scholarly journals Chloride and sulphate solutions as extractants for soil P: III Effect of increasing sulphate concentration on P desorption 

1983 ◽  
Vol 55 (4) ◽  
pp. 363-369
Author(s):  
Helinä Hartikainen ◽  
Markku Yli-Halla
Keyword(s):  
Ionic Strength ◽  
Mineral Soil ◽  
Soil Samples ◽  
Constant Ionic Strength ◽  
Oxide Surfaces ◽  
Promoting Effect ◽  
Soil P ◽  
Sulphate Concentration ◽  
Extraction Power ◽  
P Desorption

The effect of increasing sulphate concentration on P desorption was studied in 102 mineral soil samples with: a) solutions of a constant ionic strength I=0.1 adjusted with KCI and b) 0.1 M and 0.033 M sulphate solutions of different ionic strengths. Further, the efficiency of chloride and sulphate solutions of equal anion concentration (0.1 M) was compared. At a constant ionic strength, P desorption was enhanced as the sulphate concentration of the extractant increased. Even despite a much higher ionic strength the extraction power of the K2SO4 solution was greater than that of the KCI solution of the same anion concentration. Comparison of the 0.1 M and 0.033 M K2SO4 solutions revealed in 53 soil samples the extractability of P to be depressed by an increase in sulphate concentration (and ionic strength). In 49 samples, on the contrary, the 0.1 M K2SO4 solution extracted equal or greater P amounts than did the 0.033 M K2SO4. It was observed that the lower the P coverage on the oxide surfaces in the soil was, the more obviously the promoting effect of increasing sulphate concentration overruled the depression induced by increasing ionic strength, and the more superior the K2SO4 solution was as compared to the KCI solution.

scholarly journals Chloride and sulphate solutions as extractants for soil P: II Dependence of the relative extraction power of chloride and sulphate solutions on some soil properties 

1982 ◽  
Vol 54 (4) ◽  
pp. 297-304
Author(s):  
Helinä Hartikainen ◽  
Markku Yli-Halla
Keyword(s):  
Soil Properties ◽  
Opposite Effect ◽  
Extraction Efficiency ◽  
Mineral Soil ◽  
Soil Samples ◽  
Point Of Zero Charge ◽  
Molar Ratio ◽  
Soil P ◽  
Soluble P ◽  
Extraction Power

The relative P extraction power of KCI and K2SO solutions of the same ionic strength was investigated in 102 mineral soil samples. By using the ratio of chloride soluble P to sulphate soluble P (”Cl-P”/”SO4-P”) instead of absolute differences it was possible to find out a more accurate relationship between soil properties and varying extraction efficiency of salt solutions. In the soils of low P intensity, the extractability ratio of P (”Cl-P’/”SO4-P”) seemed to decrease with an increase in the molar ratio of NH4F soluble P (CHANG and JACKSON’s method) to oxalate extractable Al, which indicates the improvement of the relative replacement power of sulphate. Conversely, in the samples of high or medium P intensity an increase in NH4F-P/AI had an opposite effect: the ratio ”Cl-P”/ √(”S04-P”) rather than ”Cl-P”/”SO4-P” was raised, suggesting a marked depression in the efficiency of sulphate. The superiority of sulphate, as compared to chloride, tended to be reduced also with increasing soil pH; the decrease seemed to be the greater the poorer the P status of the soil was. A theory explaining the variation in the relative extraction power of chloride and sulphate solutions was presented and the possible contributory influence of point of zero charge (pzc) was discussed.

scholarly journals Effect of decreasing acidity on the extractability of inorganic soil phosphorus

1981 ◽  
Vol 53 (1) ◽  
pp. 16-26 ◽  
Author(s):  
Helinä Hartikainen
Keyword(s):  
Extraction Method ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Soil Phosphorus ◽  
Analytical Data ◽  
Mineral Soil ◽  
Soil Samples ◽  
Inorganic P ◽  
Soil Material ◽  
Soil P

The extractability of P by the water and anion exchange resin methods and reactions of soil inorganic P were investigated with seven acid mineral soil samples incubated with KOH solutions of various concentrations. The results were compared with the analytical data obtained from three soil samples incubated in a prolonged liming experiment. The resin extraction method proved more effective than the water extraction method. The amounts of P desorbed by both methods seemed to increase exponentially as the pH in the soil suspensions rose. The factors involved were discussed. On the basis of fractionation analyses P reacting to changes in the pH and participating in desorption processes was supposed to originate from secondary NH4F and NaOH soluble reserves. In general, as the acidity decreased NH4F-P increased at the expense of NaOH-P. In heavily limed gyttja soil also H2SO4-P increased. This was possibly induced by the precipitation of mobilized P as a Ca compound. The significance of pH in the extractability of soil P seemed somewhat to lessen as the amount of secondary P increased. The results were in accordance with the conception that liming improves the availability of inorganic P to plants and reduces the need for P fertilization. However, increasing of the soil pH involves the risk that P is more easily desorbed to the recipient water by the eroded soil material carried into the watercourse. Therefore, intensive liming is not recommendable close to the shoreline. Further, it should be taken into account that liming of lakes may also result in eutrophication as desorption of sedimentary inorganic P is enhanced.

