested, to represent the bioaccumulation of lead and phosphorus in roots. Pseudo-second order and irreversible kinetic models described the lead bioaccumulation data well, however, an irreversible kinetic model better fitted phosphorus uptake in roots. Copyright © 2013 Elsevier Ltd. All rights reserved.

Estimates of long-term water total phosphorus (TP) concentrations in three large shallow lakes in the Yangtze River basin, China.

Science.gov (United States)

Wu, Pan; Qin, Boqiang; Yu, Ge

2016-03-01

The shallow lakes in the eastern China developed on alluvial plains with high-nutrient sediments, and most overflow into the Yangtze River with short hydraulic residence times, whereas they become eutrophic over long time periods. Assuming strong responses to hydrogeological changes in the basin, we attempted to determine the dynamic eutrophication history of these lakes. Although evaluation models for internal total phosphorus (TP) loading are widely used for deep lakes in Europe and North America, the accuracy of these models for shallow lakes that have smaller water volumes controlled by the geometrical morphology and greater basin area of alluvial plains is unknown. To describe the magnitude of changes in velocity of trophic state for the studied shallow lakes, we first evaluated the P retention model in relation to the major forces driving lake morphology, basin climate, and external discharge and then used the model to estimate changes in TP in three large shallow lakes (Taihu, Chao, and Poyang) over 60 years (1950-2009 AD). The observed levels of TP were verified against the relative error of the three lakes (Yangtze River basin. This work will contribute to the development of an internal P loading model for further evaluating trophic states.

Temporal changes in nitrogen and phosphorus concentrations with comparisons to conservation practices and agricultural activities in the Lower Grand River, Missouri and Iowa, and selected watersheds, 1969–2015

Science.gov (United States)

Krempa, Heather M.; Flickinger, Allison K.

2017-08-01

This report presents the results of a cooperative study by the U.S. Geological Survey and Missouri Department of Natural Resources to estimate total nitrogen (TN) and total phosphorus (TP) concentrations at monitoring sites within and near the Lower Grand River hydrological unit. The primary objectives of the study were to quantify temporal changes in TN and TP concentrations and compare those concentrations to conservation practices and agricultural activities. Despite increases in funding during 2011–15 for conservation practices in the Lower Grand River from the Mississippi River Basin Healthy Watersheds Initiative, decreases in flow-normalized TN and TP concentrations during this time at the long-term Grand River site were less than at other long-term sites, which did not receive funding from the Mississippi River Basin Healthy Watersheds Initiative. The relative differences in the magnitude of flow-normalized TN and TP concentrations among long-term sites are directly related to the amount of agricultural land use within the watershed. Significant relations were determined between nitrogen from cattle manure and flow-normalized TN concentrations at selected long-term sites, indicating livestock manure may be a substantial source of nitrogen within the selected long-term site watersheds. Relations between flow-normalized TN and TP concentrations with Conservation Reserve Program acres and with nitrogen and phosphorus from commercial fertilizer indicate that changes in these factors alone did not have a substantial effect on stream TN and TP concentrations; other landscape activities, runoff, within-bank nutrients that are suspended during higher streamflows, or a combination of these have had a greater effect on stream TN and TP concentrations; or there is a lag time that is obscuring relations. Temporal changes in flow-adjusted TN and TP concentrations were not substantial at Lower Grand River Mississippi River Basin Healthy Watersheds Initiative sites

Quantifying phosphorus levels in soils, plants, surface water, and shallow groundwater associated with bahiagrass-based pastures.

Science.gov (United States)

Sigua, Gilbert C; Hubbard, Robert K; Coleman, Samuel W

2010-01-01

Recent assessments of water quality status have identified eutrophication as one of the major causes of water quality 'impairment' not only in the USA but also around the world. In most cases, eutrophication has accelerated by increased inputs of phosphorus due to intensification of crop and animal production systems since the early 1990 s. Despite substantial measurements using both laboratory and field techniques, little is known about the spatial and temporal variability of phosphorus dynamics across landscapes, especially in agricultural landscapes with cow-calf operations. Critical to determining environmental balance and accountability is an understanding of phosphorus excreted by animals, phosphorus removal by plants, acceptable losses of phosphorus within the manure management and crop production systems into soil and waters, and export of phosphorus off-farm. Further research effort on optimizing forage-based cow-calf operations to improve pasture sustainability and protect water quality is therefore warranted. We hypothesized that properly managed cow-calf operations in subtropical agroecosystem would not be major contributors to excess loads of phosphorus in surface and ground water. To verify our hypothesis, we examined the comparative concentrations of total phosphorus among soils, forage, surface water, and groundwater beneath bahiagrass-based pastures with cow-calf operations in central Florida, USA. Soil samples were collected at 0-20; 20-40, 40-60, and 60-100 cm across the landscape (top slope, middle slope, and bottom slope) of 8 ha pasture in the fall and spring of 2004 to 2006. Forage availability and phosphorus uptake of bahiagrass were also measured from the top slope, middle slope, and bottom slope. Bi-weekly (2004-2006) groundwater and surface water samples were taken from wells located at top slope, middle slope, and bottom slope, and from the runoff/seepage area. Concentrations of phosphorus in soils, forage, surface water, and shallow

Differences among total and in vitro digestible phosphorus content of meat and milk products.

Science.gov (United States)

Karp, Heini; Ekholm, Päivi; Kemi, Virpi; Hirvonen, Tero; Lamberg-Allardt, Christel

2012-05-01

Meat and milk products are important sources of dietary phosphorus (P) and protein. The use of P additives is common both in processed cheese and meat products. Measurement of in vitro digestible phosphorus (DP) content of foods may reflect absorbability of P. The objective of this study was to measure both total phosphorus (TP) and DP contents of selected meat and milk products and to compare amounts of TP and DP and the proportion of DP to TP among different foods. TP and DP contents of 21 meat and milk products were measured by inductively coupled plasma optical emission spectrometry (ICP-OES). In DP analysis, samples were digested enzymatically, in principle, in the same way as in the alimentary canal before the analyses. The most popular national brands of meat and milk products were chosen for analysis. The highest TP and DP contents were found in processed and hard cheeses; the lowest, in milk and cottage cheese. TP and DP contents in sausages and cold cuts were lower than those in cheeses. Chicken, pork, beef, and rainbow trout contained similar amounts of TP, but slightly more variation was found in their DP contents. Foods containing P additives have a high content of DP. Our study confirms that cottage cheese and unenhanced meats are better choices than processed or hard cheeses, sausages, and cold cuts for chronic kidney disease patients, based on their lower P-to-protein ratios and sodium contents. The results support previous findings of better P absorbability in foods of animal origin than in, for example, legumes. Copyright © 2012 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Effect of phytase supplementation on apparent phosphorus digestibility and phosphorus output in broiler chicks fed low-phosphorus diets

Directory of Open Access Journals (Sweden)

Xian-Ren Jiang

2015-04-01

Full Text Available This study was conducted to evaluate the effect of supplemental phytase in broiler chicks fed different low levels of total phosphorus (P on the apparent phosphorus digestibility (APD and phosphorus output (PO in the faeces and ileal digesta. After fed a standard broiler starter diet from day 0 to 14 post-hatch, a total of 144 male broiler chicks were allocated to 6 groups for a 7-d experiment with a 2 × 3 factorial design comparing phytase (supplemented without (CTR or with 400 FTU/kg phytase (PHY and total P levels (2.0, 2.5 and 3.0 g/kg. The faecal samples were collected from day 17 to 21 post-hatch. At 22 days of age, all the chicks were slaughtered and collected the ileal digesta. Phytase supplementation significantly (P < 0.01 increased APD and decreased PO in the faeces and ileal digesta in comparison with the CTR group. In addition, PO in the faeces expressed as g/kg DM diets and faeces (Diet × P level, P = 0.047 and < 0.01, respectively as well as PO in the ileal digesta expressed as g/kg DM digesta (Diet × P level, P = 0.04 were affected by diet and P level, which were due to the significant reduction (P < 0.01 by PHY supplementation to the diets with 3.0 g/kg total P. The results evidenced that supplemental phytase improved the APD and PO when chicks was fed 3.0 g/kg total P diet, while lower total P levels may limit exogenous phytase efficacy.

Anthropogenic phosphorus flow analysis of Hefei City, China

International Nuclear Information System (INIS)

Li Sisi; Yuan Zengwei; Bi Jun; Wu Huijun

2010-01-01

The substance flow analysis (SFA) method was employed to examine phosphorus flow and its connection to water pollution in the city of Hefei, China, in 2008. As human activity is the driving force of phosphorus flux from the environment to the economy, the study provides a conceptual framework for analyzing an anthropogenic phosphorus cycle that includes four stages: extraction, fabrication and manufacturing, use, and waste management. Estimates of phosphorus flow were based on existing data as well as field research, expert advice, local accounting systems, and literature. The total phosphorus input into Hefei in 2008 reached 7810 tons, mainly as phosphate ore, chemical fertilizer, pesticides, crops and animal products. Approximately 33% of the total phosphorus input left the area, and nearly 20% of that amount was discharged as waste to surface water. Effluent containing excessive fertilizer from farming operations plays an important role in phosphorus overloads onto surface water; the other major emission source is sewage discharge. We also provide suggestions for reducing phosphorus emissions, for example reducing fertilizer use, recycling farming residues, and changing human consumption patterns.

Phosphorus forms and chemistry in the soil profile under long-term conservation tillage: a phosphorus-31 nuclear magnetic resonance study.

Science.gov (United States)

Cade-Menun, Barbara J; Carter, Martin R; James, Dean C; Liu, Corey W

2010-01-01

In many regions, conservation tillage has replaced conventional tilling practices to reduce soil erosion, improve water conservation, and increase soil organic matter. However, tillage can have marked effects on soil properties, specifically nutrient redistribution or stratification in the soil profile. The objective of this research was to examine soil phosphorus (P) forms and concentrations in a long-term study comparing conservation tillage (direct drilling, "No Till") and conventional tillage (moldboard plowing to 20 cm depth, "Till") established on a fine sandy loam (Orthic Humo-Ferric Podzol) in Prince Edward Island, Canada. No significant differences in total carbon (C), total nitrogen (N), total P, or total organic P concentrations were detected between the tillage systems at any depth in the 0- to 60-cm depth range analyzed. However, analysis with phosphorus-31 nuclear magnetic resonance spectroscopy showed differences in P forms in the plow layer. In particular, the concentration of orthophosphate was significantly higher under No Till than Till at 5 to 10 cm, but the reverse was true at 10 to 20 cm. Mehlich 3-extractable P was also significantly higher in No Till at 5 to 10 cm and significantly higher in Till at 20 to 30 cm. This P stratification appears to be caused by a lack of mixing of applied fertilizer in No Till because the same trends were observed for pH and Mehlich 3-extractable Ca (significantly higher in the Till treatment at 20 to 30 cm), reflecting mixing of applied lime. The P saturation ratio was significantly higher under No Till at 0 to 5 cm and exceeded the recommended limits, suggesting that P stratification under No Till had increased the potential for P loss in runoff from these sites.

Filter Membrane Effects on Water-Extractable Phosphorus Concentrations from Soil.

Science.gov (United States)

Norby, Jessica; Strawn, Daniel; Brooks, Erin

2018-03-01

To accurately assess P concentrations in soil extracts, standard laboratory practices for monitoring P concentrations are needed. Water-extractable P is a common analytical test to determine P availability for leaching from soils, and it is used to determine best management practices. Most P analytical tests require filtration through a filter membrane with 0.45-μm pore size to distinguish between particulate and dissolved P species. However, filter membrane type is rarely specified in method protocols, and many different types of membranes are available. In this study, three common filter membrane materials (polyether sulfone, nylon, and nitrocellulose), all with 0.45-μm pore sizes, were tested for analytical differences in total P concentrations and dissolved reactive P (DRP) concentrations in water extracts from six soils sampled from two regions. Three of the extracts from the six soil samples had different total P concentrations for all three membrane types. The other three soil extracts had significantly different total P results from at least one filter membrane type. Total P concentration differences were as great as 35%. The DRP concentrations in the extracts were dependent on filter type in five of the six soil types. Results from this research show that filter membrane type is an important parameter that affects concentrations of total P and DRP from soil extracts. Thus, membrane type should be specified in soil extraction protocols. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Cyanobacteria and cyanotoxins: the influence of nitrogen versus phosphorus.

Directory of Open Access Journals (Sweden)

Andrew M Dolman

Full Text Available The importance of nitrogen (N versus phosphorus (P in explaining total cyanobacterial biovolume, the biovolume of specific cyanobacterial taxa, and the incidence of cyanotoxins was determined for 102 north German lakes, using methods to separate the effects of joint variation in N and P concentration from those of differential variation in N versus P. While the positive relationship between total cyanobacteria biovolume and P concentration disappeared at high P concentrations, cyanobacteria biovolume increased continually with N concentration, indicating potential N limitation in highly P enriched lakes. The biovolumes of all cyanobacterial taxa were higher in lakes with above average joint NP concentrations, although the relative biovolumes of some Nostocales were higher in less enriched lakes. Taxa were found to have diverse responses to differential N versus P concentration, and the differences between taxa were not consistent with the hypothesis that potentially N(2-fixing Nostocales taxa would be favoured in low N relative to P conditions. In particular Aphanizomenon gracile and the subtropical invasive species Cylindrospermopsis raciborskii often reached their highest biovolumes in lakes with high nitrogen relative to phosphorus concentration. Concentrations of all cyanotoxin groups increased with increasing TP and TN, congruent with the biovolumes of their likely producers. Microcystin concentration was strongly correlated with the biovolume of Planktothrix agardhii but concentrations of anatoxin, cylindrospermopsin and paralytic shellfish poison were not strongly related to any individual taxa. Cyanobacteria should not be treated as a single group when considering the potential effects of changes in nutrient loading on phytoplankton community structure and neither should the N(2-fixing Nostocales. This is of particular importance when considering the occurrence of cyanotoxins, as the two most abundant potentially toxin producing

Cyanobacteria and cyanotoxins: the influence of nitrogen versus phosphorus.

Science.gov (United States)

Dolman, Andrew M; Rücker, Jacqueline; Pick, Frances R; Fastner, Jutta; Rohrlack, Thomas; Mischke, Ute; Wiedner, Claudia

2012-01-01

The importance of nitrogen (N) versus phosphorus (P) in explaining total cyanobacterial biovolume, the biovolume of specific cyanobacterial taxa, and the incidence of cyanotoxins was determined for 102 north German lakes, using methods to separate the effects of joint variation in N and P concentration from those of differential variation in N versus P. While the positive relationship between total cyanobacteria biovolume and P concentration disappeared at high P concentrations, cyanobacteria biovolume increased continually with N concentration, indicating potential N limitation in highly P enriched lakes. The biovolumes of all cyanobacterial taxa were higher in lakes with above average joint NP concentrations, although the relative biovolumes of some Nostocales were higher in less enriched lakes. Taxa were found to have diverse responses to differential N versus P concentration, and the differences between taxa were not consistent with the hypothesis that potentially N(2)-fixing Nostocales taxa would be favoured in low N relative to P conditions. In particular Aphanizomenon gracile and the subtropical invasive species Cylindrospermopsis raciborskii often reached their highest biovolumes in lakes with high nitrogen relative to phosphorus concentration. Concentrations of all cyanotoxin groups increased with increasing TP and TN, congruent with the biovolumes of their likely producers. Microcystin concentration was strongly correlated with the biovolume of Planktothrix agardhii but concentrations of anatoxin, cylindrospermopsin and paralytic shellfish poison were not strongly related to any individual taxa. Cyanobacteria should not be treated as a single group when considering the potential effects of changes in nutrient loading on phytoplankton community structure and neither should the N(2)-fixing Nostocales. This is of particular importance when considering the occurrence of cyanotoxins, as the two most abundant potentially toxin producing Nostocales in our study

Derivation of a fuzzy national phosphorus export model using 84 Irish catchments

Energy Technology Data Exchange (ETDEWEB)

Nasr, Ahmed [School of Civil and Building Services Engineering, College Of Engineering and Built Environment, Dublin Institute of Technology, Bolton Street, Dublin 1 (Ireland); Bruen, Michael, E-mail: michael.bruen@ucd.ie [Centre for Water Resources Research, University College Dublin, Newstead Building, Richview, Belfield, Dublin 4 (Ireland)

2013-01-15

Implementation of appropriate management strategies to mitigate diffuse phosphorus (P) pollution at the catchment scale is vitally important for the sustainable development of water resources in Ireland. An important element in the process of implementing such strategies is the prediction of their impacts on P concentrations in a catchment using a reliable mathematical model. In this study, a state-of-the-art adaptive neuro-fuzzy inference system (ANFIS) has been used to develop a new national P model capable of estimating average annual ortho-P concentrations at un-gauged catchments. Data from 84 catchments dominated by diffuse P pollution were used in developing and testing the model. Six different split-sample scenarios were used to partition the total number of the catchments into two sets, one to calibrate and the other to validate the model. The k-means clustering algorithm was used to partition the sets into clusters of catchments with similar features. Then for each scenario and for each cluster case, 11 different models, each of which consists of a linear regression sub-model for each cluster, were formulated by using different input variables selected from among six spatially distributed variables including phosphorus desorption index (PDI), runoff risk index (RRI), geology (GEO), groundwater (GW), land use (LU), and soil (SO). The success of the new approach over the conventional lumped, empirical, modelling approach was evident from the improved results obtained for most of the cases. In addition the results highlighted the importance of using information on PDI and RRI as explanatory input variables to simulate the average annual ortho-P concentrations. - Highlights: ► Develops a new national phosphorus export model for agricultural catchments in Ireland ► Improves on earlier empirical phosphorus export models by using k-means clustering method for partitioning data ► Uses ANFIS model to predict annual average ortho-phosphorus concentrations

Derivation of a fuzzy national phosphorus export model using 84 Irish catchments

International Nuclear Information System (INIS)

Nasr, Ahmed; Bruen, Michael

2013-01-01

Implementation of appropriate management strategies to mitigate diffuse phosphorus (P) pollution at the catchment scale is vitally important for the sustainable development of water resources in Ireland. An important element in the process of implementing such strategies is the prediction of their impacts on P concentrations in a catchment using a reliable mathematical model. In this study, a state-of-the-art adaptive neuro-fuzzy inference system (ANFIS) has been used to develop a new national P model capable of estimating average annual ortho-P concentrations at un-gauged catchments. Data from 84 catchments dominated by diffuse P pollution were used in developing and testing the model. Six different split-sample scenarios were used to partition the total number of the catchments into two sets, one to calibrate and the other to validate the model. The k-means clustering algorithm was used to partition the sets into clusters of catchments with similar features. Then for each scenario and for each cluster case, 11 different models, each of which consists of a linear regression sub-model for each cluster, were formulated by using different input variables selected from among six spatially distributed variables including phosphorus desorption index (PDI), runoff risk index (RRI), geology (GEO), groundwater (GW), land use (LU), and soil (SO). The success of the new approach over the conventional lumped, empirical, modelling approach was evident from the improved results obtained for most of the cases. In addition the results highlighted the importance of using information on PDI and RRI as explanatory input variables to simulate the average annual ortho-P concentrations. - Highlights: ► Develops a new national phosphorus export model for agricultural catchments in Ireland ► Improves on earlier empirical phosphorus export models by using k-means clustering method for partitioning data ► Uses ANFIS model to predict annual average ortho-phosphorus concentrations

Nutrient concentrations, loads, and yields in the Eucha-Spavinaw Basin, Arkansas and Oklahoma, 2002-09

Science.gov (United States)

Esralew, Rachel A.; Tortorelli, Robert L.

2010-01-01

The city of Tulsa, Oklahoma, uses Lake Eucha and Spavinaw Lake in the Eucha-Spavinaw Basin in northwestern Arkansas and northeastern Oklahoma for public water supply. The city has spent millions of dollars over the last decade to eliminate taste and odor problems in the drinking water from the Eucha-Spavinaw system, which may be attributable to blue-green algae. Increases in the algal biomass in the lakes may be attributable to increases in nutrient concentrations in the lakes and in the waters feeding the lakes. The U.S. Geological Survey, in cooperation with the City of Tulsa, investigated and summarized total nitrogen and total phosphorus concentrations in water samples and provided estimates of nitrogen and phosphorus loads, yields, and flow-weighted concentrations during base flow and runoff for two streams discharging to Lake Eucha for the period January 2002 through December 2009. This report updates a previous report that used data from water-quality samples collected from January 2002 through December 2006. Based on the results from the Mann-Whitney statistical test, unfiltered total nitrogen concentrations were significantly greater in runoff water samples than in base-flow water samples collected from Spavinaw Creek near Maysville and near Cherokee City, Arkansas; Spavinaw Creek near Colcord, Oklahoma, and Beaty Creek near Jay, Oklahoma. Nitrogen concentrations in runoff water samples collected from all stations generally increased with increasing streamflow. Nitrogen concentrations in base-flow and runoff water samples collected in Spavinaw Creek significantly increased from the station furthest upstream (near Maysville) to the Sycamore station and then significantly decreased from the Sycamore station to the station furthest downstream (near Colcord). Nitrogen concentrations in base-flow and runoff water samples collected from Beaty Creek were significantly less than base-flow and runoff water samples collected from Spavinaw Creek. Based on the results

[Effects of selective cutting on soil phosphorus forms and availability in Korean pine broad-leaved forest in Xiaoxing'an Mountains of China.

Science.gov (United States)

Zhang, Xin; Gu, Hui Yan; Chen, Xiang Wei

2018-02-01

In order to clarify the effects of selective cutting on soil phosphorus availability in Korean pine broad-leaved forest, surface soil (0-10 cm) samples from original Korean pine broad-leaved forest and natural forests with mild, medium and intensive cutting disturbances were collected. The Sui modified Hedley phosphorus fractionation method was used to continuously extract soil samples and analyzed the differences and changes of soil phosphorus fractions from different experimental stands. The results showed that the soil total phosphorus content of Korean pine broad-leaved forest varied from 1.09 to 1.66 g·kg -1 , with the original stand and intensive cutting disturbance stand being the maximum and minimum one, respectively. The differences of soil total phosphorus content among cutting disturbance levels were significant. The Olsen phosphorus and phosphorus activation coefficients changed with an amplitude of 7.26-17.79 mg·kg -1 and 0.67%-1.07%, respectively. Both of them significantly decreased with the increase of selective cutting disturbance level. The concentrations of all P fractions except HCl-P o , i.e., H 2 O-P i , NaHCO 3 -P, NaOH-P, HCl-P i , Residual-P, decreased with increasing cutting disturbance levels compared with original forest. The correlation coefficient between H 2 O-P i and soil Olsen phosphorus was the highest (0.98), though it only accounted for 1.5%-2.2% of the total phosphorus. NaOH-P content contributed to more than 48.0% of the total phosphorus, acknowledged as the potential source of soil phosphorus. In conclusion, selective cutting disturbance could constrain phosphorus storage and soil phosphorus availabi-lity of the Korean pine broad-leaved forests by significantly reducing the content of soil inorganic phosphorus and NaOH-P o , and such trends were positively dependent on the intensity of selective cutting.

Phosphorus fractions and its potential release in the sediments of Koycegiz Lake, Turkey

Directory of Open Access Journals (Sweden)

Yalçın Şahin

2012-12-01

Full Text Available This study was conducted to find out the seasonal and spatial patterns of the phosphorus in the littoral sediment and its potential release into the Koycegiz Lake, south west Turkey, between November 2011 and March 2012 at two months intervals. The scanning electron microscopy was used for elemental compositions of the sediment. The amounts and forms of phosphorus (P in surface sediments of Koycegiz Lake were examined using a not sequential chemical extraction procedure. Four fractions of sedimentary P, including organic bound phosphorus fraction (Org≈P, calcium bound phosphorus fraction (Ca≈P, iron+aluminium bound phosphorus fraction (Fe+Al≈P and carbonate bound phosphorus fraction (CO3≈P were separately quantified. The results indicated that the contents of different phosphorus fractions in the sediments varied greatly. The proportion of phosphorus fractions was estimated as Org≈P (90.20 %, this fraction was followed by Ca≈P (9.06 %, Fe+Al≈P (0.47 % and CO3≈P (0.27 % in this study. The level of phosphorus release from the sediment to the lake is calculated as low. The sediment phosphorus release fluctuated between -6.647–75.883 μg/m2.d-1 and the total phosphorus (TP concentrations of the sediment samples were changed between 980.39 μg/gDW (Dry Weight - 1990.81 μg/gDW. The results show that it can be evaluation as eutrophic for Koycegiz Lake.

Comparison of Serum Concentrations of Total Cholesterol and Total ...

African Journals Online (AJOL)

Tuberculosis (TB) is one of the most dangerous tropical diseases that complicates HIV infection in Nigeria to date. Over two million Nigerians are known to be infected with TB and many more are at risk of the infection. Serum concentrations of total cholesterol and total lipid of 117 female TB patients attending chest clinic at ...

Phosphorus-defect interactions during thermal annealing of ion implanted silicon

Science.gov (United States)

Keys, Patrick Henry

Ion implantation of dopant atoms into silicon generates nonequilibrium levels of crystal defects that can lead to the detrimental effects of transient enhanced diffusion (TED), incomplete dopant activation, and p-n junction leakage. In order to control these effects, it is vital to have a clear understanding of dopant-defect interactions and develop models that account for these interactions. This research focuses on experimentally investigating and modeling the clustering of phosphorus dopant atoms with silicon interstitials. Damage recovery of 40keV Si+ implants in phosphorus doped wells is experimentally analyzed. The effects of background phosphorus concentration, self implant dose, and anneal temperature are investigated. Phosphorus concentrations ranging from 2.0 x 1017 to 4.0 x 1019 cm-3 and Si+ doses ranging from 5.0 x 1013 cm-2 to 2.0 x 1014 cm-2 are studied during 650-800°C anneals. A dramatic reduction in the number of interstitials bound in {311} defects with increasing phosphorus background concentration is observed. It is suggested that the reduction of interstitials in {311} defects at high phosphorus concentrations is due to the formation of phosphorus-interstitial clusters (PICs). The critical concentration for clustering (approximately 1.0 x 1019 cm-3 at 750°C) is strongly temperature dependent and in close agreement with the kink concentration of phosphorus diffusion. Information gained from these "well experiments" is applied to the study of direct phosphorus implantation. An experimental study is conducted on 40keV phosphorus implanted to a dose of 1.0 x 1014 cm-2 during 650-800°C anneals. Electrically inactive PICs are shown to form at concentrations below the solid solubility limit due to high interstitial supersaturations. Data useful for developing a model to accurately predict phosphorus diffusion under nonequilibrium conditions are extracted from the experimental results. A cluster-mediated diffusion model is developed using the

Characterisation and quantification of organic phosphorus and organic nitrogen components in aquatic systems: A Review

Energy Technology Data Exchange (ETDEWEB)

Worsfold, Paul J. [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL48AA (United Kingdom)], E-mail: pworsfold@plymouth.ac.uk; Monbet, Philippe [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL48AA (United Kingdom); Water Studies Centre, School of Chemistry, Monash University, Clayton 3800, Victoria (Australia); Tappin, Alan D.; Fitzsimons, Mark F.; Stiles, David A. [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL48AA (United Kingdom); McKelvie, Ian D. [Water Studies Centre, School of Chemistry, Monash University, Clayton 3800, Victoria (Australia)

2008-08-22

This review provides a critical assessment of knowledge regarding the determination of organic phosphorus (OP) and organic nitrogen (ON) in aquatic systems, with an emphasis on biogeochemical considerations and analytical challenges. A general background on organic phosphorus and organic nitrogen precedes a discussion of sample collection, extraction, treatment/conditioning and preconcentration of organic phosphorus/nitrogen from sediments, including suspended particulate matter, and waters, including sediment porewaters. This is followed by sections on the determination of organic phosphorus/nitrogen components. Key techniques covered for organic phosphorus components are molecular spectrometry, atomic spectrometry and enzymatic methods. For nitrogen the focus is on the measurement of total organic nitrogen concentrations by carbon hydrogen nitrogen analysis and high temperature combustion, and organic nitrogen components by gas chromatography, high-performance liquid chromatography, gel electrophoresis, mass spectrometry, nuclear magnetic resonance spectrometry, X-ray techniques and enzymatic methods. Finally future trends and needs are discussed and recommendations made.

The effects of phosphorus limitation on carbon metabolism in diatoms.

Science.gov (United States)

Brembu, Tore; Mühlroth, Alice; Alipanah, Leila; Bones, Atle M

2017-09-05

Phosphorus is an essential element for life, serving as an integral component of nucleic acids, lipids and a diverse range of other metabolites. Concentrations of bioavailable phosphorus are low in many aquatic environments. Microalgae, including diatoms, apply physiological and molecular strategies such as phosphorus scavenging or recycling as well as adjusting cell growth in order to adapt to limiting phosphorus concentrations. Such strategies also involve adjustments of the carbon metabolism. Here, we review the effect of phosphorus limitation on carbon metabolism in diatoms. Two transcriptome studies are analysed in detail, supplemented by other transcriptome, proteome and metabolite data, to gain an overview of different pathways and their responses. Phosphorus, nitrogen and silicon limitation responses are compared, and similarities and differences discussed. We use the current knowledge to propose a suggestive model for the carbon flow in phosphorus-replete and phosphorus-limited diatom cells.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'. © 2017 The Authors.

Controlling Eutrophication in A Mediterranean Shallow Reservoir by Phosphorus Loading Reduction: The Need for an Integrated Management Approach

Science.gov (United States)

Zaragüeta, Mikel; Acebes, Pablo

2017-04-01

Increased nutrient enrichment in Mediterranean standing waters has enhanced the risk of being affected by cyanobacterial blooms. Because phosphorus abatement is shaped as a crucial strategy for controlling eutrophication, this study introduces a structural thinking, experiential learning laboratory with animation dynamic model elaborated for Cazalegas Reservoir (Spain) to assess the feasibility of implementing a set of internal and external control measures and hydromorphological adjustments to meet the goal of oligotrophication. This shallow reservoir is another case where recurrent eutrophication has led to reach annual mean total phosphorus concentrations (0.16 ± 0.08 mg total phosphorus/L) over the threshold of current water policies, triggering cyanobacterial growth up to undesirable levels in summer time (approximately 50,000 cells/mL). Modeling results showed that (i) after upgrading water treatment in the main tributary, (ii) applying a lanthanum-modified bentonite into the water column and sediment, and (iii) increasing reservoir water level, in-lake P concentrations and cyanobacterial abundance decreased in an 88% (below 0.01 mg total phosphorus/L) and 84% (below 6000 cells/mL), respectively in the most critical periods. However, the constraints of the proposed management strategies are associated with their costs of implementation and the time span for a stable trophic recovery of the reservoir. In that end, integrated management approaches are aimed to be adopted by water managers to reach adequate ecological status of freshwater bodies.

Functionally relevant microorganisms to enhanced biological phosphorus removal performance at full-scale wastewater treatment plants in the United States.

Science.gov (United States)

Gu, April Z; Saunders, A; Neethling, J B; Stensel, H D; Blackall, L L

2008-08-01

The abundance and relevance ofAccumulibacter phosphatis (presumed to be polyphosphate-accumulating organisms [PAOs]), Competibacter phosphatis (presumed to be glycogen-accumulating organisms [GAOs]), and tetrad-forming organisms (TFOs) to phosphorus removal performance at six full-scale enhanced biological phosphorus removal (EBPR) wastewater treatment plants were investigated. Coexistence of various levels of candidate PAOs and GAOs were found at these facilities. Accumulibacter were found to be 5 to 20% of the total bacterial population, and Competibacter were 0 to 20% of the total bacteria population. The TFO abundance varied from nondetectable to dominant. Anaerobic phosphorus (P) release to acetate uptake ratios (P(rel)/HAc(up)) obtained from bench tests were correlated positively with the abundance ratio of Accumulibacter/(Competibacter +TFOs) and negatively with the abundance of (Competibacter +TFOs) for all plants except one, suggesting the relevance of these candidate organisms to EBPR processes. However, effluent phosphorus concentration, amount of phosphorus removed, and process stability in an EBPR system were not directly related to high PAO abundance or mutually exclusive with a high GAO fraction. The plant that had the lowest average effluent phosphorus and highest stability rating had the lowest P(rel)/HAc(up) and the most TFOs. Evaluation of full-scale EBPR performance data indicated that low effluent phosphorus concentration and high process stability are positively correlated with the influent readily biodegradable chemical oxygen demand-to-phosphorus ratio. A system-level carbon-distribution-based conceptual model is proposed for capturing the dynamic competition between PAOs and GAOs and their effect on an EBPR process, and the results from this study seem to support the model hypothesis.

Phosphorus use efficiency of maize: an investigation using radiotracer phosphorus (32P)

International Nuclear Information System (INIS)

Meena, S.

2017-01-01

A better understanding on the nutrient uptake and utilization by plants is essential for developing better nutrient efficient cultivars suited for optimal production. Precise information on the PUE of crops and P dynamics can be obtained with the help of radiotracer technique. To study the phosphorus acquisition and phosphorus use efficiency of added sources in maize using 32 P, a pot culture experiment was conducted in a medium P soil (21.26 kg ha -1 ). The treatments were P as Single Superphosphate, Enriched FYM with Single Superphosphate (EFYM), DAP, Nutriseed pack (SSP), Nutriseed pack (DAP). The above treatments were applied along with phosphobacteria. Totally there were ten treatments replicated four times. Phosphorus sources were tagged with 32 P (obtained as 32 P in orthophosphoric medium from the Board of Radiation and Isotope Technology) and applied as per the treatments. Radioactive 32 P in the grain and stover sample was determined using Liquid Scintillation Counter (Perkin Elmer Tricarb 2810 R). Using the data, per cent phosphorus derived from fertilizer (%Pdff), per cent phosphorus derived from soil (%Pdfs), Phosphorus Use Efficiency (PUE) and A value were determined. Application of Phosphorus (SSP, DAP, enriched FYM with SSP, Nutriseed pack (SSP) and Nutriseed pack (DAP)) along with PB increased the per cent phosphorus derived from fertilizer (% Pdff), P uptake from fertilizer and PUE. The highest PUE of 25.38 was recorded in the treatment where enriched FYM with SSP was applied along with PB. (author)

Full-scale operating experience of deep bed denitrification filter achieving phosphorus.

Science.gov (United States)

Husband, Joseph A; Slattery, Larry; Garrett, John; Corsoro, Frank; Smithers, Carol; Phipps, Scott

2012-01-01

The Arlington County Wastewater Pollution Control Plant (ACWPCP) is located in the southern part of Arlington County, Virginia, USA and discharges to the Potomac River via the Four Mile Run. The ACWPCP was originally constructed in 1937. In 2001, Arlington County, Virginia (USA) committed to expanding their 113,500 m³/d, (300,000 pe) secondary treatment plant to a 151,400 m³/d (400,000 pe) to achieve effluent total nitrogen (TN) to phosphorus (TP) phosphorus, to very low concentrations. This paper will review the steps from concept to the first year of operation, including pilot and full-scale operating data and the capital cost for the denitrification filters.

Effects of copper source and concentration on in vitro phytate phosphorus hydrolysis by phytase.

Science.gov (United States)

Pang, Yanfang; Applegate, Todd J

2006-03-08

Five copper (Cu) sources were studied at pH 2.5, 5.5, and 6.5 to determine how Cu affects phytate phosphorus (PP) hydrolysis by phytase at concentrations up to 500 mg/kg diet (60 min, 40-41 degrees C). Subsequently, Cu solubility with and without sodium phytate was measured. Adding Cu inhibited PP hydrolysis at pH 5.5 and pH 6.5 (P copper chloride and copper lysinate inhibited PP hydrolysis much less than copper sulfate pentahydrate, copper chloride, and copper citrate (P copper-phytin complexes.

Effect of continuous intravenous administration of a 50% dextrose solution on phosphorus homeostasis in dairy cows.

Science.gov (United States)

Grünberg, Walter; Morin, Dawn E; Drackley, James K; Barger, Anne M; Constable, Peter D

2006-08-01

To determine the effect of continuous IV administration of 50% dextrose solution on phosphorus homeostasis in lactating dairy cows. Clinical trial. 4 multiparous Jersey cows. Cows were administered 50% dextrose solution IV (0.3 g/kg/h [0.14 g/lb/h]) for 5 days. Plasma concentrations of glucose, immune-reactive insulin (IRI), and phosphorus were determined before, during, and for 72 hours after dextrose infusion. Phosphorus intake and losses of phosphorus in urine, feces, and milk were determined. Each cow received a sham treatment that included instrumentation and sampling but not administration of dextrose. Plasma glucose, IRI, and phosphorus concentrations were stable during sham treatment. Plasma phosphorus concentration decreased rapidly after onset of dextrose infusion, reaching a nadir in 24 hours and remaining less than baseline value for 36 hours. Plasma phosphorus concentration increased after dextrose infusion was stopped, peaking in 6 hours. Urinary phosphorus excretion did not change during dextrose infusion, but phosphorus intake decreased because of reduced feed intake, followed by decreased fecal phosphorus loss and milk yield. Rapid changes in plasma phosphorus concentration at the start and end of dextrose infusion were temporally associated with changes in plasma glucose and IRI concentrations and most likely caused by compartmental shifts of phosphorus. Hypophosphatemia developed in response to hyperglycemia or hyperinsulinemia in dairy cows administered dextrose via continuous IV infusion. Veterinarians should monitor plasma phosphorus concentration when administering dextrose in this manner, particularly in cows with decreased appetite or preexisting hypophosphatemia.

A new detailed map of total phosphorus stocks in Australian soil.

Science.gov (United States)

Viscarra Rossel, Raphael A; Bui, Elisabeth N

2016-01-15

Accurate data are needed to effectively monitor environmental condition, and develop sound policies to plan for the future. Globally, current estimates of soil total phosphorus (P) stocks are very uncertain because they are derived from sparse data, with large gaps over many areas of the Earth. Here, we derive spatially explicit estimates, and their uncertainty, of the distribution and stock of total P in Australian soil. Data from several sources were harmonized to produce the most comprehensive inventory of total P in soil of the continent. They were used to produce fine spatial resolution continental maps of total P in six depth layers by combining the bootstrap, a decision tree with piecewise regression on environmental variables and geostatistical modelling of residuals. Values of percent total P were predicted at the nodes of a 3-arcsecond (approximately 90 m) grid and mapped together with their uncertainties. We combined these predictions with those for bulk density and mapped the total soil P stock in the 0-30 cm layer over the whole of Australia. The average amount of P in Australian topsoil is estimated to be 0.98 t ha(-1) with 90% confidence limits of 0.2 and 4.2 t ha(-1). The total stock of P in the 0-30 cm layer of soil for the continent is 0.91 Gt with 90% confidence limits of 0.19 and 3.9 Gt. The estimates are the most reliable approximation of the stock of total P in Australian soil to date. They could help improve ecological models, guide the formulation of policy around food and water security, biodiversity and conservation, inform future sampling for inventory, guide the design of monitoring networks, and provide a benchmark against which to assess the impact of changes in land cover, land use and management and climate on soil P stocks and water quality in Australia. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Anthropogenic phosphorus flow analysis of Hefei City, China.

Science.gov (United States)

Li, Sisi; Yuan, Zengwei; Bi, Jun; Wu, Huijun

2010-11-01

The substance flow analysis (SFA) method was employed to examine phosphorus flow and its connection to water pollution in the city of Hefei, China, in 2008. As human activity is the driving force of phosphorus flux from the environment to the economy, the study provides a conceptual framework for analyzing an anthropogenic phosphorus cycle that includes four stages: extraction, fabrication and manufacturing, use, and waste management. Estimates of phosphorus flow were based on existing data as well as field research, expert advice, local accounting systems, and literature. The total phosphorus input into Hefei in 2008 reached 7810 tons, mainly as phosphate ore, chemical fertilizer, pesticides, crops and animal products. Approximately 33% of the total phosphorus input left the area, and nearly 20% of that amount was discharged as waste to surface water. Effluent containing excessive fertilizer from farming operations plays an important role in phosphorus overloads onto surface water; the other major emission source is sewage discharge. We also provide suggestions for reducing phosphorus emissions, for example reducing fertilizer use, recycling farming residues, and changing human consumption patterns. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

[Surface Property and Sorption Characteristics of Phosphorus onto Surface Sediments in Sanggou Bay].

