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.

scholarly journals The influence of long-term sewage sludge application on the activity of phosphatases in the rhizosphere of plants

2008 ◽  
Vol 53 (No. 9) ◽  
pp. 375-381 ◽  
Author(s):  
J. Balík ◽  
D. Pavlíková ◽  
V. Vaněk ◽  
M. Kulhánek ◽  
B. Kotková
Keyword(s):  
Sewage Sludge ◽  
Fertilizer Application ◽  
Water Soluble ◽  
Organic Fertilizers ◽  
Lower Content ◽  
Alkaline Phosphatases ◽  
Soil P ◽  
Water Soluble P ◽  
Soluble P

Model experiments using rhizoboxes were carried out in order to evaluate the influence of different plants (wheat, rape) on the changes in water extractable contents of P, the pH/H2O value and the activity of acidic and alkaline phosphatase in soil of plant rhizosphere. For this experiment, a Cambisol with different long-term fertilizing systems was used: (i) control (with no fertilizer application), (ii) sewage sludge, and (iii) manure. A lower content of water-soluble P was observed in close vicinities of root surfaces (up to 2 mm) at all the studied variants. The control (non-treated) variant reflected a significantly lower content of water-soluble P in the rhizosphere compared to the fertilized ones. The activities of the acidic and alkaline phosphatases were significantly higher in the rhizosphere compared to the bulk soil (soil outside the rhizosphere). The long-term application of organic fertilizers significantly increased phosphatase activity; the activity of the acidic phosphatase was significantly higher in the rhizosphere of rape plants compared to wheat. The variant treated with manure exhibited an increased activity of both the acidic and alkaline phosphatases compared to the variant treated with sewage sludge. In the case of the variant treated long-term with sewage sludge, the portion of inorganic P to total soil P content proportionally increased compared to the manure-treated variant. Soil of the rape rhizosphere showed a trend of lower pH/H<sub>2</sub>O value of all variants, whereas the wheat rhizosphere showed an opposite pH tendency.

scholarly journals Relationship between phosphorus intensity and capacity parameters in Finnish mineral soils: II Sorption-desorption isotherms and their relation to soil characteristics

1982 ◽  
Vol 54 (4) ◽  
pp. 251-262
Author(s):  
Helinä Hartikainen
Keyword(s):  
Mineral Soil ◽  
Zero Point ◽  
Soil Characteristics ◽  
Water Soluble ◽  
Clay Soils ◽  
Practical Significance ◽  
Water Soluble P ◽  
P Concentration ◽  
Desorption Isotherms ◽  
Soluble P

The relationship between P intensity and capacity parameters in 104 mineral soil samples was studied by means of sorption-desorption isotherms of two types. In the isotherm A the P exchange was expressed as a function of P concentration in the initial solution, in the isotherm B as a function of P concentration in the final equilibrium solution. Both isotherms conformed to the equation y = a + bx, where y stands for the amount of P sorbed or desorbed and x the P concentration in the solution. In the isotherm A the constant a is the intensity factor expressing the amount of water soluble P at a given soil-solution ratio. The term a in the isotherm B, on the contrary, was only poorly related to water soluble P in soil. In both isotherms the slope b of the line seemed to be most effectively affected by oxalate extractable Al. The relative importance of oxalate soluble Fe appeared to be greater in affecting the effectiveness of sorption-desorption reactions than in affecting the buffer reactions. However, the slope b of both isotherms was found to be a semi-intensive parameter: it was quite markedly dependent also on soil characteristics which control the level of water soluble P in soil. The ratio of the term —a to b (termed as EBS or EPC), expressing the zero point of net P exchange, varied from 0.003 to 13.89 mg P per liter, the lowest values tending to be in the heavy clay soils and the highest ones in the non-clay soils. The practical significance of this quantity was discussed.

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.

Water-soluble p-carboxybenzylated beechwood 4-O-methylglucuronoxylan: structural features and properties

2000 ◽  
Vol 42 (2) ◽  
pp. 123-131 ◽  
Author(s):  
A. Ebringerová ◽  
J. Alföldi ◽  
Z. Hromádková ◽  
G.M. Pavlov ◽  
S.E. Harding
Keyword(s):  
Structural Features ◽  
Water Soluble ◽  
Water Soluble P ◽  
Soluble P

A route to virtually unlimited functionalization of water-soluble p-sulfonatocalix[4]arenes

2020 ◽  
Vol 56 (29) ◽  
pp. 4122-4125
Author(s):  
Alexander Gorbunov ◽  
Anna Iskandarova ◽  
Kirill Puchnin ◽  
Valentine Nenajdenko ◽  
Vladimir Kovalev ◽  
...  
Keyword(s):  
Water Soluble ◽  
Reaction Sequence ◽  
Water Soluble P ◽  
Cuaac Reaction ◽  
Soluble P

Diverse narrow-rim derivatives can be easily prepared from p-sulfonatocalix[4]arenes using the propargylation/CuAAC reaction sequence.

Mechanochemical Activation and Characterization of Low-Medium Grade Phosphorite Ore

2013 ◽  
Vol 690-693 ◽  
pp. 3529-3532
Author(s):  
Yu Xing ◽  
Hong Gao ◽  
Yuan Fang Ying ◽  
De Zheng Qu
Keyword(s):  
Mechanochemical Activation ◽  
Planetary Mill ◽  
Water Soluble ◽  
Particle Sizes ◽  
Leaching Rate ◽  
Activation Time ◽  
Activation Effect ◽  
Water Soluble P ◽  
Soluble P

The activation effect of ball-to-powder ratio and activation time on phosphorite ore that takes place in mechanochemical activation has been investigated in present paper, which is carried out in a planetary mill AGO-II. The results show that, particle sizes decreased after activation; the leaching rate of water-soluble P2O5 increased 4.6 percentage as ball-to-powder ratio rose from 8:1 to 40:1; the activated particle of samples has been highly dispersed, while the leaching rate of water-soluble P2O5 reached 10.1% after milling 15 minutes during activation, which was 4 times as high as the un-activated samples. The results show a potential utilization of low-medium grade phosphorite ore with mechanochemical activation directly.

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