A Comparison of Different Phosphorus Fractions as Predictors of Particulate Pigment Levels in Lake Memphremagog and its Tributaries

1982 ◽  
Vol 39 (5) ◽  
pp. 785-790 ◽  
Author(s):  
Robert Henry Peters ◽  
Martin Bergmann
Keyword(s):  
Molecular Weight ◽  
Soluble Reactive Phosphorus ◽  
Particulate Material ◽  
Phosphorus Fractions ◽  
Particulate Phosphorus ◽  
Small Molecular Weight ◽  
Large Molecular Weight ◽  
Reactive Phosphorus ◽  
Lake Waters ◽  
Total P

The amounts of colored particulate material (measured by reflectance) in surface waters of Lake Memphremagog and its tributaries were regressed against concentrations of total phosphorus and several of its component fractions: soluble phosphorus, particulate phosphorus, soluble reactive phosphorus, orthophosphate, large molecular weight phosphorus (> 5000 mol wt) and small molecular weight phosphorus (< 400 mol wt). The correlations were examined to see if one of these fractions was a better predictor of seston concentration, and presumably of other biologically related lake properties, than total P, and to determine if riverine samples differed from lake waters in the relation between concentrations of P and suspended particulates. Total P correlated with colored particulates in both lotic and lentic samples as well as or better than any other fraction. Although river samples showed greater variation than lake samples, the regression lines describing the relations were similar in both lakes and rivers.Key words: phosphorus fractions, lakes, rivers, empirical models, particulate concentration, seston

Concentrations and Kinetics of Phosphorus Fractions Along the Trophic Gradient of Lake Memphremagog

1979 ◽  
Vol 36 (8) ◽  
pp. 970-979 ◽  
Author(s):  
Robert Henry Peters
Keyword(s):  
Molecular Weight ◽  
Total Phosphorus ◽  
Gel Filtration ◽  
Soluble Reactive Phosphorus ◽  
Small Molecular Weight ◽  
P Deficiency ◽  
Large Molecular Weight ◽  
Soluble P ◽  
Phosphorus Production ◽  
Total P

Published relationships between chlorophyll and total phosphorus concentrations show that the amount of chlorophyll developed per unit of total P increases as total P increases. If the availability of phosphorus changes with lake trophy, this should be reflected in the proportion of total P found in different analytical fractions. From June 1975 to September 1976, the concentrations of total phosphorus, soluble phosphorus, orthophosphate, large molecular weight phosphorus (> 5000 mol wt) and small molecular weight phosphorus (< 400 mol wt) were measured at six sites along the phosphorus-production gradient of Lake Memphremagog; 32P-PO4 was used to follow short-term exchanges between available orthophosphate and other fractions. Total P declined threefold among sites but the proportion of different fractions remained relatively constant which suggests that any disproportionate loss from one compartment is made good by exchanges with the others. On average, soluble P formed\of total P, soluble reactive phosphorus formed 14%, and PO4 8%; gel filtration showed that ~40% of soluble P was associated with large molecular weight phosphorus and ~40% with small molecular weight phosphorus. Within this basic similarity, was a trend to decreased PO4 concentrations and increased concentrations of soluble P and soluble unreactive phosphorus at more oligotrophic sites. Tracer experiments showed that all fractions exchanged some P with 32P-PO4, although soluble fractions, especially large molecular weight phosphorus, interacted more slowly with orthophosphate than did particulate P. Faster orthophosphate turnover suggested greater P deficiency in more oligotrophic sites. This deficiency may promote the formation of a refractory soluble P which may explain a part of the reduced ratio of chlorophyll to phosphorus when total P is reduced. Key words: orthophosphate, phosphorus, turnover, availability, lakes, gel fitration, soluble organic P

scholarly journals Effects of Lanthanum Modified Bentonite and Polyaluminium Chloride on the Environmental Variables in the Water and Sediment Phosphorus Form in Lake Yanglan, China

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1947
Author(s):  
Ling Su ◽  
Chen Zhong ◽  
Lei Gan ◽  
Xiaolin He ◽  
Jinlei Yu ◽  
...  
Keyword(s):  
Suspended Solids ◽  
Soluble Reactive Phosphorus ◽  
Particulate Phosphorus ◽  
Modified Bentonite ◽  
Combined Application ◽  
Water And Sediment ◽  
Phosphorus Form ◽  
Labile P ◽  
Reactive Phosphorus ◽  
Polyaluminium Chloride