Science.gov (United States)

Zhu, Jia-mei; Cao, Xiao-yan; Liu, Su-mei; Wang, Li-sha; Yang, Gui-peng; Ge, Cheng-feng; Lu, Min

2016-02-15

Kinetic curves and isotherms were investigated to study the sorption mechanism of phosphorus onto the sediments of Sanggou Bay, together with the surface charge properties of sediments and the forms of phosphorus studied. The results showed that the sorption including a fast process and a slow one, and could be described by a two-compartment first order equation. The thermodynamic isotherms were well fitted with a modified Langmuir equation. The maximum adsorption capacity was larger in summer than in spring, and the smaller particle size was favorable to the sorption. The maximum adsorption capacities (Qm) were 0.0471-0.1230 mg x g(-1), and the zero equilibrium phosphorus concentration (EPC0) of the sediments ranged from 0.0596 mg x L(-1) to 0.1927 mg x L(-1), which indicated that the sediments from Sanggou Bay were sources of phosphorus. Inorganic phosphorus (IP) was the main form of total phosphorus (TP). The contents of exchangeable or loosely absorbed P and Fe-bound P increased significantly in the samples after sorption. The sorption process involved physical sorption and chemical sorption, with the former being the predominant.

Effect of phosphorus concentration of the nutrient solution on the volatile constituents of leaves and bracts of Origanum dictamnus.

Science.gov (United States)

Economakis, C; Skaltsa, Helen; Demetzos, Costas; Soković, M; Thanos, Costas A

2002-10-23

The chemical composition of the essential oils obtained from the leaves and bracts of hydroponically cultivated Origanum dictamnus were analyzed by GC-MS techniques. Three different concentrations of phosphorus (5, 30, and 60 mg/L) in the nutrient solution were used for the cultivation, using the nutrient film technique (NFT). A total of 46 different compounds were identified and significant differences (qualitative and quantitative) were observed between the samples. Carvacrol and p-cymene were identified as the main compounds in all samples analyzed, whereas thymoquinone was found in higher percentage in the leaves than in bracts. The essential oils were tested for their antibacterial activity against Gram-positive and Gram-negative bacteria. The oils obtained from the bracts were found to be more active. The results obtained from GC-MS analyses were submitted to chemometric analysis.

Further developments and field deployment of phosphorus functionalized polymeric scale inhibitors

Energy Technology Data Exchange (ETDEWEB)

Todd, Malcolm J.; Thornton, Alex R.; Wylde, Jonathan J.; Strachan, Catherine J.; Moir, Gordon [Clariant Oil Services, Muttenz (Switzerland); Goulding, John [John Goulding Consultancy, York (United Kingdom)

2012-07-01

compared to the incumbent product. This indicated that the use of total phosphorus for concentration identification was accurate in this case. Following the successful deployment in a carbonate reservoir the novel inhibitor class was also deployed in a number of North Sea sandstone reservoirs and one field wide case study is reported with details on the innovative management and implementation strategy has been given. Focus has been given to the application of these products and a detailed analysis of field proven benefits given. This paper concludes with a detailed comparison of these phosphorous functionalized scale inhibitors with the incumbent products they have replaced in the case histories described. The benefits application of these novel and innovative products have given to the operator are described along with a technical synopsis of incremental performance benefits. (author)

Phosphorus and Nutrition in Chronic Kidney Disease

Directory of Open Access Journals (Sweden)

Emilio González-Parra

2012-01-01

Full Text Available Patients with renal impairment progressively lose the ability to excrete phosphorus. Decreased glomerular filtration of phosphorus is initially compensated by decreased tubular reabsorption, regulated by PTH and FGF23, maintaining normal serum phosphorus concentrations. There is a close relationship between protein and phosphorus intake. In chronic renal disease, a low dietary protein content slows the progression of kidney disease, especially in patients with proteinuria and decreases the supply of phosphorus, which has been directly related with progression of kidney disease and with patient survival. However, not all animal proteins and vegetables have the same proportion of phosphorus in their composition. Adequate labeling of food requires showing the phosphorus-to-protein ratio. The diet in patients with advanced-stage CKD has been controversial, because a diet with too low protein content can favor malnutrition and increase morbidity and mortality. Phosphorus binders lower serum phosphorus and also FGF23 levels, without decreasing diet protein content. But the interaction between intestinal dysbacteriosis in dialysis patients, phosphate binder efficacy, and patient tolerance to the binder could reduce their efficiency.

High performance of nitrogen and phosphorus removal in an electrolysis-integrated biofilter.

Science.gov (United States)

Gao, Y; Xie, Y W; Zhang, Q; Yu, Y X; Yang, L Y

A novel electrolysis-integrated biofilter system was developed in this study to evaluate the intensified removal of nitrogen and phosphorus from contaminated water. Two laboratory-scale biofilter systems were established, one with electrolysis (E-BF) and one without electrolysis (BF) as control. The dynamics of intensified nitrogen and phosphorus removal and the changes of inflow and outflow water qualities were also evaluated. The total nitrogen (TN) removal rate was 94.4% in our newly developed E-BF, but only 74.7% in the control BF. Ammonium removal rate was up to 95% in biofilters with or without electrolysis integration with an influent ammonium concentration of 40 mg/L, and the accumulation of nitrate and nitrite was much lower in the effluent of E-BF than that of BF. Thus electrolysis plays an important role in TN removal especially the nitrate and nitrite removal. Phosphorus removal was significantly enhanced, exceeding 90% in E-BF by chemical precipitation, physical adsorption, and flocculation of phosphorus because of the in situ formation of ferric ions by the anodizing of sacrificial iron anodes. Results from this study indicate that the electrolysis integrated biofilter is a promising solution for intensified nitrogen and phosphorus removal.

[Kinetic simulation of enhanced biological phosphorus removal with fermentation broth as carbon source].

Science.gov (United States)

Zhang, Chao; Chen, Yin-Guang

2013-07-01

As a high-quality carbon source, fermentation broth could promote the phosphorus removal efficiency in enhanced biological phosphorus removal (EBPR). The transformation of substrates in EBPR fed with fermentation broth was well simulated using the modified activated sludge model No. 2 (ASM2) based on the carbon source metabolism. When fermentation broth was used as the sole carbon source, it was found that heterotrophic bacteria acted as a promoter rather than a competitor to the phosphorus accumulating organisms (PAO). When fermentation broth was used as a supplementary carbon source of real municipal wastewater, the wastewater composition was optimized for PAO growth; and the PAO concentration, which was increased by 3.3 times compared to that in EBPR fed with solely real municipal wastewater, accounting for about 40% of the total biomass in the reactor.

Effects of nitrogen and phosphorus on anatoxin-a, homoanatoxin-a, dihydroanatoxin-a and dihydrohomoanatoxin-a production by Phormidium autumnale.

Science.gov (United States)

Heath, Mark W; Wood, Susanna A; Barbieri, Rafael F; Young, Roger G; Ryan, Ken G

2014-12-15

Anatoxins are powerful neuromuscular blocking agents produced by some cyanobacteria. Consumption of anatoxin-producing cyanobacterial mats or the water containing them has been linked to numerous animal poisonings and fatalities worldwide. Despite this health risk, there is a poor understanding of the environmental factors regulating anatoxin production. Non-axenic Phormidium autumnale strain CAWBG557 produces anatoxin-a (ATX), homoanatoxin-a (HTX) and their dihydrogen-derivatives dihydroanatoxin-a (dhATX) and dihydrohomoanatoxin-a (dhHTX). The effects of varying nitrogen and phosphorus concentrations on the production of these four variants were examined in batch monocultures. The anatoxin quota (anatoxin per cell) of all four variants increased up to four fold in the initial growth phase (days 0-9) coinciding with the spread of filaments across the culture vessel during substrate attachment. Dihydroanatoxin-a and dhHTX, accounted for over 60% of the total anatoxin quota in each nitrogen and phosphorus treatment. This suggests they are being internally synthesised and not just derived following cell lysis and environmental degradation. The four anatoxin variants differed in their response to varying nitrogen and phosphorus concentrations. Notably, dhATX quota significantly decreased (P ≤ 0.03) when nitrogen and phosphorus concentrations were elevated (nitrogen = 21 mg L(-1); phosphorus = 3 mg L(-1)), while HTX quota increased when the phosphorus concentrations were reduced (ca. < 0.08 mg L(-1)). This is of concern as HTX has a high toxicity and anatoxin producing P. autumnale blooms in New Zealand usually occur in rivers with low water column dissolved reactive phosphorus. Copyright © 2014. Published by Elsevier Ltd.

Distributed and dynamic modelling of hydrology, phosphorus and ecology in the Hampshire Avon and Blashford Lakes: evaluating alternative strategies to meet WFD standards.

Science.gov (United States)

Whitehead, P G; Jin, L; Crossman, J; Comber, S; Johnes, P J; Daldorph, P; Flynn, N; Collins, A L; Butterfield, D; Mistry, R; Bardon, R; Pope, L; Willows, R

2014-05-15

The issues of diffuse and point source phosphorus (P) pollution in the Hampshire Avon and Blashford Lakes are explored using a catchment model of the river system. A multibranch, process based, dynamic water quality model (INCA-P) has been applied to the whole river system to simulate water fluxes, total phosphorus (TP) and soluble reactive phosphorus (SRP) concentrations and ecology. The model has been used to assess impacts of both agricultural runoff and point sources from waste water treatment plants (WWTPs) on water quality. The results show that agriculture contributes approximately 40% of the phosphorus load and point sources the other 60% of the load in this catchment. A set of scenarios have been investigated to assess the impacts of alternative phosphorus reduction strategies and it is shown that a combined strategy of agricultural phosphorus reduction through either fertiliser reductions or better phosphorus management together with improved treatment at WWTPs would reduce the SRP concentrations in the river to acceptable levels to meet the EU Water Framework Directive (WFD) requirements. A seasonal strategy for WWTP phosphorus reductions would achieve significant benefits at reduced cost. Copyright © 2014 Elsevier B.V. All rights reserved.

A Study of Phosphorus and Calcium Dynamics in an Integrated Rainbow Trout and Spinach (Nores variety Aquaponic System with Different Crop Densities

Directory of Open Access Journals (Sweden)

Stefan Mihai Petrea

2014-10-01

Full Text Available The goal of this study is to quantify both calcium and phosphorus budgets for an integrated rainbow trout – spinach (Nores variety aquaponic system, where three crops densities were used (BH1 –59 crops/m2, BH2 – 48 crops/m2 and BH3 – 39 crops/m2 and a control variant. Fish were fed with two types of feed (41% and 50% protein, using 3 different feeding regimes. Total calcium and total phosphorus retention rates for each of the three tested spinach biomass densities were individually determined by water chemical and plant biochemical analysis. Also, the concentration of those two macroelements was determined from fish meat and fish faeces.  Significant differences (p<0.05 were recorded between fish faeces total phosphorus content and between total calcium and total phosphorus retention rates for each of the three variants of tested crops densities (significant higher at BH1 compared to BH3, p < 0.05. It is recommended that lower densities to be used for a better crop absorption of both calcium and phosphorus or a lower hydraulic flow regime and a better light intensity to be applied in case of the used integrated aquaponic system.

Phytoextraction of excess soil phosphorus

International Nuclear Information System (INIS)

Sharma, Nilesh C.; Starnes, Daniel L.; Sahi, Shivendra V.

2007-01-01

In the search for a suitable plant to be used in P phytoremediation, several species belonging to legume, vegetable and herb crops were grown in P-enriched soils, and screened for P accumulation potentials. A large variation in P concentrations of different plant species was observed. Some vegetable species such as cucumber (Cucumis sativus) and yellow squash (Cucurbita pepo var. melopepo) were identified as potential P accumulators with >1% (dry weight) P in their shoots. These plants also displayed a satisfactory biomass accumulation while growing on a high concentration of soil P. The elevated activities of phosphomonoesterase and phytase were observed when plants were grown in P-enriched soils, this possibly contributing to high P acquisition in these species. Sunflower plants also demonstrated an increased shoot P accumulation. This study shows that the phytoextraction of phosphorus can be effective using appropriate plant species. - Crop plants such as cucumber, squash and sunflower accumulate phosphorus and thus can be used in the phytoextraction of excess phosphorus from soils

Phytoextraction of excess soil phosphorus

Energy Technology Data Exchange (ETDEWEB)

Sharma, Nilesh C. [Department of Biology, Western Kentucky University, 1906 College Heights Boulevard 11080, Bowling Green, KY 42101-1080 (United States); Starnes, Daniel L. [Department of Biology, Western Kentucky University, 1906 College Heights Boulevard 11080, Bowling Green, KY 42101-1080 (United States); Sahi, Shivendra V. [Department of Biology, Western Kentucky University, 1906 College Heights Boulevard 11080, Bowling Green, KY 42101-1080 (United States)]. E-mail: shiv.sahi@wku.edu

2007-03-15

In the search for a suitable plant to be used in P phytoremediation, several species belonging to legume, vegetable and herb crops were grown in P-enriched soils, and screened for P accumulation potentials. A large variation in P concentrations of different plant species was observed. Some vegetable species such as cucumber (Cucumis sativus) and yellow squash (Cucurbita pepo var. melopepo) were identified as potential P accumulators with >1% (dry weight) P in their shoots. These plants also displayed a satisfactory biomass accumulation while growing on a high concentration of soil P. The elevated activities of phosphomonoesterase and phytase were observed when plants were grown in P-enriched soils, this possibly contributing to high P acquisition in these species. Sunflower plants also demonstrated an increased shoot P accumulation. This study shows that the phytoextraction of phosphorus can be effective using appropriate plant species. - Crop plants such as cucumber, squash and sunflower accumulate phosphorus and thus can be used in the phytoextraction of excess phosphorus from soils.

Phosphorus and Calcium Metabolism in Postmenopausal Women with Diabetes Mellitus: Effects of the Type and Duration of the Disease, Time of Menopause and Body Mass

Directory of Open Access Journals (Sweden)

M.L. Kyryliuk

2016-02-01

Full Text Available The article deals with the impact of diabetes mellitus (DM on the phosphorus and calcium metabolism in postmenopausal women, depending on the type and duration of the disease, duration of menopause, body mass and type of hypoglycemic therapy. The state of phosphorus and calcium metabolism in 86 women with type 1 DM (13 patients and type 2 DM (73 patients was studied. In all patients, the concentration of calcium and phosphorus in the blood was within normal limits. It was found that the concentration of ionized calcium, total calcium and inorganic phosphorus in the blood can not be the main criterion for the state of bone mineral density in postmenopausal women with DM. Sulfonylureas and insulin in combination with biguanides have no effect on the status of phosphorus and calcium metabolism in postmenopausal women with type 2 DM.

Removing Phosphorus from Aqueous Solutions Using Lanthanum Modified Pine Needles.

Directory of Open Access Journals (Sweden)

Xianze Wang

Full Text Available The renewable pine needles was used as an adsorbent to remove phosphorus from aqueous solutions. Using batch experiments, pine needles pretreated with alkali-isopropanol (AI failed to effectively remove phosphorus, while pine needles modified with lanthanum hydroxide (LH showed relatively high removal efficiency. LH pine needles were effective at a wide pH ranges, with the highest removal efficiency reaching approximately 85% at a pH of 3. The removal efficiency was kept above 65% using 10 mg/L phosphorus solutions at desired pH values. There was no apparent significant competitive behavior between co-existing anions of sulfate, nitrate, and chloride (SO4(2-, NO3(- and Cl(-; however, CO3(2- exhibited increased interfering behavior as concentrations increased. An intraparticle diffusion model showed that the adsorption process occurred in three phases, suggesting that a boundary layer adsorption phenomena slightly affected the adsorption process, and that intraparticle diffusion was dominant. The adsorption process was thermodynamically unfavorable and non-spontaneous; temperature increases improved phosphorus removal. Total organic carbon (TOC assays indicated that chemical modification reduced the release of soluble organic compounds from 135.6 mg/L to 7.76 mg/L. This new information about adsorption performances provides valuable information, and can inform future technological applications designed to remove phosphorus from aqueous solutions.

Coupling loss characteristics of runoff-sediment-adsorbed and dissolved nitrogen and phosphorus on bare loess slope.

Science.gov (United States)

Wu, Lei; Qiao, Shanshan; Peng, Mengling; Ma, Xiaoyi

2018-05-01

Soil and nutrient loss is a common natural phenomenon but it exhibits unclear understanding especially on bare loess soil with variable rainfall intensity and slope gradient, which makes it difficult to design control measures for agricultural diffuse pollution. We employ 30 artificial simulated rainfalls (six rainfall intensities and five slope gradients) to quantify the coupling loss correlation of runoff-sediment-adsorbed and dissolved nitrogen and phosphorus on bare loess slope. Here, we show that effects of rainfall intensity on runoff yield was stronger than slope gradient with prolongation of rainfall duration, and the effect of slope gradient on runoff yield reduced gradually with increased rainfall intensity. But the magnitude of initial sediment yield increased significantly from an average value of 6.98 g at 5° to 36.08 g at 25° with increased slope gradient. The main factor of sediment yield would be changed alternately with the dual increase of slope gradient and rainfall intensity. Dissolved total nitrogen (TN) and dissolved total phosphorus (TP) concentrations both showed significant fluctuations with rainfall intensity and slope gradient, and dissolved TP concentration was far less than dissolved TN. Under the double influences of rainfall intensity and slope gradient, adsorbed TN concentration accounted for 7-82% of TN loss concentration with an average of 58.6% which was the main loss form of soil nitrogen, adsorbed TP concentration accounted for 91.8-98.7% of TP loss concentration with an average of 96.6% which was also the predominant loss pathway of soil phosphorus. Nitrate nitrogen (NO 3 - -N) accounted for 14.59-73.92% of dissolved TN loss, and ammonia nitrogen (NH 4 + -N) accounted for 1.48-18.03%. NO 3 - -N was the main loss pattern of TN in runoff. Correlation between dissolved TN, runoff yield, and rainfall intensity was obvious, and a significant correlation was also found between adsorbed TP, sediment yield, and slope gradient. Our

Effect of pre-calving zeolite, magnesium and phosphorus supplemention on periparturient serum mineral concentrations

DEFF Research Database (Denmark)

Pallesen, Anders; Pallesen, Flemming; Jørgensen, Rolf Jess

2008-01-01

The objective of this study was to test whether supplementing dry cow rations with phosphorus (P) and magnesium (Mg) would interfere with the beneficial effect of zeolite supplementation on the periparturient blood calcium (Ca) concentration in dairy cattle. Three groups (A-C) of 10 Danish Jersey...... cows were each given the following daily supplements from 2 weeks before the expected date of calving until actual calving: group A: zeolite, monoammonium phosphate, standard dry cow mineral and vitamin mix, containing 61g magnesium phosphate; group B: zeolite, standard mineral and vitamin mix without...... the magnesium phosphate and group C: standard mineral and vitamin mix, monoammonium phosphate. All cows in group B had an apparently less variable serum calcium concentration around calving with no cases of milk fever and no subclinical hypocalcaemia or hypomagnesaemia recorded. In contrast, a parturient drop...

Lab-on-a-chip based total-phosphorus analysis device utilizing a photocatalytic reaction

Science.gov (United States)

Jung, Dong Geon; Jung, Daewoong; Kong, Seong Ho

2018-02-01

A lab-on-a-chip (LOC) device for total phosphorus (TP) analysis was fabricated for water quality monitoring. Many commercially available TP analysis systems used to estimate water quality have good sensitivity and accuracy. However, these systems also have many disadvantages such as bulky size, complex pretreatment processes, and high cost, which limit their application. In particular, conventional TP analysis systems require an indispensable pretreatment step, in which the fluidic analyte is heated to 120 °C for 30 min to release the dissolved phosphate, because many phosphates are soluble in water at a standard temperature and pressure. In addition, this pretreatment process requires elevated pressures of up to 1.1 kg cm-2 in order to prevent the evaporation of the heated analyte. Because of these limiting conditions required by the pretreatment processes used in conventional systems, it is difficult to miniaturize TP analysis systems. In this study, we employed a photocatalytic reaction in the pretreatment process. The reaction was carried out by illuminating a photocatalytic titanium dioxide (TiO2) surface formed in a microfluidic channel with ultraviolet (UV) light. This pretreatment process does not require elevated temperatures and pressures. By applying this simplified, photocatalytic-reaction-based pretreatment process to a TP analysis system, greater degrees of freedom are conferred to the design and fabrication of LOC devices for TP monitoring. The fabricated LOC device presented in this paper was characterized by measuring the TP concentration of an unknown sample, and comparing the results with those measured by a conventional TP analysis system. The TP concentrations of the unknown sample measured by the proposed LOC device and the conventional TP analysis system were 0.018 mgP/25 mL and 0.019 mgP/25 mL, respectively. The experimental results revealed that the proposed LOC device had a performance comparable to the conventional bulky TP analysis

Digestible phosphorus levels for barrows from 50 to 80 kg

Directory of Open Access Journals (Sweden)

Viviane Maria Oliveira dos Santos Nieto

2016-05-01

Full Text Available ABSTRACT This study was carried out to evaluate the levels of digestible phosphorus in diets for barrows with a high potential for lean meat deposition from 50 to 80 kg. Eighty barrows, with an initial weight of 47.93±3.43 kg, were distributed in completely randomized blocks, with each group given five levels of digestible phosphorus (1.86, 2.23, 2.61, 2.99, and 3.36 g kg−1. There were eight replicates, and two animals per experimental unit. Phosphorus levels did not significantly influence feed intake, weight gain, or feed conversion ratio. Daily digestible phosphorus intake increased linearly as levels of phosphorus in the diet were increased. Phosphorus levels did not significantly influence muscle depth, loin eye area, backfat thickness, or the percentage and quantity of lean meat in the carcass. A linear increase was observed for feeding cost as the levels of digestible phosphorus in the diet were increased, and the level of 1.86 g kg−1 cost 29.4% less when compared with the level of 2.61 g kg−1. The dry matter, natural matter, the coefficient of the residue, and volatile solids of the waste were not significantly influenced by phosphorus levels. Conversely, it was possible to observe an increasing linear effect for total solids, total phosphorus, and total nitrogen in the waste of animals receiving diets with increased levels of digestible phosphorus. The level of 1.86 g kg−1, which corresponded to a daily intake of 4.77 g−1 of digestible phosphorus, meets the requirements of barrows weighing 50 to 80 kg.

Influence of phosphorus availability on the community structure and physiology of cultured biofilms.

Science.gov (United States)

Li, Shuangshuang; Wang, Chun; Qin, Hongjie; Li, Yinxia; Zheng, Jiaoli; Peng, Chengrong; Li, Dunhai

2016-04-01

Biofilms have important effects on nutrient cycling in aquatic ecosystems. However, publications about the community structure and functions under laboratory conditions are rare. This study focused on the developmental and physiological properties of cultured biofilms under various phosphorus concentrations performed in a closely controlled continuous flow incubator. The results showed that the biomass (Chl a) and photosynthesis of algae were inhibited under P-limitation conditions, while the phosphatase activity and P assimilation rate were promoted. The algal community structure of biofilms was more likely related to the colonization stage than with the phosphorus availability. Cyanobacteria were more competitive than other algae in biofilms, particularly when cultured under low P levels. A dominance shift occurred from non-filamentous algae in the early stage to filamentous algae in the mid and late stages under P concentrations of 0.01, 0.1 and 0.6 mg/L. However, the total N content, dry weight biomass and bacterial community structure of biofilms were unaffected by phosphorus availability. This may be attributed to the low respiration rate, high accumulation of extracellular polymeric substances and high alkaline phosphatase activity in biofilms when phosphorus availability was low. The bacterial community structure differed over time, while there was little difference between the four treatments, which indicated that it was mainly affected by the colonization stage of the biofilms rather than the phosphorus availability. Altogether, these results suggested that the development of biofilms was influenced by the phosphorus availability and/or the colonization stage and hence determined the role that biofilms play in the overlying water. Copyright © 2015. Published by Elsevier B.V.

Characterization of phosphorus leaching from phosphate waste rock in the Xiangxi River watershed, Three Gorges Reservoir, China.

Science.gov (United States)

Jiang, Li-Guo; Liang, Bing; Xue, Qiang; Yin, Cheng-Wei

2016-05-01

Phosphate mining waste rocks dumped in the Xiangxi River (XXR) bay, which is the largest backwater zone of the Three Gorges Reservoir (TGR), are treated as Type I industry solid wastes by the Chinese government. To evaluate the potential pollution risk of phosphorus leaching from phosphate waste rocks, the phosphorus leaching behaviors of six phosphate waste rock samples with different weathering degrees under both neutral and acidic conditions were investigated using a series of column leaching experiments, following the Method 1314 standard of the US EPA. The results indicate that the phosphorus release mechanism is solubility-controlled. Phosphorus release from waste rocks increases as pH decreases. The phosphorus leaching concentration and cumulative phosphorus released in acidic leaching conditions were found to be one order of magnitude greater than that in neutral leaching conditions. In addition, the phosphorus was released faster during the period when environmental pH turned from weak alkalinity to slight acidity, with this accelerated release period appearing when L/S was in the range of 0.5-2.0 mL/g. In both neutral and acidic conditions, the average values of Total Phosphorus (TP), including orthophosphates, polyphosphates and organic phosphate, leaching concentration exceed the availability by regulatory (0.5 mg/L) in the whole L/S range, suggesting that the phosphate waste rocks stacked within the XXR watershed should be considered as Type II industry solid wastes. Therefore, the phosphate waste rocks deposited within the study area should be considered as phosphorus point pollution sources, which could threaten the adjacent surface-water environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantitative autoradiography of semiconductor materials by means of diffused phosphorus standards

International Nuclear Information System (INIS)

Treutler, H.C.; Freyer, K.

1983-01-01

A suitable standard sample was developed and tested on the basis of phosphorus for the quantitative autoradiography of elements of interest in semiconductor technology. By the aid of silicon disks with a phosphorus concentration of 6x10 17 atomsxcm - 2 the error of the quantitative autoradiogprahic method is determined. The relative mean error of the density measurement is at best +-4%; the relative mean error of the determination of phosphorus concentration by use of an error-free standard sample is about +-15%. The method will be extended to other elements by use of this standard sample of phosphorus. (author)

Nitrifying aerobic granular sludge fermentation for releases of carbon source and phosphorus: The role of fermentation pH.

Science.gov (United States)

Zou, Jinte; Pan, Jiyang; He, Hangtian; Wu, Shuyun; Xiao, Naidong; Ni, Yongjiong; Li, Jun

2018-07-01

The effect of fermentation pH (uncontrolled, 4 and 10) on the releases of carbon source and phosphorus from nitrifying aerobic granular sludge (N-AGS) was investigated. Meanwhile, metal ion concentration and microbial community characterization were explored during N-AGS fermentation. The results indicated that N-AGS fermentation at pH 10 significantly promoted the releases of soluble chemical oxygen demand (SCOD) and total volatile fatty acids (TVFAs). However, SCOD and TVFA released from N-AGS were inhibited at pH 4. Moreover, acidic condition promoted phosphorus release (mainly apatite) from N-AGS during anaerobic fermentation. Nevertheless, alkaline condition failed to increase phosphorus concentration due to the formation of chemical-phosphate precipitates. Compared with the previously reported flocculent sludge fermentation, N-AGS fermentation released more SCOD and TVFAs, possibly due to the greater extracellular polymeric substances content and some hydrolytic-acidogenic bacteria in N-AGS. Therefore, N-AGS alkaline fermentation facilitated the carbon source recovery, while N-AGS acidic fermentation benefited the phosphorus recovery. Copyright © 2018. Published by Elsevier Ltd.

The influence of excess vacancy generation on the diffusion of ion implanted phosphorus into silicon

International Nuclear Information System (INIS)

Bakowski, A.

1985-01-01

The diffusion of ion implanted phosphorus in silicon has been studied. It was found that the diffusion coefficient is not only dependent on the phosphorus surface concentration (the concentration effect) but also on the conditions at the silicon surface (the surface effect). The phosphorus diffusion coefficient is considerably lower when the silicon surface during annealing is covered with a CVD oxide layer. It is suggested that excess vacancies generated at the surface are reponsible for both the concentration and surface effects. Enhanced phosphorus diffusion is attributed to the disturbance of thermodynamic equilibrium in the crystal through phosphorus-vacancy part formation by vacancies introduced into silicon at the surface. On the basis of the data presented, it can be concluded that two mechanisms for excess vacancy generation are involved. Assuming that phosphorus diffuses via E-centers, calculations of the concentration profiles and the diffusion coefficient were performed for different concentrations and surface conditions. (orig.)

A new model of anomalous phosphorus diffusion in silicon

International Nuclear Information System (INIS)

Budil, M.; Poetzl, H.; Stingeder, G.; Grasserbauer, M.

1989-01-01

A model is presented to describe the 'kink and tail' diffusion of phosphorus. The diffusion behaviour of phosphorus is expplained by the motion of phosphorus-interstitial and phosphorus-vacancy pairs in different charge states. The model yields the enhancement of diffusion in the tail region depending on surface concentration. Furthermore it yields the same selfdiffusion coefficient for interstitials as the gold diffusion experiments. A transformation of the diffusion equation was found to reduce the number of simulation equations. (author) 7 refs., 5 figs

Nitrogen and phosphorus removed from a subsurface flow multi-stage filtration system purifying agricultural runoff.

Science.gov (United States)

Zhao, Yaqi; Huang, Lei; Chen, Yucheng

2018-07-01

Agricultural nonpoint source pollution has been increasingly serious in China since the 1990s. The main causes were excessive inputs of nitrogen fertilizer and pesticides. A multi-stage filtration system was built to test the purification efficiencies and removal characteristics of nitrogen and phosphorus when treating agricultural runoff. Simulated runoff pollution was prepared by using river water as source water based on the monitoring of local agricultural runoff. Experimental study had been performed from September to November 2013, adopting 12 h for flooding and 12 h for drying. The results showed that the system was made adaptive to variation of inflow quality and quantity, and had good removal for dissolved total nitrogen, total nitrogen, dissolved total phosphorus (DTP), and total phosphorus, and the average removal rate was 27%, 36%, 32%, and 48%, respectively. Except nitrate ([Formula: see text]), other forms of nitrogen and phosphorus all decreased with the increase of stages. Nitrogen was removed mainly in particle form the first stage, and mostly removed in dissolved form the second and third stage. Phosphorus was removed mainly in particulate during the first two stages, but the removal of particulate phosphorus and DTP were almost the same in the last stage. An approximate logarithmic relationship between removal loading and influent loading to nitrogen and phosphorus was noted in the experimental system, and the correlation coefficient was 0.78-0.94. [Formula: see text]: ammonium; [Formula: see text]: nitrite; [Formula: see text]: nitrate; DTN: dissolved total nitrogen; TN: total nitrogen; DTP: dissolved total phosphorus; TP: total phosphorus; PN: particulate nitrogen; PP: particulate phosphorus.

Phosphorus Uptake and Partitioning in Maize as Affected by Tillage ...

African Journals Online (AJOL)

Higher phosphorus concentrations were found in the ears than in the shoots and leaves at physiological maturity. Tillage x phospho-rus interactions influenced phosphorus partitioning in the ears and the leaves on the Dystric Cam-bisol but not on the Ferric Acrisol. PUE in the plant parts were significantly higher under ...

Phosphorus reduces the zinc concentration in cereals pot-grown on calcareous Vertisols from southern Spain.

Science.gov (United States)

Sánchez-Rodríguez, Antonio Rafael; Del Campillo, María Carmen; Torrent, José

2017-08-01

Zinc deficiency, a major problem in crops grown on soils low in available Zn, is even more important in phosphorus-rich soils. This work aimed to elucidate the effects of soil P and Zn levels, and of fertilizer application, on yield and Zn concentration in cereal grains. Wheat and barley were successively pot-grown on 20 calcareous Vertisols low in available Zn and ranging widely in available P. Grain yield in the plants grown on the native soils was positively correlated with Olsen P but not with diethylenetriaminepentaacetic acid (DTPA)-extractable Zn except for wheat on P-rich soils. Grain Zn concentration was negatively correlated with Olsen P. Grain Zn uptake differed little among soils. Application of P to the soils increased grain yield insignificantly and P concentration significantly; however, it reduced grain Zn concentration (particularly at low Olsen P values). Applying Zn alone only increased grain Zn concentration, whereas applying P and Zn in combination increased yield and grain Zn concentration at low and high Olsen P values, respectively. Applying P alone to plants grown on calcareous Vertisols low in available P and Zn may in practice reduce grain Zn concentrations while not increasing grain yield significantly. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Relationships between soluble sugar concentrations in roots and ecosystem stress for first-year sugar maple seedlings

Energy Technology Data Exchange (ETDEWEB)

McLaughlin, J.W.; Reed, D.D.; Jurgensen, M.F.; Mroz, G.D.; Bagley, S.T. [Michigan Technological University, Houghton, MI (United States). School of Forestry and Wood Products

1996-03-01

Accumulation of reducing sugars (i.e. glucose and fructose) in plant roots has been consistently correlated with forest dieback and decline and, therefore, has potential as a biological indicator of ecosystem stress. In this study, the relationships between acidic deposition and `natural` (temperature, mycorrhizae, and nutrition) factors with first-year sugar maple seedling root sugar concentrations and growth were assessed in two sugar maple dominated forests in Michigan. Seedlings at the southern site (Wellston) had greater root growth, phosphorus, total sugar, and sucrose concentrations in roots, but lower reducing sugar concentration in roots. In addition, percent root length colonized by vesicular-arbuscular mycorrhizal fungi was less than that found for seedlings growing at the northern site (Alberta). Throughfall deposition of nitrate, sulfate, and hydrogen ions was not significantly correlated with seedling total or reducing sugar concentration. Total sugar concentration in seedling roots was positively correlated with air and soil temperatures at the southern site, but not at the northern site. Seedling tissue phosphorus concentration was correlated with total sugars at both sites, with sucrose at the southern site, and reducing sugars at the northern site. Mycorrhizal colonization rates at the Alberta site were positively correlated with reducing sugar concentration in seedling roots and negatively correlated with sucrose concentration. The results suggest that differences in seedling root sugar concentrations in these two forests are related to seedling root growth and are most likely due to ecological variables, such as available soil phosphorus, temperature, and growing season length through some complex interaction with mycorrhizae rather than acidic deposition stress. 56 refs., 3 figs.

Enhancement of lipid accumulation by oleaginous yeast through phosphorus limitation under high content of ammonia.

Science.gov (United States)

Huang, Xiangfeng; Luo, Huijuan; Mu, Tianshuai; Shen, Yi; Yuan, Ming; Liu, Jia

2018-04-18

Low concentrations of acetic acid were used as carbon source to cultivate Cryptococcus curvatus MUCL 29819 for lipid production under high content of ammonia. Phosphorus limitation combined with initial pH regulation (pH = 6) weakened inhibition of free ammonia and promoted lipid accumulation. In batch cultivation, the produced lipid content and yield was 30.3% and 0.92 g/L, higher than those under unlimited condition (18.3% and 0.64 g/L). The content of monounsaturated fatty acid also increased from 37.3% (unlimited condition) to 45.8% (phosphorus-limited condition). During sequencing batch cultivation (SBC), the lipid content reached up to 51.02% under phosphorus-limited condition while only 31.88% under unlimited condition, which can be explained by the higher conversion efficiency of the carbon source to lipid. The total energy consumption including lipid extraction, transesterification and purification was 7.47 and 8.33 GJ under phosphorus-limited and unlimited condition, respectively. Copyright © 2018. Published by Elsevier Ltd.

Evaluation of an automated struvite reactor to recover phosphorus ...

African Journals Online (AJOL)

In the present study we attempted to develop a reactor system to recover phosphorus by struvite precipitation, and which can be installed anywhere in the field without access to a laboratory. A reactor was developed that can run fully automated and recover up to 93% of total phosphorus (total P). Turbidity and conductivity ...

Fibroblast growth factor-23 and phosphorus related factors in young Japanese women: a cross-sectional study.

Science.gov (United States)

Ito, Sanae; Ishida, Hiromi; Uenishi, Kazuhiro

2016-01-01

Phosphorus homeostasis is determined by dietary intake, intestinal absorption, and renal tubular reabsorption of phosphorus. Serum fibroblast growth factor-23 (FGF-23) is considered to be a sensitive early biomarker of disordered phosphorus metabolism in both patients with chronic kidney diseases and healthy subjects. However, the number of studies evaluating serum FGF-23 concentrations in healthy subjects is limited. The objective of this cross-sectional study was to examine the relationship between serum FGF-23 concentrations and phosphorus related factors in 182 young Japanese women (mean age, 19.5±0.4 years). We found that higher serum concentrations of inorganic phosphorus and lower serum concentrations of 1,25-dihydroxy vitamin D as well as lower fat but higher phosphorus and calcium intake were weakly but significantly associated with high serum concentrations of FGF-23, adjusted for postmenarcheal age and body weight. These results suggested that in young Japanese women, serum FGF-23 might be indicative of phosphorus nutrition status. However, it is worthy of note that maturity factors, including postmenarcheal age and physical attributes, such as body weight, might be related to serum FGF-23 concentrations.

Substoichiometric determination of phosphorus

International Nuclear Information System (INIS)

Shigematsu, T.; Kudo, K.

1981-01-01

Phosphorus in orchard leaves (NBS SRM-1571) and spinach (SRM-1570) was determined by various substoichiometric analytical methods such as the direct method, Gravshchenko's method and the method of carrier amount variation. All samples were labelled with 32 P radioisotope. The data obtained by the method of carrier amount variation were also treated by the method of least squares instead of De Voe's method. Phosphorus concentration in orchard leaves was 0.206+-0.011% by the direct method, 0.219+-0.011% by Gravshchenko's method, 0.211+-0.011% by the method of carrier amount variation and 0.207+-0.007% by the method of least squares, respectively. These values agree with the value reported by NBS (0.21+-0.01%). Furthermore, these concentrations obtained by various substoichiometric methods were compared with those by radioactivation reported in a previous paper. (author)

Effect of phosphorus sources on phosphorus and nitrogen utilization by three sweet potato cultivars

International Nuclear Information System (INIS)

Montanez, A.; Zapata, F.; Kumarasinghe, K.S.

1996-01-01

A greenhouse experiment was conducted at the FAO/IAEA Agriculture and Biotechnology Laboratory in Seibersdorf, Austria using three sweet potato cultivars, TIS 2, TIS 3053 and TIS 1487. The three sweet potato cultivars were grown at two levels of phosphorus (0 kg P/kg soil and 60 kg P/kg soil). The fertilizer treatments consisted of two sources of phosphorus, Gafza rock Phosphate and triple super phosphate with 14.19 and 19.76% total phosphorus, respectively. 15 N labelled urea was used to study the nitrogen recovery in tubers from the applied nitrogen fertilizer. The results from these preliminary studies indicate that there is considerable genotypic variation among cultivars in the efficiency with which phosphorus and nitrogen are taken up and used to produce biomass. Their response to different sources of phosphorus are also variable. TIS-2 and TIS-1487 have a greater ability to absorb phosphorus from Gafza rock phosphate and produce higher tube yields indicating their greater potential for using alternative sources of natural phosphate fertilizers more effectively. Gafza rock phosphate also increased accumulation of nitrogen in TIS-1487, a characteristic which will place this cultivar at an advantage when growing in soils low in nitrogen. On an overall basis taking into account tuber yield, phosphorus use efficiency, and nitrogen use efficiency, TIS-2 may be considered the better candidate for introduction into soils poor in resources particularly phosphorus. This study was conducted with a limited number of cultivars due to limitation in the availability of germplasma. In spite of this, the differences in their abilities for phosphorus and nitrogen uptake and use are clearly visible which justifies large scale screening experiments using a broader germplasm base, in the future. (author). 14 refs, 1 fig., 3 tabs

Effect of phosphorus sources on phosphorus and nitrogen utilization by three sweet potato cultivars

Energy Technology Data Exchange (ETDEWEB)

Montanez, A; Zapata, F [FAO/IAEA Agriculture and Biotechnology Lab., Seibersdorf (Austria). Soils Science Unit; Kumarasinghe, K S [Joint FAO/IAEA Div. of Nuclear Techniques in Food and Agriculture, Vienna (Austria). Soil Fertility, Irrigation and Crop Production Section

1996-07-01

A greenhouse experiment was conducted at the FAO/IAEA Agriculture and Biotechnology Laboratory in Seibersdorf, Austria using three sweet potato cultivars, TIS 2, TIS 3053 and TIS 1487. The three sweet potato cultivars were grown at two levels of phosphorus (0 kg P/kg soil and 60 kg P/kg soil). The fertilizer treatments consisted of two sources of phosphorus, Gafza rock Phosphate and triple super phosphate with 14.19 and 19.76% total phosphorus, respectively. {sup 15}N labelled urea was used to study the nitrogen recovery in tubers from the applied nitrogen fertilizer. The results from these preliminary studies indicate that there is considerable genotypic variation among cultivars in the efficiency with which phosphorus and nitrogen are taken up and used to produce biomass. Their response to different sources of phosphorus are also variable. TIS-2 and TIS-1487 have a greater ability to absorb phosphorus from Gafza rock phosphate and produce higher tube yields indicating their greater potential for using alternative sources of natural phosphate fertilizers more effectively. Gafza rock phosphate also increased accumulation of nitrogen in TIS-1487, a characteristic which will place this cultivar at an advantage when growing in soils low in nitrogen. On an overall basis taking into account tuber yield, phosphorus use efficiency, and nitrogen use efficiency, TIS-2 may be considered the better candidate for introduction into soils poor in resources particularly phosphorus. This study was conducted with a limited number of cultivars due to limitation in the availability of germplasma. In spite of this, the differences in their abilities for phosphorus and nitrogen uptake and use are clearly visible which justifies large scale screening experiments using a broader germplasm base, in the future. (author). 14 refs, 1 fig., 3 tabs.

