Salinity total dissolved solids

The effect of water salinity on crop growth is largely of osmotic nature. Osmotic pressure is related to the total salt concentration rather than the concentration of individual ionic elements. Salinity is commonly expressed as the electric conductivity of the irrigation water. Salt concentration can be determined by Total Dissolved Solids (TDS) or by Electrical Conductivity (EC). Under a water scarcity condition, salt tolerance of agricultural crops will be the primordial parameter when the quality of irrigation water is implicated for the integrated water resources management [10]. 

The Okuaizu geothermal system is characterized by high temperatures (maximum 340°C), high salinity (about 2 wt% total dissolved solids (TDS)) and large amounts of non-condensable gases (1 wt% CO2 and 200 ppm H2S). The pH of the hydrothermal solution measured at 25°C is 6.44 (Table 2.6). However, the pH of the original fluid in the reservoir is computed to be 4.05. This pH as well as alkali and alkali earth element concentrations are plotted near the equilibrium curve of albite, K-mica, anhydrite and calcite (Fig. 2.19) (Seki, 1991). 

Salinity is defined as the concentration of total dissolved solids (TDS) in a solution, usually expressed in mg/L. The TDS concentration in water is usually determined from the weight of the dry residue remaining after evaporation of the volatile portion of the original solution. Groundwater may be classified into four salinity classes64 ... 

Low salinity brine is produced from and injected into the Main Zone of the Torrance Field. Brine produced from Well TU-101, located within the pilot pattern, contains 16,000 mg/kg of total dissolved solids (TDS) while brine injected into the pilot injector, Well TU-120, contains 15010 mg/kg of TDS. The brine contains approximately 560 mg/kg of Ca2 + and 250 mg/kg of Mg2+. ... 

The formation brine used to establish the core s initial permeability contained 2.7% total dissolved solids, TDS, with a monovalent-divalent (calcium) ratio of 30. Once a core is equilibrated with this brine, any increase in the ratio or drastic decrease in TDS has the potential for decreasing permeability. Obviously fresh water represents a significant decrease in TDS and, hence, the 54% permeability damage. Adding KC1 helps overcome the decreased salinity but, in so doing, increases the ionic ratio resulting in still measureable but usually reduced permeability damage. 

Rhoades J. Salinity electrical conductivity and total dissolved solids. In Bartels JM (ed.), Methods of Soil Analysis Part 3 Chemical Methods. Madison, WI Soil Science Society of America and American Society of Agronomy 1996, pp. 417 436. 

The concentrations of seawater and brackish water can vary significantly, and as such there is a difference between the concentrate produced from seawater desalination plants and brackish water desahnation plants. Seawater typically has a level of total dissolved solids (TDS) between 33,000-37,000 mg/L. The average major ion concentration of seawater is shown in Table 2.1 along with water from the Mediterranean Sea, and water from Wonthaggi off the southern coast of Australia. Seawater sahnity increases in areas where water evaporates or freezes, and it decreases due to rain, river runoff, and melting ice. The areas of greatest salinity occur and latitudes of 30° N and S where there are high evaporation rates. 

Salinity, or total salt concentration, is usually expressed in terms of total dissolved solids (TDS) or as the electrical conductivity (EC) of the solution. The major fractions of anions are composed of Cl", SO , and NOj" and the common cations are Ca ", Mg +, Na, and K. The composition of the snbsnrface solution varies between the composition of water entering the system and that of the solution in equilibrinm with the solid phase. 

Total salinity based on K2 (second ionization constant for carbonic acid) and Kj (solubility product constant for CaCC>3) (in practice measured as total dissolved solids)... 

Seawater membranes are used to treat high-salinity (35,000 to 50,000 ppm total dissolved solids (TDS)) feed waters. These membranes can operate at pressures up to 1,500 psi. Typical membrane test conditions are as follows ... 

At any given matrix potential, m, under a constant gravitational potential, g, as salinity increases, w decreases. This is because osmotic potential, is directly related to total dissolved solids (TDS). The relationship between osmotic potential and TDS can be expressed by... 

Interestingly, the relative proportions of the major ions are approximately constant throughout the oceans as observed in Table 6.5. These ions are not very reactive, and as such they are more permanent in solution. As discussed above, NaCl is the major compound present at a typical (although not constant) concentration of 500-560 mmol/L, which accounts for about 75% of the total dissolved solids. The rest of salinity comes mainly from Mg, Ca, and K chlorides and sulfates. 

A river salinity scale based on is also proposed (Figure 5). The least mineralized waters (S" < 0.185 meq L ), termed here extremely dilute correspond to a concentration of total dissolved solids of 10mgL in NaCl equivalent. The most mineralized waters (S" > 24 meq F ) are here termed saline up to 1.4 gL NaCl equivalent, a value slightly less than the conventional limit of 3gL NaCl adopted for saline lakes. 

