The Impact of TDS & pH on Quality of Drinking Water

pH in Drinking-water:

The pH of water is a measure of the acid-base equilibrium and, in most natural waters, is controlled by the carbon dioxide–bicarbonate–carbonate equilibrium system. An increased carbon dioxide concentration will, therefore, lower pH, whereas a decrease will cause it to rise.

The corrosive effect of pH on water:

The pH is of water is of great significance in deciding the corrosivity of water As it can influence the level of corrosion of metals and any impact on health is probably going to be indirect because of absorption of metals from water pipes. The pH of the water has to be maintained to minimize the corrosion of water mains and pipes. Failure to achieve this can bring about the contamination of water and result in unfavorable outcomes on its taste, odor, and appearance. Be that as it may, as a rule, the lower the pH, higher the level of corrosion.

Effects of temperature on pH:

The temperature will have a very slight effect on the pH of water. As water temperature goes up, pH goes down and similarly colder water has a relatively higher pH value.

An acceptable range of pH in drinking water:
The pH of most drinking-water lies within the range 6.5–8.5.

TDS in Drinking-water:
Total dissolved solids (TDS) is used to describe the inorganic salts and small amounts of organic material present in water. The vital constituents are usually calcium, magnesium, sodium, potassium cations, hydrogen carbonate, potassium carbonate, chloride, sulfate, and nitrate anions.

Source of Dissolved Solids:
TDS in water supplies originate from natural sources, sewage, and industrial wastewater. Dissolved solids can be introduced via inorganic materials such as rocks and air that may have traces of nitrogen, calcium bicarbonate, iron phosphorous, sulphur, and other minerals.

Effect of temperature on TDS:
As water temperature increases, the conductivity of water also increases; where TDS in water is directly related to conductivity. For each 1°C increment, conductivity rise by 2–4%. Temperature influences conductivity by increasing ions mobility and additionally the dissolvability of many salts and minerals.

Level of TDS in drinking water:
Different organizations, companies, and government have different regulations for the TDS level. According to World Health Organization, TDS concentration of 1000 mg/ litre is considered acceptable for water consumers but this acceptability factor may change as TDS concentration has a direct impact on the taste of water.

TDS concentration levels and its corresponding taste quality is suggested by the KENT’s Mineral RO, following is the preferable level of TDS in water:

Level of TDS

A very low concentration of TDS produces undesirable taste of water, as many people buy mineral water, which has natural levels of dissolved solids. Increased concentrations of dissolved solids can also have technical effects.

pH is one of the most important operational water quality parameters. Careful attention to pH control is necessary to ensure satisfactory water clarification and to avoid the corrosivity of water. A very low concentration of TDS has been found to give water a flat taste, which is considered to be unacceptable to many people and same goes the case with increased concentrations of dissolved solids as it produces hard water, leaving deposits and films on fixtures, and on the insides of hot water pipes and household appliances.