Phosphorus metabolism and estimation of phosphorus requirements for sheep

International Nuclear Information System (INIS)

Louvandini, H.; Vitti, D.M.S.S.

1996-01-01

The main objective of the present work was to determine the effects of different dietary phosphorus (P) levels on endogenous faecal loss and to estimate the minimum daily requirement of P for sheep. The study was conducted with 24 Suffolk sheep which received a basic diet consisting of a hay-concentrate mixture. The treatment consisted of different amounts of bone meal, added to the basic diet, so as to obtain supplementary P levels of 0, 2 and 3 g/day. Twenty-one days after the introduction of the experimental diet, 7.4 MBq radioactive P ( 32 P) was injected in the left jugular vein of each sheep and blood, feces and urine were collected daily for 8 days at 24-hour intervals. The samples were analysed for inorganic P and for radioactive specific activities. Mean endogenous faecal losses of P were 10.00, 31.79, 39.35 and 38.06 mg/kg live weight (LW) per day in sheep supplemented with 0, 1, 2 and 3 g respectively. A positive linear relation ship was observed between endogenous faecal loss and consumed P, indicating that this loss was linked to dietary P. Total P excretion in the faeces, as well as P absorption, retention urinary excretion and salivary secretion were also directly related to P intake, as part of the mechanism of homeostatic control of organism animal. The minimum endogenous faecal loss for zero P intake, calculated by interpolation, was 8.27 mg/kg LW per day, and for zero balance, the calculated phosphorus consumption was 21.36 mg/kg LW per day. (author)

Assessment of the characteristic of nutrients, total metals, and fecal coliform in Sibu Laut River, Sarawak, Malaysia

Science.gov (United States)

Soo, Chen-Lin; Ling, Teck-Yee; Lee, Nyanti; Apun, Kasing

2016-03-01

The concentrations of nutrients (nitrogen and phosphorus), total metals, and fecal coliform (FC) coupling with chlorophyll- a (chl- a), 5-day biochemical oxygen demand (BOD5) and other general environmental parameters were evaluated at the sub-surface and near-bottom water columns of 13 stations in the Sibu Laut River during low and high slack waters. The results indicated that inorganic nitrogen (mainly nitrate) was the primary form of nitrogen whereas organic phosphorus was the major form of phosphorus. The abundance of total heavy metals in Sibu Laut River and its tributaries was in the order of Pb < Cu < Zn < Cd. Fecal coliform concentration was relatively low along Sibu Laut River. The shrimp farm effluents contributed a substantial amount of chl- a, BOD5, nutrients, and FC to the receiving creek except for total metals. Nevertheless, the influence was merely noticeable in the intake creek and amended rapidly along Selang Sibu River and brought minimal effects on the Sibu Laut River. Besides, the domestic sewage effluents from villages nearby also contributed a substantial amount of pollutants.

Hydrology, water quality, and response to changes in phosphorus loading of Minocqua and Kawaguesaga Lakes, Oneida County, Wisconsin, with special emphasis on effects of urbanization

Science.gov (United States)

Garn, Herbert S.; Robertson, Dale M.; Rose, William J.; Saad, David A.

2010-01-01

Minocqua and Kawaguesaga Lakes are 1,318- and 690-acre interconnected lakes in the popular recreation area of north-central Wisconsin. The lakes are the lower end of a complex chain of lakes in Oneida and Vilas Counties, Wis. There is concern that increased stormwater runoff from rapidly growing residential/commercial developments and impervious surfaces from the urbanized areas of the Town of Minocqua and Woodruff, as well as increased effluent from septic systems around their heavily developed shoreline has increased nutrient loading to the lakes. Maintaining the quality of the lakes to sustain the tourist-based economy of the towns and the area was a concern raised by the Minocqua/Kawaguesaga Lakes Protection Association. Following several small studies, a detailed study during 2006 and 2007 was done by the U.S. Geological Survey, in cooperation with the Minocqua/Kawaguesaga Lakes Protection Association through the Town of Minocqua to describe the hydrology and water quality of the lakes, quantify the sources of phosphorus including those associated with urban development and to better understand the present and future effects of phosphorus loading on the water quality of the lakes. The water quality of Minocqua and Kawaguesaga Lakes appears to have improved since 1963, when a new sewage-treatment plant was constructed and its discharge was bypassed around the lakes, resulting in a decrease in phosphorus loading to the lakes. Since the mid-1980s, the water quality of the lakes has changed little in response to fluctuations in phosphorus loading from the watershed. From 1986 to 2009, summer average concentrations of near-surface total phosphorus in the main East Basin of Minocqua Lake fluctuated from 0.009 mg/L to 0.027 mg/L but generally remained less than 0.022 mg/L, indicating that the lake is mesotrophic. Phosphorus concentrations from 1988 through 1996, however, were lower than the long-term average, possibly the result of an extended drought in the area

Determination of phosphorus in gold or silver brazing alloys

International Nuclear Information System (INIS)

Antepenko, R.J.

1976-01-01

A spectrophotometric method has been devised for measuring microgram levels of phosphorus in brazing alloys of gold or silver alloys is normally measured by solid mass spectrometry, but the high nickel concentration produces a double ionized nickel spectral interference. The described procedures is based upon the formation of molybdovandophosphoric acid when a molybdate solution is added to an acidic solution containing orthophosphate and vanadate ions. The optimum acidity for forming the yellow colored product is 0.5 N hydrochloric acid. The working concentration range is from 0.1 to 1 ppm phosphorus using 100-mm cells and measuring the absorbance at 460 nm. The sample preparation procedure employs aqua regia to dissolve the alloy oxidize the phosphorus to orthophosphate. Cation-exchange chromatography is used to remove nickel ions and anion-exchange and chromatography to remove gold ions as the chloride complex. Excellent recoveries are obtained for standard phosphorus solutions run through the sample procedure. The procedure is applicable to a variety of gold or silver braze alloys requiring phosphorus analysis

Toxicity of acid mine pit lake water remediated with limestone and phosphorus

Energy Technology Data Exchange (ETDEWEB)

Neil, L.L.; McCullough, C.D.; Lund, M.A.; Evans, L.H.; Tsvetnenko, Y. [Edith Cowan University, Joondalup, WA (Australia)

2009-11-15

Pit lakes are increasingly common worldwide and have potential to provide many benefits. However, lake water toxicity may require remediation before beneficial end uses can be realised. Three treatments to remediate AMD (pH similar to 4.8) pit lake water containing elevated concentrations of Al and Zn from Collie, Western Australia were tested in mesocosms. Treatments were: (a) limestone neutralisation (L), (b) phosphorus amendment (P), and c) combined limestone neutralisation and phosphorus amendment (L+P). Laboratory bioassays with Ceriodaphnia cf. dubia, Chlorella protothecoides and Tetrahymena thermophila assessed remediation. Limestone neutralisation increased pH and reduced heavy metal concentrations by 98% (Al) to 14% (Mg), removing toxicity to the three test species within 2 months. Phosphorus amendment removed toxicity after 6 months of treatment. However, phosphorus amendment to prior limestone neutralisation failed to reduce toxicity more than limestone neutralisation alone. Low concentrations of both phosphorus and nitrogen appear to limit phytoplankton population growth in all treatments.

Toxicity of acid mine pit lake water remediated with limestone and phosphorus.

Science.gov (United States)

Neil, Luke L; McCullough, Clint D; Lund, Mark A; Evans, Louis H; Tsvetnenko, Yuri

2009-11-01

Pit lakes are increasingly common worldwide and have potential to provide many benefits. However, lake water toxicity may require remediation before beneficial end uses can be realised. Three treatments to remediate AMD (pH approximately 4.8) pit lake water containing elevated concentrations of Al and Zn from Collie, Western Australia were tested in mesocosms. Treatments were: (a) limestone neutralisation (L), (b) phosphorus amendment (P), and (c) combined limestone neutralisation and phosphorus amendment (L+P). Laboratory bioassays with Ceriodaphnia cf. dubia, Chlorella protothecoides and Tetrahymena thermophila assessed remediation. Limestone neutralisation increased pH and reduced heavy metal concentrations by 98% (Al) to 14% (Mg), removing toxicity to the three test species within 2 months. Phosphorus amendment removed toxicity after 6 months of treatment. However, phosphorus amendment to prior limestone neutralisation failed to reduce toxicity more than limestone neutralisation alone. Low concentrations of both phosphorus and nitrogen appear to limit phytoplankton population growth in all treatments.

Phosphorus Regulation in Chronic Kidney Disease.

Science.gov (United States)

Suki, Wadi N; Moore, Linda W

2016-01-01

Serum phosphorus levels stay relatively constant through the influence of multiple factors-such as parathyroid hormone, fibroblast growth factor 23, and vitamin D-on the kidney, bone, and digestive system. Whereas normal serum phosphorus ranges between 3 mg/dL to 4.5 mg/dL, large cross-sectional studies have shown that even people with normal kidney function are sometimes found to have levels ranging between 1.6 mg/dL and 6.2 mg/dL. While this may partially be due to diet and the factors mentioned above, total understanding of these atypical ranges of serum phosphorus remains uncertain. Risks for bone disease are high in people aged 50 and older, and this group comprises a large proportion of people who also have chronic kidney disease. Consuming diets low in calcium and high in phosphorus, especially foods with phosphate additives, further exacerbates bone turnover. Existing bone disease increases the risk for high serum phosphorus, and higher serum phosphorus has been associated with increased adverse events and cardiovascular-related mortality both in people with chronic kidney disease and in those with no evidence of disease. Once kidney function has deteriorated to end-stage disease (Stage 5), maintaining normal serum phosphorus requires dietary restrictions, phosphate-binding medications, and dialysis. Even so, normal serum phosphorus remains elusive in many patients with Stage 5 kidney disease, and researchers are testing novel targets that may inhibit intestinal transport of phosphorus to achieve better phosphate control. Protecting and monitoring bone health should also aid in controlling serum phosphorus as kidney disease advances.

Total recovery of nitrogen and phosphorus from three wetland plants by fast pyrolysis technology.

Science.gov (United States)

Liu, Wu-Jun; Zeng, Fan-Xin; Jiang, Hong; Yu, Han-Qing

2011-02-01

Fast pyrolysis of three wetland plants (Alligator weed, Oenanthe javanica and Typha angustifolia) in a vertical drop fixed bed reactor was investigated in this study. The experiments were carried out at different pyrolysis temperatures, and the maximum bio-oil yields achieved were 42.3%, 40.2% and 43.6% for Alligator weed, Oenanthe javanica and Typha angustifolia, respectively. The elemental composition of the bio-oil and char were analyzed, and the results show that a low temperature was appropriate for the nitrogen and phosphorus enrichment in char. GC-MS analysis shows that nitrogenous compounds, phenols and oxygenates were the main categories in the bio-oil. A series of leaching tests were carried out to examine the recovery of the nitrogen and phosphorus in the char, and the results indicate that significant fractions of nitrogen and phosphorus could be recovered by leaching process. Copyright © 2010 Elsevier Ltd. All rights reserved.

Phosphorus loss to runoff water twenty-four hours after application of liquid swine manure or fertilizer.

Science.gov (United States)

Tabbara, Hadi

2003-01-01

Phosphorus (P) added to soil from fertilizer or manure application could pose a threat to water quality due to its role in eutrophication of fresh water resources. Incorporating such amendments into the soil is an established best management practice (BMP) for reducing soluble P losses in runoff water, but could also lead to higher erosion. The objective of this study was to test whether incorporation of manure or fertilizer 24 h before an intense rain could also reduce sediment-bound and total phosphorus (TP) losses in runoff. A rainfall simulation study was conducted on field plots (sandy loam with 6-7% slope, little surface residue, recently cultivated) that received two application rates of liquid swine manure or liquid ammonium polyphosphate fertilizer, using either surface-broadcast or incorporated methods of application. Incorporation increased the total suspended solids (TSS) concentrations in runoff but mass losses were not affected. Incorporation also reduced flow-weighted concentrations and losses of dissolved reactive phosphorus (DRP) and TP by as much as 30 to 60% depending on source (fertilizer vs. manure) and application rate. Phosphorus is moved below the mixing zone of interaction on incorporation, and thus the effect of the amount and availability of P in this zone is more important than cultivation on subsequent P losses in runoff. Incorporating manure or fertilizer in areas of intense erosive rain, recent extensive tillage, and with little or no surface residue is therefore a best management practice that should be adhered to in order to minimize contamination of surface water. Results also show comparatively lower P losses from manure than fertilizer.

Prediction of phosphorus mobilisation in inundated floodplain soils

Energy Technology Data Exchange (ETDEWEB)

Loeb, Roos [Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland Research, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen (Netherlands)], E-mail: r.loeb@science.ru.nl; Lamers, Leon P.M.; Roelofs, Jan G.M. [Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland Research, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen (Netherlands)

2008-11-15

After flooding, iron reduction in riverine wetlands may cause the release of large quantities of phosphorus. As phosphorus is an important nutrient causing eutrophication in aquatic systems, it is important to have a tool to predict this potential release. In this study we examined the P release to the soil pore water in soil cores from floodplains in the Netherlands and from less anthropogenically influenced floodplains from Poland. During the inundation experiment, concentrations of P in the pore water rose to 2-90 times the initial concentrations. P release was not directly related to the geographic origin of the soils. An important predictor variable of P release was found in the ratio between the concentration of iron-bound P and amorphous iron. This ratio may provide a practical tool for the selection of new areas for wetland creation, and for impact assessment of plans for riverine wetland restoration and floodwater storage. - Mobilisation of phosphorus in floodplain wetland soils can be predicted with easily measurable soil characteristics.

Prediction of phosphorus mobilisation in inundated floodplain soils

International Nuclear Information System (INIS)

Loeb, Roos; Lamers, Leon P.M.; Roelofs, Jan G.M.

2008-01-01

After flooding, iron reduction in riverine wetlands may cause the release of large quantities of phosphorus. As phosphorus is an important nutrient causing eutrophication in aquatic systems, it is important to have a tool to predict this potential release. In this study we examined the P release to the soil pore water in soil cores from floodplains in the Netherlands and from less anthropogenically influenced floodplains from Poland. During the inundation experiment, concentrations of P in the pore water rose to 2-90 times the initial concentrations. P release was not directly related to the geographic origin of the soils. An important predictor variable of P release was found in the ratio between the concentration of iron-bound P and amorphous iron. This ratio may provide a practical tool for the selection of new areas for wetland creation, and for impact assessment of plans for riverine wetland restoration and floodwater storage. - Mobilisation of phosphorus in floodplain wetland soils can be predicted with easily measurable soil characteristics

Amendment in phosphorus levels moderate the chromium toxicity in Raphanus sativus L. as assayed by antioxidant enzymes activities.

Science.gov (United States)

Sayantan, D; Shardendu

2013-09-01

Chromium (Z=24), a d-block element, is a potent carcinogen, whereas phosphorus is an essential and limiting nutrient for the plant growth and development. This study undertakes the role of phosphorus in moderating the chromium toxicity in Raphanus sativus L., as both of them compete with each other during the uptake process. Two-factor complete randomized experiment (5 chromium × 5 phosphorus concentrations) was conducted for twenty eight days in green house. The individuals of R. sativus were grown in pots supplied with all essential nutrients. The toxic effects of chromium and the moderation of toxicity due to phosphorus amendment were determined as accumulation of chromium, nitrogen, phosphorus in root tissues and their effects were also examined in the changes in biomass, chlorophyll and antioxidant enzyme levels. Cr and N accumulation were almost doubled at the highest concentration of Cr supply, without any P amendment, whereas at the highest P concentration (125 mM), the accumulation was reduced to almost half. A significant reduction in toxic effects of Cr was determined as there was three-fold increase in total chlorophyll and biomass at the highest P amendment. Antioxidant enzymes like superoxide dismutase, catalase, peroxidase and lipid peroxidation were analyzed at various levels of Cr each amended with five levels of P. It was observed that at highest level of P amendment, the reduction percentage in toxicity was 33, 44, 39 and 44, correspondingly. Conclusively, the phosphorus amendment moderates the toxicity caused by the supplied chromium in R. sativus. This finding can be utilized to develop a novel technology for the amelioration of chromium stressed fields. Copyright © 2013 Elsevier Inc. All rights reserved.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of the total phosphorus by a Kjeldahl digestion method and an automated colorimetric finish that includes dialysis

Science.gov (United States)

Patton, Charles J.; Truitt, Earl P.

1992-01-01

A method to determine total phosphorus (TP) in the same digests prepared for total Kjeldahl nitrogen (TKN) determinations is desribed. The batch, high-temperature (block digester), HG(II)-catalyzed digestion step is similar to U.S. Geological Survey methods I-2552-85/I-4552-85 and U.S. Environmental Protection Agency method 365.4 except that sample and reagent volumes are halved. Prepared digests are desolvated at 220 degrees Celsius and digested at 370 degrees Celsius in separate block digesters set at these temperatures, rather than in a single, temperature-programmed block digester. This approach is used in the method escribed here, which permits 40 calibrants, reference waters, and smaples to be digested and resolvated in about an hour. Orthophosphate ions originally present in samples, along with those released during the digestion step, are determined colorimetrically at a rate of 90 tests per hour by an automated version of the phosphoantimonylmolybdenum blue procedure. About 100 microliters of digest are required per determination. The upper concentration limit is 2 milligrams per liter (mg/L) with a method detection limt of 0.01 mg/L. Repeatability for a sample containing approximately 1.6 mg/L of TP in a high suspended-solids matrix is 0.7 percent. Between-day precision for the same sample is 5.0 percent. A dialyzer in the air-segmented continuous flow analyzer provides on-line digest cleanup, eliminated particulates that otherwise would interfere in the colorimetric finish. An single-channel analyzer can process the resolvated digests from two pairs of block digesters each hour. Paired t-test analysis of TP concentrations for approximately 1,600 samples determined by the new method (U.S. Geologial Survey methods I-2610-91 and I-4610-91) and the old method (U.S. Geological Survey methods I-2600-85 and I-4600-85) revealed positive bias in the former of 0.02 to 0.04 mg/L for surface-water samples in agreement with previous studies. Concentrations of total

Application of contact stabilization activated sludge for enhancing biological phosphorus removal (EBPR in domestic wastewater

Directory of Open Access Journals (Sweden)

Ehab M. Rashed

2014-04-01

Full Text Available The experiment has been performed in order to investigate the effect of using contact stabilization activated sludge as an application of enhancing biological phosphorous removal (EBPR by using contact tank as a phosphorus uptake zone and using thickening tank as a phosphorus release zone. The study involved the construction of a pilot plant which was setup in Quhafa waste water treatment plant (WWTP that included contact, final sedimentation, stabilization and thickening tanks, respectively with two returns sludge in this system one of them to contact tank and another to stabilization tank. Then observation of the uptake and release of total phosphorus by achievement through two batch test using sludge samples from thickener and final sedimentations. Results showed the removal efficiencies of COD, BOD and TP for this pilot plant with the range of 94%, 85.44% and 80.54%, respectively. On the other hand the results of batch tests showed that the reason of high ability of phosphorus removal for this pilot plant related to the high performance of microorganisms for phosphorus accumulating. Finally the mechanism of this pilot plant depends on the removal of the phosphorus from the domestic waste water as a concentrated TP solution from the supernatant above the thickening zone not through waste sludge like traditional systems.

Total water, phosphorus relaxation and inter-atomic organic to inorganic interface are new determinants of trabecular bone integrity.

Directory of Open Access Journals (Sweden)

Ratan Kumar Rai

Full Text Available Bone is the living composite biomaterial having unique structural property. Presently, there is a considerable gap in our understanding of bone structure and composition in the native state, particularly with respect to the trabecular bone, which is metabolically more active than cortical bones, and is readily lost in post-menopausal osteoporosis. We used solid-state nuclear magnetic resonance (NMR to compare trabecular bone structure and composition in the native state between normal, bone loss and bone restoration conditions in rat. Trabecular osteopenia was induced by lactation as well as prolonged estrogen deficiency (bilateral ovariectomy, Ovx. Ovx rats with established osteopenia were administered with PTH (parathyroid hormone, trabecular restoration group, and restoration was allowed to become comparable to sham Ovx (control group using bone mineral density (BMD and µCT determinants. We used a technique combining (1H NMR spectroscopy with (31P and (13C to measure various NMR parameters described below. Our results revealed that trabecular bones had diminished total water content, inorganic phosphorus NMR relaxation time (T1 and space between the collagen and inorganic phosphorus in the osteopenic groups compared to control, and these changes were significantly reversed in the bone restoration group. Remarkably, bound water was decreased in both osteopenic and bone restoration groups compared to control. Total water and T1 correlated strongly with trabecular bone density, volume, thickness, connectivity, spacing and resistance to compression. Bound water did not correlate with any of the microarchitectural and compression parameters. We conclude that total water, T1 and atomic space between the crystal and organic surface are altered in the trabecular bones of osteopenic rats, and PTH reverses these parameters. Furthermore, from these data, it appears that total water and T1 could serve as trabecular surrogates of micro-architecture and

Effect Of Wood-Based Biochar And Sewage Sludge Amendments For Soil Phosphorus Availability

Directory of Open Access Journals (Sweden)

Frišták Vladimír

2015-06-01

Full Text Available This study investigated the effects of two biochars (pyrolysed wood chips and garden clippings on phosphorus (P availability in a heavy-metal contaminated soil poor in phosphorus. Short-term 14-days incubation experiments were conducted to study how applications of biochars at different rates (1 and 5 % in combination with (1:1 and without dried sewage sludge from a municipal waste water treatment plant (WWTP affected the content of soil extractable P. For P-availability analyses deionized water, calcium acetate lactate (CAL, Mehlich 3 and Olsen extraction protocols were applied. In addition, the content of total and mobile forms of potentially toxic heavy metals (PTHM was studied. Application of both biochars caused a significant decrease of PTHM available forms in sewage sludge amended soil samples. The concentration of total and available P increased with higher biochar and sewage sludge application rates.

Phosphorus determination by various substoichiometric methods

International Nuclear Information System (INIS)

Shigematsu, Toshio; Kudo, Kiyoshi

1981-01-01

Various substoichiometric methods have been classified from a view point of the substoichiometric separation. Based upon the substoichiometric separation, phosphorus was determined substoichiometrically by a direct method, a method of carrier amount variation and a comparison method for the irradiated sample. The direct method was applied to the determination of phosphorus in orchard leaves (SRM-1571). The analytical value was 0.23 +- 0.01%. Phosphorus in orchard leaves and spinach (SRM-1570) was determined by an ordinary method which devided the sample into equal parts in the method of carrier amount variation. Analytical values of orchard leaves and spinach were 0.22 +- 0.02% and 0.56 +- 0.04%, respectively. Moreover, a new modification of the method of carrier amount variation was studied by the use of various standard samples such as red phosphorus, spinach and orchard leaves. These standard samples were also employed for the determination of phosphorus in orchard leaves and 0.21 +- 0.01% was obtained. All these results are in good agreement with the value reported by NBS. The comparison method was applied to the determination of phosphorus in a semiconductor silicon single crystal. As a result of the correction of 32 P activity induced by the secondary nuclear reaction of 30 Si, 7.9 ppb and 3.1 ppb were obtained for the phosphorus concentrations in the single crystal silicon. (author)

Inverse-model estimates of the ocean's coupled phosphorus, silicon, and iron cycles

Science.gov (United States)

Pasquier, Benoît; Holzer, Mark

2017-09-01

The ocean's nutrient cycles are important for the carbon balance of the climate system and for shaping the ocean's distribution of dissolved elements. Dissolved iron (dFe) is a key limiting micronutrient, but iron scavenging is observationally poorly constrained, leading to large uncertainties in the external sources of iron and hence in the state of the marine iron cycle. Here we build a steady-state model of the ocean's coupled phosphorus, silicon, and iron cycles embedded in a data-assimilated steady-state global ocean circulation. The model includes the redissolution of scavenged iron, parameterization of subgrid topography, and small, large, and diatom phytoplankton functional classes. Phytoplankton concentrations are implicitly represented in the parameterization of biological nutrient utilization through an equilibrium logistic model. Our formulation thus has only three coupled nutrient tracers, the three-dimensional distributions of which are found using a Newton solver. The very efficient numerics allow us to use the model in inverse mode to objectively constrain many biogeochemical parameters by minimizing the mismatch between modeled and observed nutrient and phytoplankton concentrations. Iron source and sink parameters cannot jointly be optimized because of local compensation between regeneration, recycling, and scavenging. We therefore consider a family of possible state estimates corresponding to a wide range of external iron source strengths. All state estimates have a similar mismatch with the observed nutrient concentrations and very similar large-scale dFe distributions. However, the relative contributions of aeolian, sedimentary, and hydrothermal iron to the total dFe concentration differ widely depending on the sources. Both the magnitude and pattern of the phosphorus and opal exports are well constrained, with global values of 8. 1 ± 0. 3 Tmol P yr-1 (or, in carbon units, 10. 3 ± 0. 4 Pg C yr-1) and 171. ± 3. Tmol Si yr-1. We diagnose the

Spatial variation in sediment-water exchange of phosphorus in Florida Bay: AMP as a model organic compound.

Science.gov (United States)

Huang, Xiao-Lan; Zhang, Jia-Zhong

2010-10-15

Dissolved organic phosphorus (DOP) has been recognized as dominant components in total dissolved phosphorus (TDP) pools in many coastal waters, and its exchange between sediment and water is an important process in biogeochemical cycle of phosphorus. Adenosine monophosphate (AMP) was employed as a model DOP compound to simulate phosphorus exchange across sediment-water interface in Florida Bay. The sorption data from 40 stations were fitted to a modified Freundlich equation and provided a detailed spatial distribution both of the sediment's zero equilibrium phosphorus concentration (EPC(0-T)) and of the distribution coefficient (K(d-T)) with respect to TDP. The K(d-T) was found to be a function of the index of phosphorus saturation (IPS), a molar ratio of the surface reactive phosphorus to the surface reactive iron oxide content in the sediment, across the entire bay. However, the EPC(0-T) was found to correlate to the contents of phosphorus in the eastern bay only. Sediment in the western bay might act as a source of the phosphorus in the exchange process due to their high EPC(0-T) and low K(d-T), whereas sediments in the eastern bay might act as a sink because of their low EPC(0-T) and high K(d-T). These results strongly support the hypothesis that both phosphorus and iron species in calcareous marine sediments play a critical role in governing the sediment-water exchange of both phosphate and DOP in the coastal and estuarine ecosystems.

Fluctuation contents of phosphorus and natural radionuclide in the water column of the Mersing river, Johor, Malaysia

International Nuclear Information System (INIS)

Saili, Noor Affizah Bujang; Mohamed, Che Abd Rahim

2013-01-01

Studies on natural radionuclides such as 210 Po and 210 Pb with the concentration of phosphorus in water column related to suspended particulate matter (SPM) were carried out at the Mersing River, Johor, Malaysia. Sixteen water samples were collected from nine stations on the 4 th July 2010. 210 Po and 210 Pb activities varied between 0.76 to 2.24 mBq/L and 0.16 to 1.60 mBq/L respectively. The phosphorus concentrations, comprising total dissolved phosphorus (TDP), soluble reactive phosphorus (SRP) and dissolved organic phosphorus (DOP), were within the ranges of 6.06 to 23.31 μg/L, 2.24 to 13.42 μg/L and 0.47 to 16.10 μ/L, respectively. The concentration of TDP and salinity shows weak positive correlation (r = 0.39), perhaps due to the shallow depth of the Mersing River. There is a high positive correlation (r = 0.85) of 210 Po activity with SPM concentration and a moderately positive correlation (r =0.59) of 210 Po and TDP in water. The K d values in suspended particulate matter are much higher compare to that in dissolved phase, proving that the adsorption of radionuclides to particles is more dominant. This implies that SPM significantly influences the variation of the P compound and both radionuclides in the Mersing River. This corresponds with agricultural activities from palm oil estates; erosion of the river bank due to river runoff; advection of suspended particulates from surface sediment due to boat and ferry traffic at the jetties; sedimentation; domestic sewage from nearby terrestrial areas; and natural processes; all of which might have resulted in their introduction to the Mersing River. (author)

Spatial and temporal variations in non-point source losses of nitrogen and phosphorus in a small agricultural catchment in the Three Gorges Region.

Science.gov (United States)

Chen, Chenglong; Gao, Ming; Xie, Deti; Ni, Jiupai

2016-04-01

Losses of agricultural pollutants from small catchments are a major issue for water quality in the Three Gorges Region. Solutions are urgently needed. However, before pollutant losses can be controlled, information about spatial and temporal variations in pollutant losses is needed. The study was carried out in the Wangjiagou catchment, a small agricultural catchment in Fuling District, Chongqing, and the data about non-point source losses of nitrogen and phosphorus was collected here. Water samples were collected daily by an automatic water sampler at the outlets of two subcatchments from 2012 to 2014. Also, samples of surface runoff from 28 sampling sites distributed through the subcatchments were collected during 12 rainfall events in 2014. A range of water quality variables were analyzed for all samples and were used to demonstrate the variation in non-point losses of nitrogen and phosphorus over a range of temporal and spatial scales and in different types of rainfall in the catchment. Results showed that there was a significant linear correlation between the mass concentrations of total nitrogen (TN) and nitrate (NO3-N) in surface runoff and that the relationship was maintained with changes in time. Concentrations of TN and NO3-N peaked after fertilizer was applied to crops in spring and autumn; concentrations decreased rapidly after the peak values in spring but declined slowly in autumn. N and P concentrations fluctuated more and showed a greater degree of dispersion during the spring crop cultivation period than those in autumn. Concentrations of TN and NO3-N in surface runoff were significantly and positively correlated with the proportion of the area that was planted with corn and mustard tubers, but were negatively correlated with the proportion of the area taken up with rice and mulberry plantations. The average concentrations of TN and NO3-N in surface runoff reached the highest level from the sampling points at the bottom of the land used for corn

Interactions between Microcystis aeruginosa and coexisting amoxicillin contaminant at different phosphorus levels.

Science.gov (United States)

Liu, Ying; Chen, Shi; Chen, Xiao; Zhang, Jian; Gao, Baoyu

2015-10-30

Microcystis aeruginosa was cultured with 0.05-5 mg L(-1) of phosphorus and exposed to 200-500 ng L(-1) of amoxicillin for seven days. Amoxicillin presented no significant effect (p>0.05) on the growth of M. aeruginosa at phosphorus levels of 0.05 and 0.2 mg L(-1), but stimulated algal growth as a hormesis effect at phosphorus levels of 1 and 5 mg L(-1). Phosphorus and amoxicillin affected the contents of chlorophyll-a, adenosine triphosphate (ATP) and malondialdehyde, the expression of psbA and rbcL, as well as the activities of adenosinetriphosphatase and glutathione S-transferase in similar manners, but regulated the production and release of microcystins and the activities of superoxide dismutase and peroxidase in different ways. Increased photosynthesis activity was related with the ATP consumption for the stress response to amoxicillin, and the stress response was enhanced as the phosphorus concentration increased. The biodegradation of amoxicillin by M. aeruginosa increased from 11.5% to 28.2% as the phosphorus concentration increased. Coexisting amoxicillin aggravated M. aeruginosa pollution by increasing cell density and concentration of microcystins, while M. aeruginosa alleviated amoxicillin pollution via biodegradation. The interactions between M. aeruginosa and amoxicillin were significantly regulated by phosphorus (p<0.05) and led to a complicated situation of combined pollution. Copyright © 2015 Elsevier B.V. All rights reserved.

Transformation of apatite phosphorus and non-apatite inorganic phosphorus during incineration of sewage sludge.

Science.gov (United States)

Li, Rundong; Zhang, Ziheng; Li, Yanlong; Teng, Wenchao; Wang, Weiyun; Yang, Tianhua

2015-12-01

The recovery of phosphorus from incinerated sewage sludge ash (SSA) is assumed to be economical. Transformation from non-apatite inorganic phosphorus (NAIP) to apatite phosphorus (AP), which has a higher bioavailability and more extensive industrial applications, was studied at 750-950°C by sewage sludge incineration and model compound incineration with a calcium oxide (CaO) additive. Thermogravimetric differential scanning calorimetry analysis and X-ray diffraction measurements were used to analyze the reactions between NAIP with CaO and crystallized phases in SSA. High temperatures stimulated the volatilization of NAIP instead of AP. Sewage sludge incineration with CaO transformed NAIP into AP, and the percentage of AP from the total phosphorus reached 99% at 950°C. Aluminum phosphate reacted with CaO, forming Ca2P2O7 and Ca3(PO4)2 at 750-950°C. Reactions between iron phosphate and CaO occurred at lower temperatures, forming Ca(PO3)2 before reaching 850°C. Copyright © 2015 Elsevier Ltd. All rights reserved.

Growth and nutrient efficiency of Betula alnoides clones in response to phosphorus supply

Directory of Open Access Journals (Sweden)

Lin Chen

2016-12-01

Full Text Available As phosphorus deficiency limits the productivity of many plantation forests in Asia, there is considerable interest in developing phosphorus-efficient clones for the region through targeted breeding programs. Therefore, we determined growth, nutrient concentrations and nutrient absorption and utility efficiencies of four Betula alnoides clones (C5, C6, 1-202 and BY1 in response to six phosphorus levels of 0, 17, 52, 70, 140 and 209 mg P plant-1 coded as P1 to P6, respectively. Maximum growth occurred in the P4, P5 and P6 plants since they had the largest height, biomass, leaf area and branch number. Phosphorus application increased the phosphorus concentrations of all clones. Nutrient loading was achieved with the P6 treatment because growth and biomass were not significantly higher, but root, stem and leaf phosphorus concentrations were approximately twice those of P4 plants. Clone BY1 had the highest phosphorus-efficiency, and is recommended for field application due to its maximum root collar diameter, biomass, root/shoot ratio, leaf area, nutrient absorption and utility efficiency among the four clones. The findings will help to improve the nutrient efficiency of this species in plantation forestry in Asia.

Determination of Phosphorus Adsorption Using Various Forms of Isotherms in Soils of Adıyaman Çamgazi Plain

OpenAIRE

AĞCA, Necat

2014-01-01

Samples from 8 widespread soil series from Adıyaman Çamgazi Plain were equilibriated at a constant temperature with 16 different solutions containing 0 to 50 mg/ml phosphorus in batch-type experiments. The phosphorus concentrations of the equilibrium solutions and the amounts of phosphorus adsorbed by the soils at these concentrations were determined. These phosphorus-adsorption data were evaluated statistically for their suitability for adsorption isotherms in various concentration ranges.

Nutrient Concentrations in Upper and Lower Echo, Fallen Leaf, Spooner, and Marlette Lakes and Associated Outlet Streams, California and Nevada, 2002-03

National Research Council Canada - National Science Library

2004-01-01

.... Water samples were collected to determine seasonal and spatial concentrations of dissolved nitrite plus nitrate, dissolved ammonia, total Kjeldahl nitrogen, dissolved orthophosphate, total phosphorus...

[Effects of tobacco garlic crop rotation and intercropping on tobacco yield and rhizosphere soil phosphorus fractions].

Science.gov (United States)

Tang, Biao; Zhang, Xi-zhou; Yang, Xian-bin

2015-07-01

A field plot experiment was conducted to investigate the tobacco yield and different forms of soil phosphorus under tobacco garlic crop rotation and intercropping patterns. The results showed that compared with tobacco monoculture, the tobacco yield and proportion of middle/high class of tobacco leaves to total leaves were significantly increased in tobacco garlic crop rotation and intercropping, and the rhizosphere soil available phosphorus contents were 1.3 and 1.7 times as high as that of tobacco monoculture at mature stage of lower leaf. For the inorganic phosphorus in rhizosphere and non-rhizosphere soil in different treatments, the contents of O-P and Fe-P were the highest, followed by Ca2-P and Al-P, and Ca8-P and Ca10-P were the lowest. Compared with tobacco monoculture and tobacco garlic crop intercropping, the Ca2-P concentration in rhizosphere soil under tobacco garlic crop rotation at mature stage of upper leaf, the Ca8-P concentration at mature stage of lower leaf, and the Ca10-P concentration at mature stage of middle leaf were lowest. The Al-P concentrations under tobacco garlic crop rotation and intercropping were 1.6 and 1.9 times, and 1.2 and 1.9 times as much as that under tobacco monoculture in rhizosphere soil at mature stages of lower leaf and middle leaf, respectively. The O-P concentrations in rhizosphere soil under tobacco garlic crop rotation and intercropping were significantly lower than that under tobacco monoculture. Compared with tobacco garlic crop intercropping, the tobacco garlic crop rotation could better improve tobacco yield and the proportion of high and middle class leaf by activating O-P, Ca10-P and resistant organic phosphorus in soil.

What aspect of dietary modification in broilers controls litter water-soluble phosphorus: dietary phosphorus, phytase, or calcium?

Science.gov (United States)

Leytem, A B; Plumstead, P W; Maguire, R O; Kwanyuen, P; Brake, J

2007-01-01

Environmental concerns about phosphorus (P) losses from animal agriculture have led to interest in dietary strategies to reduce the concentration and solubility of P in manures and litters. To address the effects of dietary available phosphorus (AvP), calcium (Ca), and phytase on P excretion in broilers, 18 dietary treatments were applied in a randomized complete block design to each of four replicate pens of 28 broilers from 18 to 42 d of age. Treatments consisted of three levels of AvP (3.5, 3.0, and 2.5 g kg(-1)) combined with three levels of Ca (8.0, 6.9, and 5.7 g kg(-1)) and two levels of phytase (0 and 600 phytase units [FTU]). Phytase was added at the expense of 1.0 g kg(-1) P from dicalcium phosphate. Fresh litter was collected from pens when the broilers were 41 d of age and analyzed for total P, soluble P, and phytate P as well as P composition by (31)P nuclear magnetic resonance (NMR) spectroscopy. Results indicated that the inclusion of phytase at the expense of inorganic P or reductions in AvP decreased litter total P by 28 to 43%. Litter water-soluble P (WSP) decreased by up to 73% with an increasing dietary Ca/AvP ratio, irrespective of phytase addition. The ratio of WSP/total P in litter decreased as the dietary Ca/AvP ratio increased and was greater in the phytase-amended diets. This study indicated that while feeding reduced AvP diets with phytase decreased litter total P, the ratio of Ca/AvP in the diet was primarily responsible for effects on WSP. This is important from an environmental perspective as the amount of WSP in litter could be related to potential for off-site P losses following land application of litter.

Dynamics of Intracellular Polymers in Enhanced Biological Phosphorus Removal Processes under Different Organic Carbon Concentrations

Directory of Open Access Journals (Sweden)

Lizhen Xing

2013-01-01

Full Text Available Enhanced biological phosphorus removal (EBPR may deteriorate or fail during low organic carbon loading periods. Polyphosphate accumulating organisms (PAOs in EBPR were acclimated under both high and low organic carbon conditions, and then dynamics of polymers in typical cycles, anaerobic conditions with excess organic carbons, and endogenous respiration conditions were examined. After long-term acclimation, it was found that organic loading rates did not affect the yield of PAOs and the applied low organic carbon concentrations were advantageous for the enrichment of PAOs. A low influent organic carbon concentration induced a high production of extracellular carbohydrate. During both anaerobic and aerobic endogenous respirations, when glycogen decreased to around 80 ± 10 mg C per gram of volatile suspended solids, PAOs began to utilize polyphosphate significantly. Regressed by the first-order reaction model, glycogen possessed the highest degradation rate and then was followed by polyphosphate, while biomass decay had the lowest degradation rate.