Salinity. Synonymous with total dissolved solids (TDS), generally reported in milligrams per liter (mg L ) as determined either (i) directly by summing measured dissolved constituents or by weighing solid residues after evaporation, or (ii) indirectly from electrical conductivity or spontaneous potential response. 

Fig. 2-49. Typical shape of natural water cathodic polarograms TDS- total dissolved solids or salinity in gram/litre (g/l) 1- TDS>5 2- 1

With respect to the propagation of fish and wildlife, there is no recommended ambient water quality criterion for the protection of aquatic life for sulfate because sulfate is not generally considered a significant ecological concern, except perhaps where it is a dominant component of total dissolved solids, when sulfate would contribute significantly to excessive salinities (greater than 1000 mg 1 ). There are... 

Perennial saline lakes may also be important sites for evaporite formation, either around their margins or by subaqueous precipitation of evaporite minerals. For example, the Dead Sea now precipitates halite on its floor, beneath its lake water which has exceeded halite saturation, and about 400 years ago subaqueous carbonate laminites were also formed (Neev and Emery, 1967). The salinity of today s Dead Sea is approaching 350 gL-1 TDS (total dissolved solids), tenfold that of modem seawater. 

Increased interest in use of subsurface strata as waste-disposal sites, in problems involving seawater encroachment, and in extension of the concept of freshwater resources to water containing as much as lOg/kg total dissolved solids (TDS) (Kohout, 1981) has increased interest in the composition and distribution of deeper saline fluids in sedimentary strata. 

Salinity can be represented in several ways. One of the simplest ways to quantify salinity is to use total dissolved solids (often abbreviated TDS). TDS is the total mass content of dissolved ions and molecules or suspended microgranules in a liquid medium. Generally, the operational definition is that the solids must be small enough to survive filtration through a sieve size of two micrometers. Because sodium chloride (NaCl) is the main salt in saline water, we commonly use the mass of sodium chloride as the salinity. The common units are ppm or wt.%. Of course, we can almost always use meq/mL. 

The effect of increasing salinity (NaCl) concentration is to increase the level of polymer adsorption, as shown in Figure 5.40, where the adsorption at 2% total dissolved solids (TDS) is higher than that at 0.1% TDS for each pair of data (Martin et al., 1983). This observation is consistent with the prediction made by Eq. 5.31. Adding a low concentration of divalent calcium ion, Csl, promotes HPAM adsorption on silica, as shown by data from Smith (1970) in Table 5.10, because the divalent ions compress the size of the flexible HPAM molecules and reduce the static repulsion between the polymer carboxyl group and silica surface. 

Thus, with reference to a three-layer lake model in which the eddy diffusion coefficient in the middle layer depends on the concentration (or density) gradient, the eddy diffusion coefficient may be estimated by a relationship of the type of Equation 22 for different values of the gradient and concentration difference between the well-mixed top and bottom layer. A case in which this model might apply is transport of dissolved salts from a saline brine layer on the bottom into a more dilute layer above, when the concentration of total dissolved solids in the pycnocline and surface layer changes continuously in the process. Use of this model to estimate the length of time to a complete mixing of a stratified brine lake, the Dead Sea, will be demonstrated. 

As the salt concentration of the soil increases, so does the potential for salinity effects on plant growth. Early appraisals of the salinity of irrigation waters were in terms of total dissolved solids (TDS). The TDS were determined by evaporating a known volume of water to dryness. The presence of hygroscopic water in the resultant salt mixtures made the values for TDS strongly dependent on the drying conditions. The concentration of salts in most irrigation waters is less than 1000 mg... 

Twin Cond is a conductivity meter, available from HORIBA Jobin Yvon, which features a waterproof flat sensor. Twin Cond can measure the conductivity of a solution from a single drop of sample and is therefore very suitable for both field measurements in rivers and lakes and for rain samples. It features a measurement range from 1 p,S/cm to 19.9 mS/cm. It also has one-touch auto-calibration, automatic temperature conversion and a salinity conversion function (from 0-1.1 %). Multiparameter meters can test for pH, conductivity, total dissolved solids and temperature in the one device. 

Reservoir Salinity. The test equipment was operated for extended periods with no blowdown from the reservoir. Salinity in the reservoir was allowed to build up approximately an order of magnitude, with no detectable effect on unit output or product purity. Short tests were made using a simulated sea water solution containing approximately 35,000 p.p.m. of dissolved sodium chloride. The distillate produced contained less than 1 p.p.m. of total dissolved solids. 

The nation s first saline water conversion plant to treat an entire municipal supply, built for the town of Buckeye, Ariz., went into operation early in September 1962. It has the capability to reduce water of 2200 p.p.m. total dissolved solids to 500 p.p.m., at a rate of 650,000 gallons per day. The plant was financed by a 305,000 issue of 25-year, 41/2% water revenue bonds sold at competitive bidding through normal municipal bond channels. No federal or state funds were utilized in the financing of this plant. 

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