Phosphorus In River Water Research Articles

Developing a method to measure bioavailable phosphorus in river water via simultaneous multisample ultrasonic extraction

To reduce aquatic eutrophication, measurements of bioavailable phosphorus (BAP) rather than total phosphorus (TP) are deemed critical. However, current methods require much time to separate sediments from river water, which limits the routine measurement of BAP in rivers. Therefore, in this study, a simultaneous multisample ultrasonic extraction method is proposed to directly measure total BAP (TBAP) in river water without the separation of sediment and water. Spike-and-recovery assessments showed that at least three extractions are required to maintain efficiency. A process including 2-min extraction time and three extractions was suggested. The concentrations of TBAP extracted by this process showed no significant differences with the spike calculations. Furthermore, river water TBAP was quantified using the conventional and proposed method to examine the practicality of using the proposed method for simultaneous multisample ultrasonic extraction and to evaluate its adaptability to actual river water analysis. The extracted concentrations matched those obtained using the conventional method, in which total BAP is calculated as the sum of dissolved BAP and particulate BAP; no significant difference was observed between the concentrations. Ultrasonic extraction was considerably less time-consuming than the conventional method because more samples could be analyzed during a single run. Therefore, the simultaneous multisample ultrasonic extraction method proposed in this study can be used to directly quantify total BAP in river water.

Current assessment of nitrogen and phosphorus content in the river water and snow cover of the Southern Baikal basin

The paper presents the results of long-term studies of chemical composition of water of tributaries and snow cover of the south-eastern and south-western coasts of Lake Baikal. The content of different forms of nitrogen and phosphorus in river water and snow cover was analyzed. A quantitative assessment of total nitrogen and phosphorus input from the atmosphere to the Southern Baikal catchment area for 2019-2023 is given. The south-western coast of the lake experiences a great load in terms of the content of various forms of nitrogen and phosphorus in the snow cover and water of tributaries. Nitrogen in the snow cover and tributaries of Southern Baikal is represented mainly by its mineral form. The rivers of the south-eastern coast, which are exclusively atmosphere-fed, are generally not subjected to anthropogenic impact. In contrast, the minor watercourses of the south-western coast of the lake (Listvyanka settlement) are significantly influenced by economic activities. The organic form of phosphorus predominates in the snow cover of Southern Baikal and in river waters of the south-eastern coast. In the water of tributaries of the south-west coast phosphorus is found in its mineral form. A comparison of current data with the results of previous years was carried out.

Role of Mine Tailings in the Spatio-Temporal Distribution of Phosphorus in River Water: The Case of B1 Dam Break in Brumadinho

Human actions in the drainage network of hydrographic basins interfere with the functioning of ecosystems, causing negative impacts on the environment. Among these impacts, mass loads with a high concentration of phosphorus (P) have a significant potential for point and diffuse pollution of freshwater. The objective of this work was to model P spatially in the Paraopeba River basin, namely in the main water course and 67 sub-basins, and temporally in the years of 2019, 2020, and 2021, after the rupture of B1 tailings dam of Vale, SA company in Brumadinho (Minas Gerais Brazil). The distribution of total phosphorus concentrations (Pt) in relation to environmental attributes (terrain slope, soil class, and land use) and stream flow was assessed with the help of SWAT, the well-known Soil and Water Assessment Tool, coupled with box-plot and cluster analyses. The Pt were obtained from 33 sampling points monitored on a weekly basis. Mean values varied from 0.02 to 1.1 mg/L and maximum from 0.2 to 15.9 mg/L across the basin. The modeling results exposed an impact on the quality of Paraopeba River water in a stretch extending 8.8–155.3 km from the B1 dam, related with the rupture. In this sector, if the contribution from the rupture could be isolated from the other sources, the average Pt would be 0.1 mg/L. The highest Pt (15.9 mg/L) was directly proportional to the urban area of a sub-basin intersecting the limits of Betim town and Belo Horizonte Metropolitan Region. In general, urban sprawl as well as forest-agriculture and forest-mining conversions showed a close relationship with increased Pt, as did sub-basins with a predominance of argisols and an accentuated slope (>20%). There were various moments presenting Pt above legal thresholds (e.g., >0.15 mg/L), mainly in the rainy season.