Neutron activation analysis for calibration of phosphorus implantation dose

International Nuclear Information System (INIS)

Paul, Rick L.; Simons, David S.

2001-01-01

A feasibility study was undertaken to determine if radiochemical neutron activation analysis (RNAA) can be used to certify the retained dose of phosphorus implanted in silicon, with the goal of producing a phosphorus SRM. Six pieces of silicon, implanted with a nominal phosphorus dose of 8.5x10 14 atoms·cm -2 were irradiated at a neutron flux of 1.05x10 14 cm -2 ·s -1 . The samples were mixed with carrier, dissolved in acid, the phosphorus isolated by chemical separation, and 32 P measured using a beta proportional counter. A mean phosphorus concentration of (8.35±0.20)x10 14 atoms·cm -2 (uncertainty=1 standard deviation) was determined for the six samples, in agreement with the nominal implanted dose

Speciation of phosphorus in the continental shelf sediments in the Eastern Arabian Sea

Science.gov (United States)

Acharya, Shiba Shankar; Panigrahi, Mruganka Kumar; Kurian, John; Gupta, Anil Kumar; Tripathy, Subhasish

2016-03-01

The distributions of various forms of phosphorus (P) and their relation with sediment geochemistry in two core sediments near Karwar and Mangalore offshore have been studied through the modified SEDEX procedure (Ruttenberg et al., 2009) and bulk chemical analysis. The present study provides the first quantitative analysis of complete phosphorus speciation in the core sediments of the Eastern Arabian shelf. The chemical index of alteration (CIA), chemical Index of Weathering (CIW) and Al-Ti-Zr ternary diagram suggest low to moderate source area weathering of granodioritic to tonalitic source rock composition, despite the intense orographic rainfall in the source area. Due to the presence of same source rock and identical oxic depositional environment, the studied sediments show the same range of variation of total phosphorus (24 to 83 μmol/g) with a down-depth depleting trend. Organic bound P and detrital P are the two major chemical forms followed by iron-bound P, exchangeable/loosely bound P and authigenic P. The authigenic P content in the sediments near Mangalore coast varies linearly with calcium (r=0.88) unlike that of Karwar coast. The different reactive-phosphorus pools exhibit identical depleting trend with depth. This indicates that the phosphorus released from the organic matter and Fe bound fractions are prevented from precipitating as authigenic phosphates in the deeper parts of the sediment column. The low concentration of total P, dominance of detrital non-reactive fraction of P and inhibition of formation of authigenic phosphate result in the absence of active phosphatization in the Eastern Arabian Shelf in the studied region. High sedimentation rate (35-58 cm/kyr) and absence of winnowing effect appear to be the dominant factor controlling the P-speciation in the studied sediments.

Phosphorus runoff from turfgrass as affected by phosphorus fertilization and clipping management.

Science.gov (United States)

Bierman, Peter M; Horgan, Brian P; Rosen, Carl J; Hollman, Andrew B; Pagliari, Paulo H

2010-01-01

Phosphorus enrichment of surface water is a concern in many urban watersheds. A 3-yr study on a silt loam soil with 5% slope and high soil test P (27 mg kg(-1) Bray P1) was conducted to evaluate P fertilization and clipping management effects on P runoff from turfgrass (Poa pratensis L.) under frozen and nonfrozen conditions. Four fertilizer treatments were compared: (i) no fertilizer, (ii) nitrogen (N)+potassium (K)+0xP, (iii) N+K+1xP, and (iv) N+K+3xP. Phosphorus rates were 21.3 and 63.9 kg ha(-1) yr(-1) the first year and 7.1 and 21.3 kg ha(-1) yr(-1) the following 2 yr. Each fertilizer treatment was evaluated with clippings removed or clippings recycled back to the turf. In the first year, P runoff increased with increasing P rate and P losses were greater in runoff from frozen than nonfrozen soil. In year 2, total P runoff from the no fertilizer treatment was greater than from treatments receiving fertilizer. This was because reduced turf quality resulted in greater runoff depth from the no fertilizer treatment. In year 3, total P runoff from frozen soil and cumulative total P runoff increased with increasing P rate. Clipping management was not an important factor in any year, indicating that returning clippings does not significantly increase P runoff from turf. In the presence of N and K, P fertilization did not improve turf growth or quality in any year. Phosphorus runoff can be reduced by not applying P to high testing soils and avoiding fall applications when P is needed.

Optimization of enhanced biological phosphorus removal after periods of low loading.

Science.gov (United States)

Miyake, Haruo; Morgenroth, Eberhard

2005-01-01

Enhanced biological phosphorus removal is a well-established technology for the treatment of municipal wastewater. However, increased effluent phosphorus concentrations have been reported after periods (days) of low organic loading. The purpose of this study was to evaluate different operating strategies to prevent discharge of effluent after such low-loading periods. Mechanisms leading to these operational problems have been related to the reduction of polyphosphate-accumulating organisms (PAOs) and their storage compounds (polyhydroxy alkanoates [PHA]). Increased effluent phosphorus concentrations can be the result of an imbalance between influent loading and PAOs in the system and an imbalance between phosphorus release and uptake rates. The following operating conditions were tested in their ability to prevent a reduction of PHA and of overall biomass during low organic loading conditions: (a) unchanged operation, (b) reduced aeration time, (c) reduced sludge wastage, and (d) combination of reduced aeration time and reduced sludge wastage. Experiments were performed in a laboratory-scale anaerobic-aerobic sequencing batch reactor, using acetate as the carbon source. Without operational adjustments, phosphorus-release rates decreased during low-loading periods but recovered rapidly. Phosphorus-uptake rates also decreased, and the recovery typically required several days to increase to normal levels. The combination of reduced aeration time and reduced sludge wastage allowed the maintenance of constant levels of both PHA and overall biomass. A mathematical model was used to explain the influence of the tested operating conditions on PAO and PHA concentrations. While experimental results were in general agreement with model predictions, the kinetic expression for phosphorus uptake deviated significantly for the first 24 hours after low-loading conditions. Mechanisms leading to these deviations need to be further investigated.

Biochar as phosphorus transporter to support the closure of the phosphorus cycle

Science.gov (United States)

Soja, Gerhard; Jagerhofer, Reinhard; Fristak, Vladimir; Pfeifer, Christoph

2017-04-01

Waste materials rich in phosphorus could partly substitute rock phosphate-based mineral fertilizers. As rock phosphate is listed as critical raw material, measures for increasing the recovery rate of phosphorus and for closing the phosphorus cycle are required. However, direct use of the waste materials as fertilizers are frequently not possible because of legal constraints, adverse side effects because of co-occurring contaminants or hygienic concerns. So this study had the objective to test the appropriateness of carbonizing P-rich residues that can be used as secondary P resources for producing P fertilizers. The resulting biochar or hydrochar products should be tested for the bioavailability of P for plant uptake. Feedstock materials tested as secondary P resources were chicken manure, animal bone flour, sewage sludge, and digestates. These materials were either pyrolyzed at different temperatures, partly with different chemical modifications, or hydrothermally carbonized. The biochar and hydrochar products were analyzed for their total and available P concentrations, and the plant bioavailability was determined with a standardized plant growth test with rye (Neubauer-test). The results showed that biochar produced from a mixture of chicken manure and saw dust was equivalent to a standard phosphate fertilizer (superphosphate) with respect to P available for plant uptake. For most materials, a pyrolysis temperature of 400 °C was slightly more beneficial for P availability than 500 °C. Pyrolytic carbonization mostly was more supportive for plant growth than hydrothermal carbonization of the tested feedstocks. For some feedstocks the addition of sodium carbonate improved the P uptake of the plants without affecting the biomass production. The results show that P-rich waste materials used as secondary resources for carbonization can effectively contribute to increased P recovery, savings in the use of mineral phosphate fertilizers and reduced P loads to non

The Contribution of Opal-Associated Phosphorus to Bioavailable Phosphorus in Surface and Core Sediments in the East China Sea

Science.gov (United States)

Li, Huanxin; He, Huijun; Yang, Shifeng; Liu, Yanli; Che, Hong; Li, Mujian; Zhang, Jing

2018-06-01

To improve the burial flux calculations of bioavailable phosphorus (P) and study opal-associated P (Opal-P) in the East China Sea (ECS), surface and core sediments were collected in the Changjiang Estuary (CE) and the south of the Cheju Island. In this study, sedimentary P was operationally divided into seven different forms using modified sedimentary extraction (SEDEX) technique: LSor-P (exchangeable or loosely sorbed P), Fe-P (easily reducible or reactive ferric Fe-bound P), CFA-P (authigenic carbonate fluorapatite and biogenic apatite and CaCO3-bound P), Detr-P (detrital apatite), Org-P (organic P), Opal-P and Ref-P (refractory P). The data revealed that the concentrations of the seven different P forms rank as Detr-P > CFA-P > Org-P > Ref-P > Opal-P > Fe-P > LSor-P in surface sediments and CFA-P > Detr-P > Org-P > Ref-P > Fe-P > Opal-P > LSor-P in core sediments. The distributions of the total phosphorus (TP), TIP, CFA-P, Detr-P are similar and decrease from the CE to the south of the Cheju Island. Meanwhile, Org-P and Opal-P exhibit different distribution trends; this may be affected by the grain size and TOM. The concentrations of potentially bioavailable P are 9.6-13.0 μmol g-1 and 10.0-13.6 μmol g-1, representing 61%-70% and 41%-64% of the TP in surface and core sediments, respectively. The concentrations of Opal-P are 0.6-2.3 μmol g-1 and 0.6-1.4 μmol g-1 in surface and core sediments, accounting for 5.3%-19.8% and 4.2%-10.6% of bioavailable P, respectively. The total burial fluxes of Opal-P and bioavailable P are 1.4×109 mol yr-1 and 1.1×1010 mol yr-1 in the ECS, respectively. Opal-P represents about 12.7% of potentially bioavailable P, which should be recognized when studying P cycling in marine ecosystems.

A Hierarchical Phosphorus Nanobarbed Nanowire Hybrid: Its Structure and Electrochemical Properties.

Science.gov (United States)

Zhao, Dan; Li, Beibei; Zhang, Jinying; Li, Xin; Xiao, Dingbin; Fu, Chengcheng; Zhang, Lihui; Li, Zhihui; Li, Jun; Cao, Daxian; Niu, Chunming

2017-06-14

Nanostructured phosphorus-carbon composites are promising materials for Li-ion and Na-ion battery anodes. A hierarchical phosphorus hybrid, SiC@graphene@P, has been synthesized by the chemical vapor deposition of phosphorus on the surfaces of barbed nanowires, where the barbs are vertically grown graphene nanosheets and the cores are SiC nanowires. A temperature-gradient vaporization-condensation method has been used to remove the unhybridized phosphorus particles formed by homogeneous nucleation. The vertically grown barb shaped graphene nanosheets and a high concentration of edge carbon atoms induced a fibrous red phosphorus (f-RP) growth with its {001} planes in parallel to {002} planes of nanographene sheets and led to a strong interpenetrated interface interaction between phosphorus and the surfaces of graphene nanosheets. This hybridization has been demonstrated to significantly enhance the electrochemical performances of phosphorus.

Long term operation of continuous-flow system with enhanced biological phosphorus removal granules at different COD loading.

Science.gov (United States)

Li, Dong; Lv, Yufeng; Zeng, Huiping; Zhang, Jie

2016-09-01

In this study, a continuous-flow system with enhanced biological phosphorus removal (EBPR) granules was operated at different COD concentrations (200, 300 and 400mgL(-)(1)) to investigate the effect of COD loading on this system. The results showed that when the COD concentration in influent was increased to 400mgL(-)(1), the anaerobic COD removal efficiency and total phosphorus removal efficiency reduced obviously and the settling ability of granules deteriorated due to the proliferation of filamentous bacteria. Moreover, high COD loading inhibited the EPS secretion and destroyed the stability of granules. Results of high-through pyrosequencing indicated that filamentous bacteria had a competitive advantage over polyphosphate-accumulating organisms (PAOs) at high COD loading. The performance of system, settling ability of granules and proportion of PAOs gradually recovered to the initial level after the COD concentration was reduced to 200mgL(-)(1) on day 81. Copyright © 2016 Elsevier Ltd. All rights reserved.

Processes Affecting Phosphorus and Copper Concentrations and Their Relation to Algal Growth in Two Supply Reservoirs in the Lower Coastal Plain of Virginia, 2002-2003, and Implications for Alternative Management Strategies

Science.gov (United States)

Speiran, Gary K.; Simon, Nancy S.; Mood-Brown, Maria L.

2007-01-01

Elevated phosphorus concentrations commonly promote excessive growth of algae in waters nationwide. When such waters are used for public supply, the algae can plug filters during treatment and impart tastes and odors to the finished water. This increases treatment costs and results in finished water that may not be of the quality desired for public supply. Consequently, copper sulfate is routinely applied to many reservoirs to control algal growth but only is a 'temporary fix' and must be reapplied at intervals that can range from more than 30 days in the winter to less than 7 days in the summer. Because copper has a maximum allowable concentration in public drinking water and can be toxic to aquatic life, water suppliers commonly seek to develop alternative, long-term strategies for managing reservoirs. Because these are nationwide issues and part of the mission of the U.S. Geological Survey (USGS) is to define and protect the quality of the Nation's water resources and better understand the physical, chemical, and biological processes in wetlands, lakes, reservoirs, and estuaries, investigations into these issues are important to the fulfillment of the mission of the USGS. The City of Newport News, Virginia, provides 50 million gallons per day of treated water for public supply from Lee Hall and Harwoods Mill Reservoirs (terminal reservoirs) to communities on the lower York-James Peninsula. About 3,500 pounds of copper sulfate are applied to each reservoir at 3- to 99-day intervals to control algal growth. Consequently, the USGS, in cooperation with the City of Newport News, investigated the effects of management practices and natural processes on phosphorus (the apparent growth-limiting nutrient), copper, and algal concentrations in the terminal reservoirs to provide information that can be used to develop alternative management strategies for the terminal reservoirs. Initial parts of the research evaluated circulation and stratification in the reservoirs

Contribution of food additives to sodium and phosphorus content of diets rich in processed foods.

Science.gov (United States)

Carrigan, Anna; Klinger, Andrew; Choquette, Suzanne S; Luzuriaga-McPherson, Alexandra; Bell, Emmy K; Darnell, Betty; Gutiérrez, Orlando M

2014-01-01

Phosphorus-based food additives increase the total phosphorus content of processed foods. However, the extent to which these additives augment total phosphorus intake per day is unclear. To examine the contribution of phosphorus-based food additives to the total phosphorus content of processed foods, separate 4-day menus for a low-additive and additive-enhanced diet were developed using Nutrition Data System for Research (NDSR) software. The low-additive diet was designed to conform to U.S. Department of Agriculture guidelines for energy and phosphorus intake (∼2,000 kcal/day and 900 mg of phosphorus per day), and it contained minimally processed foods. The additive-enhanced diet contained the same food items as the low-additive diet except that highly processed foods were substituted for minimally processed foods. Food items from both diets were collected, blended, and sent for measurement of energy and nutrient intake. The low-additive and additive-enhanced diet provided approximately 2,200 kcal, 700 mg of calcium, and 3,000 mg of potassium per day on average. Measured sodium and phosphorus content standardized per 100 mg of food was higher each day of the additive-enhanced diet as compared with the low-additive diet. When averaged over the 4 menu days, the measured phosphorus and sodium contents of the additive-enhanced diet were 606 ± 125 and 1,329 ± 642 mg higher than the low-additive diet, respectively, representing a 60% increase in total phosphorus and sodium content on average. When comparing the measured values of the additive-enhanced diet to NDSR-estimated values, there were no statistically significant differences in measured versus estimated phosphorus contents. Phosphorus and sodium additives in processed foods can substantially augment phosphorus and sodium intake, even in relatively healthy diets. Current dietary software may provide reasonable estimates of the phosphorus content in processed foods. Copyright © 2014 National Kidney

Evaluating Spatial Variability in Sediment and Phosphorus Concentration-Discharge Relationships Using Bayesian Inference and Self-Organizing Maps

Science.gov (United States)

Underwood, Kristen L.; Rizzo, Donna M.; Schroth, Andrew W.; Dewoolkar, Mandar M.

2017-12-01

Given the variable biogeochemical, physical, and hydrological processes driving fluvial sediment and nutrient export, the water science and management communities need data-driven methods to identify regions prone to production and transport under variable hydrometeorological conditions. We use Bayesian analysis to segment concentration-discharge linear regression models for total suspended solids (TSS) and particulate and dissolved phosphorus (PP, DP) using 22 years of monitoring data from 18 Lake Champlain watersheds. Bayesian inference was leveraged to estimate segmented regression model parameters and identify threshold position. The identified threshold positions demonstrated a considerable range below and above the median discharge—which has been used previously as the default breakpoint in segmented regression models to discern differences between pre and post-threshold export regimes. We then applied a Self-Organizing Map (SOM), which partitioned the watersheds into clusters of TSS, PP, and DP export regimes using watershed characteristics, as well as Bayesian regression intercepts and slopes. A SOM defined two clusters of high-flux basins, one where PP flux was predominantly episodic and hydrologically driven; and another in which the sediment and nutrient sourcing and mobilization were more bimodal, resulting from both hydrologic processes at post-threshold discharges and reactive processes (e.g., nutrient cycling or lateral/vertical exchanges of fine sediment) at prethreshold discharges. A separate DP SOM defined two high-flux clusters exhibiting a bimodal concentration-discharge response, but driven by differing land use. Our novel framework shows promise as a tool with broad management application that provides insights into landscape drivers of riverine solute and sediment export.

[Fractions and adsorption characteristics of phosphorus on sediments and soils in water level fluctuating zone of the Pengxi River, a tributary of the Three Gorges Reservoir].

Science.gov (United States)

Sun, Wen-Bin; Du, Bin; Zhao, Xiu-Lan; He, Bing-Hui

2013-03-01

The sediment, one of the key factors leading to the eutrophication of water bodies, is an important ecological component of natural water body. In order to investigate the morphological characteristics and moving-transiting rule of phosphorus in the sediments of the Pengxi River, a tributary of the Three Gorges Reservoir, the distributions of different phosphorus forms on the three cross-section in the sediments and three soil types of riparian zone were investigated using the sequential extraction method. The characteristics of phosphorus adsorption on the sediments were also investigated by batch experiments. The equilibrium phosphorus concentrations at zero adsorption (EPC0) on those sediments were estimated using the Henry linear models. The results show that the total phosphorus (TP) contents of these sediments and soils of riparian zone were 0.80-1.45 g x kg(-1) and 0.65-1.16 g x kg(-1), respectively. Phosphorus in sediments and soils were divided into inorganic phosphorus (IP) and organic phosphorus (Or-P), and the inorganic phosphorus was the dominant component of TP. Of the inorganic phosphorus fractions, the percentages of phosphorus bounded to calcium (Ca-P) and occluded phosphorus (O-P) from sediments were higher than 80%, implying that the contents of phosphorus were mainly influenced by their bedrocks and the sedimentary environmental conditions, not by the activities of human beings. The fractions of Ca-P and O-P were the dominant components of inorganic phosphorus in alluvial soil and purple soil, while the fraction of O-P was the highest in the paddy soil. The EPC0 values of the sediments from the sections of Huangshi, Shuangjiang and Gaoyang were 0.08, 0.13 and 0.11 mg x L(-1) respectively, but the EPC0 values of the alluvial soil, purple soil and paddy soil located in riparian zone were 0.08, 0.09 and 0.04 mg x L(-1), respectively. Correlation analysis shows that the values of EPC0 positively related to the contents of total phosphorus and clay

[Impacts of Asian clams (Corbicula fluminea) on lake sediment properties and phosphorus movement].

Science.gov (United States)

Zhang, Lei; Gu, Xiao-Zhi; Shao, Shi-Guang; Hu, Hai-Yan; Zhong, Ji-Cheng; Fan, Cheng-Xin

2011-01-01

To examine the impact of Corbicula fluminea on sediment properties and phosphorus dynamics across sediment-water interface in lake, the microcosm experiment was carried out with sediment and lake water from the estuary of Dapu River, a eutrophic area in Taihu Lake. Rhizon samplers were used to acquire pore water, and soluble reactive phosphorus (SRP) flux across sediment-water interface and sediment properties were determined. The activity of C. fluminea destroyed the initial sediment structure, mixed sediment in different depths, increased oxygen penetration depth, sediment water content, and total microbial activity in sediment. The downward movement of overlying water was enhanced by the activity of C. fluminea, which decreased Fe2+ in pore water by oxidation. The production of ferric iron oxyhydroxide adsorbed SRP from pore water and decreased SRP concentration in pore water, and this increased iron bound phosphorus in corresponding sediment. The emergence of C. fluminea accelerated SRP release from sediment to overlying water, and enhanced SRP flux increased with the rise of introduced C. fluminea density. Metabolization of C. fluminea might play an important role in accelerating SRP release.

Phosphorus fractionation distribution in Guapimirim estuary: SE Brazil.

Science.gov (United States)

Vicente, Michel Arthur Faria; de Melo, Gustavo Vaz; Baptista Neto, José Antonio; de Oliveira, Allan Sandes

2016-01-01

The Guapimirim estuary is the main tributary of Guanabara bay and is located in the northeast portion. Although it is protected, this estuary has been experiencing strong anthropogenic pressure, which has led to changes in the natural characteristics. Large amounts of sewage are dumped into the bay through tributaries, thereby changing the water and bottom sediment quality. One of the main elements of sewage is phosphorus. Despite its importance to life, a high concentration of this nutrient in the environment can result in eutrophication. This work describes the phosphorus distribution in its different fractions in the bottom sediment at 16 stations located in the main channel of the Guapimirim estuary. These results are correlated with data on grain size, organic matter and calcium carbonate content in the bottom sediment and with physicochemical parameters of the bottom water. The grain size decreases toward the mouth of the estuary, whereas the organic matter and carbonate content increase. The salinity increases significantly at 3.5 km upstream from the mouth, where there is also a notable increase in fine sediments; the same site is the mean position of the salinity front. The temperature and pH increase in the same direction. The Pinorg-total ranges between 3.18 and 7.13 µmol g(-1), increasing toward the mouth. The same trend is observed for the other phosphorus fractions P-Ca, P-Fe and P-f.a., which range from 0.68 to 1.91, 0.79 to 1.71 and 0.03 to 0.93 µmol g(-1), respectively. The P-Ca and P-Fe fractions are the most representative in the Pinorg-total, occurring at 26.3 and 26.0 %, respectively.

[Studies on nitrogen, phosphorus and organic matter in ponds around Chaohu Lake].

Science.gov (United States)

Sun, Qing-ye; Ma, Xiu-ling; Yang, Gui-de; Chen, Zheng; Wu, Hong-lin; Xuan, Huai-xiang

2010-07-01

There are a lot of ponds around Chaohu Lake. According to location and runoff supply of ponds, the ponds are divided into three types: ponds inner vellage (PIV), ponds adjacent vellage (PAV) and ponds outer vellage (POV). The samples of water and sediment were collected from 136 ponds around Chaohu Lake and the contents of nitrogen, phosphorus and organic matter in water and sediments were analyzed in this study. The results showed that mean contents of total nitrogen (TN), NH4+ -N, NO3- -N, NO2- -N, total phosphorus (TP), soluble PO4(3-) -P and COD were 2.53, 0.65, 0.18, 0.02, 0.97, 0.38 and 51.58 mg x L(-1) in pond water, respectively; and mean contents of TN, NH4+ -N, NO3- -N, NO2- -N, TP, inorganic phosphorus (IP), organic phosphorus (OP) and loss of ignition (LOI) in pond sediment were 1575.36, 35.73, 13.30, 2.88, 933.19, 490.14, 414.75 mg x kg(-1) and 5.44%, respectively. The ponds of more than 90% presented eutrophication in the contents of total nitrogen and phosphorus in water. The contents of TN and NH4+ -N in water and sediment of PIV were significantly higher than that of POV. And the contents of inorganic nitrogen in pond water and sediment displayed a following order: NH4+ -N > NO3- -N > NO2- -N. Data analysis indicated that there was a significantly positive correlation between organic matter and total nitrogen and phosphorus in water and sediment. The nitrogen, phosphorus and organic matter in ponds mainly sourced farmlands and village land surface. The contents of nitrogen, phosphorus and organic matter in ponds were affected by location and runoff supply of ponds. By retaining nitrogen, phosphorus and organic matter in runoff, the ponds can effectively decrease nutrient content into Chaohu Lake.

Phosphorus runoff from waste water treatment biosolids and poultry litter applied to agricultural soils.

Science.gov (United States)

White, John W; Coale, Frank J; Sims, J Thomas; Shober, Amy L

2010-01-01

Differences in the properties of organic phosphorus (P) sources, particularly those that undergo treatment to reduce soluble P, can affect soil P solubility and P transport in surface runoff. This 2-yr field study investigated soil P solubility and runoff P losses from two agricultural soils in the Mid-Atlantic region after land application of biosolids derived from different waste water treatment processes and poultry litter. Phosphorus speciation in the biosolids and poultry litter differed due to treatment processes and significantly altered soil P solubility and dissolved reactive P (DRP) and bioavailable P (FeO-P) concentrations in surface runoff. Runoff total P (TP) concentrations were closely related to sediment transport. Initial runoff DRP and FeO-P concentrations varied among the different biosolids and poultry litter applied. Over time, as sediment transport declined and DRP concentrations became an increasingly important component of runoff FeO-P and TP, total runoff P was more strongly influenced by the type of biosolids applied. Throughout the study, application of lime-stabilized biosolids and poultry litter increased concentrations of soil-soluble P, readily desorbable P, and soil P saturation, resulting in increased DRP and FeO-P concentrations in runoff. Land application of biosolids generated from waste water treatment processes that used amendments to reduce P solubility (e.g., FeCl(3)) did not increase soil P saturation and reduced the potential for DRP and FeO-P transport in surface runoff. These results illustrate the importance of waste water treatment plant process and determination of specific P source coefficients to account for differential P availability among organic P sources.

Ocean acidification: One potential driver of phosphorus eutrophication.

Science.gov (United States)

Ge, Changzi; Chai, Yanchao; Wang, Haiqing; Kan, Manman

2017-02-15

Harmful algal blooms which may be limited by phosphorus outbreak increases currently and ocean acidification worsens presently, which implies that ocean acidification might lead to phosphorus eutrophication. To verify the hypothesis, oxic sediments were exposed to seawater with different pH 30days. If pH was 8.1 and 7.7, the total phosphorus (TP) content in sediments was 1.52±0.50 and 1.29±0.40mg/g. The inorganic phosphorus (IP) content in sediments exposed to seawater with pH8.1 and 7.7 was 1.39±0.10 and 1.06±0.20mg/g, respectively. The exchangeable phosphorus (Ex-P) content in sediments was 4.40±0.45 and 2.82±0.15μg/g, if seawater pH was 8.1 and 7.7. Ex-P and IP contents in oxic sediments were reduced by ocean acidification significantly (pocean acidification was one potential facilitator of phosphorus eutrophication in oxic conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Phosphorus cycles of forest and upland grassland ecosystems and some effects of land management practices.

Science.gov (United States)

Harrison, A F

The distribution of phosphorus capital and net annual transfers of phosphorus between the major components of two unfertilized phosphorus-deficient UK ecosystems, an oak--ash woodland in the Lake District and an Agrostis-Festuca grassland in Snowdonia (both on acid brown-earth soils), have been estimted in terms of kg P ha--1. In both ecosystems less than 3% of the phosphorus, totalling 1890 kg P ha--1 and 3040 kg P ha--1 for the woodland and grassland, respectively, is contained in the living biomass and half that is below ground level. Nearly all the phosphorus is in the soil matrix. Although the biomass phosphorus is mostly in the vegetation, the soil fauna and vegetation is slower (25%) than in the grassland vegetatation (208%). More than 85% of the net annual vegetation uptake of phosphorus from the soil is returned to the soil, mainly in organic debris, which in the grassland ecosystem is more than twice as rich in phosphorus (0.125% P) as in the woodland ecosystem (0.053% P). These concentrations are related to the rates of turnover (input/P content) of phosphorus in the litter layer on the soil surface; it is faster in the grassland (460%) than in the woodland (144%). In both cycles plant uptake of phosphorus largely depends on the release of phosphorus through decomposition of the organic matter returned to soil. In both the woodland and the grassland, the amount of cycling phosphorus is potentially reduced by its immobilization in tree and sheep production and in undecomposed organic matter accumulating in soil. It is assumed that the reductions are counterbalanced by the replenishment of cycling phosphorus by (i) some mineralization of organically bound phosphorus in the mineral soil, (ii) the income in rainfall and aerosols not being effectively lost in soil drainage waters and (iii) rock weathering. The effects of the growth of conifers and sheep grazing on the balance between decomposition and accumulation of organic matter returned to soil are

Biological phosphorus and nitrogen removal in sequencing batch reactors: effects of cycle length, dissolved oxygen concentration and influent particulate matter.

Science.gov (United States)

Ginige, Maneesha P; Kayaalp, Ahmet S; Cheng, Ka Yu; Wylie, Jason; Kaksonen, Anna H

2013-01-01

Removal of phosphorus (P) and nitrogen (N) from municipal wastewaters is required to mitigate eutrophication of receiving water bodies. While most treatment plants achieve good N removal using influent carbon (C), the use of influent C to facilitate enhanced biological phosphorus removal (EBPR) is poorly explored. A number of operational parameters can facilitate optimum use of influent C and this study investigated the effects of cycle length, dissolved oxygen (DO) concentration during aerobic period and influent solids on biological P and N removal in sequencing batch reactors (SRBs) using municipal wastewaters. Increasing cycle length from 3 to 6 h increased P removal efficiency, which was attributed to larger portion of N being removed via nitrite pathway and more biodegradable organic C becoming available for EBPR. Further increasing cycle length from 6 to 8 h decreased P removal efficiencies as the demand for biodegradable organic C for denitrification increased as a result of complete nitrification. Decreasing DO concentration in the aerobic period from 2 to 0.8 mg L(-1) increased P removal efficiency but decreased nitrification rates possibly due to oxygen limitation. Further, sedimented wastewater was proved to be a better influent stream than non-sedimented wastewater possibility due to the detrimental effect of particulate matter on biological nutrient removal.

Effect of phosphorus addition on the reductive transformation of pentachlorophenol (PCP) and iron reduction with microorganism involvement.

Science.gov (United States)

Wang, Yongkui; Liu, Xianli; Huang, Jiexun; Xiao, Wensheng; Zhang, Jiaquan; Yin, Chunqin

2017-10-01

The transformation of phosphorus added to the soil environment has been proven to be influenced by the Fe biochemical process, which thereby may affect the transformation of organic chlorinated contaminants. However, the amount of related literatures regarding this topic is limited. This study aimed to determine the effects of phosphorus addition on pentachlorophenol (PCP) anaerobic transformation, iron reduction, and paddy soil microbial community structure. Results showed that the transformation of phosphorus, iron, and PCP were closely related to the microorganisms. Moreover, phosphorus addition significantly influenced PCP transformation and iron reduction, which promoted and inhibited these processes at low and high concentrations, respectively. Both the maximum reaction rate of PCP transformation and the maximum Fe(II) amount produced were obtained at 1 mmol/L phosphorus concentration. Among the various phosphorus species, dissolved P and NaOH-P considerably changed, whereas only slight changes were observed for the remaining phosphorus species. Microbial community structure analysis demonstrated that adding low concentration of phosphorus promoted the growth of Clostridium bowmanii, Clostridium hungatei, and Clostridium intestinale and Pseudomonas veronii. By contrast, high-concentration phosphorus inhibited growth of these microorganisms, similar to the curves of PCP transformation and iron reduction. These observations indicated that Clostridium and P. veronii, especially Clostridium, played a vital role in the transformation of related substances in the system. All these findings may serve as a reference for the complicated reactions among the multiple components of soils.

Phosphorus retention in a newly constructed wetland receiving agricultural tile drainage water.

Science.gov (United States)

Kynkäänniemi, Pia; Ulén, Barbro; Torstensson, Gunnar; Tonderski, Karin S

2013-01-01

One measure used in Sweden to mitigate eutrophication of waters is the construction of small wetlands (free water surface wetland for phosphorus retention [P wetlands]) to trap particulate phosphorus (PP) transported in ditches and streams. This study evaluated P retention dynamics in a newly constructed P wetland serving a 26-ha agricultural catchment with clay soil. Flow-proportional composite water samples were collected at the wetland inlet and outlet over 2 yr (2010-2011) and analyzed for total P (TP), dissolved P (DP), particulate P (PP), and total suspended solids (TSS). Both winters had unusually long periods of snow accumulation, and additional time-proportional water samples were frequently collected during snowmelt. Inflow TP and DP concentrations varied greatly (0.02-1.09 mg L) during the sampling period. During snowmelt in 2010, there was a daily oscillation in P concentration and water flow in line with air temperature variations. Outflow P concentrations were generally lower than inflow concentrations, with net P losses observed only in August and December 2010. On an annual basis, the wetland acted as a net P sink, with mean specific retention of 69 kg TP, 17 kg DP, and 30 t TSS ha yr, corresponding to a reduction in losses of 0.22 kg TP ha yr from the agricultural catchment. Relative retention was high (36% TP, 9% DP, and 36% TSS), indicating that small constructed wetlands (0.3% of catchment area) can substantially reduce P loads from agricultural clay soils with moderately undulating topography. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Experiments on accumulation of phosphorus in the plants Myosotis palustris, Glyceria maxima and Nasturtium officinale

Directory of Open Access Journals (Sweden)

O. Prokopchuk

2016-10-01

Full Text Available The problem of availability of quality water is highly relevant today, so the technologies of prediction and prevention of water pollution and purification are very important. Biological methods of cleaning, in paticular cleaning water by the so-called method of biosorption, have been increasingly used in the last decade. This method means the removal of dangerous substances and improvement of water condition by using aquatic organisms, in particular plants. Therefore, in view of the rich experience of research conducted in the biosorption sphere, we decided to predict the effectiveness of this method by using the cumulative ability of higher water plants to absorb phosphorus compounds. For this purpose, we selected water and plant samples (Glyceria maxima (C. Hartm. Holmb., Nasturtium officinale R. Br., Myosotis palustris (L. L. from the river Seret (Ternopil, Ukraine. The plants were placed into sterilized glass jars filled with 3 liters of water from the river Seret (control samples and still tap water with addition of sodium phosphate with phosphorus concentration of 3.5 mg/dm³ (research sample, which were cultured in laboratory conditions for four months. We determined the content of phosphates, permanganate and dichromate oxidation in the water and the total content of phosphorus in the plants. We traced the dynamic of organic substances and the content of phosphates in the water, the accumulation of phosphorus in plants and the rate of accumulation of phosphorus in the plants and in the water. We calculated correlation coefficients to detect the dependence between phosphorus indicators in the aquatic plants and the concentration of phosphate ions in the water. We found that M. palustris had the greatest capacity to accumulate phosphorus and the highest rate of phosphorus accumulation from water, which allows us to consider it the most effective aquatic plant for absorption of elements and decreasing water pollution. We also established

Sensitivity of soil phosphorus tests in predicting the potential risk of phosphorus loss from pasture soil

Directory of Open Access Journals (Sweden)

H. SOINNE

2008-12-01

Full Text Available The objective of this study was to examine the effects of urine and dung additions on the phosphorus (P chemistry of pasture land and to compare the sensitivity of two soil extraction methods in assessing the P-loading risk. In a field experiment, urine and dung were added to soil in amounts corresponding to single excrement portions and the soil samples, taken at certain intervals, were analysed for pHH2O, acid ammonium acetate extractable P (PAc and water extractable total P (TPw, and molybdate reactive P (MRPw. Urine additions immediately increased soil pH and MRPw, but no such response was observed in PAc extraction due to the low pH (4.65 of the extractant enhancing the resorption of P. The PAc responded to the dunginduced increase in soil total P similarly as did Pw, which suggests that both tests can serve to detect areas of high P concentration. However, water extraction was a more sensitive method for estimating short-term changes in P solubility. In pasture soils, the risk of P loss increases as a result of the interaction of urination and high P concentration in the topsoil resulting from continuous dung excretion.;

Nonimaging light concentration using total internal reflection films.

Science.gov (United States)

Ouellette, G; Waltham, C E; Drees, R M; Poon, A; Schubank, R; Whitehead, L A

1992-05-01

We present a method of fabricating nonimaging light concentrators from total internal reflection film. A prototype has been made and tested and found to operate in agreement with predictions of ray-tracing codes. The performance of the prototype is comparable with that of concentrators made from specular reflecting materials.

Influence of the calcium concentration in the presence of organic phosphorus on the physicochemical compatibility and stability of all-in-one admixtures for neonatal use

Directory of Open Access Journals (Sweden)

de Sousa Valeria

2009-10-01

Full Text Available Abstract Background Preterm infants need high amounts of calcium and phosphorus for bone mineralization, which is difficult to obtain with parenteral feeding due to the low solubility of these salts. The objective of this study was to evaluate the physicochemical compatibility of high concentrations of calcium associated with organic phosphate and its influence on the stability of AIO admixtures for neonatal use. Methods Three TPN admixture formulas were prepared in multilayered bags. The calcium content of the admixtures was adjusted to 0, 46.5 or 93 mg/100 ml in the presence of a fixed organic phosphate concentration as well as lipids, amino acids, inorganic salts, glucose, vitamins and oligoelements at pH 5.5. Each admixture was stored at 4°C, 25°C or 37°C and evaluated over a period of 7 days. The physicochemical stability parameters evaluated were visual aspect, pH, sterility, osmolality, peroxide formation, precipitation, and the size of lipid globules. Results Color alterations occurred from the first day on, and reversible lipid film formation from the third day of study for the admixtures stored at 25°C and 37°C. According to the parameters evaluated, the admixtures were stable at 4°C; and none of them presented precipitated particles due to calcium/phosphate incompatibility or lipid globules larger than 5 μm, which is the main parameter currently used to evaluate lipid emulsion stability. The admixtures maintained low peroxide levels and osmolarity was appropriate for parenteral administration. Conclusion The total calcium and calcium/phosphorus ratios studied appeared not to influence the physicochemical compatibility and stability of AIO admixtures.

Preparation of phosphorus targets using the compound phosphorus nitride

International Nuclear Information System (INIS)

Maier-Komor, P.

1987-01-01

Commercially available phosphorus nitride (P 3 N 5 ) shows a high oxygen content. Nevertheless, this material is attractive for use as phosphorus targets in experiments where red phosphorus would disappear due to its high vapor pressure and where a metal partner in the phosphide must be excluded due to its high atomic number. Methods are described to produce phosphorus nitride targets by vacuum evaporation condensation. (orig.)

Effect of phosphorus and zinc on growth and their uptake in hybrid maize grown in a calcareous alluvial soil

International Nuclear Information System (INIS)

Parik, B.L.; Santikari, A.K.; Das, S.K.; Chowdhury, B.

1977-01-01

Hybrid maize (Zea mays L., var. Ganga 101) was grown in glasshouse at different levels of phosphorus with and without zinc, in a calcareous alluvial soil of North Bihar. Phosphorus was applied at 0, 11, 22, 44 and 88 ppm as tagged P in single superphosphats. Zinc was applied at 0 and 10 ppm as 65 ZnCl 2 . Application of phosphorus and zinc significantly increased the dry matter yield up to P 44 . Higher dose of P resulted in depressed growth accompanied by decreased zinc concentration and uptake by plants, exhibiting zinc deficiency symptoms. Higher levels of P and Zn increased their concentrations in the plant, but their total uptake was reduced at P 88 . With higher levels of P the percent utilization of fertilizer P decreased, while in zinc treated soils uptake of fertilizer P increased. Percent utilization of added zinc increased with increase in P levels upto P 44 and decreased thereafter, although at this level of P a greater percentage of zinc was derived from the fertilizer. (author)

Water quality, hydrology, and simulated response to changes in phosphorus loading of Mercer Lake, Iron County, Wisconsin, with special emphasis on the effects of wastewater discharges

Science.gov (United States)

Robertson, Dale M.; Garn, Herbert S.; Rose, William J.; Juckem, Paul F.; Reneau, Paul C.