The application of lanthanum modified bentonite (Phoslock®) and polyaluminium chloride (PAC) is popular in the restoration of European temperate lakes; however, the effects of the application on the concentrations of phosphorus (P) in both the water and the sediments have been poorly evaluated to date. We studied the effects of the application of Phoslock® + PAC on the concentrations of total phosphorus (TP), particulate phosphorus (PP), soluble reactive phosphorus (SRP), total suspended solids (TSS) and chlorophyll a (Chla) in the water, and different P forms in the sediments, in an isolated part of Lake Yanglan. The results showed that the concentrations of TP, PP, SRP, TSS and Chla decreased significantly after the addition of Phoslock® + PAC. Moreover, the concentrations of labile-P, reductant-soluble-P and organic-P in the sediments were also significantly decreased after the Phoslock® + PAC application. However, the concentrations of both the stable apatite-P and residual-P in the sediments after application of Phoslock® + PAC were much higher than the pre-addition values, while the concentrations of metal-oxide-P did not differ significantly between the pre- and post- application conditions. Our findings imply that the combined application of Phoslock® and PAC can be used in the restoration of subtropical shallow lakes, to reduce the concentrations of P in the water and suppress the release of P from the sediments.

Silica and Phosphorus Flux from Sediments: Importance of Internal Recycling in Lake Michigan

1988 ◽  
Vol 45 (6) ◽  
pp. 1030-1035 ◽  
Author(s):  
Daniel J. Conley ◽  
Michael A. Quigley ◽  
Claire L. Schelske
Keyword(s):  
Lake Michigan ◽  
Water Mass ◽  
Sediment Cores ◽  
Soluble Reactive Phosphorus ◽  
Dissolved Silica ◽  
Sediment Fluxes ◽  
Species Succession ◽  
Reactive Phosphorus ◽  
Annual Primary Production ◽  
Total P

Estimated lake-wide sediment fluxes of silica and phosphorus (P) were determined and then compared with other components in the biogeochemical cycle to investigate the importance of sediment regeneration in Lake Michigan. Dissolved silica (Si) and soluble reactive phosphorus (SRP) fluxes from sediments were measured by the incubation of intact sediment cores. Estimated Si flux from sediments can supply 21% of the total mass of silica in the water annually and 26% of the Si used during annual diatom production. By contrast, estimated SRP flux from lake sediments can supply only 4.1% of the mass of total P in the water annually and <1% of the P utilized for annual primary production. Because the internal regeneration of P occurs rapidly in the water column, compared with the much slower regeneration of Si (0.8∙yr−1), P can be used many times during an annual cycle whereas Si is used only once. Thus, differences in the supply rates and in the biogeochemical recycling rates of Si and P can lead to seasonal Si depletion in the water mass and influence the outcome of seasonal phytoplankton species succession by limiting Si availability necessary for diatom production.

Concentrations and Kinetics of Phosphorus Fractions in Water from Streams Entering Lake Memphremagog

1978 ◽  
Vol 35 (3) ◽  
pp. 315-328 ◽  
Author(s):  
Robert Henry Peters
Keyword(s):  
Molecular Weight ◽  
River Water ◽  
Weight Fraction ◽  
Water Soluble ◽  
Organic P ◽  
P Fractions ◽  
P Concentration ◽  
Large Molecular Weight ◽  
Soluble P ◽  
Total P

This study examines the possibility that the proportions of different P fractions may vary among rivers, and hence, that the P supplied to lakes may differ in its availability for algae regardless of any similarities in the total P concentration of river waters. Surface water from eight streams and groundwater was collected at roughly monthly intervals from June 1975 to September 1976 and analyzed to determine the concentrations of P fractions and the interrelations between these forms and orthophosphate. Despite differences in total P concentration, (18–64 μg/L) the proportions of P in different fractions were relatively constant seasonally and geographically. Soluble P formed about one third and PO4 < 10% of the total P. These values were not greatly affected by urban drainage but both were increased in small headwater streams during periods of low water. Soluble P was divided into two roughly equal fractions by gel filtration: a large molecular weight fraction (> 5000 mol wt) which eluted at void volume and a small molecular weight fraction (< 400 mol wt) which eluted with 32P-PO4. This latter fraction also included some small organic phosphates. Soluble reactive phosphate consistently overestimated PO4. The exchange of P between PO4 and suspended material was slow in winter and more rapid in summer, although only rivers draining lakes, embayments, or bogs reached the very rapid values reported from lakes. As in lakes, soluble organic P entered into the short-term P dynamics of streams as indicated by the labeling of large molecular weight P during equilibration of river water with radioactive phosphate. This exchange shows that at least a portion of the soluble organic and particulate P is available to the plankton once the river water enters a lake. The uncertainty as to the size of this portion leads to uncertainty in predicting the impact of P loading on lakes. Key words: nutrient budget, P loading, orthophosphate, soluble organic P, drainage basins

scholarly journals Spatial–Temporal Distribution of Phosphorus Fractions and Their Relationship in Water–Sediment Phases in the Tuojiang River, China

