List of top Water & Wastewater Treatment and Management Questions on Water Quality: Parameters and Measurement

The analysis of a water sample is shown in the table. The hardness of the water sample is ______ mg/L as CaCO₃.

Atomic weight (g/mol): Ca = 40; Mg = 24; Na = 23; Cl = 35.5; S = 32; O = 16; N = 14

Species	Concentration (mg/L)
Na⁺	30
Ca²⁺	10
Mg²⁺	15
Cl^-	30
SO₄^2-	60
NO₃^-	5

In the context of water quality, which of the following is/are correct for the most probable number (MPN) of a water sample?

The characteristics of a water sample are as follows: Na\(^+\) = 92 mg/L, K\(^+\) = 19.5 mg/L, Ca\(^{2+}\) = 40 mg/L, and Mg\(^{2+}\) = 24 mg/L. What is the sodium adsorption ratio (SAR) of the water sample which may be considered for irrigation purposes?