2012-01-01

Mercer Lake is a relatively shallow drainage lake in north-central Wisconsin. The area near the lake has gone through many changes over the past century, including urbanization and industrial development. To try to improve the water quality of the lake, actions have been taken, such as removal of the lumber mill and diversion of all effluent from the sewage treatment plant away from the lake; however, it is uncertain how these actions have affected water quality. Mercer Lake area residents and authorities would like to continue to try to improve the water quality of the lake; however, they would like to place their efforts in the actions that will have the most beneficial effects. To provide a better understanding of the factors affecting the water quality of Mercer Lake, a detailed study of the lake and its watershed was conducted by the U.S. Geological Survey in collaboration with the Mercer Lake Association. The purposes of the study were to describe the water quality of the lake and the composition of its sediments; quantify the sources of water and phosphorus loading to the lake, including sources associated with wastewater discharges; and evaluate the effects of past and future changes in phosphorus inputs on the water quality of the lake using eutrophication models (models that simulate changes in phosphorus and algae concentrations and water clarity in the lake). Based on analyses of sediment cores and monitoring data collected from the lake, the water quality of Mercer Lake appears to have degraded as a result of the activities in its watershed over the past 100 years. The water quality appears to have improved, however, since a sewage treatment plant was constructed in 1965 and its effluent was routed away from the lake in 1995. Since 2000, when a more consistent monitoring program began, the water quality of the lake appears to have changed very little. During the two monitoring years (MY) 2008-09, the average summer near-surface concentration of total

Estimating total maximum daily loads with the Stochastic Empirical Loading and Dilution Model

Science.gov (United States)

Granato, Gregory; Jones, Susan Cheung

2017-01-01

The Massachusetts Department of Transportation (DOT) and the Rhode Island DOT are assessing and addressing roadway contributions to total maximum daily loads (TMDLs). Example analyses for total nitrogen, total phosphorus, suspended sediment, and total zinc in highway runoff were done by the U.S. Geological Survey in cooperation with FHWA to simulate long-term annual loads for TMDL analyses with the stochastic empirical loading and dilution model known as SELDM. Concentration statistics from 19 highway runoff monitoring sites in Massachusetts were used with precipitation statistics from 11 long-term monitoring sites to simulate long-term pavement yields (loads per unit area). Highway sites were stratified by traffic volume or surrounding land use to calculate concentration statistics for rural roads, low-volume highways, high-volume highways, and ultraurban highways. The median of the event mean concentration statistics in each traffic volume category was used to simulate annual yields from pavement for a 29- or 30-year period. Long-term average yields for total nitrogen, phosphorus, and zinc from rural roads are lower than yields from the other categories, but yields of sediment are higher than for the low-volume highways. The average yields of the selected water quality constituents from high-volume highways are 1.35 to 2.52 times the associated yields from low-volume highways. The average yields of the selected constituents from ultraurban highways are 1.52 to 3.46 times the associated yields from high-volume highways. Example simulations indicate that both concentration reduction and flow reduction by structural best management practices are crucial for reducing runoff yields.

Total protein and cholesterol concentrations in brain regions of male ...

African Journals Online (AJOL)

The results showed similarities (P>0.05) between the treatments in total protein concentrations in the cerebral cortex, medulla, hypothalamus, amygdala, mesencephalon and hippocampus. Total protein concentrations however differed significantly between diets (P<0.05) in the cerebellum and pons varoli with the lowest ...

Fungicide application and phosphorus uptake by hyphae of arbuscular mycorrhizal fungi into field-grown peas

DEFF Research Database (Denmark)

Schweiger, P.F.; Spliid, N.H.; Jakobsen, I.

2001-01-01

The effect of two commercial fungicide formulations on phosphorus (P) uptake into peas via hyphae of a native arbuscular mycorrhizal (AM) fungal community was examined in the field. The fungicides contained carbendazim or a mixture of propiconazole and fenpropimorph as their active ingredients...... from overall P uptake, Fungicides were added to the soil inside the HCs at concentrations assumed to reflect their concentration in the surrounding soil. At two harvests, plant growth, total P and P-32 uptake as well as root length density and AM root colonisation were measured. Length of hyphae inside...

Contributions of systematic tile drainage to watershed-scale phosphorus transport.

Science.gov (United States)

King, Kevin W; Williams, Mark R; Fausey, Norman R

2015-03-01

Phosphorus (P) transport from agricultural fields continues to be a focal point for addressing harmful algal blooms and nuisance algae in freshwater systems throughout the world. In humid, poorly drained regions, attention has turned to P delivery through subsurface tile drainage. However, research on the contributions of tile drainage to watershed-scale P losses is limited. The objective of this study was to evaluate long-term P movement through tile drainage and its manifestation at the watershed outlet. Discharge data and associated P concentrations were collected for 8 yr (2005-2012) from six tile drains and from the watershed outlet of a headwater watershed within the Upper Big Walnut Creek watershed in central Ohio. Results showed that tile drainage accounted for 47% of the discharge, 48% of the dissolved P, and 40% of the total P exported from the watershed. Average annual total P loss from the watershed was 0.98 kg ha, and annual total P loss from the six tile drains was 0.48 kg ha. Phosphorus loads in tile and watershed discharge tended to be greater in the winter, spring, and fall, whereas P concentrations were greatest in the summer. Over the 8-yr study, P transported in tile drains represented 90% of all measured concentrations exceeded recommended levels (0.03 mg L) for minimizing harmful algal blooms and nuisance algae. Thus, the results of this study show that in systematically tile-drained headwater watersheds, the amount of P delivered to surface waters via tile drains cannot be dismissed. Given the amount of P loss relative to typical application rates, development and implementation of best management practices (BMPs) must jointly consider economic and environmental benefits. Specifically, implementation of BMPs should focus on late fall, winter, and early spring seasons when most P loading occurs. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Molybdenum blue reaction and determination of phosphorus in waters containing arsenic, silicon, and germanium

Science.gov (United States)

Levine, H.; Rowe, J.J.; Grimaldi, F.S.

1955-01-01

Microgram amounts of phosphate are usually determined by the molybdenum blue reaction, but this reaction is not specific for phosphorus. The research established the range of conditions under which phosphate, arsenate, silicate, and germanate give the molybdenum blue reaction for differentiating these elements, and developed a method for the determination of phosphate in waters containing up to 10 p.p.m. of the oxides of germanium, arsenic(V), and silicon. With stannous chloride or 1-amino-2-naphthol-4-sulfonic acid as the reducing agent no conditions were found for distinguishing silicate from germanate and phosphate from arsenate. In the recommended procedure the phosphate is concentrated by coprecipitation on aluminum hydroxide, and coprecipitated arsenic, germanium, and silicon are volatilized by a mixture of hydrofluoric, hydrochloric, and hydrobromic acids prior to the determination of phosphate. The authors are able to report that the total phosphorus content of several samples of sea water from the Gulf of Mexico ranged from 0.018 to 0.059 mg. of phosphorus pentoxide per liter of water.

Effects of P-efficient Transgenic Rice OsPT4 on Inorganic Phosphorus Fractions in Red Soil

Directory of Open Access Journals (Sweden)

WEI Lin-lin

2017-08-01

Full Text Available In a rhizobox experiment with phosphorus(P fertilizer application and P-deficiency, planting wild-type rice(Nipp, P-efficient mutant rice(PHO2, P-efficient transgenic rice(OsPT4 were chosen to evaluate effects of phosphorus efficient transgenic rice on inorganic phosphorus in the rhizosphere and non-rhizosphere soil. The obtained results were summarized as follows:(1Significant higer dry weight and P accumulation were observed in OsPT4 and PHO2 than in Nipp, but lower total P and inorganic phosphorus observed in OsPT4 and PHO2 than in Nipp;(2The concentrations of inorganic phosphorus fractions in the rhizosphere and non-rhizosphere soil were sorted as follows:O-P > Fe-P > Al-P > Ca-P, and the order of inorganic phosphorus fractions adapted to three rice materials;(3When added phosphorus fertilizer, the concents of rhizospheric Al-P, Fe-P and non-rhizospheric Ca-P in three rice materials had no significant difference. The concents of rhizospheric soil O-P and Ca-P in OsPT4 and PHO2 were significantly inferior to Nipp, and their concents of non-rhizospheric soil Al-P, Fe-P and O-P were significantly lower than Nipp. When added no phosphorus fertilizer, the concents of rhizospheric Al-P, O-P, Ca-P and non-rhizosphere Al-P, Ca-P in three rice materials had no significant difference, and the concents of rhizosphere Fe-P and non-rhizosphere soil Fe-P, O-P in OsPT4 and PHO2 were significantly lower than Nipp, but rhizosphere Ca-P was significantly higher than Nipp.

Concentration changeability of phosphorus, calcium and magnesium in selected partial drainage basins of the River Drwęca

Directory of Open Access Journals (Sweden)

Pius Bożena

2015-12-01

Full Text Available The paper presents the results of the research conducted between November 2008 and October 2009. The research included seasonal dynamics of the flow and runoff of phosphorus compounds (TP and P-PO43-, as well as Ca2+ and Mg2+ from 13 partial drainage basins of the River Drwęca. Water levels were registered automatically every day by recorders, and measurements of the flow were conducted once a month. Major differences were found in the water abundance as indicated by specific discharges in individual, partial drainage basins: from 1.87 dm3 s-1 km-2 (Lubianka - a lower part of the River Drwęca drainage basin to 8.22 dm3 s-1 km-2 (Gizela - an upper part of the River Drwęca drainage basin. The studied rivers were characterised by very diverse average content of total phosphorus compounds: from 0.047 mg dm-3 (Iłga to 0.816 mg dm-3 (Sandela; calcium: from 47.18 mg dm-3 (Iłga to 131.65 mg dm-3 (Trynka; and magnesium: from 9.71 mg dm-3 (Wel to 36.76 mg dm-3 (Struga Rychnowska. Analysis of variance carried out on hydrochemical properties of the studied rivers divides the rivers into two separate groups: rivers with much higher content of phosphorus, calcium and magnesium compounds (Struga Rychnowska, Trynka, Ruziec, Lubianka, Kujawka, Sandela and Gizela, and a group of rivers with low content of these compounds (Brynica, Brodniczanka, Skarlanka, Wel, Iłga.

PHOSPHORUS CONTAMINATION AS A BARRIER TO WATER QUALITY OF SMALL RETENTION RESERVOIRS IN PODLASIE REGION

Directory of Open Access Journals (Sweden)

Joanna Ewa Szczykowska

2016-06-01

Full Text Available Dam retention reservoirs created on the rivers play a special role as an environmentally friendly forms of stopping and slowing of water runoff. The aim of this study was to evaluate the quality of water flowing into small retention reservoirs in terms of the concentration of total phosphorus and phosphates. The study involved three small retention reservoirs located in the municipalities of: Bransk, Dubicze Cerkiewne and Kleszczele in Podlasie region. Selection of the research facilities was made due to the similarity in the soil management type within catchment of the flowing watercourse, retained water utilization ways, and a small surface of reservoirs. Watercourse reaching the reservoir provides biogens along with water, which directly affect the water quality resulting in high concentrations in water, either indirectly by initiating or accelerating the process of degradation of the reservoir and the loss of its usability. Given the concentration of total phosphorus, it can be said that only in the case of 20.8% of water samples from Nurzec river feeding the Otapy-Kiersnówek reservoir, about 25% of water samples of Orlanka river feeding Bachmaty reservoir, and 17% of samples taken from the watercourse supplying Repczyce reservoir, corresponded to values specified for the second class in the current Regulation of the Minister of the Environment [Regulation 2014]. It can be assumed that this situation is caused by a long-term fertilization using manure, which in consequence led to the oversaturation of soils and phosphorus compounds penetration into the river waters in areas used for agricultural purposes. Especially in the early spring periods, rising temperature together with rainfall caused soil thawing resulting in increasing concentrations of contaminants carried along with the washed soil particles during the surface and subsurface runoff. Values of TSI(TP calculated for Otapy-Kiersnówek reservoir amounted to 112.4 in hydrological

Inverse-model estimates of the ocean's coupled phosphorus, silicon, and iron cycles

Directory of Open Access Journals (Sweden)

B. Pasquier

2017-09-01

Full Text Available The ocean's nutrient cycles are important for the carbon balance of the climate system and for shaping the ocean's distribution of dissolved elements. Dissolved iron (dFe is a key limiting micronutrient, but iron scavenging is observationally poorly constrained, leading to large uncertainties in the external sources of iron and hence in the state of the marine iron cycle. Here we build a steady-state model of the ocean's coupled phosphorus, silicon, and iron cycles embedded in a data-assimilated steady-state global ocean circulation. The model includes the redissolution of scavenged iron, parameterization of subgrid topography, and small, large, and diatom phytoplankton functional classes. Phytoplankton concentrations are implicitly represented in the parameterization of biological nutrient utilization through an equilibrium logistic model. Our formulation thus has only three coupled nutrient tracers, the three-dimensional distributions of which are found using a Newton solver. The very efficient numerics allow us to use the model in inverse mode to objectively constrain many biogeochemical parameters by minimizing the mismatch between modeled and observed nutrient and phytoplankton concentrations. Iron source and sink parameters cannot jointly be optimized because of local compensation between regeneration, recycling, and scavenging. We therefore consider a family of possible state estimates corresponding to a wide range of external iron source strengths. All state estimates have a similar mismatch with the observed nutrient concentrations and very similar large-scale dFe distributions. However, the relative contributions of aeolian, sedimentary, and hydrothermal iron to the total dFe concentration differ widely depending on the sources. Both the magnitude and pattern of the phosphorus and opal exports are well constrained, with global values of 8. 1  ±  0. 3 Tmol P yr−1 (or, in carbon units, 10. 3  ±  0. 4�

Defects in heavily phosphorus-doped Si epitaxial films probed by monoenergetic positron beams

International Nuclear Information System (INIS)

Uedono, Akira; Tanigawa, Shoichiro; Suzuki, Ryoichi; Ohgaki, Hideaki; Mikado, Tomohisa.

1994-01-01

Vacancy-type defects in heavily phosphorus-doped Si epitaxial films were probed by monoenergetic positron beams. Doppler broadening profiles of the annihilation radiation and lifetime spectra of positrons were measured for the epitaxial films grown on the Si substrates by plasma chemical vapor deposition. For the as-deposited film, divacancy-phosphorus complexes were found with high concentration. After 600degC annealing, vacancy clusters were formed near the Si/Si interface, while no drastic change in the depth distribution of the divacancy-phosphorus complexes was observed. By 900degC annealing, the vacancy clusters were annealed out; however, the average number of phosphorus atoms coupled with divacancies increased. The relationship between the vacancy-type defects probed by the positron annihilation technique and the carrier concentration was confirmed. (author)

Defects in heavily phosphorus-doped Si epitaxial films probed by monoenergetic positron beams

Energy Technology Data Exchange (ETDEWEB)

Uedono, Akira; Tanigawa, Shoichiro [Tsukuba Univ., Ibaraki (Japan). Inst. of Materials Science; Suzuki, Ryoichi; Ohgaki, Hideaki; Mikado, Tomohisa

1994-11-01

Vacancy-type defects in heavily phosphorus-doped Si epitaxial films were probed by monoenergetic positron beams. Doppler broadening profiles of the annihilation radiation and lifetime spectra of positrons were measured for the epitaxial films grown on the Si substrates by plasma chemical vapor deposition. For the as-deposited film, divacancy-phosphorus complexes were found with high concentration. After 600degC annealing, vacancy clusters were formed near the Si/Si interface, while no drastic change in the depth distribution of the divacancy-phosphorus complexes was observed. By 900degC annealing, the vacancy clusters were annealed out; however, the average number of phosphorus atoms coupled with divacancies increased. The relationship between the vacancy-type defects probed by the positron annihilation technique and the carrier concentration was confirmed. (author).

Sedimentary deposition and reflux of phosphorus (P in the Eastern Gotland Basin and their coupling with P concentrations in the water column

Directory of Open Access Journals (Sweden)

Sven Hille

2005-12-01

Full Text Available In order to describe the role of sedimentary processes for the phosphorus (P cycle in the open Baltic Proper, P deposition and reflux were quantified for the predominately anoxic sediments of the Eastern Gotland Basin. The study is based on investigations of 53 surface sediment samples and pore water samples from 8 sediment cores. The average P deposition rate was estimated at 0.20 g ± 0.18 g -2 yr-1, the fluctuation being due to variable bulk sediment deposition rates. P refluxes were estimated by applying Fick's First Law of Diffusion. A fairly good positive correlation between sedimentary P deposition and P release was obtained. P release from sediments by diffusion exceeds net P deposition by a factor of 2. This suggests that 2/3 of the deposited gross P is recycled in the sediments and released back into the water column; only 1/3 remains in the sediment permanently. A budget calculation demonstrates that the released dissolved inorganic phosphorus (DIP accounts for the observed increase in DIP concentrations in the deep water during periods of stagnation, which is noticeable even at the surface P concentrations. Under such conditions and with the present remediation conditions it is not possible to freely manage P concentrations in the water column on short time scales.

Sustainable Phosphorus Measures: Strategies and Technologies for Achieving Phosphorus Security

Directory of Open Access Journals (Sweden)

Stuart White

2013-01-01

Full Text Available Phosphorus underpins the world’s food systems by ensuring soil fertility, maximising crop yields, supporting farmer livelihoods and ultimately food security. Yet increasing concerns around long-term availability and accessibility of the world’s main source of phosphorus—phosphate rock, means there is a need to investigate sustainable measures to buffer the world’s food systems against the long and short-term impacts of global phosphorus scarcity. While the timeline of phosphorus scarcity is contested, there is consensus that more efficient use and recycling of phosphorus is required. While the agricultural sector will be crucial in achieving this, sustainable phosphorus measures in sectors upstream and downstream of agriculture from mine to fork will also need to be addressed. This paper presents a comprehensive classification of all potential phosphorus supply- and demand-side measures to meet long-term phosphorus needs for food production. Examples range from increasing efficiency in the agricultural and mining sector, to technologies for recovering phosphorus from urine and food waste. Such measures are often undertaken in isolation from one another rather than linked in an integrated strategy. This integrated approach will enable scientists and policy-makers to take a systematic approach when identifying potential sustainable phosphorus measures. If a systematic approach is not taken, there is a risk of inappropriate investment in research and implementation of technologies and that will not ultimately ensure sufficient access to phosphorus to produce food in the future. The paper concludes by introducing a framework to assess and compare sustainable phosphorus measures and to determine the least cost options in a given context.

On the use of 31P NMR for the quantification of hydrosoluble phosphorus-containing compounds in coral host tissues and cultured zooxanthellae

Science.gov (United States)

Godinot, Claire; Gaysinski, Marc; Thomas, Olivier P.; Ferrier-Pagès, Christine; Grover, Renaud

2016-02-01

31P Nuclear Magnetic Resonance (NMR) was assessed to investigate the phosphorus-containing compounds present in the tissues of the scleractinian coral Stylophora pistillata as well as of cultured zooxanthellae (CZ). Results showed that phosphorus-containing compounds observed in CZ were mainly phosphate and phosphate esters. Phosphate accounted for 19 ± 2% of the total phosphorus compounds observed in CZ maintained under low P-levels (0.02 μM). Adding 5 mM of dissolved inorganic phosphorus (KH2PO4) to the CZ culture medium led to a 3.1-fold increase in intracellular phosphate, while adding 5 mM of dissolved organic phosphorus led to a reduction in the concentration of phosphorus compounds, including a 2.5-fold intracellular phosphate decrease. In sharp contrast to zooxanthellae, the host mainly contained phosphonates, and to a lesser extent, phosphate esters and phosphate. Two-months of host starvation decreased the phosphate content by 2.4 fold, while bleaching of fed corals did not modify this content. Based on 31P NMR analyses, this study highlights the importance of phosphonates in the composition of coral host tissues, and illustrates the impact of phosphorus availability on the phosphorus composition of host tissues and CZ, both through feeding of the host and inorganic phosphorus enrichment of the CZ.

Management of Natural and Added Dietary Phosphorus Burden in Kidney Disease

Science.gov (United States)

Cupisti, Adamasco; Kalantar-Zadeh, Kamyar

2018-01-01

Phosphorus retention occurs from higher dietary phosphorus intake relative to its renal excretion or dialysis removal. In the gastrointestinal tract the naturally existing organic phosphorus is only partially (~60%) absorbable; however, this absorption varies widely and is lower for plant-based phosphorus including phytate (80%). The latter phosphorus often remains unrecognized by patients and health care professionals, even though it is widely used in contemporary diets, in particular low-cost foods. In a non-enhanced mixed diet, the digestible phosphorus is closely correlated with total protein content, making protein-rich foods a main source of natural phosphorus. Phosphorus burden is more appropriately limited in pre-dialysis patients who are on low protein diets (~0.6 g/kg/day), whereas dialysis patients who require higher protein intake (~1.2 g/kg/day) are subject to a higher dietary phosphorus load. An effective and patient-friendly approach to reduce phosphorus intake without depriving patients of adequate proteins is to educate patients to avoid foods with high phosphorus relative to protein such as egg yolk and those with high amounts of phosphorus-based preservatives such as certain soft drinks and enhanced cheese and meat. Protein-rich foods should be prepared by boiling, which reduces phosphorus as well as sodium and potassium content, or by other types of cooking induced demineralization. The dose of phosphorus-binding therapy should be adjusted separately for the amount and absorbability of phosphorus in each meal. Dietician counselling to address the foregoing aspects of dietary phosphorus management is instrumental for achieving reduction of phosphorus load. PMID:23465504

Weather conditions influencing phosphorus concentration in the growing period in the large shallow Lake Peipsi (Estonia/Russia

Directory of Open Access Journals (Sweden)

Olga Tammeorg

2014-01-01

Full Text Available The impact of water temperature (T, water level (L, photosynthetically active radiation (PAR, and wind speed (V on the total phosphorus concentration (TP in shallow eutrophic lake Peipsi, the fourth largest lake in Europe, was studied. We used a long-term dataset (1985-2010 of TP concentrations and weather factors. A Thin Plate Spline (TPS model was used to predict TP by year, by day of the year, and by geographical coordinates. Deviations between observed and predicted TP values (residuals, or TP anomalies were related to the weather variables to clarify how the weather anomalies in a year might correlate with the observed fluctuations in TP dynamics. Notable seasonal variations in TP, typical for many shallow lake systems, were found: TP was two to three times higher during late summer-early autumn than during winter. Patterns of TP variability were well predicted by using geographical coordinates, year and day of the year (R2=0.69; P<0.0001. However, TP anomalies were ascribed to the effects of T, L, PAR, and V, which were proved to play a significant additional role in TP dynamics. Moreover, L had consistently negative effects over the year, whereas the effects of T and PAR on TP change were seen to be dependent on the season. TP anomalies in lake Peipsi were most sensitive to wind anomalies. V was associated with frequent switches between increasing and decreasing TP values, though it appeared mainly as a negative driver of TP anomalies in the season prior to the 180th day, and as a positive driver in the subsequent season.

Effect of Low Dose Gamma Radiation Upon the Concentration of Calcium and Inorganic Phosphorus in the Blood Plasma of Chickens

International Nuclear Information System (INIS)

Kraljevic, P.; Vilic, M.; Miljanic, S.; Simpraga, M.

2003-01-01

In our previous paper it has been showed that the irradiation of chickens eggs before incubation by low dose gamma irradiation effects upon growth of the chickens hatched from irradiated eggs as well as upon activity of ALT and AST, and on the concentration of total proteins, glucose and cholesterol in the blood plasma of those chickens. Therefore in this paper an attempt was made to determine the effects of irradiation of eggs by low dose of ionizing radiation on the 19th day of incubation upon the concentration of calcium (Ca) and inorganic phosphorus (P) in the blood plasma of chickens hatched from irradiated eggs. The eggs of heavy breeding chickens (Gent, line COBB 500) were irradiated by a dose of 0.15 Gy gamma radiation (6 0C o source) on the 19th day of incubation. Along with the chickens, which were hatched from irradiated eggs, there was a control group of chickens hatched from nonirradiated eggs. All other conditions were the same for both groups. After hatching, blood samples were taken on day 1, 3, 5, 7, 10, 20, 30 and 42. The concentration of Ca was determined calorimetrically using Randox optimized kits, while the concentration of P was determined by Herbos dijagnostika Sisak (Croatia) optimized kits. The concentration of Ca in the blood plasma of chickens hatched from irradiated eggs was significantly increased on the first day, while it was decreased on the day 42. The concentration of P was decreased on the first day in blood plasma of chickens hatched from irradiated eggs. The fact that the concentration of both minerals in blood plasma of chickens hatched from irradiated eggs was significantly changed on the first day proves that the irradiation of eggs by low dose of ionizing radiation on the nineteenth day of incubation had an effect on metabolism of both minerals in those chickens. (author)

Dietary phosphorus requirement of pejerrey fingerlings (Odontesthes bonariensis

Directory of Open Access Journals (Sweden)

Cleber Bastos Rocha

2014-02-01

Full Text Available To determine the available phosphorus requirement of pejerrey fish, four semi-purified diets were formulated to contain increasing available phosphorus levels (0.90, 2.7, 5.7 and 8.3 g/kg. Each diet was assigned to groups of 10 fish with average weight of 1.26±0.17 g, distributed into a completely randomized design with four treatments and four replications. Fish were fed at a rate of 10% total biomass four times a day for 60 days. The parameters productive performance, body chemical composition and mineral composition of bones and scales were evaluated. The best productive performance of fingerlings was obtained with the diet containing 4.3 g/kg available phosphorus. The average level of 6.3 g/kg available phosphorus promotes better mineralization of bones and scales in pejerrey fish.

Phosphorus and nitrogen in the eutrophication of waters

International Nuclear Information System (INIS)

Salonen, S.; Frisk, T.; Kaermeniemi, T.; Niemi, J.; Pitkaenen, H.; Silvo, K.; Vuoristo, H.

1992-01-01

This report is a summary of the contribution of nitrogen and phosphorus in the eutrophication process of inland and coastal waters. Special attention was paid to the mechanisms of these nutrients in regulating biological processes and to the methods available in estimating their effects in the eutrophication of water bodies. The report includes five chapters which are entitled: Introduction, which is a general background to the subject with special attention to the requirements of the Finnish Water Act. Phosphorus and nitrogen as factors regulating biological processes. The topics included are: definition of eutrophication, forms of phosphorus and nitrogen and their sources to inland and coastal waters, effects of these nutrients as growth factors of phytoplankton and macrophytes and consequences of eutrophication. Estimation of the effects of phosphorus and nitrogen. The topics discussed from the point of view of the tasks of the National Board of Waters and the Environment are: estimation of the effects of phosphorus and nitrogen in the planning and supervision of industry, fish farming, peat production, municipalities, agriculture and forestry. A brief state-of-the art of the research carried out in the National Board of Waters and the Environment is given. Methods of estimating the effects of phosphorus and nitrogen loading in waters. The topics are: relationships between phosphorus and nitrogen concentrations in waters, material balances, water quality models, classification of waters and different groups of organisms as indicators of water quality. Conclusions for the estimation of the effects of phosphorus and nitrogen in receiving waters

Temporal variability in phosphorus transfers: classifying concentration-discharge event dynamics

Science.gov (United States)

Haygarth, P.; Turner, B. L.; Fraser, A.; Jarvis, S.; Harrod, T.; Nash, D.; Halliwell, D.; Page, T.; Beven, K.

The importance of temporal variability in relationships between phosphorus (P) concentration (Cp) and discharge (Q) is linked to a simple means of classifying the circumstances of Cp-Q relationships in terms of functional types of response. New experimental data at the upstream interface of grassland soil and catchment systems at a range of scales (lysimeters to headwaters) in England and Australia are used to demonstrate the potential of such an approach. Three types of event are defined as Types 1-3, depending on whether the relative change in Q exceeds the relative change in Cp (Type 1), whether Cp and Q are positively inter-related (Type 2) and whether Cp varies yet Q is unchanged (Type 3). The classification helps to characterise circumstances that can be explained mechanistically in relation to (i) the scale of the study (with a tendency towards Type 1 in small scale lysimeters), (ii) the form of P with a tendency for Type 1 for soluble (i.e., <0.45 μm P forms) and (iii) the sources of P with Type 3 dominant where P availability overrides transport controls. This simple framework provides a basis for development of a more complex and quantitative classification of Cp-Q relationships that can be developed further to contribute to future models of P transfer and delivery from slope to stream. Studies that evaluate the temporal dynamics of the transfer of P are currently grossly under-represented in comparison with models based on static/spatial factors.

Use of water quality surrogates to estimate total phosphorus concentrations in Iowa rivers

Directory of Open Access Journals (Sweden)

Keith E. Schilling

2017-08-01

New hydrological insights for the region: TP concentrations were highly correlated to turbidity (0.78 ± 0.20 and OP (0.69 ± 0.13 across all sites and less correlated to chlorophyll a (0.07 ± 0.15, chloride (−0.10 ± 0.24 and discharge (0.41 ± 0.23. When the regression models included OP as a variable, the mean r2 for all 43 sites was 0.90 ± 0.08 and ten of the 43 sites had r2 values greater than 0.95. When OP was excluded in the regression model, the overall mean r2 values decreased to 0.72 ± 0.14 and for six of the river sites, the r2 value decreased by 50%. Other variables (discharge, chlorophyll a, chloride were included in the regression equations on a case-by-case basis. Including OP in the regression models was critically important for rivers draining the tile-drained Des Moines Lobe region.

Investigations of different doping concentration of phosphorus and boron into silicon substrate on the variable temperature Raman characteristics

Science.gov (United States)

Li, Xiaoli; Ding, Kai; Liu, Jian; Gao, Junxuan; Zhang, Weifeng

2018-01-01

Different doped silicon substrates have different device applications and have been used to fabricate solar panels and large scale integrated circuits. The thermal transport in silicon substrates are dominated by lattice vibrations, doping type, and doping concentration. In this paper, a variable-temperature Raman spectroscopic system is applied to record the frequency and linewidth changes of the silicon peak at 520 cm-1 in five chips of silicon substrate with different doping concentration of phosphorus and boron at the 83K to 1473K temperature range. The doping has better heat sensitive to temperature on the frequency shift over the low temperature range from 83K to 300K but on FWHM in high temperature range from 300K to 1473K. The results will be helpful for fundamental study and practical applications of silicon substrates.

Phosphorus utilization by three rice varieties at different stages of growth in a vertisol

International Nuclear Information System (INIS)

Rastogi, A.K.; Mahajan, J.P.; Sinha, S.B.

1981-01-01

A pot experiment was conducted using labelled superphosphate to study the utilization of applied fertilizer phosphorus by three rice varieties, viz., Jaya, Ratna and Sona at tillering, flowering and harvesting stages. Total phosphorus uptake and phosphorus derived from fertilizer increased significantly with increasing level of phosphorus, but per cent utilization of applied phosphorus showed a reverse trend in all the three varieties at all the growth stages. Dry matter yield in general, increased significantly with increasing P levels in all the three varieties. Average soil-p uptake decreased with increasing levels of phosphorus at all the stages. (author)

Non-protein nitrogen and reduced phosphorus supply to sheep. 1. Phosphorus, volatile fatty acids, NH3 and pH of rumen liquid and daily fluid and phosphorus outflow from the rumen

International Nuclear Information System (INIS)

Hoeller, H.; Breves, G.; Martens, H.

1983-01-01

Sheep were fitted with cannulas in the rumen and in the abomasum and fed a straw/pellet diet providing 29% of total N as urea-N. The diet was deficient in P, and daily P intake during P depletion was about 1.3g. Phosphorus repletion was obtained in the same sheep by daily infusion of 2.85gP as phosphoric acid into the abomasum. During experimental periods, Cr-EDTA and 15 N-urea were continuously infused into the rumen for five days. During the last two days, blood samples and a total of ten samples from both rumen and abomasum were taken. Three depletion and three repletion experiments were performed. The following significant changes were noted in the P-deficient state (means): blood plasma inorganic P fell from 2.38 to 0.67mmol/L and rumen liquid total P from 5.65 to 1.71mmol/L, i.e. both levels decreased by approximately 70%. Fluid outflow from the rumen was raised by about 10% but P outflow decreased by about 68%. NH 3 concentrations in rumen fluid increased from 3.60 to 7.51mmol/L whereas total VFA concentration was reduced from 125 to 100mmol/L. Average pH values changed from 6.06 to 6.56. It is suggested that P depletion led to reduced microbial growth and activity in the rumen although data on microbial protein outflow from the rumen are not yet available. (author)

Availability for plants of phosphorus in some virgin peat samples

Directory of Open Access Journals (Sweden)

Armi Kaila

1958-01-01

Full Text Available The availability to plants of native peat phosphorus was studied by chemical methods and by a pot experiment in which three successive oat crops were grown with peat as the only source of phosphorus. The eight samples were collected from virgin peat lands. They were air-dried and ground. The samples were found to represent three different types of phosphorus condition: the first group contained relatively high amounts of inorganic phosphorus which was fairly easily available; the second group had a very high capacity to fix phosphorus which made its high quantity of inorganic phosphorus difficultly available; the third group was very poor in total and inorganic phosphorus but the latter was easily soluble and available to plants. On the basis of the capacity and intensity factors determined according to the method by Teräsvuori and also on the basis of inorganic phosphorus extractable by water fairly reliable predictions could be made of the mutual order of the samples as phosphorus supplyer to the plants in the pot experiment. In an incubation experiment at 27°C the amounts of organic phosphorus mineralized during the period of four months were in some of the samples quite marked, even 40 mg/l, and in most of the samples they corresponded to 5 to 15 per cent of the organic phosphorus. The amounts of phosphorus taken up by the oat crops under the favourable conditions of the pot experiment varied from 11 to 60 mg/l or from 20 to 120 kg/ha.

Improving phosphorus availability in an acid soil using organic amendments produced from agroindustrial wastes.

Science.gov (United States)

Ch'ng, Huck Ywih; Ahmed, Osumanu Haruna; Majid, Nik Muhamad Ab

2014-01-01

In acid soils, soluble inorganic phosphorus is fixed by aluminium and iron. To overcome this problem, acid soils are limed to fix aluminium and iron but this practice is not economical. The practice is also not environmentally friendly. This study was conducted to improve phosphorus availability using organic amendments (biochar and compost produced from chicken litter and pineapple leaves, resp.) to fix aluminium and iron instead of phosphorus. Amending soil with biochar or compost or a mixture of biochar and compost increased total phosphorus, available phosphorus, inorganic phosphorus fractions (soluble inorganic phosphorus, aluminium bound inorganic phosphorus, iron bound inorganic phosphorus, redundant soluble inorganic phosphorus, and calcium bound phosphorus), and organic phosphorus. This was possible because the organic amendments increased soil pH and reduced exchangeable acidity, exchangeable aluminium, and exchangeable iron. The findings suggest that the organic amendments altered soil chemical properties in a way that enhanced the availability of phosphorus in this study. The amendments effectively fixed aluminium and iron instead of phosphorus, thus rendering phosphorus available by keeping the inorganic phosphorus in a bioavailable labile phosphorus pool for a longer period compared with application of Triple Superphosphate without organic amendments.

Improving Phosphorus Availability in an Acid Soil Using Organic Amendments Produced from Agroindustrial Wastes

Directory of Open Access Journals (Sweden)

Huck Ywih Ch’ng

2014-01-01

Full Text Available In acid soils, soluble inorganic phosphorus is fixed by aluminium and iron. To overcome this problem, acid soils are limed to fix aluminium and iron but this practice is not economical. The practice is also not environmentally friendly. This study was conducted to improve phosphorus availability using organic amendments (biochar and compost produced from chicken litter and pineapple leaves, resp. to fix aluminium and iron instead of phosphorus. Amending soil with biochar or compost or a mixture of biochar and compost increased total phosphorus, available phosphorus, inorganic phosphorus fractions (soluble inorganic phosphorus, aluminium bound inorganic phosphorus, iron bound inorganic phosphorus, redundant soluble inorganic phosphorus, and calcium bound phosphorus, and organic phosphorus. This was possible because the organic amendments increased soil pH and reduced exchangeable acidity, exchangeable aluminium, and exchangeable iron. The findings suggest that the organic amendments altered soil chemical properties in a way that enhanced the availability of phosphorus in this study. The amendments effectively fixed aluminium and iron instead of phosphorus, thus rendering phosphorus available by keeping the inorganic phosphorus in a bioavailable labile phosphorus pool for a longer period compared with application of Triple Superphosphate without organic amendments.

The effect of molybdenum on the grain boundary segregation of phosphorus in steel

International Nuclear Information System (INIS)

Moller, R.; Brenner, S.S.; Grabke, A.J.

1986-01-01

The beneficial effect of molybdenum on the temper embrittlement of steels is well known but has not yet been satisfactorily explained. Yu and McMahon suggested a strong interaction between molybdenum and phosphorus to form Mo-P clusters which decrease the concentration of phosphorus in the matrix and consequently the amount segregated to grain boundaries. Such clusters have as yet not been observed but this may have been owing to the insufficient resolution of conventional analytical methods. However, since no scavenging of phosphorus was observed in carbon-free Fe-Mo-P alloys, i.e. Mo alone did not affect the grain boundary concentration of phosphorus, it is improbable that the Mo-P cluster formation mechanisms can be operative. Instead, it is more likely that a requisite for the scavenging of phosphorus is the formation of Mo carbides in the steel. This work was undertaken to determine the distribution of phosphorus in two similar Fe-Mo-P alloys, one of which contained carbon while the other was carbon-free. The emphasis of the study was to determine the interaction of phosphorus with molybdenum and molybdenum carbides in the steel. Field-ion microscopy combined with atom probe microanalysis was used for this purpose. The atom-by-atom sampling method and the near-atomic spatial resolution of the FIM/atom probe make this instrument ideally suited for this type of investigations

Water Quality in the Upper Anacostia River, Maryland: Continuous and Discrete Monitoring with Simulations to Estimate Concentrations and Yields, 2003-05

Science.gov (United States)

Miller, Cherie V.; Gutierrez-Magness, Angelica L.; Feit Majedi, Brenda L.; Foster, Gregory D.

2007-01-01

From 2003 through 2005, continuous and discrete waterquality data were collected at two stations on the Anacostia River in Maryland: Northeast Branch at Riverdale, Maryland (U.S. Geological Survey Station 01649500) and Northwest Branch near Hyattsville, Maryland (Station 01651000). Both stations are above the heads of tide for the river, and measurements approximately represent contributions of chemicals from the nontidal watersheds in the Anacostia River. This study was a cooperative effort between the U.S. Geological Survey, the Prince George's County Department of Environmental Resources, the Maryland Department of the Environment, the U.S. Environmental Protection Agency, and George Mason University. Samples were collected for suspended sediment, nutrients, and trace metals; data were used to calculate loads of selected chemical parameters, and to evaluate the sources and transport processes of contaminants. Enrichment factors were calculated for some trace metals and used to interpret patterns of occurrence over different flow regimes. Some metals, such as cadmium, lead, and zinc, were slightly enriched as compared to global averages for shales; overall, median values of enrichment factors for all metals were approximately 15 to 35. Stepwise linear regression models were developed on log-transformed concentrations to estimate the concentrations of suspended sediment, total nitrogen, and total phosphorus from continuous data of discharge and turbidity. The use of multiple explanatory variables improved the predictions over traditional rating curves that use only streamflow as the explanatory variable, because other variables such as turbidity measure the hysteretic effects of fine-grained suspended sediment over storm hydrographs. Estimates of the concentrations of suspended sediment from continuous discharge and turbidity showed coefficients of determination for the predictions (multiple R2) of 0.95 and biases of less than 4 percent. Models to estimate the

Phosphorus and groundwater: Establishing links between agricultural use and transport to streams

Science.gov (United States)

Domagalski, Joseph L.; Johnson, Henry

2012-01-01

Phosphorus is a highly reactive element that is essential for life and forms a variety of compounds in terrestrial and aquatic ecosystems. In water, phosphorus may be present as the orthophosphate ion (PO43-) and is also present in all life forms as an essential component of cellular material. In natural ecosystems, phosphorus is derived from the erosion of rocks and is conserved for plant growth as it is returned to the soil through animal waste and the decomposition of plant and animal tissue; but in agricultural systems, a portion of the phosphorus is removed with each harvest, especially since phosphorus is concentrated in the seeds and fruit. Phosphorus is added to soil by using chemical fertilizers, manure, and composted materials. Agricultural use of chemical phosphorus fertilizer, in the United States, in 2008 was 4,247,000 tons, which is an increase of 25 percent since 1964 (http://www.ers.usda.gov/Data/FertilizerUse/). Widely grown corn, soybeans, and wheat use the greatest amount of phosphorus fertilizer among agricultural crops.

