Hach-Lange WTOS P-RTC - Manual (Page 35)

35
Parameterization and operation
With the setting Q INFLUENT SMOOTH = 2 , it takes three
minutes for the smoothed value to reach 95 % of the final
value (following a sudden change of the influent rate).
4.5.8 Precipitants
For calculations, the effective metal content of the precipitant
must be specified in g/l as well as the relative atomic weight of
the metal in g/mol.
4.5.8.1 Metal content
The metal content (active component) of the precipitant is
specified by the manufacturer in:
• g/kg
multiply the value by the density δ of the product to obtain the
metal content in g/L
• %
multiply the value by 10 to obtain the concentration in g/kg.
Multiply this value by the density
δ of the product to obtain the
metal content in g/L
• mol/L
This value can be entered instead of the concentration in g/L.
Enter a 1 for the atomic weight of the metal.
4.5.8.2 Atomic weight of metal
The type of the precipitant is determined by the atomic weight.
Atomic weight of iron: 55.8 g/mol
Atomic weight of aluminum: 26.9 g/mol
Composite products
For products that contain both aluminum and iron, the molar
metal concentration is calculated from the sum of the molar
concentrations of iron and aluminum.
Example: Compound of iron (12 %) and aluminum (8 %):
Molar aluminum concentration:
Molar iron concentration:
80
g
= 2.97
kg mol
26.9
g kg
mol
120
g
= 2.15
kg mol
55.8
g kg
mol