Зональные особенности химического состава вод малых рек бассейна Рыбинского водохранилища

The work is devoted to the study of the chemical composition of small rivers in the southwestern part of the territory of the Vologda region, which form the river flow of the Rybinsk reservoir basin. The determination of the chemical composition of water in rivers is carried out by generally accepted methods according to standard procedures. A distinctive feature of the river waters of the studied drainage basin is their significant difference in color and color intensity, total iron ion content, and ratio of basic anions. Most of the catchment area of this territory is represented by swamps and numerous lakes, many of them are sources of small and medium length watercourses. A comparative analysis of the ion-salt composition of the waters of rivers shows a certain similarity in the manifestation of the zonal features of the formation of their chemical composition. The composition of the water of the rivers in its salt part is mainly due to the climatic conditions. The waters of the rivers have a hydrocarbonate and sulphate-hydrocarbonate magnesium-calcium composition and relatively low mineralization. Statistical processing of the results of analytical data shows a high correlation in terms of color, permanganate oxidation and chemical oxygen consumption of the investigated water samples. Nutrients represented by the mineral forms of nitrogen and phosphorus in river waters within the studied catchment basin are determined by similar concentrations. A single directivity has been established in the distributions of the contents of heavy metal ions. From the number of heavy metal ions (iron, manganese, aluminum, copper, zinc, nickel, lead, arsenic, chromium, cadmium), which were determined in the analyzed samples, the excess of water quality standards for fishery water bodies was established of by iron and manganese ions. Excess of the established standards of quality of natural waters for other identified ions was not detected.

Spatial Variations in the Abundance and Chemical Speciation of Phosphorus across the River–Sea Interface in the Northern Beibu Gulf

Water samples were collected to measure dissolved and particulate phosphorus species in order to examine the dynamics of phosphorus in the water column across the river–sea interface from the lower Dafengjiang River to the open Beibu Gulf. Dissolved inorganic phosphorus concentrations were as high as 0.90 ± 0.42 μM in river water but decreased dramatically to as low as 0.02 ± 0.01 μM in open coastal waters. Total dissolved phosphorus was largely measured in the form of dissolved inorganic phosphorus in river waters (58% ± 18%), whereas dissolved organic phosphorus became the predominant species (>90% on average) in open coastal waters. Total dissolved phosphorus was the dominant species, comprising 76% ± 16% of the total phosphorus, while total particulate phosphorus only comprised 24% ± 16% of the total phosphorus pool. Riverine inputs, physical and biological processes, and particulate phosphorus regeneration were the dominant factors responsible for the dynamic variations of phosphorus species in the study area. Based on a two-end-member mixing model, the biological uptake resulted in a dissolved inorganic phosphorus depletion of 0.12 ± 0.08 μM in the coastal surface water, whereas the replenishment of dissolved inorganic phosphorus in the lower river from particle P regeneration and release resulted in an increase (0.19 ± 0.22 μM) of dissolved inorganic phosphorus in the estuarine mixing region. The molar ratios of dissolved inorganic nitrogen to dissolved inorganic phosphorus and dissolved silicate to dissolved inorganic phosphorus in the open surface waters were >22, suggesting that, although the lower Dafengjiang River contained elevated concentrations of dissolved inorganic phosphorus, the northern Beibu Gulf was an overall P-limited coastal ecosystem.

Carbon, nitrogen and phosphorus stoichiometry of rivers in the light of Redfield ratio

