How is Langelier calculated?

LSI Formula: pHs = (9.3 + A + B) – (C + D) where: A = (Log10[TDS] – 1)/10 = 0.15. B = -13.12 x Log10(oC + 273) + 34.55 = 2.09 at 25°C and 1.09 at 82°C.

What does Langelier index measure?

The Langelier Index is an approximate measure of the saturation degree of calcium carbonate (CaCO3) in water. It is calculated using the Hydrogen Ion (pH) , Alkalinity (CaCO3), Calcium concentration, Total Dissolved Solids, and water temperature of a tap water sample.

What is the Langelier Saturation Index?

The Langelier Saturation Index (LI), a measure of a solution’s ability to dissolve or deposit calcium carbonate, is often used as an indicator of the corrosivity of water. The Langelier Index is defined as the difference between actual pH (measured) and calculated pHs.

What is Langelier Index & Ryznar Stability Index?

The Ryznar index is based loosely off of the Langelier saturation index that was created in the 1930s. The Ryznar index is logarithmic, similar to other indices that are used to calculate calcium carbonate formation. Generally, any value above 6 indicates that the water is likely to form a calcium carbonate scale.

At what pH is water corrosive?

If the pH is below 6.0, the water is considered highly corrosive. If the pH is between 6.0 and 6.9, the water is somewhat corrosive, and stagnant testing is probably appropriate. If the pH is between 7.0 and 7.5, the water is probably notexcessively corrosive.

What is saturated pH?

The Langelier saturation level approaches the concept of saturation using pH as a main variable. The LSI can be interpreted as the pH change required to bring water to equilibrium. Water with a Langelier saturation index of 1.0 is one pH unit above saturation.

How do you calculate aggressive index?

The formulae used in the aggressive Index is stated as AI = pH + log (A * H). In this statement, “AI” represents the aggressive Index. “A” is the alkalinity of the water. “H” is the hardness of the water.

What is Larson Skold index?

The Larson-Skold index refers to an empirical scale used to measure the degree of corrosiveness of water relative to mild steel metal surfaces. It is generated based on the in-situ corrosion of mild steel pipelines used to transport naturally occurring water from lakes and other freshwater sources.

Is 9.5 pH water good?

Normal drinking water generally has a neutral pH of 7. Alkaline water typically has a pH of 8 or 9. However, pH alone isn’t enough to impart substantial alkalinity to water. Alkaline water must also contain alkaline minerals and negative oxidation reduction potential (ORP).

What pH water is best for drinking?

The U.S. Environmental Protection Agency recommends that the pH level of water sources should be at a pH measurement level between 6.5 to 8.5 on a scale that ranges from 0 to 14. The best pH of drinking water sits right in the middle at a 7.

How do you increase LSI in water?

To raise your LSI value, add sodium bicarbonate or baking soda (can be found in pool supply stores). Consult the calculator above to determine the target Alkalinity value (recommended range is 80-120ppm; however, you may find that a level lower than 80 may be ideal for a balanced LSI value).

What do you need to know about the Langelier Index?

Consult the Water Glossary, Water Cooling Towers See also:Calcium carbonate, Carbon dioxide, Chlorination, Dissolved oxygen, Langelier calculation, Langelier index, Larson-Skold index, Oddo-Tomson index, pH, Puckorius index, Ryznar index, Scaling Indices, Stiff-Davis index, Total dissolved solids, Water corrosivity

What is the formula for the Langelier Saturation Index?

Here’s the formula: (pH) + (Temperature ºF factor) + (Calcium Hardness factor) + [ (Total Alkalinity ppm) – (CYA ppm x correction factor @ current pH)] – (TDS factor) = LSI In school, our math teachers required us to show our work when solving problems.

What is the Langelier Index for water treatment?

Saturation Index Description General Recommendation -5 Severe Corrosion Treatment Recommended -3 Moderate Corrosion Treatment Recommended -2 Moderate Corrosion Treatment May Be Needed -1 Mild Corrosion Treatment May Be Needed

What was Langelier’s equation for the pH of water?

In developing the LI, Langelier derived an equation for the pH at which water is saturated with calcium carbonate (pHs). This equation is based on the equilibrium expressions for calcium carbonate solubility and bicarbonate dissociation.