Water ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 27
Author(s):  
Dandan Liu ◽  
Xueying Li ◽  
Yue Zhang ◽  
Zhibo Lu ◽  
Lu Bai ◽  
...  
Keyword(s):  
Organic Phosphorus ◽  
Anthropogenic Activities ◽  
Soluble Reactive Phosphorus ◽  
Temporal Distribution ◽  
Principal Component ◽  
Phosphorus Fractions ◽  
Primary Data ◽  
Particulate Phosphorus ◽  
Overlying Water ◽  
Water And Sediment

Understanding the distribution and transportation of phosphorus is vital for the sustainable development of aquatic environmental protection and ecological security. The spatial–temporal distribution of phosphorus fractions in water–sediment phases in river systems and their relationships remain unclear in Southwest China. In this study, the spatial and temporal distribution of phosphorus fractions in water–sediment phases in the Tuojiang River, a primary tributary of the Yangtze River which plays important roles in the economy and ecology of the region, and the relationships among the different phosphorus fractions were analyzed. These fractions were soluble reactive phosphorus (SRP), dissolved organic phosphorus (DOP), and total particulate phosphorus (PP) fractions in water, and exchangeable phosphorus (Ex-P), organic phosphorus (Or-P), phosphorus bound by Fe oxides (Fe-P), authigenic phosphorus (Ca-P), detrital phosphorus (De-P), and refractory phosphorus (Res-P) fractions in sediment. The SPR and Fe-P were the dominant phosphorus fractions in the water and sediment, respectively. The TP content was greater in the lower reaches than in the middle and upper reaches. The average abundances of most phosphorus fractions in water–sediment phases showed significant seasonal variations. The Fe-P, Org-P, and TP in sediments were released to the water interface, resulting in the increase of phosphorus in the overlying water. Redundancy analysis (RDA) indicated that the physicochemical properties of water and sediment have a certain influence on the spatial–temporal distribution of the phosphorus fractions. Principal component analysis (PCA) revealed that the main phosphorus source was anthropogenic activities. These results provide primary data regarding phosphorus fractions and contribute to understanding phosphorus cycling and controlling phosphorus pollution in the Tuojiang River.

scholarly journals PROPERTIES OF COMPOSITE MATERIALS BASED ON MIXTURES OF EPOXY POLYMERS AND OLIGOSULFONES. PART 4. ADHESION PROPERTIES

2020 ◽  
pp. 84-93
Author(s):  
Yuriy Kochergin ◽  
Tatyana Grigorenko ◽  
V. Zolotareva
Keyword(s):  
Molecular Weight ◽  
Epoxy Oligomer ◽  
Carboxyl Groups ◽  
Maximum Effect ◽  
Optimal Range ◽  
Small Molecular Weight ◽  
Adhesion Properties ◽  
Molecular Weights ◽  
Epoxy Polymers ◽  
Large Molecular Weight

The influence of oligosulfons with terminal carboxyl and phenolic groups and a molecular weight from 1200 to 44500 on the adhesion properties of epoxy polymers during the shift and separation of adhesive compounds is studied. It is shown that modification leads to the formation of systems characterized by improved adhesion properties, especially at elevated test temperatures. It is established that there is an optimal range of concentrations and molecular weights of oligosulfons (approximately from 2000 to 20000), which provides the maximum effect of modification. It is assumed that the oligosulfon`s particles formed in the epoxy matrix with a small molecular weight have dimensions and volume that are insufficient to be an effective barrier to the propagation of a possible crack in the polymer. At the same time, an oligosulfon with a large molecular weight is able to include a certain part of the epoxy resin in its volume. This leads to a relative decrease in the composition of the share of the epoxy component, which largely determines the adhesion to the material to be bonded. It is shown that the magnitude of the modification effect practically does not depend on the nature of the end groups. The maximum set of properties is realized for oligosulfones with terminal carboxyl groups and a molecular weight in the range from 2500 to 4700, when the concentration of 3 – 10 mass parts on 100 mass parts epoxy oligomer. For oligosulfone with terminal carboxyl groups and a molecular weight of 4700 at a concentration of 10 mass parts manages to increase adhesive strength at a shear of 1.47 and 3.58 times and tensile strength of 1.39 and 5.08 times, respectively, at test temperatures of 293 and 423 K. The research results allow to recommend epoxy-oligosulfone mix to design of structural adhesives, operable in a wide temperature range.

scholarly journals The Integrated Catchments model of Phosphorus dynamics (INCA-P), a new approach for multiple source assessment in heterogeneous river systems: model structure and equations