Characterization and obtainment of phosphate rock concentrates of Turmequé, Boyacá

Science.gov (United States)

Zanguña, S. Quijano; Lozano Gómez, L. F.; Pineda Triana, Y.

2017-12-01

The work focuses on the use and exploitation of the mineral concentrates from phosphate rock (PR) coming from mines with a low percentage of phosphorus. The procedure was based on the collection of a source of phosphate rock from the department of Boyacá (municipality of Turmequé), using a randomized design with three replications. The samples were initially milled and sifted using meshes between 140 and 200 US standard, homogenizing them and improving the process of solubility of the phosphorus in the soil. We conduced Z-potential tests, which show that by performing a prior wash on the mineral and maintaining certain concentrations and pH defined, better results are achieved in terms of the buoyancy of the particles in the flotation process. The results obtained from the microflotation tests; both direct and inverse, and the results of chemical composition, with X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD), before and after the microflotation process, were carried out to obtain of commercial laws grade phosphate rock concentrate, confirm that the protocol used increases by 9% the value of total phosphorus in the collected sample. These concentrates from phosphate rock, could be used in the future for the attainment of simple superphosphate (SSP), with the help of sulphuric acid and ammonium thiosulphate mixtures.

Year-round atmospheric wet and dry deposition of nitrogen and phosphorus on water and land surfaces in Nanjing, China.

Science.gov (United States)

Sun, Liying; Li, Bo; Ma, Yuchun; Wang, Jinyang; Xiong, Zhengqin

2013-06-01

The dry deposition of ammonium, nitrate, and total phosphorus (TP) to both water (DW) and land (DD) surfaces, along with wet deposition, were simultaneously monitored from March 2009 to February 2011 in Nanjing, China. Results showed that wet deposition of total phosphorus was 1.1 kg phosphorus ha (-1)yr(-1), and inorganic nitrogen was 28.7 kg nitrogen ha (-1)yr(-1), with 43% being ammonium nitrogen. Dry deposition of ammonium, nitrate, and total phosphorus, measured by the DW/DD method, was 7.5/2.2 kg nitrogen ha (-1)yr(-1), 6.3/ 4.9 kg nitrogen ha (-1)yr(-1), and 1.9/0.4 kg phosphorus ha (-1)yr(-1), respectively. Significant differences between the DW and DD methods indicated that both methods should be employed simultaneously when analyzing deposition to aquatic and terrestrial ecosystems in watershed areas. The dry deposition of ammonium, nitrate, and total phosphorus contributed 38%, 28%, and 63%, respectively, to the total deposition in the simulated aquatic ecosystem; this has significance for the field of water eutrophication control.

Flux of nitrogen, phosphorus, and suspended sediment from the Susquehanna River Basin to the Chesapeake Bay during Tropical Storm Lee, September 2011, as an indicator of the effects of reservoir sedimentation on water quality

Science.gov (United States)

Hirsch, Robert M.

2012-01-01

Concentrations of nitrogen, phosphorus, and suspended sediment are measured at the U.S. Geological Survey streamgage at Conowingo Dam at the downstream end of the Susquehanna River Basin in Maryland, where the river flows into the Chesapeake Bay. During the period September 7-15, 2011, in the aftermath of Tropical Storm Lee, concentrations of these three constituents were among the highest ever measured at this site. These measurements indicate that sediment-storage processes behind the three dams on the lower Susquehanna River are evolving. In particular, they indicate that scouring of sediment (and the nitrogen and phosphorus attached to that sediment) may be increasing with time. Trends in flow-normalized fluxes at the Susquehanna River at Conowingo, Maryland, streamgage during 1996-2011 indicate a 3.2-percent decrease in total nitrogen, but a 55-percent increase in total phosphorus and a 97-percent increase in suspended sediment. These large increases in the flux of phosphorus and sediment from the Susquehanna River to the Chesapeake Bay have occurred despite reductions in the fluxes of these constituents from the Susquehanna River watershed upstream from the reservoirs. Although the Tropical Storm Lee flood event contributed about 1.8 percent of the total streamflow from the Susquehanna River to the Chesapeake Bay over the past decade (water years 2002-11), it contributed about 5 percent of the nitrogen, 22 percent of the phosphorus, and 39 percent of the suspended sediment during the same period. These results highlight the importance of brief high-flow events in releasing nitrogen, phosphorus, and sediment derived from the Susquehanna River watershed and stored in the Conowingo Reservoir to the Chesapeake Bay.

Evaluation of internal loading and water level changes: implications for phosphorus, algal production, and nuisance blooms in Kabetogama Lake, Voyageurs National Park, Minnesota

Science.gov (United States)

Christensen, Victoria G.; Maki, Ryan P.; Kiesling, Richard L.

2013-01-01

Hydrologic manipulations have the potential to exacerbate or remediate eutrophication in productive reservoirs. Dam operations at Kabetogama Lake, Minnesota, were modified in 2000 to restore a more natural water regime and improve water quality. The US Geological Survey and National Park Service evaluated nutrient, algae, and nuisance bloom data in relation to changes in Kabetogama Lake water levels. Comparison of the results of this study to previous studies indicates that chlorophyll a concentrations have decreased, whereas total phosphorus (TP) concentrations have not changed significantly since 2000. Water and sediment quality data were collected at Voyageurs National Park during 2008–2009 to assess internal phosphorus loading and determine whether loading is a factor affecting TP concentrations and algal productivity. Kabetogama Lake often was mixed vertically, except for occasional stratification measured in certain areas, including Lost Bay in the northeastern part of Kabetogama Lake. Stratification, higher bottom water and sediment nutrient concentrations than in other parts of the lake, and phosphorus release rates estimated from sediment core incubations indicated that Lost Bay is one of several areas that may be contributing to internal loading. Internal loading of TP is a concern because increased TP may cause excessive algal growth including potentially toxic cyanobacteria.

[Soil Phosphorus Forms and Leaching Risk in a Typically Agricultural Catchment of Hefei Suburban].

Science.gov (United States)

Fan, Hui-hui; Li, Ru-zhong; Pei, Ting-ting; Zhang, Rui-gang

2016-01-15

To investigate the soil phosphorus forms and leaching risk in a typically agricultural catchment of Ershibu River in Hefei Suburban, Chaohu Lake basin, 132 surface soil samples were collected from the catchment area. The spatial distribution of total phosphorus (TP) and bio-available phosphorus (Bio-P), and the spatial variability of soil available phosphorus (Olsen-P) and easy desorption phosphorus (CaCl2-P) were analyzed using the Kriging technology of AreGIS after speciation analysis of soil phosphorus. Moreover, the enrichment level of soil phosphorus was studied, and the phosphorus leaching risk was evaluated through determining the leaching threshold value of soil phosphorus. The results showed that the samples with high contents of TP and Bio-P mainly located in the upstream of the left tributary and on the right side of local area where two tributaries converged. The enrichment rates of soil phosphorus forms were arranged as follows: Ca-P (15.01) > OP (4.16) > TP (3. 42) > IP (2.94) > Ex-P (2.76) > Fe/Al-P (2.43) > Olsen-P (2.34). The critical value of Olsen-P leaching was 18.388 mg x kg(-1), and the leaching samples with values higher than the threshold value accounted for 16.6% of total samples. Generally, the high-risk areas mainly occurred in the upstream of the left tributary, the middle of the right tributary and the local area of the downstream of the area where two tributaries converged.

Influence of phosphorus on point defects in an austenitic alloy

International Nuclear Information System (INIS)

Boulanger, L.

1988-06-01

The influence of phosphorus on points defects clusters has been studied in an austenitic alloy (Fe/19% at. Cr/13% at. Ni). Clusters are observed by transmission electron microscopy. After quenching and annealing, five types of clusters produced by vacancies or phosphorus-vacancies complexes are observed whose presence depends on cooling-speed. Vacancy concentration (with 3.6 10 -3 at. P) in clusters is about 10 -5 and apparent vacancy migration is 2 ± 0.1 eV. These observations suggest the formation of metastable small clusters during cooling which dissociate during annealing and migrate to create the observed clusters. With phosphorus, the unfrequent formation of vacancy loops has been observed during electron irradiation. Ions irradiations show that phosphorus does not favour nucleation of interstitial loops but slowers their growth. It reduces swelling by decreasing voids diameter. Phosphorus forms vacancy complexes whose role is to increase the recombination rate and to slow vacancy migration [fr

Stream Phosphorus Dynamics Along a Suburbanizing Gradient in Southern Ontario, Canada

Science.gov (United States)

Duval, T. P.

2017-12-01

While it is well known that urban streams are subject to impaired water quality relative to natural analogues, far less research has been directed at stream water quality during the process of (sub-) urbanization. This study determines the role of housing construction activities in Brampton, Canada on the concentration and flux of phosphorus (P) of a headwater stream. Prior to development the stream was engineered with a riffle-pool sequence, riparian plantings, and a floodplain corridor that was lined with sediment fencing. Stream sites were sampled daily over a period of six months at locations representing varying stages of subdivision completion (upper site -active construction; middle site -finished construction and natural vegetation; lower site -finished construction and active construction). A nearby urban stream site developed ten years prior to this study was selected as a reference site. There were no differences in total phosphorus (TP) levels or flux between the suburbanizing and urban streams; however, the forms of P differed between sites. The urban stream TP load was dominated by particulate phosphorus (PP) while suburbanizing stream P was mainly in the dissolved organic phosphorus (DOP) form. The importance of DOP to TP flux increased with the onset of the growing season. TP levels in all stream segments frequently exceeded provincial water quality guidelines during storm events but were generally low during baseflow conditions. During storm events PP and total suspended solid levels in the suburbanizing stream reached levels of the urban stream due to sediment fence failure at several locations along the construction-hillslope interface. Along the suburbanizing gradient, the hydrological connection to a mid-reach zone of no-construction activity / fallow field and native forest resulted in significantly lower P levels than the upper suburbanizing stream site. This suggests that stream channel design features as well as timing of construction

Biologic phosphorus elimination - influencing parameters, boundary conditions, process optimation

International Nuclear Information System (INIS)

Dai Xiaohu.

1992-01-01

This paper first presents a systematic study of the basic process of biologic phosphorus elimination as employed by the original 'Phoredox (Main Stream) Process'. The conditions governing the process and the factors influencing its performance were determined by trial operation. A stationary model was developed for the purpose of modelling biologic phosphorus elimination in such a main stream process and optimising the dimensioning. The validity of the model was confirmed by operational data given in the literature and by operational data from the authors' own semitechnical-scale experimental plant. The model permits simulation of the values to be expected for effluent phosphorus and phosphate concentrations for given influent data and boundary conditions. It is thus possible to dimension a plant for accomodation of the original Phoredox (Main Stream) Process or any similar phosphorus eliminating plant that is to work according to the principle of the main stream process. (orig./EF) [de

Organic carbon, nitrogen and phosphorus contents of some tea soils

International Nuclear Information System (INIS)

Ahmed, M.S.; Zamir, M.R.; Sanauallah, A.F.M.

2005-01-01

Soil samples were collected from Rungicherra Tea-Estate of Moulvibazar district, Bangladesh. Organic carbon, organic matter, total nitrogen and available phosphorus content of the collected soil of different topographic positions have been determined. The experimental data have been analyzed statistically and plotted against topography and soil depth. Organic carbon and organic matter content varied from 0.79 to 1.24% and 1.37 to 2.14%. respectively. Total nitrogen and available phosphorus content of these soils varied respectively from 0.095 to 0.13% and 2.31 to 4.02 ppm. (author)

Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change

Science.gov (United States)

Ryberg, Karen R.; Blomquist, Joel; Sprague, Lori A.; Sekellick, Andrew J.; Keisman, Jennifer

2018-01-01

Causal attribution of changes in water quality often consists of correlation, qualitative reasoning, listing references to the work of others, or speculation. To better support statements of attribution for water-quality trends, structural equation modeling was used to model the causal factors of total phosphorus loads in the Chesapeake Bay watershed. By transforming, scaling, and standardizing variables, grouping similar sites, grouping some causal factors into latent variable models, and using methods that correct for assumption violations, we developed a structural equation model to show how causal factors interact to produce total phosphorus loads. Climate (in the form of annual total precipitation and the Palmer Hydrologic Drought Index) and anthropogenic inputs are the major drivers of total phosphorus load in the Chesapeake Bay watershed. Increasing runoff due to natural climate variability is offsetting purposeful management actions that are otherwise decreasing phosphorus loading; consequently, management actions may need to be reexamined to achieve target reductions in the face of climate variability.

Determination of phosphorus in wheat grass samples by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Kulkarni, S.D.; Rajurkar, N.S.; Acharya, R.; Nair, A.G.C.; Reddy, A.V.R.

2005-01-01

An instrumental neutron activation analysis (INAA) method using β-counting was used to determine phosphorus in wheat grass; grown in three different conditions. The phosphorus concentration was found to be in the range of 950-23000 mg/g in the samples grown in different conditions. The accuracy of the method was evaluated by determining phosphorus in three reference materials and the % deviations were within 10%. Reliability of the method was checked by following the half-life of the 32 P. (author)

[Clinical aspect of recent progress in phosphate metabolism. Distribution of phosphorus and its physiological roles in the body: the form, distribution, and physiological function].

Science.gov (United States)

Yano, Shozo; Sugimoto, Toshitsugu

2009-06-01

Phosphorus plays pivotal roles in the survival such as the cellular structure, genomic information, energy metabolism, and cell signaling. Total amount of phosphorus is 500-700 g in human, most of which is stored in the bone in an insoluble form of calcium salt. About 15% of phosphorus is located in the cell membrane and the intracellular fluid in the soft tissues in a form of organic phosphate. Only 0.1% is present in the extracellular fluid. This phosphate pool plays a role in the dynamic equilibrium through the gut, kidney, bone and other tissues. Most of inorganic phosphates in the extracellular fluid are present in a form of ions such as H2PO4- and HPO(4)2-, and the concentration of phosphatic acids is about 1.2 mM. The form, distribution, and physiological function of phosphorus in the body are summarized in this review.

Glacial-interglacial variability in ocean oxygen and phosphorus in a global biogeochemical model

Directory of Open Access Journals (Sweden)

V Palastanga

2013-02-01

Full Text Available Increased transfer of particulate matter from continental shelves to the open ocean during glacials may have had a major impact on the biogeochemistry of the ocean. Here, we assess the response of the coupled oceanic cycles of oxygen, carbon, phosphorus, and iron to the input of particulate organic carbon and reactive phosphorus from shelves. We use a biogeochemical ocean model and specifically focus on the Last Glacial Maximum (LGM. When compared to an interglacial reference run, our glacial scenario with shelf input shows major increases in ocean productivity and phosphorus burial, while mean deep-water oxygen concentrations decline. There is a downward expansion of the oxygen minimum zones (OMZs in the Atlantic and Indian Ocean, while the extension of the OMZ in the Pacific is slightly reduced. Oxygen concentrations below 2000 m also decline but bottom waters do not become anoxic. The model simulations show when shelf input of particulate organic matter and particulate reactive P is considered, low oxygen areas in the glacial ocean expand, but concentrations are not low enough to generate wide scale changes in sediment biogeochemistry and sedimentary phosphorus recycling. Increased reactive phosphorus burial in the open ocean during the LGM in the model is related to dust input, notably over the southwest Atlantic and northwest Pacific, whereas input of material from shelves explains higher burial fluxes in continental slope and rise regions. Our model results are in qualitative agreement with available data and reproduce the strong spatial differences in the response of phosphorus burial to glacial-interglacial change. Our model results also highlight the need for additional sediment core records from all ocean basins to allow further insight into changes in phosphorus, carbon and oxygen dynamics in the ocean on glacial-interglacial timescales.

Application of two phosphorus models with different complexities in a mesoscale river catchment

Directory of Open Access Journals (Sweden)

B. Guse

2007-06-01

Full Text Available The water balance and phosphorus inputs of surface waters of the Weiße Elster catchment, Germany, have been quantified using the models GROWA/MEPhos and SWAT. A comparison of the model results shows small differences in the mean long-term total runoff for the entire study area. All relevant pathways of phosphorus transport were considered in MEPhos with phosphorus inputs resulting to about 65% from point sources. SWAT focuses on agricultural areas and estimates a phosphorus input of about 60% through erosion. The mean annual phosphorus input from erosion calculated with SWAT is six times higher than the estimation with MEPhos due to the differing model concepts. This shows the uncertainty contributed by the modelling description of phosphorus pathways.

The Effects of Arbuscular Mycorrhiza Fungi on Dry Matter and Concentrations of Nitrogen, Phosphorus and Potassium in Berseem Clover, by Cadmium stress

Directory of Open Access Journals (Sweden)

hashem aram

2016-02-01

Zanjan, after the complete analysis of soil and obtaining the chemical and physical properties in the laboratory. 6 kg of soil was weighed for each pot and then the soil was contaminated. Cadmium sulfate was used in this experiment. The mycorrhizal fungi weighed 150 grams and was mixed with the soil. After mixing the soil with mycorrhizal fungi, the soil was put in pots and then it was cultivated with clover. In this study, clover seeds weighed 0/5 grams and were disinfected with 10% hydrogen peroxide solution and were added to each pot. Distilled water was used for irrigation. After the completion of growth of plants (about 70 day, plant aerial parts and roots were harvested and before measuring, they were washed with distilled water and then were dried in the oven for 72 hours. Plant aerial parts were harvested. Data were analyzed by SAS (version 9 and MSTATC (version 2.10 software, and obtained variance analysis tables. Mean comparison of different treatments was conducted by Duncan test. Charts were obtained by excel software. Results and Discussion: The results showed that the effects of arbuscular mycorrhizal fungi were significant on all traits measured (P< 0.01. With increasing cadmium concentration in soil, dry matter of 37% and 39%, nitrogen concentration of 35% and 28%, Potassium 9/27% and 37%, and phosphorus concentration of 37% and 39%, reduced in root and aerial, respectively. Also the results showed that arbuscular mycorrhizal fungi increased dry matter amount by 42% and 26%, nitrogen concentration by 40.3% and 30%, phosphorus concentration by 6% and 15.4%, potassium concentrations by 54% and 91.2% in root and aerial, respectively. Interaction between cadmium levels and mycorrhizal fungi in statistics was significant on dry matter aerial, nitrogen concentration in aerial and root, and potassium concentrations in plant root (P< 0.01. Conclusion: The results showed that mycorrhizal fungi were significant on all traits measured in one percent level. Cadmium

32P determination of phosphorus uptake by plants

International Nuclear Information System (INIS)

Rigas, J.

1986-01-01

Following drying at a temperature of 20 to 25 degC, the soil samples were ground and sieved. The fraction of a grain size below 0.25 mm was chosen for the experiments. Two parallel runs of water leaching of the samples were made. One was not labelled, 32 PO 4 3- without carrier was added to the other (about 1.5 MBq/ml). 3 ml of the water phase were taken for activity measurement. The concentration of exchangeable phosphorus in the soil was calculated from the partition ratio of the water and solid phases and from the concentration of inorganic phosphates. The Egner method was used for determining the phosphorus to be taken up by the same samples. No statistically significant differences were found between the two methods. (E.S.) 1 tab., 8 refs

Fractions and Distribution of Phosphorus in Sediments of the Yarlung Zangbo River Basin

Science.gov (United States)

Huang, W.; An, R.; Huang, Y.; Pu, X.; Li, R.; Li, J.

2017-12-01

The Yarlung Zangbo River is one of the highest rivers in the world. The ecological environment of the river basin has its specificity. It locates in the remote area of China, and the ecological environment is very fragile. The fundamental data of phosphorus content in sediments of the Yarlung Zangbo River Basin are very scarce. In order to clarify the distribution law of phosphorus in the sediments of this area and provide the fundamental data for the study of phosphorus transport in the Yarlung Zangbo River, the authors collected the sediment samples from the mainstream and its tributaries in the research area. Their particle size distributions, specific surface areas, contents of total phosphorus, organic phosphorus and different forms of inorganic phosphorus were analyzed. Then, the fractions and spatial distribution of these forms phosphorus were studied. The results showed that the fractions and distribution characteristics of phosphorus in each form are significant different in the sediments of the Yarlung Zangbo River. The phosphorus contents in the soil erosion deposits and river bed sediment samples are also different. The phosphorus content in sediment is significantly correlated with the sediment characteristics. Keywords: the Yarlung Zangbo River; sediments; fractions of phosphorus; distribution characteristics

Sources and transport of phosphorus to rivers in California and adjacent states, U.S., as determined by SPARROW modeling

Science.gov (United States)

Domagalski, Joseph L.; Saleh, Dina

2015-01-01

The SPARROW (SPAtially Referenced Regression on Watershed attributes) model was used to simulate annual phosphorus loads and concentrations in unmonitored stream reaches in California, U.S., and portions of Nevada and Oregon. The model was calibrated using de-trended streamflow and phosphorus concentration data at 80 locations. The model explained 91% of the variability in loads and 51% of the variability in yields for a base year of 2002. Point sources, geological background, and cultivated land were significant sources. Variables used to explain delivery of phosphorus from land to water were precipitation and soil clay content. Aquatic loss of phosphorus was significant in streams of all sizes, with the greatest decay predicted in small- and intermediate-sized streams. Geological sources, including volcanic rocks and shales, were the principal control on concentrations and loads in many regions. Some localized formations such as the Monterey shale of southern California are important sources of phosphorus and may contribute to elevated stream concentrations. Many of the larger point source facilities were located in downstream areas, near the ocean, and do not affect inland streams except for a few locations. Large areas of cultivated land result in phosphorus load increases, but do not necessarily increase the loads above those of geological background in some cases because of local hydrology, which limits the potential of phosphorus transport from land to streams.

Quantity and quality of phosphorus losses from an artificially drained lowland catchment

Science.gov (United States)

Nausch, Monika; Woelk, Jana; Kahle, Petra; Nausch, Günther; Leipe, Thomas; Lennartz, Bernd

2017-04-01

Currently, agricultural diffuse sources constitute the major portion of phosphorus (P) fluxes to the Baltic Sea and have to reach the good ecological status aimed by the Baltic Sea Action Plan and the Marine Strategy Framework Directive. The objective of this study was to uncover the change in phosphorus loading as well as in P fractions along the flow path of a mid-size river basin in order to derive risk assessment and management strategies for a sustainable P reduction. P-fractions and the mineral composition of particulate P were investigated in a sub-basin of the river Warnow, the second largest German catchment discharging to the Baltic Sea. Samples were collected from the sources (tile drain, ditch) and along the subsequent brook up to the river Warnow representing spatial scales of a few hectars up to 3300 km2. The investigations were performed during the discharge season from November 1th 2013 until April 30th 2014 covering a relative dry and mild winter period. We observed an increase of total phosphorus (TP) concentrations from 15.5 ± 3.9 µg L-1 in the drain outlet to 72.0 ± 7.2 µg L-1 in the river Warnow emphasizing the importance of sediment-bound P mobilization along the flow path. Particulate phosphorus (PP) of 36.6 - 61.2% accounted for the largest share of TP in the streams. Clay minerals and Fe(hydr)oxides were the main carrier of particle bound P followed by apatite. A transformation of dissolved inorganic phosphorus (DIP) into particulate organic P was observed in the river Warnow with the beginning of the growth season in February. Our investigations indicate that the overall P load could be reduced by half when PP is removed.

Phosphorus Transport in Rivers.

Science.gov (United States)

1978-11-01

be attributed to excessive nutrient inputs to the lake. These nutrients sti- mulate the phytoplankton (algae) growth which yields excess growth. The...phosphorus in relation to the restoration of Lake Erie. The various computational techniques presented herein aid in the understanding of total...as caused by the absorption on clay materials and by assimilation by periphyton . Other investigators have found correlations between flow and other

Laboratory and in-situ reductions of soluble phosphorus in swine waste slurries.

Science.gov (United States)

Burns, R T; Moody, L B; Walker, F R; Raman

2001-11-01

Laboratory and field experiments were conducted using magnesium chloride (MgCl2) to force the precipitation of struvite (MgNH4PO4 x 6H2O) and reduce the concentration of soluble phosphorus (SP) in swine waste. In laboratory experiments, reductions of SP of 76% (572 to 135 mg P l(-1)) were observed in raw swine manure after addition of magnesium chloride (MgCl2) at a rate calculated to provide a 1.6:1 molar ratio of magnesium (Mg) to total phosphorus. Adjusting the pH of the treated manure to pH 9.0 with sodium hydroxide (NaOH) increased SP reduction to 91% (572 to 50 mg P l(-1)). X-ray diffraction of the precipitate recovered from swine waste slurry treated only with MgCl2 confirmed the presence ofstruvite. The molar N:P:Mg ratio of the recovered precipitate was 1:1.95:0.24, suggesting that compounds in addition to struvite were formed. In a field experiment conducted in a swine manure holding pond, a 90% reduction in SP concentration was observed in approximately 140,000 l of swine manure slurry treated before land application with 2,000 l MgCl2 (64% solution) at ambient slurry temperatures ranging from 5 to 10 degrees C.

Substoichiometric extraction of phosphorus

International Nuclear Information System (INIS)

Shigematsu, T.; Kudo, K.

1981-01-01

A study of the substoichiometric extraction of phosphorus is described. Phosphorus was extracted in the form of ternary compounds such as ammonium phosphomolybdate, 8-hydroxyquinolinium phosphomolybdate, tetraphenylarsonium phosphomolybdate and tri-n-octylamine phosphomolybdate. Consequently, phosphorus was extracted substoichiometrically by the addition of a substoichiometric amount of molybdenum for the four phosphomolybdate compounds. On the other hand, phosphorus could be separated substoichiometrically with a substoichiometric amount of tetraphenylarsonium chloride or tri-n-octylamine. Stoichiometric ratios of these ternary compounds obtained substoichiometrically were 1:12:3 for phosphorus, molybdenum and organic reagent. The applicability of these compounds to phosphorus determination is also discussed. (author)

不同种类浮萍对磷的去除及其体内磷的累积变化研究%Study of Different Kinds of Duckweed in Different Low Concentration of Orthophosphate Culture Conditions on Phosphorus Removal and Float body Phosphorus Accumulation Change

Institute of Scientific and Technical Information of China (English)

叶平平; 金杰; 侍远

2012-01-01

Taking three common duckweed in the Chaohu Lake basin--Spirodela polyrrhiza, Lemna paucico- stata and wolffia arrhiza as the objects,this article studies the phosphorus removal function the three kinds of duckweed when the water is within the surface water concentration range (0.01 mgP/L,0. 05 mgP/L,0. 1 mgP/L,0.2 mgP/L,0.5 mgP/L),and also analyzes the accumulation change of phosphorus in three kinds of duckweed. Moreover, it discusses the treatment of phosphorus wastewater system on remove phosphorus way, and provides theoretical basis for duckweed in Chaohu Lake basin dephosphorization ecological restora- tion. The experimental results show that the plant body on phosphorus direct absorption is one of the main mechanisms for clean--up effect; three kinds of duckweed respectviely have high removal efficiency, and phosphorus removal rate is Spirodela polyrrhiza 〉 Lemna paucicostata 〉 wolffia arrhiza, and three float right utilization rate increase as the concentration reduce;the phosphorus removal rate of Spirodela polyrrhiza is 60% -48.9%,Lemna paucicostata is 90% - 47.2%,wolffia arrhiza is 90% - 34.2%. The phosphorus absorption of three duckweed basically account for more than 70% of the remove function. And there are differences among different varieties and different phosphorus concentration.%以巢湖流域常见的3种浮萍——紫背浮萍（以下称紫萍）、稀脉浮萍萍和芜萍为对象，研究了三种浮萍对地表水浓度范围内（0．01mgP／L，0．05mgP／L，0．1mgP／L，0．2mgP／L，0．5mgP／L）的磷的去除作用，以及磷在三种浮萍体内的积累变化和三种浮萍对磷的吸收作用占总去除作用。探讨了浮萍处理含磷污水系统的去除磷途径。实验表明：植物体对磷的直接吸收是其净化作用的主�

Potassium-phosphorus relationships in cotton (gossypium hirsutum L.) as affected by potassium nutrition

International Nuclear Information System (INIS)

Makhdum, M.I.; Ashraf, M.

2007-01-01

Field studies were undertaken to determine the interrelationship between potassium (K+) concentration in various organs of plant and phosphorus (P) content as influenced by K-nutrition in cotton. The experiment was conducted on Miani soil series silt loam and classified as Calcaric Cambisols, fine silty, mixed Hyperthermic Fluventic Haplocambids. The treatments consisted .of (a) four cotton (Gossypium hirsutum L.) cultivars (CI.M-448, CIM-IIOO, Karishma, S-12); and (b) four potassium fertilizer doses (0, 62.5, 125.0, 250.0 kg K ha-l). The design of experiment was split plot (main: cultivars, sub-plot: K-doses). The plant samples were collected at five stages of growth, i.e., first flower bud., first flower, peak flowering, first boll split and maturity. The various parts of plants were analyzed for phosphorus and potassium concentration at various stages of growth. Phosphorus concentration in leaves, stems, burs, seed and lint decreased with concurrent increase in K-doses. Crop maintained 0.22% phosphorus concentration in leaf tissues at first flower bud and dropped to 0.11% at maturity. Cultivars differed greatly amongst themselves in terms of maintaining P content in their different parts. Averaged across K-doses, cv. CIM-448 maintained the highest P content in all parts than other cultivars. There was a negative and significant correlation co-efficient between K and P concentration in various parts of the plant. The study demonstrated antagonistic interaction between K+ and P in cotton plant under irrigated conditions. (author)

Effect of four acidifying materials added to a calcareous soil on the availability of phosphorus to ryegrass

Energy Technology Data Exchange (ETDEWEB)

Sen Gupta, M B; Cornfield, A H

1964-12-01

Ryegrass was grown in a pot test using a calcareous soil (0.36% calcium carbonate) treated with sulfur, ammonium sulfate, ferrous sulfate, and aluminium sulfate at 0.1% sulfur-equivalent, with potassium nitrate added where necessary, including the control, to equalize nitrogen supply. The sulfur treatment was the only one which significantly increased dry matter yields, total phosphorus uptake and top/root ratios in dry matter yields and total phosphorus. The ammonium sulfate, ferrous sulfate, and aluminium sulfate treatments significantly reduced top/root ratios in dry-matter yields and total phosphorus. 6 references, 1 table.

Benthic iron and phosphorus release from river dominated shelf sediments under varying bottom water O2 concentrations.

Science.gov (United States)

Ghaisas, N. A.; Maiti, K.; White, J. R.

2017-12-01

Phosphorus (P) cycling in coastal ocean is predominantly controlled by river discharge and biogeochemistry of the sediments. In coastal Louisiana, sediment biogeochemistry is strongly influenced by seasonally fluctuating bottom water O2, which, in turn transitions the shelf sediments from being a sink to source of P. Sediment P-fluxes were 9.73 ± 0.76 mg / m2 /d and 0.67±0.16 mg/m2/d under anaerobic and aerobic conditions respectively, indicating a 14 times higher P-efflux from oxygen deprived sediments. A high sedimentary oxygen consumption rate of 889 ± 33.6 mg/m2/d was due to organic matter re-mineralization and resulted in progressively decreasing the water column dissolved O2 , coincident with a P-flux of 7.2 ± 5.5 mg/m2/d from the sediment. Corresponding water column flux of Fe total was 19.7 ± 7.80 mg/m2/d and the sediment-TP decreased from 545 mg/Kg to 513 mg/Kg. A simultaneous increase in pore water Fe and P concentrations in tandem with a 34.6% loss in sedimentary Fe-bound P underscores the importance of O2 on coupled Fe- P biogeochemistry. This study suggests that from a 14,025 sq. km hypoxia area, Louisiana shelf sediments can supply 1.33x105 kg P/day into the water column compared to 0.094 x 105 kg P/day during the fully aerobic water column conditions.

Use of Phosphorus Isotopes for Improving Phosphorus Management in Agricultural Systems

International Nuclear Information System (INIS)

2016-10-01

Phosphorus is an essential element in plant, human and animal nutrition. Soils with low levels of phosphorus are widespread in many regions of the world, and the deficiency limits plant growth and reduces crop production and food quality. This publication provides comprehensive and up to date information on several topics related to phosphorus in soil–plant systems, in agricultural systems and in the environment. It presents the theoretical background as well as practical information on how to use nuclear and radioisotope tracer techniques in both laboratory and greenhouse experiments to assess soil phosphorus forms and plant-available soil phosphorus pools, and to understand the cycling processes in soil–plant systems. The publication focuses on practical applications of radiotracer techniques and can serve as resource material for research projects on improving sustainable phosphorus management in agricultural systems and as practical guidance on the use of phosphate isotopes in soil–plant research

Boron, phosphorus, and gallium determination in silicon crystals doped with gallium

International Nuclear Information System (INIS)

Shklyar, B.L.; Dankovskij, Yu.V.; Trubitsyn, Yu.V.

1989-01-01

When studying IR transmission spectra of silicon doped with gallium in the range of concentrations 1 x 10 14 - 5 x 10 16 cm -3 , the possibility to quantity at low (∼ 20 K) temperatures residual impurities of boron and phosphorus is ascertained. The lower determination limit of boron is 1 x 10 12 cm -3 for a sample of 10 nm thick. The level of the impurities in silicon crystals, grown by the Czochralski method and method of crucible-free zone melting, is measured. Values of boron and phosphorus concentrations prior to and after their alloying with gallium are compared

Dissolved oxygen and dietary phosphorus modulate utilization and effluent partitioning of phosphorus in rainbow trout (Oncorhynchus mykiss) aquaculture

International Nuclear Information System (INIS)

McDaniel, Nichole K.; Sugiura, Shozo H.; Kehler, Thomas; Fletcher, John W.; Coloso, Relicardo M.; Weis, Peddrick; Ferraris, Ronaldo P.

2005-01-01

Phosphorus (P) is the limiting nutrient in freshwater primary production, and excessive levels cause premature eutrophication. P levels in aquaculture effluents are now tightly regulated. Increasing our understanding of waste P partitioning into soluble, particulate, and settleable fractions is important in the management of effluent P. When water supply is limited, dissolved oxygen concentration (DO) decreases below the optimum levels. Therefore, we studied effects of DO (6 and 10 mg/L) and dietary P (0.7 and 1.0% P) on rainbow trout growth, P utilization, and effluent P partitioning. Biomass increased by 40% after 3 weeks. DO at 10 mg/L significantly increased fish growth and feed efficiency, and increased the amount of P in the soluble fraction of the effluent. Soluble effluent P was greater in fish fed 1.0% P. DO increases fish growth and modulates P partitioning in aquaculture effluent. - Dissolved oxygen concentration not only influences fish growth rate, but also affects dietary phosphorus utilization by fish in intensive aquaculture

A new model of tail diffusion of phosphorus and boron in silicon

International Nuclear Information System (INIS)

Morehead, F.F.; Lever, R.F.

1986-01-01

It is well known that high surface concentration phosphorus diffusion leads to deeply penetrating tails in its concentration profile. At 700 0 C the tail diffusivity exceeds that of low concentration phosphorus by a factor of a thousand. Less spectacular, but very significant tailing also affects boron, making the conventional models contained in commonly available process simulation programs quite inaccurate for boron diffusions with high surface concentrations. The authors show that the observed tailing can be accounted for by a model whose central assumption is the local equality of dopant and oppositely directed defect fluxes. As predicted by the model, the effect is greatest for normal processing at low temperatures for high surface concentrations. It is minimal for the high temperatures of rapid thermal annealing and unrelated to transient effects

Phosphorus fractionation in sediment cores collected in 2005 before and after onset of an Aphanizomenon flos-aquae bloom in upper Klamath Lake, OR, USA

Science.gov (United States)

Simon, N.S.; Lynch, D.; Gallaher, T.N.

2009-01-01

We tested the hypothesis that there would be measurable losses of phosphorus (P) from surficial sediments of Upper Klamath Lake (UKL), Oregon, if sediments were a source of P during an algal bloom. We compared concentrations of total and forms of P at various depths in cores collected before and after the onset of a large Aphanizomenon flos-aquae bloom. Concentrations of inorganic P were determined in extraction solutions of MgCl2 (1 M, pH 8), citrate-dithionite-bicarbonate, and 1 M HCl. Sediments below 2 cm were dominated by residual P which is defined as total P minus inorganic P. During the study period, data from the top 2-cm of sediment indicated (a) significant decrease in total P concentration, primarily associated with iron oxyhydroxides at one site, and (b) significant increase in total P concentration associated with residual P at a second site. Data from two other sites indicated no net changes in concentrations of total P. ?? 2009 US Government.

Water Quality and Hydrology of Silver Lake, Barron County, Wisconsin, With Special Emphasis on Responses of a Terminal Lake to Changes in Phosphorus Loading and Water Level

Science.gov (United States)

Robertson, Dale M.; Rose, William J.; Fitzpatrick, Faith A.

2009-01-01

Silver Lake is typically an oligotrophic-to-mesotrophic, soft-water, terminal lake in northwestern Wisconsin. A terminal lake is a closed-basin lake with surface-water inflows but no surface-water outflows to other water bodies. After several years with above-normal precipitation, very high water levels caused flooding of several buildings near the lake and erosion of soil around much of the shoreline, which has been associated with a degradation in water quality (increased phosphorus and chlorophyll a concentrations and decreased water clarity). To gain a better understanding of what caused the very high water levels and degradation in water quality and collect information to better understand the lake and protect it from future degradation, the U.S. Geological Survey did a detailed study from 2004 to 2008. This report describes results of the study; specifically, lake-water quality, historical changes in water level, water and phosphorus budgets for the two years monitored in the study, results of model simulations that demonstrate how changes in phosphorus inputs affect lake-water quality, and the relative importance of changes in hydrology and changes in the watershed to the water quality of the lake. From 1987 to about 1996, water quality in Silver Lake was relatively stable. Since 1996, however, summer average total phosphorus concentrations increased from about 0.008 milligrams per liter (mg/L) to 0.018 mg/L in 2003, before decreasing to 0.011 mg/L in 2008. From 1996 to 2003, Secchi depths decreased from about 14 to 7.4 feet, before increasing to about 19 feet in 2008. Therefore, Silver Lake is typically classified as oligotrophic to mesotrophic; however, during 2002-4, the lake was classified as mesotrophic to eutrophic. Because productivity in Silver Lake is limited by phosphorus, phosphorus budgets for the lake were constructed for monitoring years 2005 and 2006. The average annual input of phosphorus was 216 pounds: 78 percent from tributary and

Phosphorus runoff from sewage sludge applied to different slopes of lateritic soil.

Science.gov (United States)

Chen, Yan Hui; Wang, Ming Kuang; Wang, Guo; Chen, Ming Hua; Luo, Dan; Ding, Feng Hua; Li, Rong

2011-01-01

Sewage sludge (SS) applied to sloping fields at rates that exceed annual forest nutrient requirements can be a source of phosphorus (P) in runoff. This study investigates the effects of different slopes (18, 27, 36, and 45%) on P in runoff from plots amended with SS (120 Mg ha). Lateritic soil (pH 5.2) was exposed to five simulated rainfalls (90 mm h) on outdoor plots. When sludge was broadcast and mixed with surface soils, the concentrations and loss in runoff of total P in the mixed sample (MTP), total P in the settled sample (STP), total particulate P (TPP), total suspended P (TSP), and total dissolved P (TDP) were highest at 1 or 18 d after application. Initially, pollution risks to surface waters generally increased to different degrees with steeper slopes, and then diminished gradually with dwindling differences between the slopes. The runoff losses coefficient of MTP increased in the order 36 > 45 > 27 > 18%. The initial event (1 and 18 d) accounted for 67.0 to 83.6% of total runoff P losses. Particulate fraction were dominant carriers for P losses, while with the lower slopes there was higher content of P per unit particulate fraction in runoff. Phosphorus losses were greatly affected by the interaction of sludge-soil-runoff and the modification of soil properties induced by sludge amendment. It is recommended to choose lower slopes (soils should be studied further in the field under a wider diversity of conditions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Eutrophication study at the Panjiakou-Daheiting Reservoir system, northern Hebei Province, People's Republic of China: Chlorophyll-a model and sources of phosphorus and nitrogen

Science.gov (United States)

Domagalski, Joseph L.; Lin, Chao; Luo, Yang; Kang, Jie; Wang, Shaoming; Brown, Larry R.; Munn, Mark D.