Abstract. A. Redfield entered the history of hydroecology due to the discovery of a unique stoichiometric ratio of Carbon, Nitrogen and Phosphorus – 106: 16: 1 – in the marine plankton, which it was later named after the author – the Redfield Ratio. Furthermore, A. Redfield established, that the stoichiometric ratio of Carbon, Nitrogen and Phosphorus in seawater is supported on the average level and it is 1017 : 15 : 1. On the basis of established stoichiometric ratios A. Redfield came to the conclusion that exactly Nitrogen is a limiting factor in the marine environment, because the ratio of its average statistical stoichiometric availability in seawater turned out lower than the average stoichiometric utilization of plankton. Also the merit of A. Redfield is the was established by him the carbon and nitrogen forms, which make the greatest contribution to the pool of these elements are available for plankton. After Redfield the studies by the CNP-stoichiometry of water and plankton in marine and ocean ecosystems were carried out by a number of researchers. However, the CNP-stoichiometry of rivers water fell out of the field of view of hydroecologists. The authors of this publication tried to fill this gap. The purpose of the studies was to establish the peculiarities of CNP-stoichiometry of river ecosystems in comparison with marine ecosystems and it determine the contribution of different forms of carbon and nitrogen to the pool of these elements which available for plankton in river water. The research was conducted during the summer low water period (2014) at the at monitoring stations of watershed of the three rivers of the Carpathian region within the Chernivtsi region. It is Dniester, Prut and Siret. Water samples were taken by a bathometer at 16 sites (near 8 forest and 8 meadow floodplains) of each of the 15 monitoring stations. Under laboratory conditions, the nitrate content was determined by the nitrate meter (H-401). Carbonates and hydrogen carbonates was determined by titrimetrically method. Phosphates, ammonia and nitrites was determined by photocolorimetrically method. Like Redfield, the stoichiometric availability of Сarbon and Nitrogen in river water was estimated as the ratio of the molar concentrations of the corresponding elements to the molar Phosphorus concentration. For the first time the features of CNP stoichiometry of the rivers were installed in comparison with the marine stoichiometry. The stoichiometric ratio of total carbon, nitrogen and phosphorus in river water of the Carpathian region is 938C: 59N: 1P and the ratios of their stoichiometric availability to stoichiometric utilization by plankton is 8,9C : 3,7N : 1P. It was shown that stoichiometric availability of energetically favorable for the assimilation by plankton by forms of carbon and nitrogen – СО2 и NH4+ – in the rivers water is greatly reduced, and do not cover the necessary level of stoichiometric utilization of these elements by plankton. It is proved that the greatest contribution in the river water to the pool of stoichiometric available of carbon and nitrogen contributes HCO3-, а азота – NО3- in accordance. It was found that the main limiting factor of growth of and development of plankton in rivers of the Carpathian region appears phosphorus whose balanced share in CNP ratio is an order of magnitude lower than that it need for the utilization by plankton.

Changes of organic phosphorus in river waters in northern Bangladesh

The variability in phosphorus concentrations and the decomposition rates of organic phosphorus were measured in five selected rivers through four surveys in July and November of 2012, and February and May of 2013. After collection the water samples were incubated for 20 days in a dark incubator and the change of forms of phosphorus such as particulate organic phosphorus (POP), dissolved organic phosphorus (DOP) and dissolved inorganic phosphorus (DIP) were analyzed. By fitting the changes to two types of models, the decomposition rates of organic phosphorus were determined. The mean total organic phosphorus (TOP) decomposition rate coefficients in the studied rivers was 0.039 day-1. The average POP decomposition rate coefficient (POP?DOP?DIP model) was 0.038 day-1 while the mean DOP decomposition rate coefficient was 0.251 day-1. The decomposition rate coefficients measured in this study might be applicable for modeling of river water quality.Int. J. Agril. Res. Innov. & Tech. 5 (2): 31-36, December, 2015

The role of riparian willows in phosphorus accumulation and PCB control for lotic water quality improvement

A better understanding of the role played by willow communities in the control of phosphorus levels in riparian zones is necessary for sustainable water management and water quality improvement. This study examines the role of communities of Salicetum triandro-viminalis in the reduction of phosphorus in river water and quantifies the phosphorus retained in the willow biomass. Significant decreases were observed in the concentrations of suspended particulate matter (SPM, 41%), soluble reactive phosphorus (SRP, 54%) and total phosphorus (TP, 36%) along a section of the Pilica River, Central Poland, nearly 40km long during the period 2005–2007. Moreover, differences in PCB concentration were observed in sediments taken from the upstream and downstream parts of the same river stretch, with a 49% decrease of PCB TEQ concentration. In this river section, natural willow communities covered an area of approximately 30ha. The accumulation of phosphorus (P) in the total biomass amounted to approximately 431kg, a mean of 14.44kgPha−1 for willow patches up to 3 years old. The paper identifies the willow riparian zones with the highest biomass concentrations of phosphorus, which are most suitable for management and seasonal clear-cutting. This could be helpful in limiting eutrophication and controlling toxic algal blooms in the Sulejów Reservoir located downstream.

