The term “TDS” refers to the total content of dissolved solids (general mineralization) and is a numerical value indicating the presence of impurities in the solution, most often in water. TDS is measured in milligrams per liter, which is commonly referred to as million-dollar fractions, or abbreviated ppm.
It should be noted that “dissolved” solids are defined as solids that can pass a filter with a porousness of 2 micrometers (mkm). Solids, which are unable to pass through the filter with such porosity, are defined as “weighted” solids.
Total Mineralization (TDS) of Water
As a rule, the total mineralization of water can be divided into two types:
Inorganic type – inorganic substances make up a significant portion of TDS water. These include minerals, metals and salts. Salts are compounds that break down in water with the formation of ion. For example, common inorganic solids dissolved in water include calcium, chlorine, sodium, magnesium, nitric acid salt, silicon dioxide, sulfate, carbonate and bicarbonate.
Organic type – a limited amount of organic solids dissolve in water, these include plant and animal residues of leaves, silt, plankton, etc.
Water Formation (TDS)
Typically, TDS comes from natural sources such as rock, air and soil. However, urban and agricultural runoff, mining, oil extraction, sewage and industrial wastewater, and more are man-made sources. For example, the control of road icing with chemicals is a major problem that contributes significantly to improving TDS water levels.
TDS natural water sources such as: lakes, streams and rivers vary greatly depending on the geological location. In particular, low TDS levels, usually below 30 ppm, are recorded in places where water comes into contact with relatively insoluble materials such as granite, quartz sand and leached soil. Higher LEVELS of TDS, usually between 200 ppm and 1500 ppm, are found in water that comes into contact with more soluble materials, such as sedimentary rocks. The TDS level will also be higher in drier areas.
The TDS level of most lakes far from man-made ecosystems is in the 50 ppm to 250 ppm range. The level of TDS of many natural reservoirs is steadily increasing, a matter of particular concern, as the increase in TDS levels is probably man-made.
TDS in your life
TDS is important because it is a good indicator of the quality of water you drink and use every day. Therefore, checking and understanding the TDS water you use should be standard procedure for ensuring a healthy lifestyle. Using a digital TDS meter is the fastest and easiest way to control your water’s TDS level.
In general, a lower TDS level is always preferable. In fact, many health professionals believe that the level of total mineralization (TDS) of ideal drinking water should be around 50 ppm.
Below is a list of pollutants, and the list includes pollutants in water that are not considered to be hazardous to health. Secondary standards indicate the recommended levels of these pollutants, and the test for these pollutants is voluntary.
pollutant Secondary maximum allowable level of pollutant (MCL) Notable effects of exceeding the secondary maximum allowable level of pollutant (MCL)
|pollutant||Secondary maximum allowable level of pollutant (MCL)||Notable effects of exceeding the secondary maximum allowable level of pollutant (MCL)|
|aluminium||0.05 – 0.2 mg/l||Coloured water|
|chlorine||250 mg/l||Salty taste|
|Color||15 units of color||Notable hue|
|copper||1.0 mg/l||Metallic smack; colouring the color of the sea wave|
|Corrosive ability||Corrosive-resistant||Metallic smack; rusted pipes/staining fittings|
|fluoride||2.0 mg/L||Changing the color of tooth enamel|
|Foaming elements||0.5 mg/L||Penisty, murky; Bitter taste; smell|
|iron||0.3 mg/L||Rusty color; precipitation; Metallic smack; coloring in reddish or orange|
|manganese||0.05 mg / l||From black to brown; Painting in black; bitter metallic smack|
|silver||0.1 mg / l||Changing skin color; coloring the squirrel’s eyes in gray|
|sulfate||250 mg/l||Salty taste|
|Total Mineralization (TDS)||500 mg / l||Hardness; Sediments Coloured water Colouring salty taste|
|zinc||5 mg / l||Metallic smack|
Based on a list of secondary pollutants provided by the Environmental Protection Agency (EPA), it is recommended that the TDS water level be below 500 ppm. Water, the level of general mineralization (TDS) of which exceeds this value, is characterized by “rigidity, sediments, colored water, staining and salty taste.”
Measuring the TDS level
There are two main methods for measuring the level of general mineralization (TDS) of water: gravimetric and electrical conductivity.
The gravimetric method is the most accurate to measure water TDS levels. He suggests first weighing the water sample. Then, this sample of water is heated until completely evaporated. Solids left after evaporation are further dried until the moisture is completely removed. The TDS level is calculated as the difference between the weight of the water sample and the weight of the remaining dry residue after drying.
The method of electrical conductivity. The electrical conductivity of the water is measured by a professional appliance. Because electrical conductivity depends on the amount of positively and negatively charged dissolved ionized solids in the water, electrical conductivity can be used to approximate THE level of TDS.
In general, although the gravimetric method of checking the TDS level is the most accurate, it is a very long process. For this reason, the electrical conduction method is often used, especially in the field, when instant measurements are required.
TDS water level limits
Although TDS is an excellent indicator of overall water quality, it is important to understand that TDS does not provide any information on the types of dissolved solids found in the water. Based only on the TDS level, it is not possible to identify specific problems found in water, such as increased stiffness, corrosion, radiation, or even the presence of harmful substances such as volatile organic compounds and pesticides.
Because the TDS level check cannot pinpoint specific issues, a high TDS level only indicates or confirms that there are problems. Low TDS does not necessarily mean that the water you are testing is drinkable.