scholarly journals Temperature dependence of phosphate sorption in mineral soils

1990 ◽  
Vol 62 (1) ◽  
pp. 17-20
Author(s):  
Raina Niskanen
Keyword(s):  
Ionic Strength ◽  
Temperature Dependence ◽  
Mineral Soil ◽  
Soil Samples ◽  
Phosphate Sorption ◽  
Mineral Soils

The sorption of phosphate was studied in 33 mineral soil samples at the temperatures of +5°C and +20°C. The soils were equilibrated for 2 days with a solution containing phosphate 0.1 mmol/l at an ionic strength of 0.01. At +5°C, the sorption remained unchanged or increased slightly as compared to the sorption at +20°C. The differences between sorbed amounts ranged from —0.03 to 0.29 mmol/kg soil and were statistically significant in 11 samples.

scholarly journals Uptake of soil P, Al, Fe, Mn, Mg and Ca by Italian rye grass (Lolium multiflorum Lam.) induced by synthetic chelating agent

1981 ◽  
Vol 53 (3) ◽  
pp. 152-160
Author(s):  
Helinä Hartikainen
Keyword(s):  
Dry Matter ◽  
Ethylenediaminetetraacetic Acid ◽  
Lolium Multiflorum ◽  
Mineral Soil ◽  
Chelating Agent ◽  
Soil Samples ◽  
Soil P ◽  
Rye Grass ◽  
Calcium Supply ◽  
The Stability

The effect of a synthetic chelating compound on the dry matter yield and the uptake of soil P, Al, Fe, Mn, Mg and Ca by Italian rye grass was studied in a pot experiment with three mineral soil samples irrigated with water or 0.001 M Na2-EDTA(dinatrium salt of ethylenediaminetetraacetic acid) solution. The Na2-EDTA treatment seemed not to affect the quantity of the dry matter yields, but it affected markedly their chemical composition. Increased contents of P, Al and Fe were found in all the harvests. In two soil samples the P supply was improved by 35—45 %. The accumulation of Al, Fe and Mn induced by Na2-EDTA tended to be the more effective the greater the stability constant for the corresponding metal-EDTA chelate was. Thus, the iron uptake increased most intensively, i.e. by 217—458 %, and that of aluminium by 33—120 %. On the basis of the first two harvests the manganese absorption by the rye grass seemed to decrease probably due to the enormous accumulation of iron. The results also suggested that the addition of Na2-EDTA to the soil was not able essentially to affect the magnesium and calcium supply to the plants.

scholarly journals Chloride and sulphate solutions as extractants for soil P: I Effect of ionic species and ionic strength on P desorption 

1982 ◽  
Vol 54 (4) ◽  
pp. 287-296
Author(s):  
Helinä Hartikainen ◽  
Markku Yli-Halla
Keyword(s):  
Ionic Strength ◽  
Extraction Efficiency ◽  
Mineral Soil ◽  
Water Soluble ◽  
Exchange Reactions ◽  
Salt Solutions ◽  
Chloride Solutions ◽  
Soil P ◽  
Water Soluble P ◽  
Soluble P

The effect of Cl and SO2-4, anions as well as that of the ionic strength on the desorption of soil P were studied in 102 mineral soil samples by extracting them with KCI and K2SO4 solutions at ionic strengths of 0.025 and 0.1. The quantities of salt soluble and water soluble P in the soils were compared. Both sulphate solutions extracted more P in every single sample than either of the chloride solutions. On the other hand, the material could be divided into three groups according to the position of water in the order of extraction efficiency. In the group W>S>Cl, consisting of 53 samples, water was the most effective extractant, in the group S>W>Cl of 37 samples water was less effective than sulphate solutions but more effective than the chloride solutions, and in 12 samples (S>Cl>W) water was the least effective, less effective than even chloride. The groups classified according to P extractability did not deviate from each other in terms of soil texture, pH or org. C %, but the salt solutions tended to be the more effective extractants the poorer the P status of the soil was. The salt soluble and water soluble P which are closely related to each other correlated with the same factors. Exclusive of the group of 12 samples (S>Cl>W), the highest value sof correlation coefficient were found for NH4F-P/Al, i.e. the molar ratio of NH4F soluble P (CHANG and JACKSON's method) to oxalate extractable Al (r=0.89***-0.93***). The absolute differences between amounts of P dissolved in KCI and K2SO4 solutions of the same initial ionic strength were the greater the more water soluble P the samples contained (r=0.58* -0.94***). An increase in ionic strength tended to depress the extractability of P in both salt solutions. Therefore the ligand exchange between sulphate and phosphate or hydroxyl was regarded unprobable. A theory of the extraction mechanism of sulphate was presented. The greater extraction efficiency of sulphate was assumed to be caused by the exchange reactions with H2O groups which affect the ionic strength in a solution and the electric condition near the surface.