Using process-based models to filter out natural variability in observed concentrations of nitrogen and phosphorus in river water.

Advances in process-based modelling of loads of nitrogen and phosphorus carried by rivers have created new possibilities to interpret time series of water quality data. We examined how model runs with constant anthropogenic forcing can be used to estimate and filter out weather-driven variation in observational data and, thereby, draw attention to other features of such data. An assessment of measured and modelled nutrient concentrations at the outlets of 45 Swedish rivers provided promising results for total nitrogen. In particular, joint analyses of observational data and outputs from the catchment model S-HYPE strengthened the evidence that downward trends in nitrogen were due to mitigation measures in agriculture. Evaluation of modelled and observed total phosphorus concentrations revealed considerable bias in the collection or chemical analysis of water samples and also identified weaknesses in the model outputs. Together, our results highlight the need for more efficient two-way communication between environmental modelling and monitoring.

Estuarine modification of nutrient and sediment exports to the Great Barrier Reef Marine Park from the Daintree and Annan River catchments

Nutrient and suspended sediment concentrations were measured in the dry season and during the rising and falling stages of flood events in the Annan and Daintree rivers to estimate catchment exports. These flood events were also sampled along the salinity gradient in the estuary and nearshore shelf to quantify the modification of terrestrial sediment and nutrient loads as they pass through estuaries into the Great Barrier Reef lagoon. In the Daintree River TSS concentrations were found to increase between the catchment and the estuary plume. The source of TSS may have been scour of the estuarine channel or from land use in the catchment of the lower estuary. In the dry season nitrogen enters the Annan and Daintree estuaries predominantly in the form of PON and DON in roughly equal proportions. Nitrogen exports to the GBR are mostly in the form of DON. In the wet season the majority of nitrogen enters the estuaries as DON and leaves as PON. Nitrogen removal in the estuaries and plumes appears to be biologically mediated once suspended sediment concentrations decrease to a point where phytoplankton growth is not light limited. In the dry season phosphorus enters and leaves the estuaries primarily in organic form. PIP is the dominant form of phosphorus in river water, but leaves the estuary more evenly distributed between all forms. These estuarine processes result in less nitrogen and phosphorus being delivered to the GBR lagoon than is exported from the catchment. The differences between these estuaries highlights the need for further work to explore modifications in estuaries that drain into the Great Barrier Reef lagoon.

Spring phytoplankton photosynthesis, growth, and primary production and relationships to a recurrent coastal sediment plume and river inputs in southeastern Lake Michigan

A recurrent coastal sediment plume (RCP) is an episodic event in the southern basin of Lake Michigan that typically coincides with the spring diatom bloom. Strong winter storm activity during El Niño conditions in 1998 resulted in a large and intense RCP event. Consistently higher values of the light‐saturated rate of photosynthesis, PmaxB, were observed in spring 1998 compared to 1999 and 2000. Higher values of PmaxB in 1998 appeared to be related to increased availability of phosphorus, as evidenced by significant correlations of PmaxB with soluble reactive phosphorus (SRP). Light‐saturated growth rates were also significantly correlated with SRP concentrations. These findings were consistent the view that the RCP was a source of enrichment. However, incubation experiments involving lake water enriched with sediments showed relatively small increases in growth and photosynthetic parameters, while enrichments with river water exhibited elevated rates. This result, along with increased levels of river discharge in 1998 and high levels of dissolved phosphorus in river water, supported the view that riverine inputs rather than the RCP were responsible for the higher photosynthetic parameters and growth seen for coastal margin assemblages. Despite the higher levels of PmaxB in 1998, model analyses revealed that reduced light availability resulting from the intense RCP event constrained phytoplankton growth rates and primary production during this season and apparently suppressed the development of a typical spring bloom. These findings indicate a potential for reduced ecosystem productivity in response to extreme storm events, the frequency of which may increase with projected long‐term climate changes.

High temporal and spatial resolution environmental monitoring using flow injection with spectroscopic detection

This article describes the use of flow-injection techniques combined with molecular spectroscopic detection (spectrophotometry, fluorescence and chemiluminescence) for the rapid determination of chemical parameters in environmental matrices. The emphasis is on field deployment in order to obtain high temporal and spatial resolution data without the need for discrete sample collection and storage. Specific examples considered are the determination of phosphorus in river water and dissolved iron in open ocean water. The environmental drivers for these determinations are presented and the analytical capabilities of flow-injection instrumentation for remote deployment are discussed.

