Regulation according to P Concentration
With a continuous monitor PO4 analyzer, the operator of water treatment plants can realize significant cost savings.
cf. Application Report PO4 1609 2003 01e
The PO4 module uses the vanadate/molybdate method (yellow method) for determining the orthophosphate content. A reagent reacts with phosphate in the sample to color the sample solution yellow. The intensity of this color is recorded photometrically and evaluated as a measure of the phosphate content.
| Measuring Ranges | PO4-P | PO4 | |
| 1: | 0.05 - 3,00 mg/l; 1.5 - 100 µmol/l |
0.15 - 9,00 mg/l; 1.5 - 100 µmol/l |
|
| 2: | 0.1 - 10.0 mg/l; 3 - 320 µmol/l |
0.3 - 30.0 mg/l; 3 - 320 µmol/l |
|
| 3: | 0.1 - 25.0 mg/l; 3 - 800 µmol/l |
0.3 - 80.0 mg/l; 3 - 800 µmol/l |
|
| Resolution (Display) | 1: 2: 3: |
0.01 mg/l bzw. µmol/l 0.1 mg/l bzw. µmol/l 0.1 mg/l bzw. µmol/l |
The PTotal module consists of two units: in the first unit (digestion unit) the sample undergoes a chemical-thermal digestion; in the second unit the total phosphorus content is determined.
During the digestion all the phosphorus compounds contained in the sample are converted to orthophosphate; this can be determined photometrically. The phosphorus compounds are oxidized by peroxodisulfate under acidic conditions. This process is accelerated by overpressure and an increased temperature so that very short digestion times are achieved.
The subsequent analysis is by the molybdenum blue method. The sample is mixed with a molybdate reagent which reacts with phosphate via an intermediate chemical step to form a blue coloration. The intensity this coloration is a measure of the original concentration of the phosphate ions. It is measured photometrically and evaluated.
| Measuring Ranges | PTotal: | 0.01 … 3.00/6.00*; 0.3 … 100/200* |
|
| Resolution (Display) | Range: | 0.01 ... 3.00 mg/l : 0.30 ... 100 µmol/l : |
0.01 mg/l 0.1 µmol/l |
| * by continuous sample dilution | in a 1:1 ratio |