Adsorption of chlorate and bromate ions on mercury electrodes from constant ionic strength solutions

1988 ◽  
Vol 85 ◽  
pp. 523-527
Author(s):  
M.M. Zuleika ◽  
Palhares SILVA ◽  
Ernesto Rafael GONZALEZ ◽  
Luis Alberto AVACA ◽  
Artur de Jesus MOTHEO
Keyword(s):  
Ionic Strength ◽  
Constant Ionic Strength ◽  
Mercury Electrodes

Kinetics and Mechanism of Hexachloroiridate(IV) Oxidation of Arsenic(III) in Acidic Perchlorate Solutions

1992 ◽  
Vol 57 (7) ◽  
pp. 1451-1458 ◽  
Author(s):  
Refat M. Hassan
Keyword(s):  
Ionic Strength ◽  
Fractional Order ◽  
Activation Parameters ◽  
Order Reaction ◽  
First Order Reaction ◽  
Intermediate Complex ◽  
Constant Ionic Strength ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Kinetics Of

The kinetics of oxidation of arsenic(III) by hexachloroiridate(IV) at lower acid concentrations and at constant ionic strength of 1.0 mol dm-3 have been investigated spectrophotometrically. A first-order reaction in [IrCl62-] and fractional order with respect to arsenic(III) have been observed. A kinetic evidence for the formation of an intermediate complex between the hydrolyzed arsenic(III) species and the oxidant was presented. The results showed that decreasing the [H+] is accompanied by an appreciable acceleration of the rate of oxidation. The activation parameters have been evaluated and a mechanism consistent with the kinetic results was suggested.

Agronomic and environmental soil test phosphorus in manured and non-manured Manitoba soils

2007 ◽  
Vol 87 (1) ◽  
pp. 73-83 ◽  
Author(s):  
D. Kimaragamage ◽  
O O Akinremi ◽  
D. Flaten ◽  
J. Heard
Keyword(s):  
Iron Oxide ◽  
Surface Soil ◽  
Single Equation ◽  
Soil Samples ◽  
Soil Test ◽  
Regression Equations ◽  
Soil P ◽  
Soil Test Phosphorus ◽  
Bray 1 ◽  
Water Extractable

Quantitative relationships between soil test phosphorus (STP) methods are needed to guide P management especially in manured soils with high P. Our objectives were: (i) to compare amounts of P extracted by different methods; (ii) to develop and verify regression equations to convert results among methods; and (iii) to establish environmental P thresholds for different methods, in manured and non-manured soils of Manitoba. We analyzed 214 surface soil samples (0–15 cm), of which 51 had previous manure application. Agronomic STP methods were Olsen (O-P), Mehlich-3 (M3-P), Kelowna-1 (original; K1-P), Kelowna-2 (modified; K2-P), Kelowna-3 (modified; K3-P), Bray-1 (B1-P) and Miller and Axley (MA-P), while environmental STP methods were water extractable (W-P), Ca Cl2 extractable (Ca-P) and iron oxide impregnated filter paper (FeO-P) methods. The different methods extracted different amounts of P, but were linearly correlated. For an O-P range of 0–30 mg kg-1, relationships between O-P and other STP were similar for manured and nonmanured soils, but the relationships diverged at higher O-P levels, indicating that one STP cannot be reliably converted to another using a single equation for manured and non-manured soils at environmentally critical P levels (0–100 mg kg-1 O-P). Suggested environmental soil P threshold ranges, in mg P kg-1, were 88–118 for O-P, 138–184 for K1-P, 108–143 for K2-P, 103–137 for K3-P, 96–128 for B1-P, 84–111 for MA-P, 15–20 for W-P, 5–8 for Ca-P and 85–111 for FeO-P. Key words: Phosphorus, soil test phosphorus, manured soils, non-manured soils, environmental threshold

Speciation of protactinium(V) at tracer scale

2009 ◽  
Vol 97 (7) ◽  
Author(s):  
Claire Le Naour ◽  
M. V. Di Giandomenico ◽  
Y. Zhao ◽  
M. Mendes
Keyword(s):  
Ionic Strength ◽  
Solvent Extraction ◽  
Distribution Coefficient ◽  
Systematic Study ◽  
Chelating Agent ◽  
Constant Ionic Strength ◽  
Diethylene Triamine ◽  
Sulphate Chloride

AbstractSolvent extraction in the conditions of tracer scale chemistry was used to study protactinium(V) complexation with sulphate, chloride, oxalate and diethylene-triamine-pentaacetate. Extraction experiments were conducted using the chelating agent thenoyltrifluoroacetone (TTA) in toluene at constant ionic strength and temperature. Information on the species involved in partition equilibria relative to protactinium(V) complexation were deduced from a systematic study of the variations of distribution coefficient of Pa(V) as function of ligands, protons and TTA concentration.

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