Review of robust measurement of phosphorus in river water: sampling, storage, fractionation and sensitivity

Abstract. This paper reviews current knowledge on sampling, storage and analysis of phosphorus (P) in river waters. Potential sensitivity of rivers with different physical, chemical and biological characteristics (trophic status, turbidity, flow regime, matrix chemistry) is examined in terms of errors associated with sampling, sample preparation, storage, contamination, interference and analytical errors. Key issues identified include: The need to tailor analytical reagents and concentrations to take into account the characteristics of the sample matrix. The effects of matrix interference on the colorimetric analysis. The influence of variable rates of phospho-molybdenum blue colour formation. The differing responses of river waters to physical and chemical conditions of storage. The higher sensitivities of samples with low P concentrations to storage and analytical errors. Given high variability of river water characteristics in space and time, no single standardised methodology for sampling, storage and analysis of P in rivers can be offered. ‘Good Practice’ guidelines are suggested, which recommend that protocols for sampling, storage and analysis of river water for P is based on thorough site-specific method testing and assessment of P stability on storage. For wider sampling programmes at the regional/national scale where intensive site-specific method and stability testing are not feasible, ‘Precautionary Practice’ guidelines are suggested. The study highlights key areas requiring further investigation for improving methodological rigour. Keywords: phosphorus, orthophosphate, soluble reactive, particulate, colorimetry, stability, sensitivity, analytical error, storage, sampling, filtration, preservative, fractionation, digestion

Nutrient Concentrations and Discharges in a Midwestern Agricultural Catchment

AbstractThe amounts of nitrogen and phosphorus in river water are significantly influenced by anthropogenic inputs associated with land cover, land use, and point sources. We quantified seasonal and spatial patterns in the concentrations of nitrate N and soluble reactive phosphorus (SRP) at 17 sites distributed among tributaries and along the mainstem of the River Raisin, Southeastern Michigan, and also determined land cover, surficial geology, and discharges from waste water treatment plants (WWTPs). Annual flow‐weighted mean concentrations (FWMCs) ranged from nondetectable levels to 18.1 mg L−1 for nitrate and to 184 µg L−1 for SRP. Nitrate concentrations increased from headwaters to river mouth, and were highest in spring and in association with high runoff episodes. Mean nitrate concentration correlated strongly with the ratio of agricultural to forested land upstream of the sampling location. Concentrations of SRP also increased markedly from headwaters downstream, and exhibited little seasonal variation other than a modest increase during the summer period of low flow. Geology and phosphorus loading from WWTPs best predicted SRP concentrations. The annual yield of nitrate was consistent with expectations based on land use. Point source loading contributed a negligible fraction of the river's discharge of nitrate and at most one‐fourth of its SRP discharge. Compared with findings from headwater sites and other, less altered rivers, nutrient concentrations in this catchment appear strongly influenced by human activity.

Size fractionation of phosphorus (dissolved, colloidal and particulate) in two tributaries to Lake Lugano

An in-situ fractionation mainly consisting of continuous flow centrifugation and cross-flow-ultrafiltration was used to separate a particulate (particle diameter >1 μm), a colloidal (particle diameter 10 kD) and a dissolved fraction (molecular weight <10 kD) of total phosphorus in river water. A similar fractionation pattern is observed in function of discharge in two tributaries to Lake Lugano, the rivers Cassarate and Vedeggio. In Cassarate river 31% of the total P is particulate, 10% colloidal and 59% dissolved at low discharge, whereas at high discharge 73% is particulate, 10% colloidal and 17% dissolved. 19% of the total P is particulate, 12% colloidal and 69% dissolved at low discharge in Vedeggio river, and at high discharge 19% of the total P is dissolved, 8% colloidal and 73% particulate. Release of ortho-phosphate (o-P) from Cassarate and Vedeggio colloids was observed at pH 10, and by the enzyme alkaline phosphatase in laboratory experiments. Calculations of a model based annual P-load into Lake Lugano showed an average total P-distribution with 60% particulate P, 10% colloidal P and 30% dissolved P in Cassarate and Vedeggio river for 1996 and 1997.