2002 ◽  
Vol 6 (3) ◽  
pp. 583-606 ◽  
Author(s):  
A. J. Wade ◽  
P. G. Whitehead ◽  
D. Butterfield
Keyword(s):  
Water Quality ◽  
Total Phosphorus ◽  
Management Practices ◽  
Soluble Reactive Phosphorus ◽  
Particulate Phosphorus ◽  
Model Structure ◽  
River Systems ◽  
Soil System ◽  
Phosphorus Dynamics ◽  
Reactive Phosphorus

Abstract. A new model has been developed for assessing the effects of multiple sources of phosphorus on the water quality and aquatic ecology in heterogeneous river systems. The Integrated Catchments model for Phosphorus (INCA-P) is a process-based, mass balance model that simulates the phosphorus dynamics in both the plant/soil system and the stream. The model simulates the spatial variations in phosphorus export from different land use types within a river system using a semi-distributed representation, thereby accounting for the impacts of different land management practices, such as organic and inorganic fertiliser and wastewater applications. The land phase of INCA-P includes a simplified representation of direct runoff, soilwater and groundwater flows, and the soil processes that involve phosphorus. In addition, the model includes a multi-reach in-stream component that routes water down the main river channel. It simulates Organic and Inorganic Phosphorus concentrations in the land phase, and Total Phosphorus (dissolved plus particulate phosphorus) concentrations in the in-stream phase. In-stream Soluble Reactive Phosphorus concentrations are determined from the Total Phosphorus concentrations and the macrophyte, epiphyte and algal biomasses are simulated also. This paper describes the model structure and equations, the limitations and the potential utility of the approach. Keywords: modelling, water quality, phosphorus, soluble reactive phosphorus, basin management

Overestimation of Orthophosphorus Concentrations in Surface Waters of Southern Lake Michigan: Effects of Acid and Ammonium Molybdate

1982 ◽  
Vol 39 (2) ◽  
pp. 296-304 ◽  
Author(s):  
Stephen J. Tarapchak ◽  
Sylvia M. Bigelow ◽  
Cora Rubitschun
Keyword(s):  
Surface Waters ◽  
Extraction Method ◽  
Time Course ◽  
Lake Michigan ◽  
Soluble Reactive Phosphorus ◽  
Particulate Material ◽  
Ammonium Molybdate ◽  
Molybdenum Blue ◽  
P Release ◽  
Reactive Phosphorus

Water from southern Lake Michigan was analyzed to determine if orthophosphorus (PO4-P) concentrations are overestimated by molybdenum blue methods and to assess the potential effects of ammonium molybdate on soluble reactive phosphorus (SRP) determinations. Time-course "hydrolysis" tests, based on the Chamberlain–Shapiro extraction method, showed that large amounts of PO4-P were released from bound sources into solution within seconds after acid molybdate was added, and that molybdate-reactive PO4-P could be retained by filters or released from particulate material into filtrates during filtration. PO4-P concentrations obtained by using the prescribed exposure of 30 s were overestimated minimally by up to 86%, and ammonium molybdate dramatically accelerated PO4-P release in filtered samples. Tests using up to a fourfold range in ammonium molybdate concentrations also showed that the extraction method and Harvey's method yielded SRP values that varied two- to three-fold or more, and that most of the PO4-P was released from "particles" in filtrates. Analytical methods, therefore, can yield substantially different SRP estimates because of differences in the length of time samples are exposed to acid molybdate and because of differences in molybdate concentrations.Key words: ammonium molybdate, hydrolysis, phosphorus, soluble reactive phosphorus, orthophosphorus

The External Shape of Human γ GI Immunoglobulin from Crystal Sections

1971 ◽  
Vol 29 ◽  
pp. 428-429
Author(s):  
L. W. Labaw
Keyword(s):  
Molecular Weight ◽  
Sodium Phosphate ◽  
Osmium Tetroxide ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Large Molecular Weight ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Crystallographic Axes

Crystals of a human γGl immunoglobulin have the external morphology of diamond shaped prisms. X-ray studies have shown them to be monoclinic, space group C2, with 2 molecules per unit cell. The unit cell dimensions are a = 194.1, b = 91.7, c = 51.6Å, 8 = 102°. The relatively large molecular weight of 151,000 and these unit cell dimensions made this a promising crystal to study in the EM.Crystals similar to those used in the x-ray studies were fixed at 5°C for three weeks in a solution of mother liquor containing 5 x 10-5M sodium phosphate, pH 7.0, and 0.03% glutaraldehyde. They were postfixed with 1% osmium tetroxide for 15 min. and embedded in Maraglas the usual way. Sections were cut perpendicular to the three crystallographic axes. Such a section cut with its plane perpendicular to the z direction is shown in Fig. 1.This projection of the crystal in the z direction shows periodicities in at least four different directions but these are only seen clearly by sighting obliquely along the micrograph.

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