Card Set Information
SAIT CLT2 ENVS348
Review for midterm: various terms relating to scale
What is the chemical formula for Gypsum (Anhydrite)?
What is the chemical formula for Magnetite?
What is the chemical formula for Aragonite?
What is the chemical formula for Calcite?
Give 2 examples of undissolved organic water contaminants
1. E. coli
2. 'Beaver Fever' - Giardia
Sodium Adsorption Ratio (a water quality parameter for agriculture)
Water from typically from petroleum reservoirs that is extremely high in TDS
Which would likely have higher TDS, connate water or boiler feed water?
Connate water has higher TDS
Equivalent weight of CaCO
50.0 mg CaCO
Formula for Dolomite
A good SAR ratio is...
SAR<3 (no restrictions on crops)
Lower is better
Permanent hardness =
Total Hardness - Temporary Hardness
For ENVS348, a water analysis is considered valid if the % Difference of the ion balance is
Less than 10%
Which is harder to remove with acid?
Scale deposited quickly
Scale deposited slowly
deposits of scale are typically harder to remove with acid
Langelier Scaling Index
Precipitates which form elsewhere and then are carried over and deposited
Precipitates which form directly on the pipe and are often hard and glassy
The water is supersaturated and scale is likely to form
The water is saturated
The water is undersaturated
Scale may dissolve
Two general schemes for removing scale
1. Chemically (Soluble scales, use water, acid, EDTA)
2. Mechanically (Insoluble scales)
Scaling Index (Scaling Tendency) in thermodynamic terms