Size distribution of colloidal molybdate reactive phosphorus in river waters and soil solution

Two river waters (a lowland chalk stream and an upland river containing humic materials) and two soil waters (freely drained leachate to 135 cm depth and storm surface runoff, both from grassland soils) were fractionated into unfiltered <0.45, <0.22, <0.1 and <0.025 μm using composite cellulose nitrate/acetate (CNA) membranes, under vacuum at 80 kPa. Fractions less than 10,000 and 1000 molecular weight (MW) size were separated by ultrafiltration at 276 kPa. Molybdate reactive phosphorus (MRP) and dissolved organic carbon (DOC) were measured using the filtrates in each size range. In three of the four waters, the concentration of MRP in the portion <1000 MW was significantly smaller ( P < 0.05) than that determined in the fraction <0.45 μm. In the soil surface runoff water, which was dominated by eroded mineral particles and colloidal organic material, the <1000 MW fraction represented 14% of the total reactive P (TRP), and most of the reactive P was associated with the unfiltered (>0.45 μm) fraction, being 71% of the TRP. In contrast, 87% of the TRP in soil leachate and 55% of the TRP in the chalk stream water was <1000 MW, with significantly different but smaller portions in the range <0.45 μm to >1000 MW. Particle and colloidal material plays an important role in the transformations of P. These findings are particularly novel for soils, where implications for mobility within the soil solution need to be considered.

河川水中における懸濁態リンの生成に関する基礎的検討

河川水中における懸濁態リンの生成に関する基礎的検討

Spectrophotometric determination of phosphorus in river water based on the reaction of vanadomolybdophosphate with malachite green

The formation of an ion-associate between vanadomolybdophosphate and malachite green in aqueous acidic solution (0.5 M sulfuric acid) enables trace amounts (0−1 × 10 −5M) of phosphate to be determined. The molar absorptivity is 1.05 × 10 5 l mol −1 cm −1 at 620 nm. The complex was stabilized in solution by adding poly (vinyl alcohol). Other ions generally found in river waters did not interfere. Interference by silicate is less than that found in the corresponding malachite green molybdophosphate procedure; interference of arsenate is avoided by reduction with thiosulfate. The method is applied to the determination of μg l −1 amounts of phosphorus in river water; the results obtained were in good agreement with those obtained by an extraction-spectrophotometric method with malachite green.

Spectrophotometric determination of phosphorus as orthophosphate based on solvent extraction of the ion associate of molybdophosphate with malachite green using flow injection

Phosphorus as orthophosphate in water was determined by a spectrophotometric method involving flow injection coupled with solvent extraction. The ion associate formed between molybdophosphate and Malachite Green was extracted into benzene-4-methylpentan-2-one (1 + 2 V/V) and the absorbance was measured at 630 nm. The carrier stream was 0.005 M sulphuric acid and the reagent stream contained ammonium molybdate, Malachite Green and sulphuric acid. A newly designed phase separator was used to separate the organic phase. The sampling rate was 40 samples per hour. Calibration graphs were linear below 30 ng ml–1 and below 1 µg ml–1 of phosphorus on injecting samples of 300 and 10 µl, respectively. The detection limit was 0.1 ng ml–1 of phosphorus. Phosphorus in river water was determined satisfactorily by the proposed method.

Solvent extraction-spectrophotometric determination of phosphate with molybdate and malachite green in river water and sea-water

Molybdophosphate, formed between orthophosphate and molybdate in sulphuric acid solution, is extracted into a mixture of toluene and 4-methylpentan-2-one (1:3 v v ) with Malachite Green as counter-ion. A single extraction with equal phase volumes gives an apparent molar absorptivity for phosphate of 2.3 × 10 5 l.mole −1.cm −1 at 630 nm; the absorbance of the reagent blank is 0.03. With an organic to aqueous phase-volume ratio of 1:10, the molar absorptivity is 2.5 × 10 5 l.mole −1.cm −1 and the absorbance of the reagent blank 0.08. By the proposed method, ng ml levels of phosphorus can be determined, and the detection limit is about 0.1 ng ml . The standard deviation and relative standard deviation for the determination of phosphorus in tap water (4.3 ng ml ) are 0.05 ng ml and 1.1%, respectively. The method can also be applied to the determination of phosphorus in river water and sea-water.