Indirect calculation of Langelier saturation index and sodium adsorption ratio for remineralised waters from data on electrical conductivity and pH prior to and following remineralisation

2021 ◽  
Vol 230 ◽  
pp. 33-37
Author(s):  
M. Hernández-Suárez ◽  
F.A. León
Author(s):  
Pınar Doğan ◽  
Üstün Şahin

Chemical quality analysis results of 5 surface and 30 groundwater resources commonly used in agricultural irrigation in Manisa province were evaluated and the possible effects on soil, plant and drip irrigation system were determined. In this context, the cation (Ca, Mg, Na, K), anion (CO3, HCO3, CI, SO4), Fe, B contents, pH and electrical conductivity values of the water resources as well as the Percentage Sodium, Sodium Adsorption Ratio and the Adjusted Sodium Adsorption Ratio determined by the calculation Permanent Sodium Carbonate, Langelier Saturation Index, Potential Salinity, Permeability Index and Hardness parameters were used. The results indicated that the potential of problem of surface water resources is higher than that of ground water. Salihli-Köseali, Necati bey farms and Alaşehir-Kasaplı underground water resources are used more serious problems than other underground water resources. According to the type of problem that may occur, recommendations were made on measures including washing, salt-resistant plant growing, addition of organic matter and natural Ca sources and the application of dilute acid.


2020 ◽  
pp. 15-27

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.


2016 ◽  
Vol 3 (1) ◽  
Author(s):  
ANSHUMAN SINGH ◽  
ASHWANI KUMAR ◽  
R.K. YADAV ◽  
ASHIM DUTTA ◽  
D.K. SHARMA

Guav a cv . Allahabad Safeda w as grown in saline soils and irrigated with the best av ailable w ater -1 -1 + -1 (EC 2.8 dS m ). Based on chemical composition (pH- 7.1, EC - 2.8 dS m , Na - 20.04 meq l and IW IW sodium adsorption ratio- 4.86), irrigation w ater w as categorized as marginally saline. The soil pH 2 -1 w as mostly below 8.5 but mean electrical conductivity (EC ) v alues ranged from 0.5-2 dS m 2 indicating moderate to high salinity in the experimental soil. After one-y ear of experimentation, fiv e plants randomly selected from each treatment and the data w ere recorded. Plant height -1 -1 significantly increased (LSD 5%) with increase in salinity from 0.5 dS m to 1.4 dS m . A similar -1 trend w as noted with respect to stem girth. The av erage plant height at 0.5, 0.9 and 1.4 dS m salinity lev els w as 98.3 cm, 108.3 cm and 123 cm, respectiv ely whereas the corresponding stem girth v alues -1 w ere 2.24 cm, 2.28 cm and 2.46 cm. At 2 dS m salinity ,how ev er , both av erage plant height (94.6 cm) and stem girth (2.24 cm) significantly decreased and w ere found to be comparable to control (0.5 dS -1 + -1 m ) v alues. Plants show ed negligible Na accumulation in leav es up to 1.4 dS m salinity , but -1 + exposure to elev ated salinity (2 dS m ) significantly increased leaf Na (0.16% DW). These data -1 indicated a salinity tolerance (EC )threshold of about 1.5 dS m inguav a cultiv ar Allahabad Safeda.


2015 ◽  
Vol 16 (2) ◽  
pp. 445-452 ◽  
Author(s):  
Tadeusz Siwiec ◽  
Magdalena M. Michel ◽  
Lidia Reczek ◽  
Piotr Nowak

A high concentration of aggressive carbon dioxide disturbs many technological processes in water treatment. It also causes the development of corrosion in steel and concrete. De-acidification of groundwater by means of air bubbles alters pH and the concentration of aggressive carbon dioxide. This was investigated for the variables of air flow (Q = 20–50 L h−1) and height of water layer (H = 25–75 cm) as well as aeration time (t = 0–20 min). The obtained three-parameter models showed good correlation with the experimental results, except in a few cases where r2 was bigger than 0.9. Furthermore, they allow for prediction of an increase of pH and a decrease in concentration of aggressive carbon dioxide in aerated water. The effectiveness of de-acidification of groundwater was evaluated using indices of water stability (Langelier Saturation Index, Precipitation Index, Ryznar Stability Index, Aggressiveness Index and Index of Aggressiveness). Although as a result of aeration an increase of pH over 7 was observed, the non-corrosive values of the indices were not reached. This was due to a very low alkalinity of water, which was 0.7 meq L−1.


2010 ◽  
Vol 5 (No. 2) ◽  
pp. 58-68
Author(s):  
S. Kužel ◽  
L. Kolář ◽  
J. Gergel ◽  
J. Peterka ◽  
J. Borová-Batt

: In average samples of three sandy-loamy acid Cambisols from a South Bohemian area labile organic matters were determined by the permangate method modified by the dichromate method, and the rate constant of their biochemical oxidation was determined in hot water extracts of the samples. The need of liming was determined by means of 2 methods. In soil solutions of these samples, all values necessary to evaluate their calcium carbonate equilibriums were determined. The soil samples were enriched with 3% of dry matter of two organic materials, farmyard manure and meadow clover meal, and were incubated at 25&deg;C for 180 days under wetting above 50% of their retention water capacity, and after this procedure all analyses were repeated. Both methods were found to increase the need of liming in all three soils: the more labile the organic matter in 3% addition, the higher the need. The meadow clover matter was more labile than the farmyard manure matter. All three methods for the study of soil carbon lability yielded similar results while the potassium permanganate method was more sensitive than the dichromate one. Increases were observed in equilibrium [Cr(H<sub>2</sub>CO<sub>3</sub>* )] and in Langelier saturation index I<sub>s</sub>. This means that soil liming cannot be considered only as an adjustment to the soil acidity and supply of calcium to plants to meet their requirements, but also as a replacement of the spontaneous adjustment to calcium carbonate equilibrium of soil water, for which through mineralisation of labile organic matters in conditions of our experiment about 220 kg CaCO<sub>3</sub> per hectare of land were consumed on condition that it was not necessary to re-establish it. The process of Ca-compound consumption to establish the calcium carbonate equilibrium is controlled exclusively by the degree of mineralising organic matters lability while the influence of soil properties is only marginal. The same results were provided by the comparison of calcium carbonate equilibriums in nine &Scaron;umava brooks of the total watershed area 78 564 km<sup>2</sup> with the degree of lability of organic matters in their sediments in 1986, 2001 and 2004. A reduction in the intensity of agricultural production in 1986&ndash;2004 resulted in an increase in the stability of organic matters in the sediments, in a decrease in I<sub>s</sub>, and in a lower corrosivity of brooks water towards CaCO<sup>3</sup>. However, the quality of soils and their potential soil fertility decreased due to the loss of labile organic matters.


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