2007-01-01

Concentrations, loads, and sources of nitrate and total phosphorus were investigated at the Panjiakou and Daheiting Reservoir system in northern Hebei Province, People's Republic of China. The Luan He River is the primary source of water to these reservoirs, and the upstream watershed has a mix of land uses including agriculture, forest, and one large urban center. The reservoirs have a primary use for storage of drinking water and partially supply Tianjin City with its annual needs. Secondary uses include flood control and aqua culture (fish cages). The response of the reservoir system from phosphorus input, with respect to chlorophyll-a production from algae, was fitted to a model of normalized phosphorus loading that regresses the average summer-time chlorophyll-a concentration to the average annual phosphorus concentration of the reservoir. Comparison of the normalized phosphorus loading and chlorophyll-a response of this system to other reservoirs throughout the world indicate a level of eutrophication that will require up to an approximate 5–10-fold decrease in annual phosphorus load to bring the system to a more acceptable level of algal productivity. Isotopes of nitrogen and oxygen in dissolved nitrate were measured from the headwater streams and at various locations along the major rivers that provide the majority of water to these reservoirs. Those isotopic measurements indicate that the sources of nitrate change from natural background in the rivers to animal manure and septic waste upstream of the reservoir. Although the isotopic measurements suggest that animal and septic wastes are a primary source of nutrients, measurements of the molar ratio of nitrogen to phosphorus are more indicative of row-cropping practices. Options for reduction of nutrient loads include changing the management practices of the aqua culture, installation of new sewage treatment systems in the large urbanized area of the upper watershed, and agricultural management practices

Contributions of Phosphorus from Groundwater to Streams in the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces, Eastern United States

Science.gov (United States)

Denver, Judith M.; Cravotta,, Charles A.; Ator, Scott W.; Lindsey, Bruce D.

2011-01-01

Phosphorus from natural and human sources is likely to be discharged from groundwater to streams in certain geochemical environments. Water-quality data collected from 1991 through 2007 in paired networks of groundwater and streams in different hydrogeologic and land-use settings of the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces in the eastern United States were compiled and analyzed to evaluate the sources, fate, and transport of phosphorus. The median concentrations of phosphate in groundwater from the crystalline and siliciclastic bedrock settings (0.017 and 0.020 milligrams per liter, respectively) generally were greater than the median for the carbonate setting (less than 0.01 milligrams per liter). In contrast, the median concentrations of dissolved phosphate in stream base flow from the crystalline and siliciclastic bedrock settings (0.010 and 0.014 milligrams per liter, respectively) were less than the median concentration for base-flow samples from the carbonate setting (0.020 milligrams per liter). Concentrations of phosphorus in many of the stream base-flow and groundwater samples exceeded ecological criteria for streams in the region. Mineral dissolution was identified as the dominant source of phosphorus in the groundwater and stream base flow draining crystalline or siliciclastic bedrock in the study area. Low concentrations of dissolved phosphorus in groundwater from carbonate bedrock result from the precipitation of minerals and (or) from sorption to mineral surfaces along groundwater flow paths. Phosphorus concentrations are commonly elevated in stream base flow in areas underlain by carbonate bedrock, however, presumably derived from in-stream sources or from upland anthropogenic sources and transported along short, shallow groundwater flow paths. Dissolved phosphate concentrations in groundwater were correlated positively with concentrations of silica and sodium, and negatively with alkalinity and concentrations of calcium

In-situ epitaxial growth of heavily phosphorus doped SiGe by low pressure chemical vapor deposition

CERN Document Server

Lee, C J

1998-01-01

We have studied epitaxial crystal growth of Si sub 1 sub - sub x Ge sub x films on silicon substrates at 550 .deg. C by low pressure chemical vapor deposition. In a low PH sub 3 partial pressure region such as below 1.25x10 sup - sup 3 Pa, both the phosphorus and carrier concentrations increased with increasing PH sub 3 partial pressure, but the deposition rate and the Ge fraction remained constant. In a higher PH sub 3 partial pressure region, the deposition rate, the phosphorus concentration, and the carrier concentration decreased, while the Ge fraction increased. These suggest that high surface coverage of phosphorus suppresses both SiH sub 4 and GeH sub 4 adsorption/reactions on the surfaces, and its suppression effect on SiH sub 4 is actually much stronger than on GeH sub 4. In particular, epitaxial crystal growth is largely controlled by surface coverage effect of phosphorus in a higher PH sub 3 partial pressure region.

Weak localization in few-layer black phosphorus

International Nuclear Information System (INIS)

Du, Yuchen; Neal, Adam T; Zhou, Hong; Ye, Peide D

2016-01-01

We have conducted a comprehensive investigation into the magneto-transport properties of few-layer black phosphorus in terms of phase coherence length, phase coherence time, and mobility via weak localization measurement and Hall-effect measurement. We present magnetoresistance data showing the weak localization effect in bare p-type few-layer black phosphorus and reveal its strong dependence on temperature and carrier concentration. The measured weak localization agrees well with the Hikami–Larkin–Nagaoka model and the extracted phase coherence length of 104 nm at 350 mK, decreasing as ∼T −0.513+−0.053 with increased temperature. Weak localization measurement allows us to qualitatively probe the temperature-dependent phase coherence time τ ϕ , which is in agreement with the theory of carrier interaction in the diffusive regime. We also observe the universal conductance fluctuation phenomenon in few-layer black phosphorus within moderate magnetic field and low temperature regime. (paper)

Response of soybean plants to phosphorus, boron and molybdenum fertilization

International Nuclear Information System (INIS)

Abdel-Aziz, H. A.; Aly, M. E.

2012-12-01

A pot experiment was carried out to study the effect of added phosphorus levels (30. 60 kg p/fed) with the addition of boron at (2, 6 ppm) and molybdenum at (5, 10.ppm) and without addition beside the control the control on growth and mineral content and root nodules in soybean plants. The results indicated that the effect of phosphorus on the formation of nodules had a clear effect when added with boron, molybdenum and when boron added at a rate of 2 ppm in the absence of phosphorus led to increase in root nodules in each of the 5, 10 ppm led to increased formation of, naldetuss in of the alluvial and calcareous soil. The molybdenum, nitrogen and phosphorus uptake increased directly proportional to the result of increased rate of addition of phosphorus and molybdenum. While the uptake born may be added with the rate of increased concentration of 2 ppm, while when added at 6 ppm led tp increased absorption of boron in the calcareous soil, but led to a decrease in the alluvial soils. (Author)

phosphorus sorption capacity as a guide for phosphorus availability

African Journals Online (AJOL)

Prof. Adipala Ekwamu

drained, light yellowish brown, loamy sand ... Dongola 2 Akked series: Deep, dark grayish brown, clay ... energy. Statistical analysis. Data collected were statistically analysed using ANOVA of MStatc ... phosphorus sorbed versus phosphorus.

Metabolismo mineral em bubalinos com ingestões de diferentes níveis de fósforo Mineral metabolism in buffaloes fed different phosphorus levels

Directory of Open Access Journals (Sweden)

Nedilse Helena de Souza

2009-06-01

Full Text Available Objetivou-se avaliar os efeitos da ingestão diária de quatro níveis de fósforo (8, 12, 15 e 18 g sobre o metabolismo de macrominerais (P, Ca, Mg, Na, K e S, incluindo a ingestão, a concentração no rúmen, a taxa de passagem do líquido ruminal, a excreção nas fezes e a disponibilidade aparente. Utilizaram-se quatro bubalinos adultos com fístulas ruminais em delineamento quadrado latino (4 × 4 com dieta total constituída de cana-de-açúcar como volumoso (85% e concentrado formulado com um dos níveis de fósforo. Os níveis de fósforo não ocasionaram diferença significativa na concentração mineral no rúmen de nenhum mineral estudado. A concentração média de fósforo no conteúdo ruminal foi de 0,98% na matéria seca, enquanto o teor de fósforo nas rações variou de 0,12 a 0,34%, comprovando alta reciclagem de fósforo pela saliva. Níveis crescentes de fósforo na dieta, variando de 8 a 18 g/animal/dia, não influenciam as disponibilidades de cálcio e magnésio. Com o nível de fósforo de 15 g/dia, houve melhor utilização do fósforo da dieta. A ingestão de níveis crescentes de fósforo em g/kg0,75 (X promoveu aumento linear na excreção fecal desse mineral em g/kg0,75 (Y e baixos valores de disponibilidade do fósforo, que pode ser estimado pela equação Y = 0,03 + 0,610X, o que indica deficiência desse elemento mineral na dieta para o metabolismo animal.The objective was to evaluate the effects of daily intake of four levels of phosphorus (8, 12, 15 and 18 g on the metabolism of macro minerals (Ca, P, Mg, Na, K and S, including the intake, concentration in rumen, ruminal fluid passage rate, excretion in feces and apparent availability. Four rumen-fistulated buffaloes were allotted to a 4 × 4 Latin Square, with total diet composed by sugar cane as forage (85% and concentrate formulated for each different phosphorus levels. Phosphorus levels did not caused difference in mineral concentration in the rumen of any

Water-soluble phosphorus in fresh broiler litter is dependent upon phosphorus concentration fed but not on fungal phytase supplementation.

Science.gov (United States)

Applegate, T J; Joern, B C; Nussbaum-Wagler, D L; Angel, R

2003-06-01

This experiment determined the effects of different phosphorus (P) feeding programs on total and water-soluble P excretion by broilers. Ross 308, male broilers were fed an industry (IND) diet (0.48, 0.35, 0.31, and 0.30% nonphytate P; NPP), an industry diet with reduced NPP and supplemental phytase [IND + PT; 600 phytase units (FTU)/kg; 0.36, 0.26, 0.20, and 0.19% NPP], a diet to more closely meet the birds' NPP requirements in which NPP was reduced further with supplemental phytase (REQ + P; 600 FTU/kg; 0.36, 0.26, 0.19, and 0.09% NPP), or a diet with low-phytate(lpa 1-1) corn with supplemental phytase (LPA + P; 600 FTU/kg; 0.37, 0.29, 0.19, 0.19% NPP). These diets were fed from hatch to 17 d, 17 to 31 d, 31 to 42 d, and 42 to 49 d of age, respectively. Fungal phytase was analyzed prior to diet formulation. Diets were fed to six replicate pens of 39 birds per pen. Litter samples were collected at 49 d of age and frozen prior to analyses. Diet did not significantly affect broiler performance (average BW at 49 d = 3.03 kg), tibia, or toe ash throughout the study (P > 0.05). Litter from broilers fed the IND diet was significantly higher (P litter from broilers fed IND + PT (0.84 and 0.14% of DM, respectively), REQ + P (0.78 and 0.11% of DM, respectively), or LPA + PT (0.64 and 0.12% of DM, respectively). Litter total and water-soluble P were not significantly different among broilers fed IND + PT, REQ + PT, or LPA + PT. In conclusion, phytase supplementation did not affect the solubility of P in the litter regardless of P feeding program.

Phosphorus and phytase levels for layer hens

Directory of Open Access Journals (Sweden)

Juliana Cristina Ramos Rezende

2013-02-01

Full Text Available The objective of this research was to evaluate the performance and bone quality of laying hens after peak production fed diets containing phosphorus levels and phytase. An experiment was conducted with 384 Hy-line distributed in a completely randomized in a factorial 4 x 3 with 4 levels of available phosphorus and 3 levels of phytase. The experimental period was divided into four periods of 28 days, at the end of each cycle were determined experimental feed intake, egg production, egg weight, feed conversion, mortality, and average egg weight, shell thickness, Haugh units and specific gravity. At the end of the experimental period were determined amounts of calcium and phosphorus excreted by the method of total excreta collection and a fowl per experimental unit was sacrificed for collection of bones and evaluation of width, length and level of robustness from femur and tibia. There was interaction between phosphorus levels and phytase on feed intake, feed conversion and percentage of posture. For inclusion levels of phytase all egg quality variables showed no significant differences. The treatments did not affect bone characteristics of laying hens.

Systematic study of the spin stiffness dependence on phosphorus alloying in the ferromagnetic semiconductor (Ga,Mn)As

International Nuclear Information System (INIS)

Shihab, S.; Thevenard, L.; Bardeleben, H. J. von; Gourdon, C.; Riahi, H.; Lemaître, A.

2015-01-01

We study the dependence of the spin stiffness constant on the phosphorus concentration in the ferromagnetic semiconductor (Ga,Mn)(As,P) with the aim of determining whether alloying with phosphorus is detrimental, neutral, or advantageous to the spin stiffness. Time-resolved magneto-optical experiments are carried out in thin epilayers. Laser pulses excite two perpendicular standing spin wave modes, which are exchange related. We show that the first mode is spatially uniform across the layer corresponding to a k≈0 wavevector. From the two frequencies and k-vector spacings we obtain the spin stiffness constant for different phosphorus concentrations using weak surface pinning conditions. The mode assessment is checked by comparison to the spin stiffness obtained from domain pattern analysis for samples with out-of-plane magnetization. The spin stiffness is found to exhibit little variation with phosphorus concentration in contradiction with ab-initio predictions

Evaluating the significance of wetland restoration scenarios on phosphorus removal.

Science.gov (United States)

Daneshvar, Fariborz; Nejadhashemi, A Pouyan; Adhikari, Umesh; Elahi, Behin; Abouali, Mohammad; Herman, Matthew R; Martinez-Martinez, Edwin; Calappi, Timothy J; Rohn, Bridget G

2017-05-01

Freshwater resources are vital for human and natural systems. However, anthropogenic activities, such as agricultural practices, have led to the degradation of the quality of these limited resources through pollutant loading. Agricultural Best Management Practices (BMPs), such as wetlands, are recommended as a valuable solution for pollutant removal. However, evaluation of their long-term impacts is difficult and requires modeling since performing in-situ monitoring is expensive and not feasible at the watershed scale. In this study, the impact of natural wetland implementation on total phosphorus reduction was evaluated both at the subwatershed and watershed levels. The study area is the Saginaw River Watershed, which is largest watershed in Michigan. The phosphorus reduction performances of four different wetland sizes (2, 4, 6, and 8 ha) were evaluated within this study area by implementing one wetland at a time in areas identified to have the highest potential for wetland restoration. The subwatershed level phosphorus loads were obtained from a calibrated Soil and Water Assessment Tool (SWAT) model. These loads were then incorporated into a wetland model (System for Urban Stormwater Treatment and Analysis IntegratioN-SUSTAIN) to evaluate phosphorus reduction at the subwatershed level and then the SWAT model was again used to route phosphorus transport to the watershed outlet. Statistical analyses were performed to evaluate the spatial impact of wetland size and placement on phosphorus reduction. Overall, the performance of 2 ha wetlands in total phosphorus reduction was significantly lower than the larger sizes at both the subwatershed and watershed levels. Regarding wetland implementation sites, wetlands located in headwaters and downstream had significantly higher phosphorus reduction than the ones located in the middle of the watershed. More specifically, wetlands implemented at distances ranging from 200 to 250 km and 50-100 km from the outlet had the

Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

Science.gov (United States)

Tu, Yunjie; Schuler, Andrew J

2013-04-16

Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure.

Effects of nitrogen sources on phosphorus absorption by wheat

International Nuclear Information System (INIS)

Muraoka, T.

1983-01-01

The effects of two sources of phosphorus (concentrated superphosphate and DAP) and ammonium sulfate, urea and ammonium nitrate on the phosphorus uptake by wheat plant were studied, utilizing superphosphate and DAP labelled with 23 P. It was observeded that the absorption of phosphrorus was influenced by the sources of nitrogen utilized. The best effect was obtained with urea, followed by ammonium nitrate and ammonium sulfate. It is suggested that the best effect of urea was due to its increasing effect on soil pH. (Author) [pt

Large magnetoresistance and Hall effect in paramagnetic black phosphorus synthesized from red phosphorus

Science.gov (United States)

Jiang, X. H.; Xiong, F.; Zhang, X. W.; Hua, Z. H.; Wang, Z. H.; Yang, S. G.

2018-05-01

Black phosphorus (BP) is an important material, which can be used in the fabrication of phosphorene. In this manuscript, a systematic study was described on the high-pressure synthesis of BP from red phosphorus. For physical characterization, the bulk BP was synthesized under the high pressure of 1.6 GPa and high temperature of 700 °C for 2 h. X-ray diffraction and Raman studies illustrated the formation of high-quality pure phase pleomorphic BP. A nonlinear Hall effect was observed in the BP sample. Magnetoresistance (MR) in the bulk BP reached 90% at 40 K, and positive-to-negative crossover in MR was measured. A paramagnetic feature was found in the prepared bulk BP, and the MR results were attributed to the combination of the effect of classical resistor network and magnetic polaron. The conduction tensors were analyzed by a two-band model to determine the carrier concentration and mobility at several temperatures.

Associations of Socioeconomic Status and Processed Food Intake with Serum Phosphorus in Community-Living Adults: the Multi-Ethnic Study of Atherosclerosis (MESA)

Science.gov (United States)

Gutiérrez, Orlando M.; Katz, Ronit; Peralta, Carmen A.; de Boer, Ian H.; Siscovick, David; Wolf, Myles; Roux, Ana Diez; Kestenbaum, Bryan; Nettleton, Jennifer A.; Ix, Joachim H.

2011-01-01

Objective Higher serum phosphorus concentrations are associated with cardiovascular disease events and mortality. Low socioeconomic status is linked with higher serum phosphorus, but the reasons are unclear. Poor individuals disproportionately consume inexpensive processed foods commonly enriched with phosphorus-based food preservatives. Accordingly, we hypothesized that excess intake of these foods accounts for a relationship between lower socioeconomic status and higher serum phosphorus. Design Cross-sectional analysis. Setting and Participants We examined a random cohort of 2,664 participants with available phosphorus measurements in the Multi-Ethnic Study of Atherosclerosis, a community-based sample of individuals free of clinically apparent cardiovascular disease from across the United States. Predictor Variables Socioeconomic status, the intake of foods commonly enriched with phosphorus additives (processed meats, sodas) and frequency of fast food consumption. Outcomes Fasting morning serum phosphorus concentrations. Results In unadjusted analyses, lower income and lower educational achievement categories were associated with modestly higher serum phosphorus (by 0.02 to 0.10 mg/dL, P fast-food consumption with serum phosphorus in multivariable-adjusted analyses. In contrast, each serving per day higher soda intake was associated with 0.02 mg/dl lower serum phosphorus (95% confidence interval, −0.04, −0.01). Conclusions Greater intake of foods commonly enriched with phosphorus additives was not associated with higher serum phosphorus in a community-living sample with largely preserved kidney function. These results suggest that excess intake of processed and fast foods may not impact fasting serum phosphorus concentrations among individuals without kidney disease. PMID:22217539

Comparison of some blood parameters, serum vitamin E and mineral concentrations of Arabian and English thoroughbred race horses

Directory of Open Access Journals (Sweden)

Bilal Tarik

2004-01-01

Full Text Available The aim of this study was to determine some blood parameters, serum vitamin E and mineral concentrations of Arabian and English thoroughbred racehorses fed the same diets. The diet was formulated to provide 2.31 Mcal DE/kg, and 10.96% crude protein. Total protein, lactate, calcium, phosphorus, potassium copper, cobalt and zinc were determined in serum obtained from 40 Arabian and 40 English healthy racing thoroughbred horses aged 2-3. The copper, cobalt and zinc concentrations were determined by atomic absorption, vitamin E by HPLC and the other biochemical parameters by a spectrophotometer. Mean values were 6.77 and 6.86 g/dl for total protein, 1.88 and 2.16 mg/dl for lactate 13.18 and 12.80 mg/dl for calcium, 4.35 and 4.39 mmol/l for phosphorus, 2.64 and 3.14 mmol/l for potassium, 129 and 166 μg/dl for copper, 36 and 44 μg/dl for cobalt and, 160 and 58 μg/dl for zinc in Arabian and English horses respectively, and Mean serum vitamin E levels were 2.65 and 2.81 μg/ml respectively. This study did not demonstrate a significant effect of breed on serum total protein, lactate, calcium, phosphorus, copper, cobalt and vitamin E. However, breed may have an effect on potassium and zinc concentration in Arabian and English thoroughbred racehorses (p<0.05.

Modeling of phosphorus fluxes produced by wild fires at watershed scales.

Science.gov (United States)

Matyjasik, M.; Hernandez, M.; Shaw, N.; Baker, M.; Fowles, M. T.; Cisney, T. A.; Jex, A. P.; Moisen, G.

2017-12-01

River runoff is one of the controlling processes in the terrestrial phosphorus cycle. Phosphorus is often a limiting factor in fresh water. One of the factors that has not been studied and modeled in detail is phosporus flux produced from forest wild fires. Phosphate released by weathering is quickly absorbed in soils. Forest wild fires expose barren soils to intensive erosion, thus releasing relatively large fluxes of phosphorus. Measurements from three control burn sites were used to correlate erosion with phosphorus fluxes. These results were used to model phosphorus fluxes from burned watersheds during a five year long period after fires occurred. Erosion in our model is simulated using a combination of two models: the WEPP (USDA Water Erosion Prediction Project) and the GeoWEPP (GIS-based Water Erosion Prediction Project). Erosion produced from forest disturbances is predicted for any watershed using hydrologic, soil, and meteorological data unique to the individual watersheds or individual slopes. The erosion results are modified for different textural soil classes and slope angles to model fluxes of phosphorus. The results of these models are calibrated using measured concentrations of phosphorus for three watersheds located in the Interior Western United States. The results will help the United States Forest Service manage phosporus fluxes in national forests.

Distribution, sedimentation, and bioavailability of particulate phosphorus in the mainstream of the Three Gorges Reservoir.

Science.gov (United States)

Tang, Xianqiang; Wu, Min; Li, Rui

2018-09-01

The transportation and sedimentation of particulate phosphorus (PP) in a huge reservoir such as the Three Gorges Reservoir (TGR) are closely related to the phosphorus distribution characteristics and nutritional status of the water body. In this study, the PP distribution, sedimentation, and bioavailability in the mainstream section of the TGR were investigated through a field survey, indoor simulated settlement experiment, and historical data analysis. The results indicated that PP was the major component of the total phosphorus (TP) and that the Three Gorges Dam (TGD) trapped nearly 76.25% of suspended sediment (SS) and 75.35% of PP in the TGR, even during the flood season. A decline in flow velocity promoted the deposition of PP; additionally, PP concentrations gradually dropped from 0.35 mg/L in Chongqing to 0.02 mg/L in Zigui. The static PP sedimentation process adequately fitted a pseudo-second-order kinetic equation with a maximum correlation coefficient of 0.97. Moreover, more than half of the PP sedimentation process was achieved in less than 60 min for samples collected from the upper river reaches within simulated sedimentation process. The median particle size of SS and absolute value of the water column's zeta potential were negatively and positively related to the t 12 values of PP sedimentation, respectively. Compared with the concentration and particle size of SS obtained in the pre-TGR period, the values in the mainstream section of the TGR were lower. However, the TP and Fe/Al-P contents in SS increased several times. Due to the combined effects of flow velocity reduction and SS trapping, the water transparency and bioavailability of water column phosphorus were enhanced. Thus, the risk of water bloom outburst significantly increased when the impounded water level of 175 m in the TGR became the normal state. Copyright © 2018 Elsevier Ltd. All rights reserved.

Age-dependent changes in the total protein concentrations in the ...

African Journals Online (AJOL)

related changes in total protein concentrations in ten regions of the pig brain and hypophyses from birth to 36 months of age. Age-related changes in protein concentrations in all the brain regions except the pons and cerebral cortex were not ...

Varying response of the concentration and content of soybean seed mineral elements, carbohydrates, organic acids, amino acids, protein, and oil to phosphorus starvation and CO2 enrichment

Science.gov (United States)

A detailed investigation of the concentration (g-1 seed weight) and content (g plant-1) of seed mineral elements and metabolic profile under phosphorus (P) starvation at ambient (aCO2) and elevated carbon dioxide (eCO2) in soybean is limited. Soybean plants were grown in a controlled environment at ...

Dominant mechanisms for the delivery of fine sediment and phosphorus to fluvial networks draining grassland dominated headwater catchments.

Science.gov (United States)

Perks, M T; Owen, G J; Benskin, C McW H; Jonczyk, J; Deasy, C; Burke, S; Reaney, S M; Haygarth, P M

2015-08-01

Recent advances in monitoring technology have enabled high frequency, in-situ measurements of total phosphorus and total reactive phosphorus to be undertaken with high precision, whilst turbidity can provide an excellent surrogate for suspended sediment. Despite these measurements being fundamental to understanding the mechanisms and flow paths that deliver these constituents to river networks, there is a paucity of such data for headwater agricultural catchments. The aim of this paper is to deduce the dominant mechanisms for the delivery of fine sediment and phosphorus to an upland river network in the UK through characterisation of the temporal variability of hydrological fluxes, and associated soluble and particulate concentrations for the period spanning March 2012-February 2013. An assessment of the factors producing constituent hysteresis is undertaken following factor analysis (FA) on a suite of measured environmental variables representing the fluvial and wider catchment conditions prior to, and during catchment-wide hydrological events. Analysis indicates that suspended sediment is delivered to the fluvial system predominantly via rapidly responding pathways driven by event hydrology. However, evidence of complex, figure-of-eight hysteresis is observed following periods of hydrological quiescence, highlighting the importance of preparatory processes. Sediment delivery via a slow moving, probably sub-surface pathway does occur, albeit infrequently and during low magnitude events at the catchment outlet. Phosphorus is revealed to have a distinct hysteretic response to that of suspended sediment, with sub-surface pathways dominating. However, high magnitude events were observed to exhibit threshold-like behaviour, whereby activation and connection of usually disconnected depositional zones to the fluvial networks results in the movement of vast phosphorus fluxes. Multiple pathways are observed for particulate and soluble constituents, highlighting the

Species-specific variation in the phosphorus nutritional sources by microphytoplankton in a Mediterranean estuary

Directory of Open Access Journals (Sweden)

MARLY CAROLINA MARTINEZ SOTO

2015-08-01

Full Text Available We investigated the species-specific phosphorus (P nutrition sources in the microphytoplankton community in the Mahon estuary (Minorca, Western Mediterranean in 2011, under two contrasting hydrographic scenarios. Estuarine flow, nutrient concentrations, phytoplankton community composition and enzyme-labeled fluorescence (ELF were measured in June and October, corresponding to the beginning and the end of summer. Dissolved inorganic nitrogen (DIN and inorganic phosphate (Pi exhibited enhanced concentrations in the inner estuary where N:P molar ratios suggested P-limitation in both surveys. Pi was low and variable (0.09±0.02 μmol•l-1 in June and 0.06±0.02 μmol•l-1 in October, whereas organic phosphorus remained a more reliable P source. Even though ambient Pi concentrations were slightly higher on June, when the microphytoplankton assemblage was dominated by dinoflagellates, the percentage of cells expressing ELF labeling was notably higher (65% of total cells than in October (12%, when the presence of diatoms characterized the microphytoplankton community. ELF was mainly expressed by dinoflagellate taxa, whereas diatoms only expressed significant AP in the inner estuary during the June survey. A P-addition bioassay in which response of AP to Pi enrichment was evaluated showed remarkable reduction in AP with increasing Pi. However, some dinoflagellate species maintained AP even when Pi was supplied in excess. We suggest that in the case of some dinoflagellate species AP is not as tightly controlled by ambient Pi as previously believed. AP activity in these species could indicate selective use of organic phosphorus, or slow metabolic response to changes in P forms, rather than physiological stress to low Pi availability. We emphasize the importance of identifying the links between the different P sources and the species-specific requirements, in order to understand the ecological response to anthropogenic biogeochemical perturbations.

Broiler diet modification and litter storage: impacts on phosphorus in litters, soils, and runoff.

Science.gov (United States)

McGrath, Joshua M; Sims, J Thomas; Maguire, Rory O; Saylor, William W; Angel, C Roselina; Turner, Benjamin L

2005-01-01

Modifying broiler diets to mitigate water quality concerns linked to excess phosphorus (P) in regions of intensive broiler production has recently increased. Our goals were to evaluate the effects of dietary modification, using phytase and reduced non-phytate phosphorus (NPP) supplementation, on P speciation in broiler litters, changes in litter P forms during long-term storage, and subsequent impacts of diets on P in runoff from litter-amended soils. Four diets containing two levels of NPP with and without phytase were fed to broilers in a three-flock floor pen study. After removal of the third flock, litters were stored for 440 d at their initial moisture content (MC; 24%) and at a MC of 40%. Litter P fractions and orthophosphate and phytate P concentrations were determined before and after storage. After storage, litters were incorporated with a sandy and silt loam and simulated rainfall was applied. Phytase and reduced dietary NPP significantly reduced litter total P. Reducing dietary NPP decreased water-extractable inorganic phosphorus (IP) and the addition of dietary phytase reduced NaOH- and HCl-extractable organic P in litter, which correlated well with orthophosphate and phytic acid measured by 31P nuclear magnetic resonance (NMR), respectively. Although dry storage caused little change in P speciation, wet storage increased concentrations of water-soluble IP, which increased reactive P in runoff from litter-amended soils. Therefore, diet modification with phytase and reduced NPP could be effective in reducing P additions on a watershed scale. Moreover, efforts to minimize litter MC during storage may reduce the potential for dissolved P losses in runoff.

Field Effect Optoelectronic Modulation of Quantum-Confined Carriers in Black Phosphorus.

Science.gov (United States)

Whitney, William S; Sherrott, Michelle C; Jariwala, Deep; Lin, Wei-Hsiang; Bechtel, Hans A; Rossman, George R; Atwater, Harry A

2017-01-11

We report measurements of the infrared optical response of thin black phosphorus under field-effect modulation. We interpret the observed spectral changes as a combination of an ambipolar Burstein-Moss (BM) shift of the absorption edge due to band-filling under gate control, and a quantum confined Franz-Keldysh (QCFK) effect, phenomena that have been proposed theoretically to occur for black phosphorus under an applied electric field. Distinct optical responses are observed depending on the flake thickness and starting carrier concentration. Transmission extinction modulation amplitudes of more than two percent are observed, suggesting the potential for use of black phosphorus as an active material in mid-infrared optoelectronic modulator applications.

Relation of nutrient concentrations, nutrient loading, and algal production to changes in water levels in Kabetogama Lake, Voyageurs National Park, northern Minnesota, 2008-09

Science.gov (United States)

Christensen, Victoria G.; Maki, Ryan P.; Kiesling, Richard L.

2011-01-01

Nutrient enrichment has led to excessive algal growth in Kabetogama Lake, Voyageurs National Park, northern Minnesota. Water- and sediment-quality data were collected during 2008-09 to assess internal and external nutrient loading. Data collection was focused in Kabetogama Lake and its inflows, the area of greatest concern for eutrophication among the lakes of Voyageurs National Park. Nutrient and algal data were used to determine trophic status and were evaluated in relation to changes in Kabetogama Lake water levels following changes to dam operation starting in 2000. Analyses were used to estimate external nutrient loading at inflows and assess the potential contribution of internal phosphorus loading. Kabetogama Lake often was mixed vertically, except for a few occasionally stratified areas, including Lost Bay in the northeastern part of Kabetogama Lake. Stratification, combined with larger bottom-water nutrient concentrations, larger sediment phosphorus concentrations, and estimated phosphorus release rates from sediment cores indicate that Lost Bay may be one of several areas that may be contributing substantially to internal loading. Internal loading is a concern because nutrients may cause excessive algal growth including potentially toxic cyanobacteria. The cyanobacterial hepatotoxin, microcystin, was detected in 7 of 14 cyanobacterial bloom samples, with total concentrations exceeding 1.0 microgram per liter, the World Health Organization's guideline for finished drinking water for the congener, microcystin-LR. Comparisons of the results of this study to previous studies indicate that chlorophyll-a concentrations and trophic state indices have improved since 2000, when the rules governing dam operation changed. However, total-phosphorus concentrations have not changed significantly since 2000.

Distribution and sources of carbon, nitrogen, phosphorus and ...

Indian Academy of Sciences (India)

(TN), total phosphorus (TP) and biogenic silica (BSi) in the sedimentary environments of Asia's largest brackish ... Chilika lagoon on water quality, ecology, metal pollution ...... coast of India; In: Mangrove Management & Conserva- tion (ed.) ...

interaction between phosphorus fertilizer and arbuscular ...

African Journals Online (AJOL)

userpc

examine the interaction between Phosphorus (P) fertilizer and Arbuscular Mycorrhizal Fungal ... recorded 28% and 4% total plant dry yield increment respectively over control. This study shows that ... ratio 1:3 inoculant: water, application per ... Table 1: Effect of P and AMF on the dry yield components of cassava (t ha-1).

Free amino nitrogen concentration correlates to total yeast assimilable nitrogen concentration in apple juice.

Science.gov (United States)

Boudreau, Thomas F; Peck, Gregory M; O'Keefe, Sean F; Stewart, Amanda C

2018-01-01

Yeast assimilable nitrogen (YAN) is essential for yeast growth and metabolism during apple ( Malus x domestica Borkh.) cider fermentation. YAN concentration and composition can impact cider fermentation kinetics and the formation of volatile aroma compounds by yeast. The YAN concentration and composition of apples grown in Virginia, USA over the course of two seasons was determined through analysis of both free amino nitrogen (FAN) and ammonium ion concentration. FAN was the largest fraction of YAN, with a mean value of 51 mg N L -1 FAN compared to 9 mg N L -1 ammonium. Observed YAN values ranged from nine to 249 mg N L -1 , with a mean value of 59 mg N L -1 . Ninety-four percent of all samples analyzed in this study contained yeast to fully utilize all of the fermentable sugars. FAN concentration was correlated with total YAN concentration, but ammonium concentration was not. Likewise, there was no correlation between FAN and ammonium concentration.

Determination of phosphorus in semiconductor grade silicon by neutron activation analysis

International Nuclear Information System (INIS)

Jaskolska, H.; Rowinska, L.

1975-01-01

A method of determination of phosphorus in silicon has been elaborated. The separation of phosphorus is based on the extraction of phosphomolybdic complex in the presence of hold-back carriers of Ta and Au. Contamination factors for various impurities were determined. The lower limit of determination equals 3.10 -11 g P. Types of errors in the determination of concentration profiles are discussed. The method meets the following requirements: 1./ It ensures good separation of phosphorus from elements occuring in silicon plates (i.e. Ta, Au, Sn, Ge, Ce, Sb, As, Cu, and Na). 2./ It ensures high chemical yield of phosphorus separation. 3./ It ensures high efficiency of the measurement of 32 P β-activity. 4./ It is simple and rapid, since, for the determination of a implantation profile, it is necessary to analyse several tens of layers. (T.G.)

Phosphorus Fluxes from Three Coastal Watersheds under Varied Agriculture Intensities to the Northern Gulf of Mexico

Directory of Open Access Journals (Sweden)

Songjie He

2018-06-01

Full Text Available This study aims to evaluate recent total phosphorus (TP and dissolved inorganic phosphorus (DIP transport from three coastal rivers—the Calcasieu, Mermentau, and Vermilion Rivers—that drain watersheds with varied agriculture intensities (21%, 67%, and 61%, respectively into the northern Gulf of Mexico, one of the world’s largest summer hypoxic zones. The study also examined the spatial trends of TP and DIP from freshwater to saltwater along an 88-km estuarine reach with salinity increasing from 0.02 to 29.50. The results showed that from 1990–2009 to 2010–2017, the TP fluxes for one of the agriculture-intensive rivers increased while no significant change was found for the other two rivers. Change in river discharge was the main reason for this TP flux trend. The two more agriculture-intensive river basins showed consistently higher TP and DIP concentrations and fluxes, as well as higher DIP:TP ratios than the river draining less agriculture-intensive land, confirming the strong effect of land uses on phosphorus input and speciation. Longitudinal profiles of DIP along the salinity gradient of the estuarine reach displayed characteristic input behavior. Desorption of DIP from suspended solids and river bed sediments, urban inputs, as well as stronger calcium carbonate and phosphorus co-precipitation at the marine endmember could be the reasons for such mixing dynamics.

Internal loading of phosphorus in western Lake Erie

Science.gov (United States)

Matisoff, Gerald; Kaltenberg, Eliza M.; Steely, Rebecca L.; Hummel, Stephanie K.; Seo, Jinyu; Gibbons, Kenneth J.; Bridgeman, Thomas B.; Seo, Youngwoo; Behbahani, Mohsen; James, William F.; Johnson, Laura; Doan, Phuong; Dittrich, Maria; Evans, Mary Anne; Chaffin, Justin D.

2016-01-01

This study applied eight techniques to obtain estimates of the diffusive flux of phosphorus (P) from bottom sediments throughout the western basin of Lake Erie. The flux was quantified from both aerobic and anaerobic incubations of whole cores; by monitoring the water encapsulated in bottom chambers; from pore water concentration profiles measured with a phosphate microelectrode, a diffusive equilibrium in thin films (DET) hydrogel, and expressed pore waters; and from mass balance and biogeochemical diagenetic models. Fluxes under aerobic conditions at summertime temperatures averaged 1.35 mg P/m2/day and displayed spatial variability on scales as small as a centimeter. Using two different temperature correction factors, the flux was adjusted to mean annual temperature yielding average annual fluxes of 0.43–0.91 mg P/m2/day and a western basin-wide total of 378–808 Mg P/year as the diffusive flux from sediments. This is 3–7% of the 11,000 Mg P/year International Joint Commission (IJC) target load for phosphorus delivery to Lake Erie from external sources. Using these average aerobic fluxes, the sediment contributes 3.0–6.3 μg P/L as a background internal contribution that represents 20–42% of the IJC Target Concentration of 15 μg P/L for the western basin. The implication is that this internal diffusive recycling of P is unlikely to trigger cyanobacterial blooms by itself but is sufficiently large to cause blooms when combined with external loads. This background flux may be also responsible for delayed response of the lake to any decrease in the external loading.

Total mercury concentration in common fish species of Lake Victoria ...

African Journals Online (AJOL)

Total mercury (THg) concentration was analysed in muscles of common fish species of Lake Victoria in the eastern and southern parts of the lake using cold vapour Atomic Absorption Spectrophotometric technique. Mercury concentration in all fish species was generally lower than the WHO maximum allowable ...

Removal of phosphorus from aqueous solution by Posidonia oceanica fibers using continuous stirring tank reactor

Energy Technology Data Exchange (ETDEWEB)

Wahab, Mohamed Ali, E-mail: waheb_med@yahoo.fr [University of Carthage, Water Research and Technologies Centre (CERTE), Wastewater Treatment and Recycling Laboratory, B.P. 273, 8020 Soliman (Tunisia); Hassine, Rafik Ben [International Environmental Green Technology (IGET) (Tunisia); Jellali, Salah, E-mail: salah.jallali@certe.rnrt.tn [University of Carthage, Water Research and Technologies Centre (CERTE), Wastewater Treatment and Recycling Laboratory, B.P. 273, 8020 Soliman (Tunisia)

2011-05-15

The present study aims to develop a new potentially low-cost, sustainable treatment approach to soluble inorganic phosphorus removal from synthetic solutions and secondary wastewater effluents in which a plant waste (Posidonia oceanica fiber: POF) is used for further agronomic benefit. Dynamic flow tests using a continuous stirred tank reactor (CSTR) were carried out to study the effect of initial concentration of phosphorus, amount of adsorbent, feeding flow rate and anions competition. The experimental results showed that the removal efficiency of phosphorus from synthetic solutions is about 80% for 10 g L{sup -1} of POF. In addition, the variation of the initial concentration of phosphorus from 8 to 50 mg L{sup -1} increased the adsorption capacity from 0.99 to 3.03 mg g{sup -1}. The use of secondary treated wastewater showed the presence of competition phenomenon between phosphorus and sulphate which could be overcoming with increasing the sorptive surface area and providing more adsorption sites when increasing the adsorbent dosage of POF. Compared with columns studies, this novel CSTR system showed more advantages for the removal of soluble phosphorus as a tertiary treatment of urban secondary effluents with more adsorption efficiency and capacity, in addition to the prospect use of saturated POF with nutriment as fertilizer and compost.

