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What is the chemical formula for Gypsum (Anhydrite)?

CaSO₄
What is the chemical formula for Magnetite?

Fe₃O₄
What is the chemical formula for Aragonite?

CaCO₃
What is the chemical formula for Calcite?

CaCO₃
Give 2 examples of undissolved organic water contaminants
- Microorganisms:
- 1. E. coli
- 2. 'Beaver Fever' - Giardia
SAR
- Sodium Adsorption Ratio (a water quality parameter for agriculture)
Water from typically from petroleum reservoirs that is extremely high in TDS

connate water
Which would likely have higher TDS, connate water or boiler feed water?

Connate water has higher TDS
Equivalent weight of CaCO₃

50.0 mg CaCO₃/meq
Formula for Dolomite

CaMg(CO₃)₂
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

Slow deposits of scale are typically harder to remove with acid
LSI

Langelier Scaling Index
Precipitates which form elsewhere and then are carried over and deposited

Mixed Deposits
Precipitates which form directly on the pipe and are often hard and glassy

Scale
LSI>0 means

The water is supersaturated and scale is likely to form
LSI=0 means

The water is saturated
LSI<0 means
- 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

Author

saitclt

180175

Card Set

Scale

Description

Review for midterm: various terms relating to scale

Updated

2012-10-27T16:42:43Z

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