Oxygen Solubility Water

Overview

Engineering reference data for Oxygen Solubility Water in miscellaneous.

Key Formulas

Unit Conversion

$y = x \cdot k$

Multiply by conversion factor.

Linear Interpolation

$y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1}$

Estimate between two known points.

Percentage

$p = \frac{\text{part}}{\text{whole}} \times 100\%$

Part as fraction of whole.

Variables

Symbol	Description	Unit
$x$	Input value	—
$y$	Output value	—
$k$	Conversion factor	—

Oxygen Solubility Data

Fresh Water (Salinity ~0)

Seawater (Salinity ~35 ppt)

Key Concepts & Notes

Salinity Definitions

• Seawater Salinity: Ranges from 30 to 50 parts per thousand (ppt), with an average of 35 ppt.
  • 35 ppt is equivalent to:
    • $35\ \text{g dissolved salt per kg of seawater}$
    • $35 \text{ ppt} = 35 \text{ o/oo} = 3.5\% = 35{,}000\ \text{ppm}$
• Brackish Water: Water with salinity between that of freshwater and seawater.

Dissolved Oxygen from Air

• In air with normal composition, the oxygen partial pressure is approximately 20% of the total atmospheric pressure.
• Consequently, the dissolution of oxygen from air is 20% of the solubility value given for pure oxygen at the same total pressure.

General Solubility Trends

1. Pressure Effect: Oxygen solubility increases linearly with increasing pressure, as described by Henry's Law.
2. Temperature Effect: Oxygen solubility decreases as temperature increases.
3. Salinity Effect: Oxygen solubility decreases significantly with increasing salinity. For a given temperature and pressure, seawater holds less dissolved oxygen than fresh water.

Interactive Charts

References

• Original Source