Removal of phosphorus from aqueous solution by Posidonia oceanica fibers using continuous stirring tank reactor

International Nuclear Information System (INIS)

Wahab, Mohamed Ali; Hassine, Rafik Ben; Jellali, Salah

2011-01-01

The present study aims to develop a new potentially low-cost, sustainable treatment approach to soluble inorganic phosphorus removal from synthetic solutions and secondary wastewater effluents in which a plant waste (Posidonia oceanica fiber: POF) is used for further agronomic benefit. Dynamic flow tests using a continuous stirred tank reactor (CSTR) were carried out to study the effect of initial concentration of phosphorus, amount of adsorbent, feeding flow rate and anions competition. The experimental results showed that the removal efficiency of phosphorus from synthetic solutions is about 80% for 10 g L -1 of POF. In addition, the variation of the initial concentration of phosphorus from 8 to 50 mg L -1 increased the adsorption capacity from 0.99 to 3.03 mg g -1 . The use of secondary treated wastewater showed the presence of competition phenomenon between phosphorus and sulphate which could be overcoming with increasing the sorptive surface area and providing more adsorption sites when increasing the adsorbent dosage of POF. Compared with columns studies, this novel CSTR system showed more advantages for the removal of soluble phosphorus as a tertiary treatment of urban secondary effluents with more adsorption efficiency and capacity, in addition to the prospect use of saturated POF with nutriment as fertilizer and compost.

Exchange of reactive nitrogen compounds: concentrations and fluxes of total ammonium and total nitrate above a spruce canopy

Directory of Open Access Journals (Sweden)

V. Wolff

2010-05-01

Full Text Available Total ammonium (tot-NH₄⁺ and total nitrate (tot-NO₃⁻ provide chemically conservative quantities in the measurement of surface exchange of reactive nitrogen compounds ammonia (NH₃, particulate ammonium (NH₄⁺, nitric acid (HNO₃, and particulate nitrate (NO₃⁻, using the aerodynamic gradient method. Total fluxes were derived from concentration differences of total ammonium (NH₃ and NH₄⁺ and total nitrate (HNO₃ and NO₃⁻ measured at two levels. Gaseous species and related particulate compounds were measured selectively, simultaneously and continuously above a spruce forest canopy in south-eastern Germany in summer 2007. Measurements were performed using a wet-chemical two-point gradient instrument, the GRAEGOR. Median concentrations of NH₃, HNO₃, NH₄⁺, and NO₃⁻ were 0.57, 0.12, 0.76, and 0.48 μg m⁻³, respectively. Total ammonium and total nitrate fluxes showed large variations depending on meteorological conditions, with concentrations close to zero under humid and cool conditions and higher concentrations under dry conditions. Mean fluxes of total ammonium and total nitrate in September 2007 were directed towards the forest canopy and were −65.77 ng m⁻² s⁻¹ and −41.02 ng m⁻² s⁻¹ (in terms of nitrogen, respectively. Their deposition was controlled by aerodynamic resistances only, with very little influence of surface resistances. Including measurements of wet deposition and findings of former studies on occult deposition (fog water interception at the study site, the total N deposition in September 2007 was estimated to 5.86 kg ha⁻¹.

Inorganic phosphorus decrease after intravenous glucose tolerance test is associated with insulin resistance in dairy cows

OpenAIRE

Cincović, Marko R.; Djoković, Radojica; Belić, Branislavav; Potkonjak, Aleksandar; Toholj, Bojan; Stojanac, Nenad; Stevančević, Ognjen; Starič, Jože

2017-01-01

Inorganic phosphorus (Pi) concentration in blood decreases during an intravenous glucose tolerance test (IVGTT) due to the increase in the level of insulin and glucose. The objective of the present study was to determine the relationship between the intensity of Pi decrease with a dynamic change of insulin and glucose during IVGTT (AUC - total area under curve, AUC increment - area under curve from start of IVGTT to time of maximal response and glucose CR-clearance rate), as well as RQUICKI (...

Simultaneous nitrification-denitrification and phosphorus removal in a fixed bed sequencing batch reactor (FBSBR)

International Nuclear Information System (INIS)

Rahimi, Yousef; Torabian, Ali; Mehrdadi, Naser; Shahmoradi, Behzad

2011-01-01

Research highlights: → Sludge production in FSBR reactor is 20-30% less than SBR reactor. → FSBR reactor showed more nutrient removal rate than SBR reactor. → FSBR reactor showed less VSS/TSS ratio than SBR reactor. - Abstract: Biological nutrient removal (BNR) was investigated in a fixed bed sequencing batch reactor (FBSBR) in which instead of activated sludge polypropylene carriers were used. The FBSBR performance on carbon and nitrogen removal at different loading rates was significant. COD, TN, and phosphorus removal efficiencies were at range of 90-96%, 60-88%, and 76-90% respectively while these values at SBR reactor were 85-95%, 38-60%, and 20-79% respectively. These results show that the simultaneous nitrification-denitrification (SND) is significantly higher than conventional SBR reactor. The higher total phosphorus (TP) removal in FBSBR correlates with oxygen gradient in biofilm layer. The influence of fixed media on biomass production yield was assessed by monitoring the MLSS concentrations versus COD removal for both reactors and results revealed that the sludge production yield (Y obs ) is significantly less in FBSBR reactors compared with SBR reactor. The FBSBR was more efficient in SND and phosphorus removal. Moreover, it produced less excess sludge but higher in nutrient content and stabilization ratio (less VSS/TSS ratio).

Simultaneous nitrification-denitrification and phosphorus removal in a fixed bed sequencing batch reactor (FBSBR)

Energy Technology Data Exchange (ETDEWEB)

Rahimi, Yousef, E-mail: you.rahimi@gmail.com [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave, Tehran (Iran, Islamic Republic of); Torabian, Ali, E-mail: atorabi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave, Tehran (Iran, Islamic Republic of); Mehrdadi, Naser, E-mail: mehrdadi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave, Tehran (Iran, Islamic Republic of); Shahmoradi, Behzad, E-mail: bshahmorady@gmail.com [Department of Environmental Science, University of Mysore, MGM-06 Mysore (India)

2011-01-30

Research highlights: {yields} Sludge production in FSBR reactor is 20-30% less than SBR reactor. {yields} FSBR reactor showed more nutrient removal rate than SBR reactor. {yields} FSBR reactor showed less VSS/TSS ratio than SBR reactor. - Abstract: Biological nutrient removal (BNR) was investigated in a fixed bed sequencing batch reactor (FBSBR) in which instead of activated sludge polypropylene carriers were used. The FBSBR performance on carbon and nitrogen removal at different loading rates was significant. COD, TN, and phosphorus removal efficiencies were at range of 90-96%, 60-88%, and 76-90% respectively while these values at SBR reactor were 85-95%, 38-60%, and 20-79% respectively. These results show that the simultaneous nitrification-denitrification (SND) is significantly higher than conventional SBR reactor. The higher total phosphorus (TP) removal in FBSBR correlates with oxygen gradient in biofilm layer. The influence of fixed media on biomass production yield was assessed by monitoring the MLSS concentrations versus COD removal for both reactors and results revealed that the sludge production yield (Y{sub obs}) is significantly less in FBSBR reactors compared with SBR reactor. The FBSBR was more efficient in SND and phosphorus removal. Moreover, it produced less excess sludge but higher in nutrient content and stabilization ratio (less VSS/TSS ratio).

Changes in water quality of the River Frome (UK) from 1965 to 2009: Is phosphorus mitigation finally working?

Energy Technology Data Exchange (ETDEWEB)

Bowes, M.J., E-mail: mibo@ceh.ac.uk [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom); Smith, J.T. [School of Earth and Environmental Sciences, Burnaby Building, University of Portsmouth, Portsmouth PO1 3QL (United Kingdom); Neal, C. [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom); Leach, D.V. [formally Centre for Ecology and Hydrology, Winfrith Technology Centre, Dorchester, Dorset, DT2 8ZD (United Kingdom); Scarlett, P.M.; Wickham, H.D.; Harman, S.A.; Armstrong, L.K. [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom); Davy-Bowker, J. [Freshwater Biological Association, River Laboratory, East Stoke, Wareham, Dorset, BH20 6BB (United Kingdom); Haft, M. [Freshwater Biological Association, Ferry Landing, Far Sawrey, Ambleside, Cumbria, LA22 0LP (United Kingdom); Davies, C.E. [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom)

2011-08-15

The water quality of the River Frome, Dorset, southern England, was monitored at weekly intervals from 1965 until 2009. Determinands included phosphorus, nitrogen, silicon, potassium, calcium, sodium, magnesium, pH, alkalinity and temperature. Nitrate-N concentrations increased from an annual average of 2.4 mg l{sup -1} in the mid to late 1960s to 6.0 mg l{sup -1} in 2008-2009, but the rate of increase was beginning to slow. Annual soluble reactive phosphorus (SRP) concentrations increased from 101 {mu}g l{sup -1} in the mid 1960s to a maximum of 190 {mu}g l{sup -1} in 1989. In 2002, there was a step reduction in SRP concentration (average = 88 {mu}g l{sup -1} in 2002-2005), with further improvement in 2007-2009 (average = 49 {mu}g l{sup -1}), due to the introduction of phosphorus stripping at sewage treatment works. Phosphorus and nitrate concentrations showed clear annual cycles, related to the timing of inputs from the catchment, and within-stream bioaccumulation and release. Annual depressions in silicon concentration each spring (due to diatom proliferation) reached a maximum between 1980 and 1991, (the period of maximum SRP concentration) indicating that algal biomass had increased within the river. The timing of these silicon depressions was closely related to temperature. Excess carbon dioxide partial pressures (EpCO{sub 2}) of 60 times atmospheric CO{sub 2} were also observed through the winter periods from 1980 to 1992, when phosphorus concentration was greatest, indicating very high respiration rates due to microbial decomposition of this enhanced biomass. Declining phosphorus concentrations since 2002 reduced productivity and algal biomass in the summer, and EpCO{sub 2} through the winter, indicating that sewage treatment improvements had improved riverine ecology. Algal blooms were limited by phosphorus, rather than silicon concentration. The value of long-term water quality data sets is discussed. The data from this monitoring programme are made

Organic chemistry of elemental phosphorus

International Nuclear Information System (INIS)

Milyukov, V A; Budnikova, Yulia H; Sinyashin, Oleg G

2005-01-01

The principal achievements and the modern trends in the development of the chemistry of elemental phosphorus are analysed, described systematically and generalised. The possibilities and advantages of the preparation of organophosphorus compounds directly from white phosphorus are demonstrated. Attention is focused on the activation and transformation of elemental phosphorus in the coordination sphere of transition metal complexes. The mechanisms of the reactions of white phosphorus with nucleophilic and electrophilic reagents are discussed. Electrochemical approaches to the synthesis of organic phosphorus derivatives based on white phosphorus are considered.

Preliminary evaluation of serum total cholesterol concentrations in dogs with osteosarcoma.

Science.gov (United States)

Leeper, H; Viall, A; Ruaux, C; Bracha, S

2017-10-01

To determine if total serum cholesterol concentrations were altered in dogs with osteosarcoma. To evaluate association of total serum cholesterol concentration with clinical outcomes in dogs with appendicular osteosarcoma. Retrospective, multi-institutional study on 64 dogs with osteosarcoma. Control population consisted of dogs with traumatic bone fractures (n=30) and healthy patients of similar age and weight as those of the osteosarcoma cases (n=31). Survival analysis was done on 35 appendicular osteosarcoma patients that received the current standard of care. Statistical associations were assessed by univariable and multi-variable analysis. Information about age, sex, primary tumour location, total cholesterol concentration, monocytes and lymphocyte counts and alkaline phosphatase were also included. Total cholesterol was elevated above the reference interval (3·89 to 7·12 mmol/L) (150 to 275 mg/dL) in 29 of 64 (45·3%) osteosarcoma-bearing dogs, whereas similar elevations were found in only 3 of 30 (10%) fracture controls (Posteosarcoma. These results suggest that elevated total cholesterol is associated with canine osteosarcoma and may have prognostic significance. © 2017 British Small Animal Veterinary Association.

Estimating phosphorus intake by grazing sheep

African Journals Online (AJOL)

phosphorus levels in various organs, tissues, bones, body fluids or excretory products of sheep reflected dietary ... did decrease bone mineral deposition slightly. Rumen fluid P and total daily urinary P levels did .... which were alike in composition except for their levels of. P and Ca. After 98 days rib biopsy specimens were.

Prevalence of Phosphorus-Based Additives in the Australian Food Supply: A Challenge for Dietary Education?

Science.gov (United States)

McCutcheon, Jemma; Campbell, Katrina; Ferguson, Maree; Day, Sarah; Rossi, Megan

2015-09-01

Phosphorus-based food additives may pose a significant risk in chronic kidney disease given the link between hyperphosphatemia and cardiovascular disease. The objective of the study was to determine the prevalence of phosphorus-based food additives in best-selling processed grocery products and to establish how they were reported on food labels. A data set of 3000 best-selling grocery items in Australia across 15 food and beverage categories was obtained for the 12 months ending December 2013 produced by the Nielsen Company's Homescan database. The nutrition labels of the products were reviewed in store for phosphorus additives. The type of additive, total number of additives, and method of reporting (written out in words or as an E number) were recorded. Presence of phosphorus-based food additives, number of phosphorus-based food additives per product, and the reporting method of additives on product ingredient lists. Phosphorus-based additives were identified in 44% of food and beverages reviewed. Additives were particularly common in the categories of small goods (96%), bakery goods (93%), frozen meals (75%), prepared foods (70%), and biscuits (65%). A total of 19 different phosphorus additives were identified across the reviewed products. From the items containing phosphorus additives, there was a median (minimum-maximum) of 2 (1-7) additives per product. Additives by E number (81%) was the most common method of reporting. Phosphorus-based food additives are common in the Australian food supply. This suggests that prioritizing phosphorus additive education may be an important strategy in the dietary management of hyperphosphatemia. Further research to establish a database of food items containing phosphorus-based additives is warranted. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

A representation of the phosphorus cycle for ORCHIDEE (revision 4520)

Science.gov (United States)

Goll, Daniel S.; Vuichard, Nicolas; Maignan, Fabienne; Jornet-Puig, Albert; Sardans, Jordi; Violette, Aurelie; Peng, Shushi; Sun, Yan; Kvakic, Marko; Guimberteau, Matthieu; Guenet, Bertrand; Zaehle, Soenke; Penuelas, Josep; Janssens, Ivan; Ciais, Philippe

2017-10-01

Land surface models rarely incorporate the terrestrial phosphorus cycle and its interactions with the carbon cycle, despite the extensive scientific debate about the importance of nitrogen and phosphorus supply for future land carbon uptake. We describe a representation of the terrestrial phosphorus cycle for the ORCHIDEE land surface model, and evaluate it with data from nutrient manipulation experiments along a soil formation chronosequence in Hawaii. ORCHIDEE accounts for the influence of the nutritional state of vegetation on tissue nutrient concentrations, photosynthesis, plant growth, biomass allocation, biochemical (phosphatase-mediated) mineralization, and biological nitrogen fixation. Changes in the nutrient content (quality) of litter affect the carbon use efficiency of decomposition and in return the nutrient availability to vegetation. The model explicitly accounts for root zone depletion of phosphorus as a function of root phosphorus uptake and phosphorus transport from the soil to the root surface. The model captures the observed differences in the foliage stoichiometry of vegetation between an early (300-year) and a late (4.1 Myr) stage of soil development. The contrasting sensitivities of net primary productivity to the addition of either nitrogen, phosphorus, or both among sites are in general reproduced by the model. As observed, the model simulates a preferential stimulation of leaf level productivity when nitrogen stress is alleviated, while leaf level productivity and leaf area index are stimulated equally when phosphorus stress is alleviated. The nutrient use efficiencies in the model are lower than observed primarily due to biases in the nutrient content and turnover of woody biomass. We conclude that ORCHIDEE is able to reproduce the shift from nitrogen to phosphorus limited net primary productivity along the soil development chronosequence, as well as the contrasting responses of net primary productivity to nutrient addition.

Colorimetric Chemical Differentiation and Detection of Phosphorus in Eutrophic and High Particulate Waters: Advantages of a New Monitoring Approach

Directory of Open Access Journals (Sweden)

Lisa Felgentreu

2018-06-01

Full Text Available Phosphorus (P is a key factor forcing eutrophication in limnic and marine systems, and all monitoring programs for water quality accordingly include P determinations. However, traditional monitoring does not allow an analysis of the different components involved in the P cycle taking place in the water column. Nonetheless, the implementation of measures addressing eutrophication requires a full understanding of the processes involved in the transformation and transport of P, in all its chemical forms. In this study, the P categories present in a river and its estuary in northern Germany, which discharge into the Baltic Sea, were characterized. Using the molybdenum blue method we found that the classification of P into the traditional fractions (DIP, DOP, POP applied in the ocean cannot be applied to turbid waters such as rivers because interferences between the fractions seems to occur. Therefore a new nomenclature has been introduced. In addition to total phosphorus (TP and dissolved molybdate-reactive phosphorus (DRP; previously referred to as inorganic phosphorus, dissolved non-molybdate-reactive phosphorus (DNP, particulate molybdatereactive phosphorus (PRP, and particulate non-molybdate-reactive phosphorus (PNP were distinguished. The high spatial and temporal variations in the proportions of these forms with respect to the TP concentration well-demonstrate the complexity of the P cycle and the involved P fractions and emphasize the need for expanded monitoring approach. The potential of eutrophication could be underestimated if not all P categories were considered. With the new operational nomenclature the common and standardized molybdenum blue reaction could be used to implement the analysis of various P components into regular monitoring programs.

Comparison of phosphorus fraction distribution and influencing factors of suspended and surface sediments in the Tiaoxi watershed, China.

Science.gov (United States)

Ye, Hongmeng; Yuan, Xuyin; Han, Lei; Yin, Heng; Jin, Jing

2017-05-01

Suspended and surface sediments from the Tiaoxi watershed, fed by the Xitiaoxi and Dongtiaoxi rivers, were analyzed for total phosphorus (TP) and the inorganic P fractions of loosely adsorbed P that were extractable with NH 4 Cl (NH 4 Cl-P), reductant P (BD-P), metal oxide-bound P extractable with NaOH (NaOH-P), and calcium-bound, HCl-extractable P (HCl-P), while other physicochemical compositions were also determined. The spatial variations of P fractions in these sediments were investigated, and the major factors influencing the various fractions were explored by multivariate statistics. Compared to surface sediments, suspended sediments contained considerably higher concentrations of total nitrogen, TP, organic matter, Al, Fe, Mn and biologically available P (BAP, given as NH 4 Cl-P, BD-P and NaOH-P combined) and lower concentrations of Si, Ca and HCl-P in the studied catchments. Dongtiaoxi sediments had higher TP, inorganic phosphorus and HCl-P concentrations and a lower BAP content compared with Xitiaoxi sediments, trends that were associated with local geological backgrounds, landscapes and anthropogenic characteristics. The results of principal component analysis showed different effects of sediment properties on P fraction distributions for Xitiaoxi and Dongtiaoxi sediments. The sediment components and structure exert a strong influence on BAP in Xitiaoxi sediments, in contrast to Dongtiaoxi sediments, where P fractions are mainly affected by urbanization and other anthropogenic activities such as shipping.

Effect of Aquatic Plants on Phosphorus Removal and Electrical Conductivity Decrease in Municipal Effluent

Directory of Open Access Journals (Sweden)

Sara Samimi Loghmani

2014-05-01

Full Text Available Phosphorus (P is one of essential elements for living organisms, though its critical concentration in surface and ground waters impose a serious problem such as eutrophication. So treatment of polluted waters is required before discharging to water resources. One of effective ways to decrease water pollution is using aquatic plants. An experiment was conducted in pilots with a closed flowing system on two plants, elodea (egria densa and duck weed (lemna minor with four treatments and three replications. Data were analyzed in a factorial completely randomized design. Treatments included effluent with and without the plants, and effluent diluted (dilution grade 1/2 with and without the plants. Total dissolved P, electrical conductivity (EC and pH value were measured after 8, 16 and 24 days in effluent samples. The results showed that pH value decreased up to 0.2 units during of 24 days of the experiment, but there was found no significant difference (p≤0.05 in pH values among the treatments. Both plants decreased EC about 7 % relative to the control (without plant after 24 days. The plants were also effective in reducing total dissolved phosphorus, so that duck weed and elodea decreased total dissolved P in the effluent about 49 and 7%, respectively. It is concluded that duck weed is more effective in the P removal from the effluent than the other plant.

PHOSPHORUS-BEARING MOLECULES IN MASSIVE DENSE CORES

Energy Technology Data Exchange (ETDEWEB)

Fontani, F.; Rivilla, V. M. [INAF-Osservatorio Astrofisico di Arcetri, L.go E. Fermi 5, I-50125 Firenze (Italy); Caselli, P.; Vasyunin, A. [Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse, D-85748 Garching (Germany); Palau, A. [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, P.O. Box 3-72, 58090 Morelia, Michoacán, México (Mexico)

2016-05-10

Phosphorus is a crucial element for the development of life, but so far P-bearing molecules have been detected only in a few astrophysical objects; hence, its interstellar chemistry is almost totally unknown. Here, we show new detections of phosphorus nitride (PN) in a sample of dense cores in different evolutionary stages of the intermediate- and high-mass star formation process: starless, with protostellar objects, and with ultracompact H ii regions. All detected PN line widths are smaller than ≃5 km s{sup −1}, and they arise from regions associated with kinetic temperatures smaller than 100 K. Because the few previous detections reported in the literature are associated with warmer and more turbulent sources, the results of this work show that PN can arise from relatively quiescent and cold gas. This information is challenging for theoretical models that invoke either high desorption temperatures or grain sputtering from shocks to release phosphorus into the gas phase. Derived column densities are of the order of 10{sup 11–12} cm{sup −2}, marginally lower than the values derived in the few high-mass star-forming regions detected so far. New constraints on the abundance of phosphorus monoxide, the fundamental unit of biologically relevant molecules, are also given.

Particle-size distribution and phosphorus forms as a function of hydrological forcing in the Yellow River.

Science.gov (United States)

Yao, Qing-Zhen; Du, Jun-Tao; Chen, Hong-Tao; Yu, Zhi-Gang

2016-02-01

Samples were collected monthly from January to December in 2010, and daily observations were made during the water-sediment regulation event in June-July 2010. Sequential extractions were applied to determine the forms of P in different particle-size fractions and to assess the potential bioavailability of particulate phosphorus (PP). The results indicated that exchangeable phosphorus, organic phosphorus, authigenic phosphorus, and refractory phosphorus increased with the decreasing of particulate size; conversely, detrital phosphorus decreased with the decreasing of particulate size. The content of bioavailable particulate phosphorus (BAPP) varied greatly in different sizes of particles. In general, the smaller the particle size, the higher the content of bioavailable phosphorus and its proportion in total phosphorous was found in these particles. Hydrological forcing controlled the variability in the major P phases found in the suspended sediments via changes in the sources and the particle grain-size distribution. The variation of particle sizes can be attributed also to different total suspended sediment (TSS) sources. Water-sediment regulation (WSR) mobilized only particulate matter from the riverbed, while during the rainstorm soil erosion and runoff were the main source. The BAPP fluxes associated with the "truly suspended" fraction was approximately 200 times larger than the dissolved inorganic phosphorus (DIP) flux. Thus, the transfer of fine particles to the open sea is most probably accompanied by BAPP release to the DIP and can support greater primary and secondary production.

Ultrasound coupled with Fenton oxidation pre-treatment of sludge to release organic carbon, nitrogen and phosphorus

Energy Technology Data Exchange (ETDEWEB)

Gong, Changxiu [School of Environment, Tsinghua University, Beijing 100084 (China); Jiang, Jianguo, E-mail: jianguoj@mail.tsinghua.edu.cn [School of Environment, Tsinghua University, Beijing 100084 (China); Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China (China); Collaborative Innovation Center for Regional Environmental Quality, Tsinghua University, Beijing (China); Li, De' an [School of Environment, Tsinghua University, Beijing 100084 (China)

2015-11-01

We focused on the effects of ultrasound and Fenton reagent in ultrasonic coupling Fenton oxidation (U + F) pre-treatment processes on the disintegration of wastewater treatment plant sludge. The results demonstrated that U + F treatment could significantly increase soluble COD, TOC, total N, proteins, total P and PO{sub 4}{sup 3−} concentrations in sludge supernatant. This method was more effective than ultrasonic (U) or Fenton oxidation (F) treatment alone. U + F treatment increased the soluble COD by 2.1- and 1.4-fold compared with U and F alone, respectively. U + F treatment increased the total N and P by 1.7- and 2.2-fold, respectively, compared with F alone. After U + F treatment, sludge showed a considerably finer particle size and looser microstructure based on scanning electron microscopy, and the highest OH· signal intensity increased from 568.7 by F treatment to 1106.3 using electron spin resonance. This demonstrated that U + F treatment induces disintegration of sludge and release of organic carbon, nitrogen and phosphorus better. - Highlights: • Combined ultrasound–Fenton pre-treatment was proposed for sludge disintegration. • Ultrasound–Fenton significantly increased carbon, nitrogen and phosphorus release. • Higher level of OH· was detected after combined disintegration than Fenton.

Ultrasound coupled with Fenton oxidation pre-treatment of sludge to release organic carbon, nitrogen and phosphorus

International Nuclear Information System (INIS)

Gong, Changxiu; Jiang, Jianguo; Li, De'an

2015-01-01

We focused on the effects of ultrasound and Fenton reagent in ultrasonic coupling Fenton oxidation (U + F) pre-treatment processes on the disintegration of wastewater treatment plant sludge. The results demonstrated that U + F treatment could significantly increase soluble COD, TOC, total N, proteins, total P and PO 4 3− concentrations in sludge supernatant. This method was more effective than ultrasonic (U) or Fenton oxidation (F) treatment alone. U + F treatment increased the soluble COD by 2.1- and 1.4-fold compared with U and F alone, respectively. U + F treatment increased the total N and P by 1.7- and 2.2-fold, respectively, compared with F alone. After U + F treatment, sludge showed a considerably finer particle size and looser microstructure based on scanning electron microscopy, and the highest OH· signal intensity increased from 568.7 by F treatment to 1106.3 using electron spin resonance. This demonstrated that U + F treatment induces disintegration of sludge and release of organic carbon, nitrogen and phosphorus better. - Highlights: • Combined ultrasound–Fenton pre-treatment was proposed for sludge disintegration. • Ultrasound–Fenton significantly increased carbon, nitrogen and phosphorus release. • Higher level of OH· was detected after combined disintegration than Fenton

[Bioretention Media Screening for the Removal of Phosphorus in Urban Stormwater].

Science.gov (United States)

Li, Li-qing; Gong, Yan-fang; Yan, Zi-qin; Shan, Bao-qing

2015-07-01

Urban runoff is an increasingly important source of excess phosphorus (P) to local receiving waters. Bioretention, a promising technology for urban stormwater pollution treatment, was investigated to determine whether the mixture of purple soil and sand could adsorb sufficient P at low concentrations in urban stormwater. The TP concentrations of urban runoff from variously impervious areas in Chongqing City ranged from 0. 04 to 7. 00 mg . L-1 (mean ± S. D. = 0. 75 mg . L-1 ± 1. 08 mg . L-1); the TDP concentrations ranged from 0. 02-0. 46 mg . L-1 ( mean ± S. D. = 0. 15 mg . L-1 ± 0. 10 mg . L-1). The media adsorption benchmark was determined for a bioretention facility sized at 10% of the 100% impervious catchment area and having 10 years of capacity according to annual rainfall pattern and the runoff TDP range. The media benchmark for adsorption was calculated as 7. 5 mg . kg-1 at soluble P concentration of 0. 30 mg . L-1 which provided the necessary stormwater treatment. The oxalate-extractable aluminum and iron content influenced the P sorption capacity for neutral and acid purple soils. A strong positive linear relationship was observed between the oxalate ratio [OR = (Alox + Feox)/Pox] and media P sorption capacity. The media mixture of 20% purple soil and 80% sand showed excellent P removal, meeting the developed benchmark for adsorptive behavior. The media mixture in a large-scale (60 cm) column consistently produced soluble reactive phosphorus effluent event with mean concentrations soil and sand can be used as a bioretention media to treat low-concentration phosphorus in urban runoff under various hydrologic and pollutant concentration conditions.

Impacts of dietary calcium, phytate, and nonphytate phosphorus concentrations in the presence or absence of phytase on inositol hexakisphosphate (IP6) degradation in different segments of broilers digestive tract

Science.gov (United States)

Li, W.; Angel, R.; Kim, S.-W.; Brady, K.; Yu, S.; Plumstead, P. W.

2016-01-01

A total of 1,440 straight-run Heritage 56M × fast-feathering Cobb 500F broiler birds were fed from 11 to 13 d of age to determine the impacts of calcium (Ca), phytate phosphorus (PP), nonphytate P (nPP) and phytase concentrations on the myo-inositol hexakisphosphate (IP6) flow through the different parts of gastrointestinal tract (GIT). The experiment was a 2×2×2×3 randomized block design with 2 Ca (0.7 and 1.0%), 2 PP (0.23 and 0.34%), 2 nPP (0.28 and 0.45%) and 3 phytase (0-, 500-, and 1,000-phytase unit (FTU)/kg) concentrations. The experiment was replicated twice (block) with 3 replicates per treatment (Trt) of 10 birds per block. Concentration of IP6 in crop, proventriculus (Prov) plus (+) gizzard (Giz) and distal ileum digesta as well as the ileal IP6 disappearance was determined at 13 d of age. In crop, higher IP6 concentration was seen with increased Ca (P phytase, higher dietary PP led to greater IP6 concentration (P phytase were also seen in Prov+Giz and ileum (P phytase improved IP6 degradation but the degree of impact was dependent on nPP and PP (P phytase inclusion significantly reduced IP6 concentration and IP6 disappearance in distal ileum regardless of GIT segments or diet composition, but impacts of dietary Ca, nPP, and PP differed depending on GIT segment examined. PMID:26740131

The determination of phosphorus in uranium minerals and resulting solutions

International Nuclear Information System (INIS)

Petrement Eguiluz, J. C.; Parellada Bellod, R.; Fernandez Cellini, R.

1964-01-01

Interferences of several elements present in Spanish uranium minerals in the phosphorus determination by the spectrophotometrical method of the molibdovanada te phosphoric acid are studied. A method is described with a previous separation of these element by a cationic resin. This method is successfully applied to the phosphorus determination in acid or alkaline lixiviation solutions of uranium minerals, as well as in the evaluates of ion exchange resins used used technically for the concentration of solutions with a low uranium content. (Author) 11 refs

Phosphogypsum analysis: total content and extractable element concentrations

International Nuclear Information System (INIS)

Gennari, Roseli F.; Medina, Nilberto H.; Garcia, Isabella; Silveira, Marcilei A.G.

2011-01-01

Phosphogypsum stand for the chemical origin gypsum generated in fertilizers production, in which phosphate rock is attacked by sulfuric acid resulting in phosphoric acid (H 3 PO 4 ) and phosphate fertilizers. Phosphogypsum is not a commercial product and it is stocked in large open areas or accumulated in lakes inducing to a major environmental problem due to the presence of toxic and radioactive elements. The increasing world agricultural demand is the real responsible for the severity of this environmental problem. Nevertheless, there are some possibilities for the application of this reject material, such as civil construction, waste water treatment, and in cultivated lands, etc. In the agriculture the phosphogypsum is commonly used as a nutrient source due to its large amounts of phosphorus, calcium and sulfur. However, there are still some environmental questions related to the use of this by-product since phosphogypsum is classified as TENORM (Technologically Enhanced Naturally Occurring Radioactive Material), which is a solid waste containing heavy metals and naturally occurring radioactive elements from the rock matrix. In this work, Plasma Mass Spectrometry (ICP-MS) was used to study phosphogypsum samples. Several acid solutions for samples digestion were evaluated in order to be feasible the chemical analysis. BCR sequential extractions were also performed. The results showed analyte concentrations are highly dependent on the acid solution used. The BCR guidelines could not be applied as used for soil, since the phosphogypsum solubility is different. So, it would be necessary to use different mass aliquots in the extractions, to be feasible an environmental evaluation. (author)

Effect of the defect-phosphorus atom complex interaction on the formation of the properties of neutron-doped silicon

International Nuclear Information System (INIS)

Kolesnik, L.I.; Lejferov, B.M.

1984-01-01

Radiation-induced defect annealing and changes in the concentration of substituting phosphorus atoms in silicon irradiated with different neutron doses have been studied by the low-temperature photoluminescence (PL) method at 4 K. Based on the PL spectrum character dependence on the fast-to-thermal neutron ration in a flux, series of lines and bands associated with the preferential formation of radiation-induced defects (within the 1.100 eV energy range) and with the presence of phosphorus impurity (1.15-1.12 eV) are identified. Some peculiarities are studied of the stage-by-stage annealing (250-500, 430-600, 600-800 deg C) of recombination-active centers (RAC) determining the radiation in the mentioned spectrum region. The relation between the RAC variations within the 1.12-1.15 eV range and the substituting phosphorus atom concentration in the 400-500 deg C temperature range is found. Activation energy of the substituting phosphorus atom concentration variation is estimated (approximately 0.5 eV). It is shown that the formation of defect-phosphorus complexes plays an important role in the formation of neutron-doped silicon properties, the presence of fast neutron in a flux being most importants

Probing Phosphorus Efficient Low Phytic Acid Content Soybean Genotypes with Phosphorus Starvation in Hydroponics Growth System.

Science.gov (United States)

Kumar, Varun; Singh, Tiratha Raj; Hada, Alkesh; Jolly, Monica; Ganapathi, Andy; Sachdev, Archana

2015-10-01

Phosphorus is an essential nutrient required for soybean growth but is bound in phytic acid which causes negative effects on both the environment as well as the animal nutrition. Lowering of phytic acid levels is associated with reduced agronomic characteristics, and relatively little information is available on the response of soybean plants to phosphorus (P) starvation. In this study, we evaluated the effects of different P starvation concentrations on the phytic acid content, growth, and yield of seven mutant genotypes along with the unirradiated control, JS-335, in a hydroponics growth system. The low phytic acid containing mutant genotypes, IR-JS-101, IR-DS-118, and IR-V-101, showed a relatively high growth rate in low P concentration containing nutrient solution (2 μM), whereas the high P concentration (50 μM) favored the growth of IR-DS-111 and IR-DS-115 mutant genotypes containing moderate phytate levels. The mutant genotypes with high phytic acid content, IR-DS-122, IR-DS-114, and JS-335, responded well under P starvation and did not have any significant effect on the growth and yield of plants. Moreover, the reduction of P concentration in nutrient solution from 50 to 2 μM also reduced the phytic acid content in the seeds of all the soybean genotypes under study. The desirable agronomic performance of low phytic acid containing mutant genotype IR-DS-118 reported in this study suggested it to be a P-efficient genotype which could be considered for agricultural practices under P limiting soils.

Thermal Effects That Arise upon Different Heat Treatments in Austenitic Steels Alloyed with Titanium and Phosphorus

Science.gov (United States)

Arbuzov, V. L.; Berger, I. F.; Bobrovskii, V. I.; Voronin, V. I.; Danilov, S. E.; Kazantsev, V. A.; Kataev, N. V.; Sagaradze, V. V.

2018-04-01

Structural and microstructural changes that arise in the course of the heat treatment of Cr-Ni-Mo austenitic stainless steels with different concentrations of titanium and phosphorus have been studied. It has been found that the alloying with phosphorus decreases the lattice parameter of these steels. The phosphorus contribution to this effect is 0.015 ± 0.002 Å/at %. Aging at a temperature of 670 K for about 20 h leads to the precipitation of dispersed needle-like particles, which are most likely to be iron phosphides. In the temperature range of 700-800 K, in austenitic steels, the atomic separation of the solid solution occurs, the intensity of which decreases upon alloying with titanium or phosphorus at concentrations of 1.0 and 0.1 wt %, respectively. At higher temperatures (about 950 K), the formed precipitates of the Ni3Ti (γ') phase increase in size to 7-10 nm.

Improved estimates of filtered total mercury loadings and total mercury concentrations of solids from potential sources to Sinclair Inlet, Kitsap County, Washington

Science.gov (United States)

Paulson, Anthony J.; Conn, Kathleen E.; DeWild, John F.

2013-01-01

Previous investigations examined sources and sinks of mercury to Sinclair Inlet based on historic and new data. This included an evaluation of mercury concentrations from various sources and mercury loadings from industrial discharges and groundwater flowing from the Bremerton naval complex to Sinclair Inlet. This report provides new data from four potential sources of mercury to Sinclair Inlet: (1) filtered and particulate total mercury concentrations of creek water during the wet season, (2) filtered and particulate total mercury releases from the Navy steam plant following changes in the water softening process and discharge operations, (3) release of mercury from soils to groundwater in two landfill areas at the Bremerton naval complex, and (4) total mercury concentrations of solids in dry dock sumps that were not affected by bias from sequential sampling. The previous estimate of the loading of filtered total mercury from Sinclair Inlet creeks was based solely on dry season samples. Concentrations of filtered total mercury in creek samples collected during wet weather were significantly higher than dry weather concentrations, which increased the estimated loading of filtered total mercury from creek basins from 27.1 to 78.1 grams per year. Changes in the concentrations and loading of filtered and particulate total mercury in the effluent of the steam plant were investigated after the water softening process was changed from ion-exchange to reverse osmosis and the discharge of stack blow-down wash began to be diverted to the municipal water-treatment plant. These changes reduced the concentrations of filtered and particulate total mercury from the steam plant of the Bremerton naval complex, which resulted in reduced loadings of filtered total mercury from 5.9 to 0.15 grams per year. Previous investigations identified three fill areas on the Bremerton naval complex, of which the western fill area is thought to be the largest source of mercury on the base

Monitoring of urinary calcium and phosphorus excretion in preterm infants: comparison of 2 methods.

Science.gov (United States)

Staub, Eveline; Wiedmer, Nicolas; Staub, Lukas P; Nelle, Mathias; von Vigier, Rodo O

2014-04-01

Premature babies require supplementation with calcium (Ca) and phosphorus (P) to prevent metabolic bone disease of prematurity. To guide mineral supplementation, 2 methods of monitoring urinary excretion of Ca and P are used: urinary Ca or P concentration and Ca/creatinine (Crea) or P/Crea ratios. We compare these 2 methods in regards to their agreement on the need for mineral supplementation. Retrospective chart review of 230 premature babies with birth weight patient characteristics to predict discordant results. A total of 24.8% of cases did not agree on the indication for Ca supplementation, and 8.8% for P. Total daily Ca intake was the only patient characteristic associated with discordant results. With the intention to supplement the respective mineral, comparison of urinary mineral concentration with mineral/Crea ratio is moderate for Ca and good for P. The results do not allow identifying superiority of either method on the decision as to which babies require Ca and/or P supplements.

Estimation of environmental capacity of phosphorus in Gorgan Bay, Iran, via a 3D ecological-hydrodynamic model.

Science.gov (United States)

Ranjbar, Mohammad Hassan; Hadjizadeh Zaker, Nasser

2016-11-01

Gorgan Bay is a semi-enclosed basin located in the southeast of the Caspian Sea in Iran and is an important marine habitat for fish and seabirds. In the present study, the environmental capacity of phosphorus in Gorgan Bay was estimated using a 3D ecological-hydrodynamic numerical model and a linear programming model. The distribution of phosphorus, simulated by the numerical model, was used as an index for the occurrence of eutrophication and to determine the water quality response field of each of the pollution sources. The linear programming model was used to calculate and allocate the total maximum allowable loads of phosphorus to each of the pollution sources in a way that eutrophication be prevented and at the same time maximum environmental capacity be achieved. In addition, the effect of an artificial inlet on the environmental capacity of the bay was investigated. Observations of surface currents in Gorgan Bay were made by GPS-tracked surface drifters to provide data for calibration and verification of numerical modeling. Drifters were deployed at five different points across the bay over a period of 5 days. The results indicated that the annual environmental capacity of phosphorus is approximately 141 t if a concentration of 0.0477 mg/l for phosphorus is set as the water quality criterion. Creating an artificial inlet with a width of 1 km in the western part of the bay would result in a threefold increase in the environmental capacity of the study area.