scholarly journals RESEARCH OF THE EFFICIENCY OF REAGENT-FREE ELECTROMAGNETIC TREATMENT OF SOURCE WATER AT PETROCHEMICAL ENTERPRISES

2021 ◽  
Vol 73 (1) ◽  
pp. 5-23
Author(s):  
E. E. Ergozhin ◽  
◽  
T. K. Chalov ◽  
K. Kh. Khakimbolatova ◽  
T. V. Kovrigina ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Test Bench ◽  
Salt Content ◽  
Technical Documentation ◽  
Electromagnetic Treatment ◽  
First Case ◽  
Total Salt Content ◽  
Reverse Osmosis Unit ◽  
Magnetic Water ◽  
Reverse Osmosis Membranes

A technological scheme and technical documentation for the manufacture of a test bench with a purified water capacity of 300 l/h have been developed. Long-term tests were carried out on a test bench, as well as analysis of the quality of the sampled water before purification, with the use of an electromagnetic treatment device and without it. As a result of the tests carried out, it was found that the total salt content after the reverse osmosis unit decreased from 535.5 to 30.0 mg / l, and in water with the use of magnetic water treat- ment – from 535.5 to 12.7. Moreover, the pH in the first case varied from 8.3 to 6.2, in the second – from 8.3 to 6.44. It has been established that the use of magnetic water treatment in desalination before the reverse osmosis unit has a positive result, namely, calcium and magnesium salts do not settle on the reverse osmosis membranes, thereby prolonging the service life of the reverse osmosis membranes.

scholarly journals The assessment of magnetic water treatment on formation calcium scale on reverse osmosis membranes

2018 ◽  
Vol 178 ◽  
pp. 09001
Author(s):  
Alexey Andrianov ◽  
Evgeny Orlov
Keyword(s):  
Calcium Carbonate ◽  
Water Treatment ◽  
Reverse Osmosis ◽  
Tap Water ◽  
Magnetic Treatment ◽  
Water Desalination ◽  
Feed Water ◽  
Calcium Deposits ◽  
Magnetic Water ◽  
Reverse Osmosis Membranes

Reverse osmosis is widely used technology for water desalination. The main problem with reverse osmosis is scaling which reduces the flow and selectivity of membranes. Normally, to prevent salt precipitation, chemicals are added to the feed water or water softening is applied. The literature data on the effect of magnetic treatment on the structure and properties of water and dissolved salts showed that there is no consensus among researchers on the mechanism of magnetic field action to prevent calcium deposits formation. The purpose of current work was to study the effect of magnetic water treatment on the rate of calcium carbonate scale formation on reverse osmosis membranes. Scaling tests were carried out on tap water using the spiral wound module with reverse osmosis membranes. Magnetic treatment efficiency was evaluated by comparison of scaling rate values (amount of calcium carbonate scales accumulated in membrane module) determined throughout experiments with and without magnetic device. The results obtained do not confirm the effect of magnetic treatment on calcium carbonate precipitate formation.

Titration of sulphates and lead using lead ion selective electrode

1981 ◽  
Vol 46 (2) ◽  
pp. 368-376 ◽  
Author(s):  
Josef Veselý
Keyword(s):  
Ionic Strength ◽  
Electrode Surface ◽  
Salt Content ◽  
Ion Selective Electrode ◽  
Lead Ion ◽  
Selective Electrode ◽  
Limit Of Determination ◽  
Total Salt Content ◽  
Automatic Titration

Titration of sulphates with lead perchlorate employing lead ion selective electrode indication was studied using additions of various organic solvents at different pH' and ionic strength values. As the optimum emerged systems with 60-70% 1,4-dioxane, pH' 5.3-5.6. After dehydration with sodium hydroxide, dioxane must be freed from the electrode surface-oxidizing impurities by their reduction with sodium metal and subsequent distillation. The method was applied to determination of sulphates in mountain spring waters. Units of ppm can be determined; the limit of determination, however, depends considerably on the content of dioxane, total salt content in the sample, and speed of the semi-automatic titration. Lead can be determined with EDTA in concentrations down to c(Pb2+) = 5 . 10-6 mol l-1.

Use of Reverse Osmosis Membranes to Remove Perfluorooctane Sulfonate (PFOS) from Semiconductor Wastewater†

2006 ◽  
Vol 40 (23) ◽  
pp. 7343-7349 ◽  
Author(s):  
Chuyang Y. Tang ◽  
Q. Shiang Fu ◽  
A. P. Robertson ◽  
Craig S. Criddle ◽  
James O. Leckie
Keyword(s):  
Reverse Osmosis ◽  
Perfluorooctane Sulfonate ◽  
Reverse Osmosis Membranes

scholarly journals Comparison of Different Interpolation Methods for Prediction of Soil Salinity in Arid Irrigation Region in Northern China

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1535
Author(s):  
Tonggang Fu ◽  
Hui Gao ◽  
Jintong Liu
Keyword(s):  
Soil Salinity ◽  
Subsurface Layer ◽  
Salt Content ◽  
Spatial Prediction ◽  
Northern China ◽  
Sodium Adsorption Ratio ◽  
Interpolation Methods ◽  
Distance Weighting ◽  
Total Salt Content ◽  
Inverse Distance

Numerous methods have been used in the spatial prediction of soil salinity. However, the most suitable method is still unknown in arid irrigation regions. In this paper, 78 locations were sampled in salt-affected land caused by irrigation in an arid area in northern China. The geostatistical characteristics of the soil pH, Sodium Adsorption Ratio (SAR), Total Salt Content (TSC), and Soil Organic Matter (SOM) of the surface (0–20 cm) and subsurface (20–40 cm) layers were analyzed. The abilities of the Inverse Distance Weighting (IDW), Ordinary Kriging (OK), and CoKriging (CK) interpolation methods were compared, and the Root Mean Square Error (RMSE) was used to justify the results of the methods. The results showed that the spatial distributions of the soil properties obtained using the different interpolation methods were similar. However, the surface layer exhibits more spatial heterogeneity than the subsurface layer. Based on the RSME, the nugget/sill value and range significantly affected which method was the most suitable. Lower nugget/sill values and lower ranges can be fitted using the IDW method, but higher nugget/sill values and higher ranges can be fitted using the OK method. These results provide a valuable reference for the prediction of soil salinity.

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